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Mack M, Frishman WH. Cardiac Myosin Activator Omecamtiv Mecarbil: Novel Treatment for Systolic Heart Failure. Cardiol Rev 2024; 32:378-383. [PMID: 36946979 DOI: 10.1097/crd.0000000000000530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Systolic Heart failure is a complex clinical syndrome characterized by a decrease in cardiac contractility and a reduction in organ perfusion. Current pharmacologic inotropes attempt to improve contractility via indirect mechanisms but are limited in terms of safety and effectiveness. Omecamtiv mecarbil is a novel agent in a new class of drugs known as cardiac myosin activators; their unique mechanism of action involves directly activating the enzymatic pathway in the cardiac myocyte as a way to improve ventricular contraction. Preclinical and clinical trials have found that omecamtiv mecarbil improves cardiac contractility without increasing the risk of any of the harmful effects that are associated with the currently available inotropic agents. Omecamtiv mecarbil is a worthwhile advance and patients with systolic heart failure would benefit from pharmacological use of this drug.
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Affiliation(s)
- Maat Mack
- From the Department of Medicine, New York Medical College/Westchester Medical Center, Valhalla, NY
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2
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Collibee SE, Romero A, Muci AR, Hwee DT, Chuang C, Hartman JJ, Motani AS, Ashcraft L, DeRosier A, Grillo M, Lu Q, Malik FI, Morgan BP. Cardiac Troponin Activator CK-963 Increases Cardiac Contractility in Rats. J Med Chem 2024; 67:7859-7869. [PMID: 38451215 PMCID: PMC11129196 DOI: 10.1021/acs.jmedchem.3c02412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/21/2024] [Accepted: 02/23/2024] [Indexed: 03/08/2024]
Abstract
Novel cardiac troponin activators were identified using a high throughput cardiac myofibril ATPase assay and confirmed using a series of biochemical and biophysical assays. HTS hit 2 increased rat cardiomyocyte fractional shortening without increasing intracellular calcium concentrations, and the biological target of 1 and 2 was determined to be the cardiac thin filament. Subsequent optimization to increase solubility and remove PDE-3 inhibition led to the discovery of CK-963 and enabled pharmacological evaluation of cardiac troponin activation without the competing effects of PDE-3 inhibition. Rat echocardiography studies using CK-963 demonstrated concentration-dependent increases in cardiac fractional shortening up to 95%. Isothermal calorimetry studies confirmed a direct interaction between CK-963 and a cardiac troponin chimera with a dissociation constant of 11.5 ± 3.2 μM. These results provide evidence that direct activation of cardiac troponin without the confounding effects of PDE-3 inhibition may provide benefit for patients with cardiovascular conditions where contractility is reduced.
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Affiliation(s)
- Scott E. Collibee
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Antonio Romero
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Alexander R. Muci
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Darren T. Hwee
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Chihyuan Chuang
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - James J. Hartman
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Alykhan S. Motani
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Luke Ashcraft
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Andre DeRosier
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Mark Grillo
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Qing Lu
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Fady I. Malik
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
| | - Bradley P. Morgan
- Cytokinetics,
Inc., 350 Oyster Point Boulevard, South San Francisco, California 94080, United States
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3
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Ananthamohan K, Stelzer JE, Sadayappan S. Hypertrophic cardiomyopathy in MYBPC3 carriers in aging. THE JOURNAL OF CARDIOVASCULAR AGING 2024; 4:9. [PMID: 38406555 PMCID: PMC10883298 DOI: 10.20517/jca.2023.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Hypertrophic cardiomyopathy (HCM) is characterized by abnormal thickening of the myocardium, leading to arrhythmias, heart failure, and elevated risk of sudden cardiac death, particularly among the young. This inherited disease is predominantly caused by mutations in sarcomeric genes, among which those in the cardiac myosin binding protein-C3 (MYBPC3) gene are major contributors. HCM associated with MYBPC3 mutations usually presents in the elderly and ranges from asymptomatic to symptomatic forms, affecting numerous cardiac functions and presenting significant health risks with a spectrum of clinical manifestations. Regulation of MYBPC3 expression involves various transcriptional and translational mechanisms, yet the destiny of mutant MYBPC3 mRNA and protein in late-onset HCM remains unclear. Pathogenesis related to MYBPC3 mutations includes nonsense-mediated decay, alternative splicing, and ubiquitin-proteasome system events, leading to allelic imbalance and haploinsufficiency. Aging further exacerbates the severity of HCM in carriers of MYBPC3 mutations. Advancements in high-throughput omics techniques have identified crucial molecular events and regulatory disruptions in cardiomyocytes expressing MYBPC3 variants. This review assesses the pathogenic mechanisms that promote late-onset HCM through the lens of transcriptional, post-transcriptional, and post-translational modulation of MYBPC3, underscoring its significance in HCM across carriers. The review also evaluates the influence of aging on these processes and MYBPC3 levels during HCM pathogenesis in the elderly. While pinpointing targets for novel medical interventions to conserve cardiac function remains challenging, the emergence of personalized omics offers promising avenues for future HCM treatments, particularly for late-onset cases.
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Affiliation(s)
- Kalyani Ananthamohan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Julian E. Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 45267, USA
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH 45267, USA
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4
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Mercurio V, Ambrosio G, Correale M, Dini FL, Ghio S, Nodari S, Palazzuoli A, Ruocco G, Pedrinelli R, Mercuro G, Filardi PP, Indolfi C, Agostoni P, Tocchetti CG, Paolillo S. Innovations in medical therapy of heart failure with reduced ejection fraction. J Cardiovasc Med (Hagerstown) 2022; 24:e47-e54. [PMID: 36729606 DOI: 10.2459/jcm.0000000000001413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Heart failure with reduced ejection fraction (HFrEF) is a pathological condition still characterized by high rates of mortality and disease exacerbation frequently leading to hospitalization, thus there is a continuous need for pharmacological treatments impacting on disease stability and long-term prognosis. Moreover, the phenotype of heart failure patients is continuously changing over time, and the development of new heart failure drugs is crucial to promote a personalized and targeted approach. In recent years, several therapeutic innovations have emerged in the landscape of acute and chronic HFrEF, largely changing and improving our approach to the disease. Various studies on new drugs and experimental therapeutic approaches are ongoing. The present review discusses the latest data on both recently approved drugs and developing therapeutic targets, in order to provide a critical overview for an informed and optimal approach to such a complex disease.
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Affiliation(s)
- Valentina Mercurio
- Department of Translational Medical Sciences, Federico II University, Naples.,Interdepartmental Center of Clinical and Translational Sciences (CIRCET), Federico II University
| | | | | | - Frank L Dini
- Cardiac, Thoracic and Vascular Department, University of Pisa, Pisa
| | - Stefano Ghio
- Division of Cardiology, Fondazione IRCCS Policlinico S.Matteo, Pavia
| | - Savina Nodari
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia
| | - Alberto Palazzuoli
- Cardiovascular Disease Unit, Department of Internal Medicine, University of Siena, Siena
| | - Gaetano Ruocco
- Cardiology Unit, Riuniti of Valdichiana Hospitals, USL Sud Est Toscana, Montepulciano
| | - Roberto Pedrinelli
- Dipartimento di Patologia Chirurgica, Medica, Molecolare e dell'Area Critica, Università di Pisa
| | - Giuseppe Mercuro
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari
| | - Pasquale Perrone Filardi
- Department of Advanced Biomedical Sciences, Federico II University, Naples.,Mediterranea Cardiocentro, Naples
| | - Ciro Indolfi
- Cardiology Unit, University Magna Graecia of Catanzaro, Catanza
| | - Piergiuseppe Agostoni
- Centro Cardiologico Monzino, IRCCS.,Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milan, Milan
| | - Carlo G Tocchetti
- Department of Translational Medical Sciences, Federico II University, Naples.,Interdepartmental Center of Clinical and Translational Sciences (CIRCET), Federico II University.,Interdepartmental Hypertension Research Center (CIRIAPA).,Center for Basic and Clinical Immunology Research (CISI), Federico II University, Naples, Italy
| | - Stefania Paolillo
- Department of Advanced Biomedical Sciences, Federico II University, Naples.,Mediterranea Cardiocentro, Naples
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5
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Nakanishi T, Oyama K, Tanaka H, Kobirumaki-Shimozawa F, Ishii S, Terui T, Ishiwata S, Fukuda N. Effects of omecamtiv mecarbil on the contractile properties of skinned porcine left atrial and ventricular muscles. Front Physiol 2022; 13:947206. [PMID: 36082222 PMCID: PMC9445838 DOI: 10.3389/fphys.2022.947206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Omecamtiv mecarbil (OM) is a novel inotropic agent for heart failure with systolic dysfunction. OM prolongs the actomyosin attachment duration, which enhances thin filament cooperative activation and accordingly promotes the binding of neighboring myosin to actin. In the present study, we investigated the effects of OM on the steady-state contractile properties in skinned porcine left ventricular (PLV) and atrial (PLA) muscles. OM increased Ca2+ sensitivity in a concentration-dependent manner in PLV, by left shifting the mid-point (pCa50) of the force-pCa curve (ΔpCa50) by ∼0.16 and ∼0.33 pCa units at 0.5 and 1.0 μM, respectively. The Ca2+-sensitizing effect was likewise observed in PLA, but less pronounced with ΔpCa50 values of ∼0.08 and ∼0.22 pCa units at 0.5 and 1.0 μM, respectively. The Ca2+-sensitizing effect of OM (1.0 μM) was attenuated under enhanced thin filament cooperative activation in both PLV and PLA; this attenuation occurred directly via treatment with fast skeletal troponin (ΔpCa50: ∼0.16 and ∼0.10 pCa units in PLV and PLA, respectively) and indirectly by increasing the number of strongly bound cross-bridges in the presence of 3 mM MgADP (ΔpCa50: ∼0.21 and ∼0.08 pCa units in PLV and PLA, respectively). It is likely that this attenuation of the Ca2+-sensitizing effect of OM is due to a decrease in the number of “recruitable” cross-bridges that can potentially produce active force. When cross-bridge detachment was accelerated in the presence of 20 mM inorganic phosphate, the Ca2+-sensitizing effect of OM (1.0 μM) was markedly decreased in both types of preparations (ΔpCa50: ∼0.09 and ∼0.03 pCa units in PLV and PLA, respectively). The present findings suggest that the positive inotropy of OM is more markedly exerted in the ventricle than in the atrium, which results from the strongly bound cross-bridge-dependent allosteric activation of thin filaments.
