“Targeting the Heart” in Heart Failure

Pyruvate plus uridine augments mitochondrial respiration and prevents cardiac hypertrophy in zebrafish and H9c2 cells

Dysfunction of mitochondrial pyruvate oxidation and aberrant respiratory chain components are common in cardiac defects. However, the precise role of mitochondrial respiration in cardiomyocyte hypertrophy is unclear. Phenylephrine (PE) treatment of rat neonatal H9c2 cardiomyocytes promotes significant hypertrophy with decreased mitochondrial oxygen consumption rate (OCR), membrane potential, respiratory subunit NDUFB8, UQCRC2 and ATP5A (ATP5F1A) expression, and accumulation of reactive oxygen species (ROS). Surprisingly, a 60% reduction in cell survival was observed in PE-treated cells relative to control cells when grown under the respiratory-proficient galactose medium. To revert H9c2 hypertrophy and increase survival, we performed a screening with compounds that boost mitochondrial OCR and scavenge ROS, and identified pyruvate plus uridine as the best hit. As corroboration of the in vitro study, supplementation of pyruvate plus uridine significantly prevented PE-induced cardiac hypertrophy, pericardial edema and bradycardia symptoms in zebrafish embryos. Moreover, pyruvate plus uridine decreased the ventricular and atrial area in cardiomyocyte-specific GFP transgenic Tg (myl7:HRAS-EGFP) lines. Using in vitro and in vivo models, we show that boosting of mitochondrial respiration through pyruvate supplementation and scavenging ROS through uridine supplementation jointly ameliorate cardiac hypertrophy and bradycardia symptoms.

Left ventricular reverse remodeling: A predictor of survival in chagasic cardiomyopathy patients with a reduced ejection fraction

BACKGROUND

Chagas disease is a major health issue in Latin America and is now spreading globally because of migration. Chronic Chagasic cardiomyopathy (CCC) leads to heart failure with a reduced ejection fraction (HFrEF). Left ventricular reverse remodeling (LVRR), defined as an improved LVEF, is associated with improved outcomes in patients with other HFrEF etiologies. Therefore, we evaluated the relationship between LVRR and survival in CCC patients with an LVEF<40%.

METHODS

This retrospective, single-center study included patients diagnosed with CCC and LVEF<40% between January 2006 and September 2021. Patients were divided into two groups: positive RR (PRR; LVEF≥40% or an absolute LVEF increase of ≥ 10%) and negative RR (NRR). Propensity score matching (PSM) was used to account for baseline differences, and Cox proportional hazards models were applied to determine independent predictors of mortality and heart transplantation.

RESULTS

A total of 1,043 patients were evaluated; 221 (21.2%) were classified as having PRR, and 822 (78.8%) were classified as having NRR. PRR status was associated with a 55% lower risk of all-cause mortality and heart transplantation over 15 years (p = 0.002). Multivariate Cox analysis revealed that predictors of total mortality and heart transplantation included NRR status, a worse NYHA class, lower serum sodium levels, larger LV dimensions, and moderate-to-severe tricuspid regurgitation (TR). The PRR predictors were smaller LV dimensions, less mitral regurgitation, and the absence of triple therapy at baseline. NRR patients were more likely to be on triple therapy at baseline.

CONCLUSIONS

PRR improves survival in CCC patients with HFrEF. Identifying patients with potential for LVRR, alongside early therapeutic interventions, may reduce mortality in this population. Future research should focus on therapies that promote LVRR in patients with CCC.

Nexilin mutations, a cause of chronic heart failure: A state-of-the-art review starting from a clinical case