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Affiliation(s)
- Tomohiro Nakanishi
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Oyama
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- Quantum Beam Science Research Directorate, National Institutes for Quantum Science and Technology, Gunma, Japan
| | - Hiroyuki Tanaka
- Laboratory of Marine Biotechnology and Microbiology, Hokkaido University, Hakodate, Japan
| | | | - Shuya Ishii
- Quantum Beam Science Research Directorate, National Institutes for Quantum Science and Technology, Gunma, Japan
| | - Takako Terui
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Shin’ichi Ishiwata
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- *Correspondence: Norio Fukuda,
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Shah AS, Sadayappan S, Urbina EM. Lipids: a Potential Molecular Pathway Towards Diastolic Dysfunction in Youth-Onset Type 2 Diabetes. Curr Atheroscler Rep 2022; 24:109-117. [PMID: 35080716 PMCID: PMC8930525 DOI: 10.1007/s11883-022-00989-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE OF THE REVIEW Obesity and type 2 diabetes (T2D) with onset in youth are emerging public health concerns. Youth with obesity and T2D are at risk for the development of heart failure with preserved ejection fraction (HFpEF) due to diabetes-related cardiomyopathy with evidence of precursor stages, namely diastolic dysfunction, present in youth. We review the literature regarding diastolic dysfunction in youth with obesity and T2D; discuss the potential mechanisms including the role of lipids, contractile proteins and their post-translational modifications, and conclude with studies to guide future treatments. RECENT FINDINGS The diabetes milieu namely hyperglycemia, hyperinsulinemia, and lipotoxicity favor development of diastolic dysfunction and HFpEF. Recent studies show HFpEF is associated with slow left ventricular relaxation and sarcomere stiffness induced by reduced calcium (Ca2+) and β-adrenergic responses. There are currently no effective therapies available for treating HFpEF. Targeting the sarcomere is an area of ongoing research.
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Affiliation(s)
- Amy S. Shah
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children’s Hospital Medical Center and The University of Cincinnati, 3333 Burnet Ave ML 7012, Cincinnati, OH, 45229, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, Ohio, USA
| | - Elaine M. Urbina
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children’s Hospital Medical Center and The University of Cincinnati, 3333 Burnet Ave ML 7012, Cincinnati, OH, 45229, USA,The Heart Institute, Cincinnati Children’s Hospital, and the University of Cincinnati, Cincinnati, Ohio, USA
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Abstract
The number of therapies for heart failure (HF) with reduced ejection fraction has nearly doubled in the past decade. In addition, new therapies for HF caused by hypertrophic and infiltrative disease are emerging rapidly. Indeed, we are on the verge of a new era in HF in which insights into the biology of myocardial disease can be matched to an understanding of the genetic predisposition in an individual patient to inform precision approaches to therapy. In this Review, we summarize the biology of HF, emphasizing the causal relationships between genetic contributors and traditional structure-based remodelling outcomes, and highlight the mechanisms of action of traditional and novel therapeutics. We discuss the latest advances in our understanding of both the Mendelian genetics of cardiomyopathy and the complex genetics of the clinical syndrome presenting as HF. In the phenotypic domain, we discuss applications of machine learning for the subcategorization of HF in ways that might inform rational prescribing of medications. We aim to bridge the gap between the biology of the failing heart, its diverse clinical presentations and the range of medications that we can now use to treat it. We present a roadmap for the future of precision medicine in HF.
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Lookin O, Kuznetsov D, Protsenko Y. Omecamtiv mecarbil attenuates length-tension relationship in healthy rat myocardium and preserves it in monocrotaline-induced pulmonary heart failure. Clin Exp Pharmacol Physiol 2021; 49:84-93. [PMID: 34459025 DOI: 10.1111/1440-1681.13584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 01/10/2023]
Abstract
The cardiac-specific myosin activator, omecamtiv mecarbil (OM), is an effective inotrope for treating heart failure but its effects on active force and Ca2+ kinetics in healthy and diseased myocardium remain poorly studied. We tested the effect of two concentrations of OM (0.2 and 1 µmol/L in saline) on isometric contraction and Ca-transient (CaT) in right ventricular trabeculae of healthy rats (CONT, n = 8) and rats with monocrotaline-induced pulmonary heart failure (MCT, n = 8). The contractions were obtained under preload of 75%-100% of optimal length (tension-length relationship). The 0.2 µmol/L OM did not affect the diastolic level, amplitude, or kinetics of isometric contraction and CaT, irrespective of the group of rats or preload. The 1 µmol/L OM significantly suppressed active tension-length relationships in CONT but not in MCT, while leading in both groups to a significantly prolonged relaxation. CaT time-to-peak was unaffected in CONT and MCT, but CaT decay was slightly accelerated in its early phase and considerably prolonged in its late phase to a similar extent in both groups. We conclude that the substantial prolongation of CaT decay is due to enhanced Ca2+ utilisation by troponin C mediated by the direct effect of OM on the cooperative activation of myofilaments. The lack of beneficial effect of OM in the healthy rat myocardium may be due to a relatively high level of activating Ca2+ in cells with normal Ca2+ handling, whereas the preservation of the tension-length relationship in the failing heart may relate to the diminished Ca2+ levels of sarcoplasmic reticulum.
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Affiliation(s)
- Oleg Lookin
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Daniil Kuznetsov
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
| | - Yuri Protsenko
- Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, Yekaterinburg, Russian Federation
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Ghionzoli N, Gentile F, Del Franco AM, Castiglione V, Aimo A, Giannoni A, Burchielli S, Cameli M, Emdin M, Vergaro G. Current and emerging drug targets in heart failure treatment. Heart Fail Rev 2021; 27:1119-1136. [PMID: 34273070 PMCID: PMC9197912 DOI: 10.1007/s10741-021-10137-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
After initial strategies targeting inotropism and congestion, the neurohormonal interpretative model of heart failure (HF) pathophysiology has set the basis for current pharmacological management of HF, as most of guideline recommended drug classes, including beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists, blunt the activation of detrimental neurohormonal axes, namely sympathetic and renin–angiotensin–aldosterone (RAAS) systems. More recently, sacubitril/valsartan, a first-in-class angiotensin receptor neprilysin inhibitor, combining inhibition of RAAS and potentiation of the counter-regulatory natriuretic peptide system, has been consistently demonstrated to reduce mortality and HF-related hospitalization. A number of novel pharmacological approaches have been tested during the latest years, leading to mixed results. Among them, drugs acting directly at a second messenger level, such as the soluble guanylate cyclase stimulator vericiguat, or other addressing myocardial energetics and mitochondrial function, such as elamipretide or omecamtiv-mecarbil, will likely change the therapeutic management of patients with HF. Sodium glucose cotransporter 2 inhibitors, initially designed for the management of type 2 diabetes mellitus, have been recently demonstrated to improve outcome in HF, although mechanisms of their action on cardiovascular system are yet to be elucidated. Most of these emerging approaches have shifted the therapeutic target from neurohormonal systems to the heart, by improving cardiac contractility, metabolism, fibrosis, inflammation, and remodeling. In the present paper, we review from a pathophysiological perspective current and novel therapeutic strategies in chronic HF.
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Affiliation(s)
- Nicolò Ghionzoli
- Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy
| | | | - Anna Maria Del Franco
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1 - 56124, Pisa, Italy
| | | | - Alberto Aimo
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alberto Giannoni
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1 - 56124, Pisa, Italy
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Matteo Cameli
- Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy
| | - Michele Emdin
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1 - 56124, Pisa, Italy
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Giuseppe Vergaro
- Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1 - 56124, Pisa, Italy.
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
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Small Molecules acting on Myofilaments as Treatments for Heart and Skeletal Muscle Diseases. Int J Mol Sci 2020; 21:ijms21249599. [PMID: 33339418 PMCID: PMC7767104 DOI: 10.3390/ijms21249599] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 01/10/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are the most prevalent forms of the chronic and progressive pathological condition known as cardiomyopathy. These diseases have different aetiologies; however, they share the feature of haemodynamic abnormalities, which is mainly due to dysfunction in the contractile proteins that make up the contractile unit known as the sarcomere. To date, pharmacological treatment options are not disease-specific and rather focus on managing the symptoms, without addressing the disease mechanism. Earliest attempts at improving cardiac contractility by modulating the sarcomere indirectly (inotropes) resulted in unwanted effects. In contrast, targeting the sarcomere directly, aided by high-throughput screening systems, could identify small molecules with a superior therapeutic value in cardiac muscle disorders. Herein, an extensive literature review of 21 small molecules directed to five different targets was conducted. A simple scoring system was created to assess the suitability of small molecules for therapy by evaluating them in eight different criteria. Most of the compounds failed due to lack of target specificity or poor physicochemical properties. Six compounds stood out, showing a potential therapeutic value in HCM, DCM or heart failure (HF). Omecamtiv Mecarbil and Danicamtiv (myosin activators), Mavacamten, CK-274 and MYK-581 (myosin inhibitors) and AMG 594 (Ca2+-sensitiser) are all small molecules that allosterically modulate troponin or myosin. Omecamtiv Mecarbil showed limited efficacy in phase III GALACTIC-HF trial, while, results from phase III EXPLORER-HCM trial were recently published, indicating that Mavacamten reduced left ventricular outflow tract (LVOT) obstruction and diastolic dysfunction and improved the health status of patients with HCM. A novel category of small molecules known as “recouplers” was reported to target a phenomenon termed uncoupling commonly found in familial cardiomyopathies but has not progressed beyond preclinical work. In conclusion, the contractile apparatus is a promising target for new drug development.
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11
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Boggu PR, Venkateswararao E, Manickam M, Sharma N, Kang JS, Jung SH. Identification of diphenylalkylisoxazol-5-amine scaffold as novel activator of cardiac myosin. Bioorg Med Chem 2020; 28:115742. [PMID: 33007555 DOI: 10.1016/j.bmc.2020.115742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/29/2020] [Indexed: 01/10/2023]
Abstract
To identify novel potent cardiac myosin activator, a series of diphenylalkylisoxazol-5-amine compounds 4-7 have been synthesized and evaluated for cardiac myosin ATPase activation. Among the 37 compounds, 4a (CMA at 10 µM = 81.6%), 4w (CMA at 10 µM = 71.2%) and 6b (CMA at 10 µM = 67.4%) showed potent cardiac myosin activation at a single concentration of 10 µM. These results suggested that the introduction of the amino-isoxazole ring as a bioisostere for urea group is acceptable for the cardiac myosin activation. Additional structure-activity relationship (SAR) studies were conducted. Para substitution (-Cl, -OCH3, -SO2N(CH3)2) to the phenyl rings or replacement of a phenyl ring with a heterocycle (pyridine, piperidine and tetrahydropyran) appeared to attenuate cardiac myosin activation at 10 µM. Additional hydrogen bonding acceptor next to the amino group of the isoxazoles did not enhance the activity. The potent isoxazole compounds showed selectivity for cardiac myosin activation over skeletal and smooth muscle myosin, and therefore these potent and selective isoxazole compounds could be considered as a new series of cardiac myosin ATPase activators for the treatment of systolic heart failure.
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Affiliation(s)
- Pulla Reddy Boggu
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea; School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Eeda Venkateswararao
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Manoj Manickam
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Niti Sharma
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Jong Seong Kang
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea.
| | - Sang-Hun Jung
- College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 34134, Republic of Korea.
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12
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Maack C, Eschenhagen T, Hamdani N, Heinzel FR, Lyon AR, Manstein DJ, Metzger J, Papp Z, Tocchetti CG, Yilmaz MB, Anker SD, Balligand JL, Bauersachs J, Brutsaert D, Carrier L, Chlopicki S, Cleland JG, de Boer RA, Dietl A, Fischmeister R, Harjola VP, Heymans S, Hilfiker-Kleiner D, Holzmeister J, de Keulenaer G, Limongelli G, Linke WA, Lund LH, Masip J, Metra M, Mueller C, Pieske B, Ponikowski P, Ristić A, Ruschitzka F, Seferović PM, Skouri H, Zimmermann WH, Mebazaa A. Treatments targeting inotropy. Eur Heart J 2020; 40:3626-3644. [PMID: 30295807 DOI: 10.1093/eurheartj/ehy600] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/06/2018] [Accepted: 09/14/2018] [Indexed: 02/06/2023] Open
Abstract
Acute heart failure (HF) and in particular, cardiogenic shock are associated with high morbidity and mortality. A therapeutic dilemma is that the use of positive inotropic agents, such as catecholamines or phosphodiesterase-inhibitors, is associated with increased mortality. Newer drugs, such as levosimendan or omecamtiv mecarbil, target sarcomeres to improve systolic function putatively without elevating intracellular Ca2+. Although meta-analyses of smaller trials suggested that levosimendan is associated with a better outcome than dobutamine, larger comparative trials failed to confirm this observation. For omecamtiv mecarbil, Phase II clinical trials suggest a favourable haemodynamic profile in patients with acute and chronic HF, and a Phase III morbidity/mortality trial in patients with chronic HF has recently begun. Here, we review the pathophysiological basis of systolic dysfunction in patients with HF and the mechanisms through which different inotropic agents improve cardiac function. Since adenosine triphosphate and reactive oxygen species production in mitochondria are intimately linked to the processes of excitation-contraction coupling, we also discuss the impact of inotropic agents on mitochondrial bioenergetics and redox regulation. Therefore, this position paper should help identify novel targets for treatments that could not only safely improve systolic and diastolic function acutely, but potentially also myocardial structure and function over a longer-term.
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Affiliation(s)
- Christoph Maack
- Comprehensive Heart Failure Center, University Clinic Würzburg, Am Schwarzenberg 15, Würzburg, Germany
| | - Thomas Eschenhagen
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.,Partner site Hamburg/Kiel/Lübeck, DZHK (German Centre for Cardiovascular Research), Hamburg, Germany
| | - Nazha Hamdani
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
| | - Frank R Heinzel
- Department of Cardiology, Charité University Medicine, Berlin, Germany
| | - Alexander R Lyon
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital and National Heart and Lung Institute, Imperial College, London, UK
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany.,Division for Structural Biochemistry, Hannover Medical School, Hannover, Germany
| | - Joseph Metzger
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Zoltán Papp
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Carlo G Tocchetti
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
| | - M Birhan Yilmaz
- Department of Cardiology, Cumhuriyet University, Sivas, Turkey
| | - Stefan D Anker
- Department of Cardiology and Pneumology, University Medical Center Göttingen and DZHK (German Center for Cardiovascular Research), Göttingen, Germany.,Division of Cardiology and Metabolism - Heart Failure, Cachexia and Sarcopenia, Department of Internal Medicine and Cardiology, Berlin-Brandenburg Center for Regenerative Therapies (BCRT) at Charité University Medicine, Berlin, Germany
| | - Jean-Luc Balligand
- Institut de Recherche Expérimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Universite Catholique de Louvain and Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Johann Bauersachs
- Department of Cardiology and Angiology, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover D-30625, Germany
| | | | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.,Partner site Hamburg/Kiel/Lübeck, DZHK (German Centre for Cardiovascular Research), Hamburg, Germany
| | - Stefan Chlopicki
- Department of Pharmacology, Medical College, Jagiellonian University, Krakow, Poland
| | - John G Cleland
- University of Hull, Kingston upon Hull, UK.,National Heart and Lung Institute, Royal Brompton and Harefield Hospitals NHS Trust, Imperial College, London, UK
| | - Rudolf A de Boer
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander Dietl
- Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Rodolphe Fischmeister
- Inserm UMR-S 1180, Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | | | | | | | | | - Gilles de Keulenaer
- Laboratory of Physiopharmacology (University of Antwerp) and Department of Cardiology, ZNA Hospital, Antwerp, Belgium
| | - Giuseppe Limongelli
- Department of Cardiothoracic Sciences, Second University of Naples, Naples, Italy
| | | | - Lars H Lund
- Division of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Josep Masip
- Intensive Care Department, Consorci Sanitari Integral, University of Barcelona, Spain
| | - Marco Metra
- Cardiology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Italy
| | - Christian Mueller
- Department of Cardiology and Cardiovascular Research Institute Basel (CRIB), University Hospital Basel, University of Basel, Switzerland
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany.,Department of Internal Medicine and Cardiology, German Heart Center Berlin, and German Centre for Cardiovascular Research (DZHK), Partner site Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
| | - Piotr Ponikowski
- Department of Cardiology, Medical University, Clinical Military Hospital, Wroclaw, Poland
| | - Arsen Ristić
- Department of Cardiology of the Clinical Center of Serbia and Belgrade University School of Medicine, Belgrade, Serbia
| | - Frank Ruschitzka
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Switzerland
| | | | - Hadi Skouri
- Division of Cardiology, American University of Beirut Medical Centre, Beirut, Lebanon
| | - Wolfram H Zimmermann
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany.,German Center for Cardiovascular Research (DZHK), Partner siteGöttingen, Göttingen, Germany
| | - Alexandre Mebazaa
- Hôpital Lariboisière, Université Paris Diderot, Inserm U 942, Paris, France
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13
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Czeiszperger TL, Wang MP, Chung CS. Membrane stabilizer Poloxamer 188 improves yield of primary isolated rat cardiomyocytes without impairing function. Physiol Rep 2020; 8:e14382. [PMID: 32109347 PMCID: PMC7048379 DOI: 10.14814/phy2.14382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/05/2020] [Accepted: 02/05/2020] [Indexed: 12/23/2022] Open
Abstract
Intact cardiomyocytes are used to investigate cardiac contractility and evaluate the efficacy of new therapeutic compounds. Primary enzymatic isolation of adult rodent cardiomyocytes has limitations, including low cardiomyocyte survival, which is likely due to ischemic conditions and/or membrane damage. The addition of Poloxamer 188 (P188) has been used to reduce ischemia‐ and membrane‐related damage in ischemia–reperfusion and muscular dystrophy studies. P188 stabilizes membranes, reducing cell death. Cardiomyocytes were isolated from rats, under three conditions: (1) using standard isolation solutions, (2) with P188 added during cannulation (ischemic event), and (3) with P188 added during cannulation, enzymatic digestion, and trituration. Cell survival was assessed by quantifying the number of rod‐shaped versus contracted cells on the day of isolation and up to 3 days post‐isolation. Adding P188 only during cannulation yielded improved survival on the day of isolation. Little difference in survival was seen among the three conditions in the days post‐isolation. Cardiomyocyte function was assessed by measuring calcium transients and unloaded sarcomere lengths for up to 2 days post‐isolation. P188 did not consistently alter calcium handling or sarcomere shortening in the isolated cardiomyocytes. We conclude that the addition of P188 to the cannulation (e.g., wash) of the isolated heart may improve initial survival of cardiomyocytes upon primary enzymatic isolation.
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Affiliation(s)
| | - Madison P Wang
- Department of Physiology, Wayne State University, Detroit, MI, USA
| | - Charles S Chung
- Department of Physiology, Wayne State University, Detroit, MI, USA
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14
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Teerlink JR, Diaz R, Felker GM, McMurray JJV, Metra M, Solomon SD, Legg JC, Büchele G, Varin C, Kurtz CE, Malik FI, Honarpour N. Omecamtiv Mecarbil in Chronic Heart Failure With Reduced Ejection Fraction: Rationale and Design of GALACTIC-HF. JACC-HEART FAILURE 2020; 8:329-340. [PMID: 32035892 DOI: 10.1016/j.jchf.2019.12.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/03/2019] [Accepted: 12/09/2019] [Indexed: 01/10/2023]
Abstract
A central factor in the pathogenesis of heart failure (HF) with reduced ejection fraction is the initial decrease in systolic function. Prior attempts at increasing cardiac contractility with oral drugs have uniformly resulted in signals of increased mortality at pharmacologically effective doses. Omecamtiv mecarbil is a novel, selective cardiac myosin activator that has been shown to improve cardiac function and to decrease ventricular volumes, heart rate, and N-terminal pro-B-type natriuretic peptide in patients with chronic HF. The GALACTIC-HF (Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure) trial tests the hypotheses that omecamtiv mecarbil can safely improve symptoms, prevent clinical HF events, and delay CV death in patients with chronic HF. The GALACTIC-HF trial is an international, multicenter, randomized, double-blind, placebo-controlled, event-driven cardiovascular outcomes trial. More than 8,000 patients with chronic symptomatic (New York Heart Association functional class II to IV) HF, left ventricular ejection fraction ≤35%, elevated natriuretic peptides, and either current hospitalization for HF or history of hospitalization or emergency department visit for HF within a year of screening will be randomized to either oral placebo or omecamtiv mecarbil employing a pharmacokinetic-guided dose titration strategy using doses of 25, 37.5, or 50 mg twice daily. The primary efficacy outcome is the time to cardiovascular death or first HF event. The study has 90% power to assess a final hazard ratio of approximately 0.80 in cardiovascular death, the first secondary outcome. The GALACTIC-HF trial is the first trial examining whether selectively increasing cardiac contractility in patients with HF with reduced ejection fraction will result in improved clinical outcomes. (Registrational Study With Omecamtiv Mecarbil/AMG 423 to Treat Chronic Heart Failure With Reduced Ejection Fraction [GALACTIC-HF]; NCT02929329).
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Affiliation(s)
- John R Teerlink
- Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California-San Francisco, San Francisco, California.
| | - Rafael Diaz
- Estudios Clinicos Latinoamérica, Rosario, Argentina
| | - G Michael Felker
- Division of Cardiology, Duke University School of Medicine, Duke Clinical Research Institute, Durham, North Carolina
| | - John J V McMurray
- British Heart Foundation Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Marco Metra
- Cardiology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Scott D Solomon
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | | | | | | | - Fady I Malik
- Cytokinetics, Inc., South San Francisco, California
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15
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Obata K, Morita H, Takaki M. The energy-saving effect of a new myosin activator, omecamtiv mecarbil, on LV mechanoenergetics in rat hearts with blood-perfused isovolumic contraction model. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:1065-1070. [PMID: 31267148 DOI: 10.1007/s00210-019-01685-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 06/26/2019] [Indexed: 01/10/2023]
Abstract
A novel myosin activator, omecamtiv mecarbil (OM), is a cardiac inotropic agent with a unique new mechanism of action, which is thought to arise from an increase in the transition rate of myosin into the actin-bound force-generating state without increasing calcium (Ca2+) transient. There remains, however, considerable controversy about the effects of OM on cardiac contractility and energy expenditure. In the present study, we investigated the effects of OM on left ventricular (LV) mechanical work and energetics, i.e., mechanoenergetics in rat normal hearts (CTL) and failing hearts induced by chronic administration of isoproterenol (1.2 mg/kg/day) for 4 weeks (ISO-HF). We analyzed the LV end-systolic pressure-volume relation (ESPVR) and the linear relation between the myocardial oxygen consumption per beat (VO2) and systolic pressure-volume area (PVA; a total mechanical energy per beat) in isovolumically contracting rat hearts at 240- or 300-bpm pacing in the absence or presence of OM. OM did not change the ESPVR in CTL and ISO-HF. OM, however, significantly decreased the slope of VO2-PVA relationship in both CTL and ISO-HF, and significantly increased the mean VO2 intercept without changes in basal metabolism in ISO-HF. These results suggested that OM improved the oxygen cost of PVA (contractile efficiency) with the unchanged LV contractility in both CTL and ISO-HF but increased VO2 for Ca2+ handling in excitation-contraction (E-C) coupling in ISO-HF. We concluded that OM improves contractile efficiency in normal and failing hearts but increases O2 consumption of Ca2+ handling in failing hearts in isovolumically contracting rat model.
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Affiliation(s)
- Koji Obata
- Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
| | - Hironobu Morita
- Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan
| | - Miyako Takaki
- Department of Physiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan
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16
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Marston S. Small molecule studies: the fourth wave of muscle research. J Muscle Res Cell Motil 2019; 40:69-76. [PMID: 31228047 PMCID: PMC6726831 DOI: 10.1007/s10974-019-09526-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 06/13/2019] [Indexed: 12/28/2022]
Abstract
The study of muscle and contractility is an unusual scientific endeavour since it has from the start been focussed on one problem—What makes muscle work?—and yet has needed a vast range of different approaches and techniques to study it. Its uniqueness lies in the fundamental fascination of a large scale molecular machine that converts chemical energy into mechanical energy at ambient temperature and with high efficiency that is also controlled by an exquisitely intricate yet utterly reliable regulatory system and is an essential component of animal life. The investigation of muscle is as innovative as any other field of research. As soon as one approach appears to be played out another comes along. It is instructive to consider this as a series of waves of novel and heightened activity starting in the 1950s. The thesis of this article is that we are approaching the fourth wave with the recent rise of interest in small molecules as research tools and possible therapies for muscle diseases.
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Affiliation(s)
- Steven Marston
- Cardiovascular Division, National Heart and Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
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17
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Psotka MA, Gottlieb SS, Francis GS, Allen LA, Teerlink JR, Adams KF, Rosano GM, Lancellotti P. Cardiac Calcitropes, Myotropes, and Mitotropes. J Am Coll Cardiol 2019; 73:2345-2353. [DOI: 10.1016/j.jacc.2019.02.051] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 02/12/2019] [Indexed: 01/19/2023]
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18
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Mamidi R, Li J, Doh CY, Holmes JB, Stelzer JE. Lost in translation: Interpreting cardiac muscle mechanics data in clinical practice. Arch Biochem Biophys 2018; 662:213-218. [PMID: 30576628 DOI: 10.1016/j.abb.2018.12.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/25/2018] [Accepted: 12/17/2018] [Indexed: 01/10/2023]
Abstract
Current inotropic therapies improve systolic function in heart failure patients but also elicit undesirable side effects such as arrhythmias and increased intracellular Ca2+ transients. In order to maintain myocyte Ca2+ homeostasis, the increased cytosolic Ca2+ needs to be actively transported back to sarcoplasmic reticulum leading to depleted ATP reserves. Thus, an emerging approach is to design sarcomere-based treatments to correct impaired contractility via a direct and allosteric modulation of myosin's intrinsic force-generating behavior -a concept that potentially avoids the "off-target" effects. To achieve this goal, various biophysical approaches are utilized to investigate the mechanistic impact of sarcomeric modulators but information derived from diverse approaches is not fully integrated into therapeutic applications. This is in part due to the lack of information that provides a coherent connecting link between biophysical data to in vivo function. Hence, our ability to clearly discern the drug-mediated impact on whole-heart function is diminished. Reducing this translational barrier can significantly accelerate clinical progress related to sarcomere-based therapies by optimizing drug-dosing and treatment duration protocols based on information obtained from biophysical studies. Therefore, we attempt to link biophysical mechanical measurements obtained in isolated cardiac muscle and in vivo contractile function.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jiayang Li
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
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19
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Mamidi R, Li J, Doh CY, Verma S, Stelzer JE. Impact of the Myosin Modulator Mavacamten on Force Generation and Cross-Bridge Behavior in a Murine Model of Hypercontractility. J Am Heart Assoc 2018; 7:e009627. [PMID: 30371160 PMCID: PMC6201428 DOI: 10.1161/jaha.118.009627] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/27/2018] [Indexed: 01/09/2023]
Abstract
Background Recent studies suggest that mavacamten (Myk461), a small myosin-binding molecule, decreases hypercontractility in myocardium expressing hypertrophic cardiomyopathy-causing missense mutations in myosin heavy chain. However, the predominant feature of most mutations in cardiac myosin binding protein-C ( cMyBPC ) that cause hypertrophic cardiomyopathy is reduced total cMyBPC expression, and the impact of Myk461 on cMyBPC -deficient myocardium is currently unknown. Methods and Results We measured the impact of Myk461 on steady-state and dynamic cross-bridge ( XB ) behavior in detergent-skinned mouse wild-type myocardium and myocardium lacking cMyBPC (knockout (KO)). KO myocardium exhibited hypercontractile XB behavior as indicated by significant accelerations in rates of XB detachment (krel) and recruitment (kdf) at submaximal Ca2+ activations. Incubation of KO and wild-type myocardium with Myk461 resulted in a dose-dependent force depression, and this impact was more pronounced at low Ca2+ activations. Interestingly, Myk461-induced force depressions were less pronounced in KO myocardium, especially at low Ca2+ activations, which may be because of increased acto-myosin XB formation and potential disruption of super-relaxed XB s in KO myocardium. Additionally, Myk461 slowed krel in KO myocardium but not in wild-type myocardium, indicating increased XB " on" time. Furthermore, the greater degree of Myk461-induced slowing in kdf and reduction in XB recruitment magnitude in KO myocardium normalized the XB behavior back to wild-type levels. Conclusions This is the first study to demonstrate that Myk461-induced force depressions are modulated by cMyBPC expression levels in the sarcomere, and emphasizes that clinical use of Myk461 may need to be optimized based on the molecular trigger that underlies the hypertrophic cardiomyopathy phenotype.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Jiayang Li
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Chang Yoon Doh
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
| | - Sujeet Verma
- Department of Horticulture SciencesIFAS, Gulf Coast Research and Education CenterUniversity of FloridaWimauma
| | - Julian E. Stelzer
- Department of Physiology and BiophysicsSchool of MedicineCase Western Reserve UniversityClevelandOH
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20
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Rønning L, Bakkehaug JP, Rødland L, Kildal AB, Myrmel T, How O. Opposite diastolic effects of omecamtiv mecarbil versus dobutamine and ivabradine co-treatment in pigs with acute ischemic heart failure. Physiol Rep 2018; 6:e13879. [PMID: 30311442 PMCID: PMC6182250 DOI: 10.14814/phy2.13879] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 02/01/2023] Open
Abstract
Acute ischemic cardiogenic shock is associated with poor prognosis, and the impact of inotropic support on diastolic function in this context is unclear. We assessed two suggested new inotropic strategies in a clinically relevant pig model of ischemic acute heart failure (AHF): treatment with the myosin activator omecamtiv mecarbil (OM) or dobutamine and ivabradine (D+I). Left ventricular (LV) ischemia was induced in anesthetized pigs by coronary microembolization (n = 12). The animals then received OM (bolus 0.75 mg/kg, followed by 0.5 mg/kg per h) (n = 6) or D+I (5 μg/kg per min + 0.29 ± 0.16 mg/kg) (n = 6), respectively. Ischemia reduced the stroke volume (SV), despite the increased left atrial pressure associated with impaired LV early relaxation, systolic dilatation, and LV late diastolic stiffness. Both treatments improved systolic ejection, but only D+I increased the SV from 26 ± 5 to 33 ± 5 mL. D+I enhanced LV early relaxation (Tau; from 45 ± 11 to 29 ± 4 msec) and prolonged the diastolic time (DT) from 338 ± 60 to 352 ± 40 msec. In contrast, OM prolonged Tau (42 ± 5 to 62 ± 10 msec) and shortened the DT (from 326 ± 68 to 248 ± 84 msec). Our data suggest that enhanced early relaxation by D+I improves LV pump function in postischemic acute heart failure. In contrast, OM worsened lusitropy in this model.
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Affiliation(s)
- Leif Rønning
- Cardiovascular Research GroupInstitute of Medical BiologyFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
| | - Jens P. Bakkehaug
- Cardiovascular Research GroupInstitute of Medical BiologyFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
| | - Lars Rødland
- Cardiovascular Research GroupInstitute of Medical BiologyFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
| | - Anders B. Kildal
- Cardiovascular Research GroupInstitute of Medical BiologyFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
| | - Truls Myrmel
- Cardiovascular Research GroupInstitute of Clinical MedicineFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
- Department of Cardiothoracic and Vascular Surgery, Heart and Lung ClinicUniversity Hospital of North NorwayTromsøNorway
| | - Ole‐Jakob How
- Cardiovascular Research GroupInstitute of Medical BiologyFaculty of Health SciencesUiT The Arctic University of NorwayTromsøNorway
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21
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Nánási P, Komáromi I, Almássy J. Perspectives of a myosin motor activator agent with increased selectivity. Can J Physiol Pharmacol 2018; 96:676-680. [PMID: 29792814 DOI: 10.1139/cjpp-2017-0741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Clinical treatment of heart failure is still not fully solved. A novel class of agents, the myosin motor activators, acts directly on cardiac myosin resulting in an increased force generation and prolongation of contraction. Omecamtiv mecarbil, the lead molecule of this group, is now in human phase 3 displaying promising clinical performance. However, omecamtiv mecarbil is not selective to myosin, because it readily binds to and activates cardiac ryanodine receptors (RyR-2), an effect that may cause complications in case of overdose. In this study, in silico analysis was performed to investigate the docking of omecamtiv mecarbil and other structural analogues to cardiac myosin heavy chain and RyR-2 to select the structure that has a higher selectivity to myosin over RyR-2. In silico docking studies revealed that omecamtiv mecarbil has comparable affinity to myosin and RyR-2: the respective Kd values are 0.60 and 0.87 μmol/L. Another compound, CK-1032100, has much lower affinity to RyR-2 than omecamtiv mecarbil, while it still has a moderate affinity to myosin. It was concluded that further research starting from the chemical structure of CK-1032100 may result a better myosin activator burdened probably less by the RyR-2 binding side effect. It also is possible, however, that the selectivity of omecamtiv mecarbil to myosin over RyR-2 cannot be substantially improved, because similar moieties seem to be responsible for the high affinity to both myosin and RyR-2.
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Affiliation(s)
- Péter Nánási
- a Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Komáromi
- b Division of Clinical Laboratory Science, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Almássy
- c Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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22
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Next-generation small molecule therapies for heart failure: 2015 and beyond. Bioorg Med Chem Lett 2018; 28:1429-1435. [PMID: 29615340 DOI: 10.1016/j.bmcl.2018.03.064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/13/2018] [Accepted: 03/22/2018] [Indexed: 12/26/2022]
Abstract
Poor prognosis coupled with significant economic burden makes heart failure (HF) one of the largest issues currently facing the world population. Although a significant number of new therapies have emerged over the past 20 years to treat the underlying physiological risk factors, only two new medications specifically for HF have been approved since 2007. This perspective provides an overview of recently approved treatment options for HF and as well as an update on additional small molecule therapies currently in clinical development.
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Mamidi R, Li J, Gresham KS, Verma S, Doh CY, Li A, Lal S, Dos Remedios CG, Stelzer JE. Dose-Dependent Effects of the Myosin Activator Omecamtiv Mecarbil on Cross-Bridge Behavior and Force Generation in Failing Human Myocardium. Circ Heart Fail 2017; 10:CIRCHEARTFAILURE.117.004257. [PMID: 29030372 DOI: 10.1161/circheartfailure.117.004257] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 09/12/2017] [Indexed: 01/10/2023]
Abstract
BACKGROUND Omecamtiv mecarbil (OM) enhances systolic function in vivo by directly binding the myosin cross-bridges (XBs) in the sarcomere. However, the mechanistic details governing OM-induced modulation of XB behavior in failing human myocardium are unclear. METHODS AND RESULTS The effects of OM on steady state and dynamic XB behavior were measured in chemically skinned myocardial preparations isolated from human donor and heart failure (HF) left ventricle. HF myocardium exhibited impaired contractile function as evidenced by reduced maximal force, magnitude of XB recruitment (Pdf), and a slowed rate of XB detachment (krel) at submaximal Ca2+ activations. Ca2+ sensitivity of force generation (pCa50) was higher in HF myocardium when compared with donor myocardium, both prior to and after OM incubations. OM incubation (0.5 and 1.0 μmol/L) enhanced force generation at submaximal Ca2+ activations in a dose-dependent manner. Notably, OM induced a slowing in krel with 1.0 μmol/L OM but not with 0.5 μmol/L OM in HF myocardium. Additionally, OM exerted other differential effects on XB behavior in HF myocardium as evidenced by a greater enhancement in Pdf and slowing in the time course of cooperative XB recruitment (Trec), which collectively prolonged achievement of peak force development (Tpk), compared with donor myocardium. CONCLUSIONS Our findings demonstrate that OM augments force generation but also prolongs the time course of XB transitions to force-bearing states in remodeled HF myocardium, which may extend the systolic ejection time in vivo. Optimal OM dosing is critical for eliciting enhanced systolic function without excessive prolongation of systolic ejection time, which may compromise diastolic filling.
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Affiliation(s)
- Ranganath Mamidi
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Jiayang Li
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Kenneth S Gresham
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Sujeet Verma
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Chang Yoon Doh
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Amy Li
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Sean Lal
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Cristobal G Dos Remedios
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.)
| | - Julian E Stelzer
- From the Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH (R.M., J.L., C.Y.D., J.E.S.); Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (K.S.G); Department of Horticulture Sciences, IFAS, Gulf Coast Research and Education Center, University of Florida, Wimauma (S.V.); Sydney Heart Bank, Discipline of Anatomy & Histology, Bosch Institute, University of Sydney, Australia (A.L., S.L., C.G.d.R.).
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24
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Moin DS, Sackheim J, Hamo CE, Butler J. Cardiac Myosin Activators in Systolic Heart Failure: More Friend than Foe? Curr Cardiol Rep 2017; 18:100. [PMID: 27568794 DOI: 10.1007/s11886-016-0778-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Despite the rising prevalence of HF, new evidence-based novel therapies for patients with worsening HF remain lacking, e.g., safe inotropic therapies. Traditional inotropes increase contractility by altering intracellular calcium flux, a pathway that may be responsible for the multitude of adverse effects associated with current options. Omecamtiv mecarbil, a direct myosin activator, increases contractility through a distinct pathway by increasing the proportion of myosin heads that are bound to actin in a high-affinity state. Phase II clinical trials in patients with chronic HF with this agent seem promising. A phase III trial investigating this therapy has not yet been pursued to date.
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Affiliation(s)
- Danyaal S Moin
- Division of Cardiology, Stony Brook University School of Medicine, Stony Brook, NY, USA
| | - Julia Sackheim
- Division of Cardiology, Stony Brook University School of Medicine, Stony Brook, NY, USA
| | - Carine E Hamo
- Division of Cardiology, Stony Brook University School of Medicine, Stony Brook, NY, USA
| | - Javed Butler
- Division of Cardiology, Stony Brook University School of Medicine, Stony Brook, NY, USA. .,Health Sciences Center, Stony Brook University Medical Center, T16-080, Stony Brook, NY, 11794, USA.
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25
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Horváth B, Szentandrássy N, Veress R, Almássy J, Magyar J, Bányász T, Tóth A, Papp Z, Nánási PP. Frequency-dependent effects of omecamtiv mecarbil on cell shortening of isolated canine ventricular cardiomyocytes. Naunyn Schmiedebergs Arch Pharmacol 2017; 390:1239-1246. [PMID: 28940010 DOI: 10.1007/s00210-017-1422-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/31/2017] [Indexed: 01/10/2023]
Abstract
Omecamtiv mecarbil (OM) is a myosin activator agent developed for the treatment of heart failure. OM was reported to increase left ventricular ejection fraction and systolic ejection time, but little is known about the effect of heart rate on the action of OM. The present study, therefore, was designed to investigate the effects of OM on unloaded cell shortening and intracellular Ca2+ ([Ca2+]i) transients as a function of the pacing frequency. Isolated cardiomyocytes were stimulated at various frequencies under steady-state conditions. Cell length was monitored by an optical edge detector and changes in [Ca2+]i were followed using the Ca2+-sensitive dye Fura-2. At the pacing frequency of 1 Hz, OM (1-10 μM) significantly decreased both diastolic and systolic cell length, however, fractional shortening was augmented only by 1 μM OM. Time to peak tension and time of 90% relaxation were progressively increased by OM. At the frequency of 2 Hz, diastolic cell length was reduced by 10 μM OM to a larger extent than systolic cell length, resulting in a significantly decreased fractional shortening under these conditions. OM had no effect on the parameters of the [Ca2+]i transient at any pacing frequency. The results suggest that supratherapeutic concentrations of OM may decrease rather than increase the force of cardiac contraction especially in tachycardic patients.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary.,Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary.,Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary.,Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary
| | - Attila Tóth
- Division of Clinical Physiology, Department of Cardiology, Research Center for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Papp
- Division of Clinical Physiology, Department of Cardiology, Research Center for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, Debrecen, 4012, Hungary. .,Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary.
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26
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Psotka MA, Teerlink JR. Direct Myosin Activation by Omecamtiv Mecarbil for Heart Failure with Reduced Ejection Fraction. Handb Exp Pharmacol 2017; 243:465-490. [PMID: 28315072 DOI: 10.1007/164_2017_13] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Myosin is the indispensable molecular motor that utilizes chemical energy to produce force for contraction within the cardiac myocyte. Myosin activity is gated by intracellular calcium levels which are regulated by multiple upstream signaling cascades that can be altered for clinical utility using inotropic medications. In contrast to clinically available cardiac inotropes, omecamtiv mecarbil is a novel direct myosin activator developed to augment left ventricular systolic function without the undesirable secondary effects of altered calcium homeostasis. Its identification and synthesis followed high-throughput screening of a reconstituted sarcomere, deliberate optimization, exquisite biochemical evaluation, and subsequently promising effects in animal models were demonstrated. Physiologically, it prolonged the duration of left ventricular systole in animal models, healthy adults, and patients with heart failure with reduced ejection fraction (HFrEF) without changing the velocity of pressure development, as assessed in animal models. It has been formulated for both intravenous and oral administration, and in both acute and chronic settings produced similar alterations in the duration of systole associated with beneficial increases in cardiac output, improvements in left ventricular volumes, and reductions in heart rate and often of natriuretic peptides. Small, asymptomatic increases in troponin were also observed in the absence of clinically evident ischemia. Clinically, the question remains as to whether the possible harm of this minimal troponin release is outweighed by the potential benefits of reduced neurohormonal activation, increased stroke volume and cardiac output, and improved ventricular remodeling in patients treated with omecamtiv mecarbil. The resolution of this question is being addressed by a phase III outcomes trial of this potential novel therapy for heart failure.
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Affiliation(s)
- Mitchell A Psotka
- School of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - John R Teerlink
- School of Medicine, University of California San Francisco, San Francisco, CA, USA.
- Section of Cardiology, 111C, San Francisco Veterans Affairs Medical Center, 4150 Clement St, San Francisco, CA, 94121-1545, USA.
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27
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Abstract
Cardiac stress can induce morphological, structural and functional changes of the heart, referred to as cardiac remodeling. Myocardial infarction or sustained overload as a result of pathological causes such as hypertension or valve insufficiency may result in progressive remodeling and finally lead to heart failure (HF). Whereas pathological and physiological (exercise, pregnancy) overload both stimulate cardiomyocyte growth (hypertrophy), only pathological remodeling is characterized by increased deposition of extracellular matrix proteins, termed fibrosis, and loss of cardiomyocytes by necrosis, apoptosis and/or phagocytosis. HF is strongly associated with age, and cardiomyocyte loss and fibrosis are typical signs of the aging heart. Fibrosis results in stiffening of the heart, conductivity problems and reduced oxygen diffusion, and is associated with diminished ventricular function and arrhythmias. As a consequence, the workload of cardiomyocytes in the fibrotic heart is further augmented, whereas the physiological environment is becoming less favorable. This causes additional cardiomyocyte death and replacement of lost cardiomyocytes by fibrotic material, generating a vicious cycle of further decline of cardiac function. Breaking this fibrosis-cell death axis could halt further pathological and age-related cardiac regression and potentially reverse remodeling. In this review, we will describe the interaction between cardiac fibrosis, cardiomyocyte hypertrophy and cell death, and discuss potential strategies for tackling progressive cardiac remodeling and HF.
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Affiliation(s)
- A Piek
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - R A de Boer
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - H H W Silljé
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands.
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28
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Abstract
Despite advances in therapy, patients with heart failure (HF) continue to experience unacceptably high rates of hospitalization and death, as well as poor quality of life. As a consequence, there is an urgent need for new treatments that can improve the clinical course of the growing worldwide population of HF patients. Serelaxin and ularatide, both based on naturally occurring peptides, have potent vasodilatory as well as other effects on the heart and kidneys. For both agents, phase 3 studies that are designed to determine whether they improve outcomes in patients with acute HF have completed enrollment. TRV027, a biased ligand for the type 1 angiotensin receptor with effects that extend beyond traditional angiotensin-receptor blockers is also being studied in the acute HF population. Omecamtiv mecarbil, an inotropic agent that improves myocardial contractility by a novel mechanism, and vericiguat, a drug that stimulates soluble guanylate cyclase, are both being developed to treat patients with chronic HF. Finally, despite the negative results of the CUPID study, gene transfer therapy continues to be explored as a means of improving the function of the failing heart. The basis for the use of these drugs and their current status in clinical trials are discussed. (Circ J 2016; 80: 1882-1891).
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29
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Omecamtiv Mecarbil, a Cardiac Myosin Activator, Increases Ca2+ Sensitivity in Myofilaments With a Dilated Cardiomyopathy Mutant Tropomyosin E54K. J Cardiovasc Pharmacol 2016; 66:347-53. [PMID: 26065842 DOI: 10.1097/fjc.0000000000000286] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Apart from transplant, there are no satisfactory therapies for the severe depression in contractility in familial dilated cardiomyopathy (DCM). Current heart failure treatments that act by increasing contractility involve signaling cascades that alter calcium homeostasis and induce arrhythmias. Omecamtiv mecarbil is a promising new inotropic agent developed for heart failure that may circumvent such limitations. Omecamtiv is a direct cardiac myosin activator that promotes and prolongs the strong myosin-actin binding conformation to increase the duration of systolic elastance. We tested the effect of omecamtiv on Ca(2+) sensitivity of myofilaments of a DCM mouse model containing a tropomyosin E54K mutation. We compared tension and ATPase activity of detergent-extracted myofilaments with and without treatment with 316 nM omecamtiv at varying pCa values. When transgenic myofilaments were treated with omecamtiv, the pCa50 for activation of tension increased from 5.70 ± 0.02 to 5.82 ± 0.02 and ATPase activity increased from 5.73 ± 0.06 to 6.07 ± 0.04. This significant leftward shift restored Ca(2+) sensitivity to levels no longer significantly different from controls. Proteomic studies lacked changes in sarcomeric protein phosphorylation. Our data demonstrate that omecamtiv can potentially augment cardiac contractility in DCM by increasing Ca(2+) sensitivity. The use of direct myosin activators addresses functional defects without incurring the adverse side effects of Ca(2+)-dependent treatments.
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30
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Tran HA, Lin F, Greenberg BH. Potential new drug treatments for congestive heart failure. Expert Opin Investig Drugs 2016; 25:811-26. [DOI: 10.1080/13543784.2016.1181749] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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31
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Lemm H, Dietz S, Janusch M, Buerke M. [Modern drug therapy in cardiovascular intensive care medicine]. Internist (Berl) 2016; 56:702, 704-8, 710-2. [PMID: 26054838 DOI: 10.1007/s00108-015-3717-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Vasoactive drugs and inotropes are important in the hemodynamic management of patients with cardiogenic shock despite modest volume administration. Currently, the concept of cardiac relief is pursued in the treatment of acute heart failure. In this article we present the use of different drugs in the intensive care unit for acute heart failure and cardiogenic shock. In acute heart failure catecholamines are only used during the transition from heart failure to cardiogenic shock. Here, the therapeutic concept of ventricular unloading is more sought after. This can be achieved by the use of diuretics, nitrates, levosimendan (inodilatator), or in the future serelaxin. The hemodynamic management in cardiogenic shock occurs after moderate volume administration with dobutamine to increase inotropy. If no adequate perfusion pressures are achieved, norepinephrine can be administered as a vasopressor. If there is still no sufficient increase in cardiac output, the inodilatator levosimendan can be used. Levosimendan instead of phosphodiesterase inhibitors in this case is preferable. The maxim of hemodynamic management in cardiogenic shock is the transient use of inotropes and vasopressors in the lowest dose possible and only for as long as necessary. This means that one should continuously check whether the dose can be reduced. There are no mortality data demonstrating the utility of hemodynamic monitoring based on objective criteria—but it makes sense to use inotropes and vasopressors sparingly.
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Affiliation(s)
- H Lemm
- Medizinische Klinik II - Kardiologie, Angiologie, Internistische Intensivmedizin, St. Marienkrankenhaus Siegen, Kampenstr. 51, 57072, Siegen, Deutschland
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32
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Bakkehaug JP, Kildal AB, Engstad ET, Boardman N, Næsheim T, Rønning L, Aasum E, Larsen TS, Myrmel T, How OJ. Response to Letter Regarding Article, "Myosin Activator Omecamtiv Mecarbil Increases Myocardial Oxygen Consumption and Impairs Cardiac Efficiency Mediated by Resting Myosin ATPase Activity". Circ Heart Fail 2016; 8:1142. [PMID: 26738203 DOI: 10.1161/circheartfailure.115.002548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Jens Petter Bakkehaug
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anders Benjamin Kildal
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Eirik Torgersen Engstad
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Neoma Boardman
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Torvind Næsheim
- Cardiovascular Research Group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Leif Rønning
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ellen Aasum
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Terje S Larsen
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Truls Myrmel
- Department of Cardiothoracic and Vascular Surgery, Heart and Lung Clinic, University Hospital of North Norway, Tromsø, Norway
| | - Ole-Jakob How
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
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33
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Nánási P, Váczi K, Papp Z. The myosin activator omecamtiv mecarbil: a promising new inotropic agent. Can J Physiol Pharmacol 2016; 94:1033-1039. [PMID: 27322915 DOI: 10.1139/cjpp-2015-0573] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Heart failure became a leading cause of mortality in the past few decades with a progressively increasing prevalence. Its current therapy is restricted largely to the suppression of the sympathetic activity and the renin-angiotensin system in combination with diuretics. This restrictive strategy is due to the potential long-term adverse effects of inotropic agents despite their effective influence on cardiac function when employed for short durations. Positive inotropes include inhibitors of the Na+/K+ pump, β-receptor agonists, and phosphodiesterase inhibitors. Theoretically, Ca2+ sensitizers may also increase cardiac contractility without resulting in Ca2+ overload; nevertheless, their mechanism of action is frequently complicated by other pleiotropic effects. Recently, a new positive inotropic agent, the myosin activator omecamtiv mecarbil, has been developed. Omecamtiv mecarbil binds directly to β-myosin heavy chain and enhances cardiac contractility by increasing the number of the active force-generating cross-bridges, presumably without major off-target effects. This review focuses on recent in vivo and in vitro results obtained with omecamtiv mecarbil, and discusses its mechanism of action at a molecular level. Based on clinical data, omecamtiv mecarbil is a promising new tool in the treatment of systolic heart failure.
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Affiliation(s)
- Péter Nánási
- a Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Krisztina Váczi
- b Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Papp
- c Division of Clinical Physiology, Department of Cardiology, Research Center for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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34
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Bernardo BC, Blaxall BC. From Bench to Bedside: New Approaches to Therapeutic Discovery for Heart Failure. Heart Lung Circ 2016; 25:425-34. [PMID: 26993094 DOI: 10.1016/j.hlc.2016.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 01/06/2016] [Indexed: 01/10/2023]
Abstract
Heart failure is a significant global health problem, which is becoming worse as the population ages, and remains one of the biggest burdens on our economy. Despite significant advances in cardiovascular medicine, management and surgery, mortality rates remain high, with almost half of patients with heart failure dying within five years of diagnosis. As a multifactorial clinical syndrome, heart failure still represents an epidemic threat, highlighting the need for deeper insights into disease mechanisms and the development of innovative therapeutic strategies for both treatment and prevention. In this review, we discuss conventional heart failure therapies and highlight new pharmacological agents targeting pathophysiological features of the failing heart, for example, non-coding RNAs, angiotensin receptor-neprilysin inhibitors, cardiac myosin activators, BGP-15 and molecules targeting GRK2 including M119, gallein and paroxetine. Finally, we address the disparity between phase II and phase III clinical trials that prevent the translation of emerging HF therapies into new and approved therapies.
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Affiliation(s)
- Bianca C Bernardo
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Burns C Blaxall
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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35
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Liu LC, Dorhout B, van der Meer P, Teerlink JR, Voors AA. Omecamtiv mecarbil: a new cardiac myosin activator for the treatment of heart failure. Expert Opin Investig Drugs 2015; 25:117-27. [PMID: 26587768 DOI: 10.1517/13543784.2016.1123248] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Current available inotropic agents increase cardiac contractility, but are associated with myocardial ischemia, arrhythmias, and mortality. A novel selective cardiac myosin activator, omecamtiv mecarbil (CK-1827452/ AMG-423) is a small molecule that activates the sarcomere proteins directly, resulting in prolonged systolic ejection time and increased cardiac contractility. AREAS COVERED This paper discusses the chemistry, pharmacokinetics, clinical efficacy and safety of omecamtiv mecarbil. Omecamtiv mecarbil represents a novel therapeutic approach to directly improve cardiac function and is therefore proposed as a potential new treatment of patients with systolic heart failure. The authors review results of previous studies investigating the effect of omecamtiv mecarbil in heart failure animal models, healthy volunteers, and patients with acute and chronic systolic heart failure. EXPERT OPINION Results of phase I and phase II studies demonstrate that omecamtiv mecarbil is safe and well tolerated both as an intravenous and oral formulation. In healthy volunteers and chronic systolic heart failure patients, administration of omecamtiv mecarbil resulted in a concentration-dependent increase of left ventricular ejection time, ejection fraction, fractional shortening, and stroke volume. The first results of a double-blind, randomized, placebo-controlled phase IIb dose-finding study with the oral formulation of omecamtiv mecarbil demonstrated beneficial effects on cardiac function and N-terminal pro-brain natriuretic peptide levels. This study will provide essential dosing information for the requisite phase III trials which will investigate whether the beneficial effects of omecamtiv mecarbil translate into improved clinical outcomes.
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Affiliation(s)
- Licette Cy Liu
- a Department of Cardiology , University Medical Center Groningen, University of Groningen , Groningen , 9713 GZ , the Netherlands
| | - Bernard Dorhout
- a Department of Cardiology , University Medical Center Groningen, University of Groningen , Groningen , 9713 GZ , the Netherlands
| | - Peter van der Meer
- a Department of Cardiology , University Medical Center Groningen, University of Groningen , Groningen , 9713 GZ , the Netherlands
| | - John R Teerlink
- b Section of Cardiology, San Francisco Veterans Affairs Medical Center and School of Medicine , University of California San Francisco , San Francisco , CA , USA
| | - Adriaan A Voors
- a Department of Cardiology , University Medical Center Groningen, University of Groningen , Groningen , 9713 GZ , the Netherlands
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Chung CS, Mechas C, Campbell KS. Myocyte contractility can be maintained by storing cells with the myosin ATPase inhibitor 2,3 butanedione monoxime. Physiol Rep 2015; 3:3/6/e12445. [PMID: 26116551 PMCID: PMC4522161 DOI: 10.14814/phy2.12445] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Isolated intact myocytes can be used to investigate contractile mechanisms and to screen new therapeutic compounds. These experiments typically require euthanizing an animal and isolating fresh cells each day or analyzing cultured myocytes, which quickly lose their rod-shaped morphology. Recent data suggest that the viability of canine myocytes can be prolonged using low temperature and N-benzyl-p-toluene sulfonamide (an inhibitor of skeletal myosin ATPase). We performed similar studies in rat myocytes in order to test whether the cardiac myosin ATPase inhibitors 2,3-Butanedione monoxime (BDM) and blebbistatin help to maintain cell-level function over multiple days. Myocytes were isolated from rats and separated into batches that were stored at 4°C in a HEPES-buffered solution that contained 0.5 mmol L(-1) Ca(2+) and (1) no myosin ATPase inhibitors; (2) 10 mmol L(-1) BDM; or (3) 3 μmol L(-1) blebbistatin. Functional viability of myocytes was assessed up to 3 days after the isolation by measuring calcium transients and unloaded shortening profiles induced by electrical stimuli in inhibitor-free Tyrode's solution. Cells stored without myosin ATPase inhibitors had altered morphology (fewer rod-shaped cells, shorter diastolic sarcomere lengths, and membrane blebbing) and were not viable for contractile assays after 24 h. Cells stored in BDM maintained morphology and contractile function for 48 h. Storage in blebbistatin maintained cell morphology for 72 h but inhibited contractility. These data show that storing cells with myosin ATPase inhibitors can extend the viability of myocytes that will be used for functional assays. This may help to refine and reduce the use of animals in experiments.
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Affiliation(s)
- Charles S Chung
- Department of Physiology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Charles Mechas
- Department of Physiology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
| | - Kenneth S Campbell
- Department of Physiology and Center for Muscle Biology, University of Kentucky, Lexington, Kentucky
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Mamidi R, Gresham KS, Li A, dos Remedios CG, Stelzer JE. Molecular effects of the myosin activator omecamtiv mecarbil on contractile properties of skinned myocardium lacking cardiac myosin binding protein-C. J Mol Cell Cardiol 2015; 85:262-72. [PMID: 26100051 DOI: 10.1016/j.yjmcc.2015.06.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 01/03/2023]
Abstract
Decreased expression of cardiac myosin binding protein-C (cMyBP-C) in the myocardium is thought to be a contributing factor to hypertrophic cardiomyopathy in humans, and the initial molecular defect is likely abnormal cross-bridge (XB) function which leads to impaired force generation, decreased contractile performance, and hypertrophy in vivo. The myosin activator omecamtiv mecarbil (OM) is a pharmacological drug that specifically targets the myosin XB and recent evidence suggests that OM induces a significant decrease in the in vivo motility velocity and an increase in the XB duty cycle. Thus, the molecular effects of OM maybe beneficial in improving contractile function in skinned myocardium lacking cMyBP-C because absence of cMyBP-C in the sarcomere accelerates XB kinetics and enhances XB turnover rate, which presumably reduces contractile efficiency. Therefore, parameters of XB function were measured in skinned myocardium lacking cMyBP-C prior to and following OM incubation. We measured ktr, the rate of force redevelopment as an index of XB transition from both the weakly- to strongly-bound state and from the strongly- to weakly-bound states and performed stretch activation experiments to measure the rates of XB detachment (krel) and XB recruitment (kdf) in detergent-skinned ventricular preparations isolated from hearts of wild-type (WT) and cMyBP-C knockout (KO) mice. Samples from donor human hearts were also used to assess the effects of OM in cardiac muscle expressing a slow β-myosin heavy chain (β-MHC). Incubation of skinned myocardium with OM produced large enhancements in steady-state force generation which were most pronounced at low levels of [Ca(2+)] activations, suggesting that OM cooperatively recruits additional XB's into force generating states. Despite a large increase in steady-state force generation following OM incubation, parallel accelerations in XB kinetics as measured by ktr were not observed, and there was a significant OM-induced decrease in krel which was more pronounced in the KO skinned myocardium compared to WT skinned myocardium (58% in WT vs. 76% in KO at pCa 6.1), such that baseline differences in krel between KO and WT skinned myocardium were no longer apparent following OM-incubation. A significant decrease in the kdf was also observed following OM incubation in all groups, which may be related to the increase in the number of cooperatively recruited XB's at low Ca(2+)-activations which slows the overall rate of force generation. Our results indicate that OM may be a useful pharmacological approach to normalize hypercontractile XB kinetics in myocardium with decreased cMyBP-C expression due to its molecular effects on XB behavior.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Kenneth S Gresham
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Amy Li
- Muscle Research Unit, Bosch Institute, University of Sydney, Sydney Australia
| | | | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA.
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Abstract
Acute heart failure (AHF) emerges as a major and growing epidemiological concern with high morbidity and mortality rates. Current therapies in patients with acute heart failure rely on different strategies. Patients with hypotension, hypoperfusion, or shock require inotropic support, whereas diuretics and vasodilators are recommended in patients with systemic or pulmonary congestion. Traditionally inotropic agents, referred to as Ca2+ mobilizers load the cardiomyocyte with Ca2+ and thereby increase oxygen consumption and risk for arrhythmias. These limitations of traditional inotropes may be avoided by sarcomere targeted agents. Direct activation of the cardiac sarcomere may be achieved by either sensitizing the cardiac myofilaments to Ca2+ or activating directly the cardiac myosin. In this review, we focus on sarcomere targeted inotropic agents, emphasizing their mechanisms of action and overview the most relevant clinical considerations.
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Abstract
Various human diseases can disrupt the balance between muscle contraction and relaxation. Sarcomeric modulators can be used to readjust this balance either indirectly by intervening in signalling pathways or directly through interaction with the muscle proteins that control contraction. Such agents represent a novel approach to treating any condition in which striated muscle function is compromised, including heart failure, cardiomyopathies, skeletal myopathies and a wide range of neuromuscular conditions. Here, we review agents that modulate the mechanical function of the sarcomere, focusing on emerging compounds that target myosin or the troponin complex.
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40
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Novel drug mechanisms in development for heart failure. Pflugers Arch 2014; 466:1219-25. [DOI: 10.1007/s00424-014-1528-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 04/23/2014] [Indexed: 01/10/2023]
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41
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Novel drug targets in clinical development for heart failure. Eur J Clin Pharmacol 2014; 70:765-74. [DOI: 10.1007/s00228-014-1671-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 03/19/2014] [Indexed: 01/24/2023]
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Chung CS, Campbell KS. Temperature and transmural region influence functional measurements in unloaded left ventricular cardiomyocytes. Physiol Rep 2013; 1:e00158. [PMID: 24400159 PMCID: PMC3871472 DOI: 10.1002/phy2.158] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 10/18/2013] [Accepted: 10/23/2013] [Indexed: 12/21/2022] Open
Abstract
Intact cardiomyocytes are increasingly being used to investigate the molecular mechanisms of contraction and to screen new therapeutic compounds. The function of the cardiomyocytes is often measured from the calcium transients and sarcomere length profiles. We studied the role of experimental temperature and transmural region on indices of function in freshly isolated, unloaded cardiomyocytes. Intact cardiomyocytes were isolated from the subendocardium, midmyocardium, and subepicardium of 3-month-old Sprague-Dawley rats. Myocytes from each region were studied at 25°C, 31°C, and 37°C. Cytosolic calcium transients were measured using Fura-2 fluorescence, whereas sarcomere length shortening and relengthening profiles were measured using high-speed video capture. For both the calcium transients and sarcomere length profiles, the time to peak and the time to half relaxation decreased significantly with increasing temperature. Increasing temperature also raised the minimum and maximum calcium levels of all cells. Of note, there was a reduced coefficient of variation (standard deviation divided by the mean) at higher temperatures for calcium fluorescence amplitudes, time to peak calcium, and rates of sarcomeric shortening and relengthening. The amplitudes and minimum of the calcium transients were significantly dependent on transmural region, and several sarcomere length parameters exhibited statistical interactions between temperature and transmural region. Together, these results show that biological variability can be reduced by performing experiments at 37°C rather than at room temperature, and by isolating cells from a specific transmural region. Adopting these procedures will improve the statistical power of subsequent analyses and increase the efficiency of future experiments.
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Affiliation(s)
- Charles S Chung
- Department of Physiology and Center for Muscle Biology, University of Kentucky Lexington, Kentucky
| | - Kenneth S Campbell
- Department of Physiology and Center for Muscle Biology, University of Kentucky Lexington, Kentucky
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A new approach to inotropic therapy in the treatment of heart failure: cardiac myosin activators in treatment of HF. Cardiol Rev 2013; 21:155-9. [PMID: 23018669 DOI: 10.1097/crd.0b013e318275889c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Systolic heart failure remains a leading cause of death and disability, and available pharmacologic treatments for heart failure are limited in both safety and effectiveness. Existing drugs focus on diverse mechanisms related to the pathophysiology of heart failure, yet none directly target the central feature of systolic heart failure, decreased cardiac contractility. Cardiac myosin activators, specifically omecamtiv mecarbil (formerly CK-1827452), directly activate the enzymatic pathway within the cardiac myocyte leading to ventricular contraction. This unique inotropic agent has been shown in preclinical and clinical studies to be effective in improving cardiac contractility by increasing systolic ejection time without the unwanted effects of the currently available indirect inotropic drugs. Cardiac myosin activators show great promise and may prove to be a safer and more effective therapeutic approach for the treatment of systolic heart failure.
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Zhang M, Mou T, Zhao Z, Peng C, Ma Y, Fang W, Zhang X. Synthesis and 18F-labeling of the analogues of Omecamtiv Mecarbil as a potential cardiac myosin imaging agent with PET. Nucl Med Biol 2013; 40:689-96. [DOI: 10.1016/j.nucmedbio.2013.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 01/31/2013] [Accepted: 02/22/2013] [Indexed: 01/28/2023]
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Ochala J, Ravenscroft G, Laing NG, Nowak KJ. Nemaline myopathy-related skeletal muscle α-actin (ACTA1) mutation, Asp286Gly, prevents proper strong myosin binding and triggers muscle weakness. PLoS One 2012; 7:e45923. [PMID: 23029319 PMCID: PMC3447773 DOI: 10.1371/journal.pone.0045923] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/23/2012] [Indexed: 12/12/2022] Open
Abstract
Many mutations in the skeletal muscle α-actin gene (ACTA1) lead to muscle weakness and nemaline myopathy. Despite increasing clinical and scientific interest, the molecular and cellular pathogenesis of weakness remains unclear. Therefore, in the present study, we aimed at unraveling these mechanisms using muscles from a transgenic mouse model of nemaline myopathy expressing the ACTA1 Asp286Gly mutation. We recorded and analyzed the mechanics of membrane-permeabilized single muscle fibers. We also performed molecular energy state computations in the presence or absence of Asp286Gly. Results demonstrated that during contraction, the Asp286Gly acts as a “poison-protein” and according to the computational analysis it modifies the actin-actin interface. This phenomenon is likely to prevent proper myosin cross-bridge binding, limiting the fraction of actomyosin interactions in the strong binding state. At the cell level, this decreases the force-generating capacity, and, overall, induces muscle weakness. To counterbalance such negative events, future potential therapeutic strategies may focus on the inappropriate actin-actin interface or myosin binding.
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Affiliation(s)
- Julien Ochala
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Sweden.
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McCann P, Hauptman PJ. Inotropic therapy: an important role in the treatment of advanced symptomatic heart failure. Med Clin North Am 2012; 96:943-54. [PMID: 22980057 DOI: 10.1016/j.mcna.2012.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Inotropic therapy remains an option in the management of patients with advanced heart failure symptoms from systolic dysfunction who do not respond to conventional therapies. The decision to use this class is largely predicated on an accurate evaluation of the patient's fluid and perfusion status. Selection of the appropriate agent and dosing regimens requires an understanding of the underlying pathophysiology of heart failure and concomitant therapy. Most important, the goals of care should be stated clearly, given inherent risks associated with this class of drug.
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Affiliation(s)
- Patrick McCann
- Division of Cardiology, Saint Louis University School of Medicine, Saint Louis, MO 63110, USA
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47
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Who needs a transplant and when? Curr Opin Organ Transplant 2012; 17:531-9. [PMID: 22890042 DOI: 10.1097/mot.0b013e3283574185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Heart transplantation remains the treatment of choice for patients with advanced heart failure. We review the current definition of optimal therapy, prediction of prognosis and revisit contraindications for transplant. RECENT FINDINGS Clinical trials of eplerenone and ivabradine were associated with improved prognosis, whereas others (nesiritide) were disappointing. Advances in cardiac resynchronization therapy and ventricular assist devices (VAD) have resulted in an expansion of their indications. Advances in catheter ablation for ventricular tachycardia have made this an uncommon indication for heart transplantation. Surgical ventricular reconstruction and mitral valve intervention have not resulted in survival benefit. Bypass surgery was associated with a lower mortality from cardiovascular causes. Prognostic risk scores have been developed in heart failure patients; however, ongoing refinements are needed. Selected patients with diabetes, HIV and pretransplant malignancy, now have favourable outcomes after heart transplantation. VAD as bridge to candidacy is an option in heart failure patients with 'fixed' pulmonary hypertension. Alternate listing strategies have also been studied to provide high-risk patients with an opportunity for heart transplantation. SUMMARY Heart failure patients should be on current optimal medical and device therapy with a poor prognosis before consideration for heart transplantation. An individualized approach to heart transplantation assessment is recommended.
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48
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Nagai T, Komuro I. Gene and cytokine therapy for heart failure: molecular mechanisms in the improvement of cardiac function. Am J Physiol Heart Circ Physiol 2012; 303:H501-12. [PMID: 22777420 DOI: 10.1152/ajpheart.00130.2012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite significant advances in pharmacological and clinical treatment, heart failure (HF) remains a leading cause of morbidity and mortality worldwide. Many new therapeutic strategies, including cell transplantation, gene delivery, and cytokines or other small molecules, have been explored to treat HF. Recent advancement of our understanding of the molecules that regulate cardiac function uncover many of the therapeutic key molecules to treat HF. Furthermore, a theory of paracrine mechanism, which underlies the beneficial effects of cell therapy, leads us to search novel target molecules for genetic or pharmacological strategy. Gene therapy means delivery of genetic materials into cells to achieve therapeutic effects. Recently, gene transfer technology in the cardiovascular system has been improved and several therapeutic target genes have been started to examine in clinical research, and some of the promising results have been emerged. Among the various bioactive reagents, cytokines such as granulocyte colony-stimulating factor and erythropoietin have been well examined, and a number of clinical trials for acute myocardial infarction and chronic HF have been conducted. Although further research is needed in both preclinical and clinical areas in terms of molecular mechanisms, safety, and efficiency, both gene and cytokine therapy have a great possibility to open the new era of the treatment of HF.
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Affiliation(s)
- Toshio Nagai
- Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, Chiba, Japan
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Sadayappan S, de Tombe PP. Cardiac myosin binding protein-C: redefining its structure and function. Biophys Rev 2012; 4:93-106. [PMID: 22707987 PMCID: PMC3374655 DOI: 10.1007/s12551-012-0067-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 01/13/2012] [Indexed: 01/10/2023] Open
Abstract
Mutations of cardiac myosin binding protein-C (cMyBP-C) are inherited by an estimated 60 million people worldwide, and the protein is the target of several kinases. Recent evidence further suggests that cMyBP-C mutations alter Ca(2+) transients, leading to electrophysiological dysfunction. Thus, while the importance of studying this cardiac sarcomere protein is clear, preliminary data in the literature have raised many questions. Therefore, in this article, we propose to review the structure and function of cMyBP-C with particular respect to the role(s) in cardiac contractility and whether its release into the circulatory system is a potential biomarker of myocardial infarction. We also discuss future directions and experimental designs that may lead to expanding the role(s) of cMyBP-C in the heart. In conclusion, we suggest that cMyBP-C is a regulatory protein that could offer a broad clinical utility in maintaining normal cardiac function.
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Affiliation(s)
- Sakthivel Sadayappan
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Ave., Maywood, IL 60153 USA
| | - Pieter P. de Tombe
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Ave., Maywood, IL 60153 USA
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Novel therapies in acute and chronic heart failure. Pharmacol Ther 2012; 135:1-17. [PMID: 22475446 DOI: 10.1016/j.pharmthera.2012.03.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 03/07/2012] [Indexed: 01/10/2023]
Abstract
Despite past advances in the pharmacological management of heart failure, the prognosis of these patients remains poor, and for many, treatment options remain unsatisfactory. Additionally, the treatments and clinical outcomes of patients with acute decompensated heart failure have not changed substantially over the past few decades. Consequently, there is a critical need for new drugs that can improve clinical outcomes. In the setting of acute heart failure, new inotrops such as cardiac myosin activators and new vasodilators such as relaxin have been developed. For chronic heart failure with reduced ejection fraction, there are several new approaches that target multiple pathophysiological mechanism including novel blockers of the renin-angiotensin-aldosterone system (direct renin inhibitors, dual-acting inhibitors of the angiotensin II receptor and neprilysin, aldosterone synthase inhibitors), ryanodine receptor stabilizers, and SERCA activators. Heart failure with preserved ejection fraction represents a substantial therapeutic problem as no therapy has been demonstrated to improve symptoms or outcomes in this condition. Newer treatment strategies target specific structural and functional abnormalities that lead to increased myocardial stiffness. Dicarbonyl-breaking compounds reverse advanced glycation-induced cross-linking of collagen and improve the compliance of aged and/or diabetic myocardium. Modulation of titin-dependent passive tension can be achieved via phosphorylation of a unique sequence on the extensible region of the protein. This review describes the pathophysiological basis, mechanism of action, and available clinical efficacy data of drugs that are currently under development. Finally, new therapies for the treatment of heart failure complications, such as pulmonary hypertension and anemia, are discussed.
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