Heart failure (HF) is a medical condition associated with high morbidity and mortality, despite ongoing advances in diagnosis and treatment. Among the various causes of HF, cardiomyopathies are particularly significant and must be thoroughly diagnosed and characterized from the outset. In this review, we aim to present a brief overview of cardiomyopathies as a driver of HF, with a specific focus on the genetic causes, particularly nexilin (NEXN) cardiomyopathy, illustrated by a clinical case. The case involves a 63-year-old male who presented with HF symptoms at moderate exertion. Six months prior, he had been asymptomatic, and a routine transthoracic echocardiography had shown a preserved left ventricular ejection fraction (LVEF). However, during the current evaluation, transthoracic echocardiography revealed a dilated left ventricle with a severely reduced LVEF of 30%. Subsequent coronary angiography ruled out ischemic heart disease, while cardiac magnetic resonance imaging indicated a non-inflammatory, non-infiltrative dilated cardiomyopathy with extensive LV fibrosis. Genetic testing identified a heterozygous in-frame deletion variant in the NEXN gene [c.1949_1951del, p.(Gly650del)], classified as likely pathogenic. State-of-the-art HF treatment was initiated, including cardiac resynchronization therapy with defibrillator support. Following treatment, the patient's symptoms resolved, and LVEF improved to 42%. Interestingly, this patient experienced the onset of symptoms and left ventricular dysfunction within just six months, a much faster progression compared to previously documented cases where the G650del NEXN variant is typically linked to a more gradual development of dilated cardiomyopathy. Current literature offers limited data on patients with NEXN mutations, and the connection between this gene and both dilated and hypertrophic cardiomyopathies remains an area of active research.

Acute Heart Failure and Non-Ischemic Cardiomyopathies: A Comprehensive Review and Critical Appraisal

Acute heart failure (AHF) is a complex clinical syndrome characterized by the rapid or gradual onset of symptoms and/or signs of heart failure (HF), leading to an unplanned hospital admission or an emergency department visit. AHF is the leading cause of hospitalization in patients over 65 years, thus significantly impacting public health care. However, its prognosis remains poor with high rates of mortality and rehospitalization. Many pre-existing cardiac conditions can lead to AHF, but it can also arise de novo due to acute events. Therefore, understanding AHF etiology could improve patient management and outcomes. Cardiomyopathies (CMPs) are a heterogeneous group of heart muscle diseases, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM), non-dilated cardiomyopathy (NDLVC), and arrhythmogenic right ventricular cardiomyopathy (ARVC), that frequently present with HF. Patients with CMPs are under-represented in AHF studies compared to other etiologies, and therefore therapeutic responses and prognoses remain unknown. In DCM, AHF represents the most frequent cause of death despite treatment improvements. Additionally, DCM is the first indication for heart transplant (HT) among young and middle-aged adults. In HCM, the progression to AHF is rare and more frequent in patients with concomitant severe left ventricle (LV) obstruction and hypertrophy or severe LV systolic dysfunction. HF is the natural evolution of patients with RCM and HF is associated with poor outcomes irrespective of RCM etiology. Furthermore, while the occurrence of AHF is rare among patients with ARVC, this condition in NDLVC patients is currently unknown. In this manuscript, we assessed the available evidence on AHF in patients with CMPs. Data on clinical presentation, therapeutic management, and clinical outcomes according to specific CMPs are limited. Future HF studies assessing the clinical presentation, treatment, and prognosis of specific CMPs are warranted.

Electroactive Nanomaterials for the Prevention and Treatment of Heart Failure: From Materials and Mechanisms to Applications

Heart failure (HF) represents a cardiovascular disease that significantly threatens global well-being and quality of life. Electroactive nanomaterials, characterized by their distinctive physical and chemical properties, emerge as promising candidates for HF prevention and management. This review comprehensively examines electroactive nanomaterials and their applications in HF intervention. It presents the definition, classification, and intrinsic characteristics of conductive, piezoelectric, and triboelectric nanomaterials, emphasizing their mechanical robustness, electrical conductivity, and piezoelectric coefficients. The review elucidates their applications and mechanisms: 1) early detection and diagnosis, employing nanomaterial-based sensors for real-time cardiac health monitoring; 2) cardiac tissue repair and regeneration, providing mechanical, chemical, and electrical stimuli for tissue restoration; 3) localized administration of bioactive biomolecules, genes, or pharmacotherapeutic agents, using nanomaterials as advanced drug delivery systems; and 4) electrical stimulation therapies, leveraging their properties for innovative pacemaker and neurostimulation technologies. Challenges in clinical translation, such as biocompatibility, stability, and scalability, are discussed, along with future prospects and potential innovations, including multifunctional and stimuli-responsive nanomaterials for precise HF therapies. This review encapsulates current research and future directions concerning the use of electroactive nanomaterials in HF prevention and management, highlighting their potential to innovating in cardiovascular medicine.

Durable left ventricular assist devices as a bridge to transplantation: what to expect along the way?

INTRODUCTION

The scarcity of donors coupled with the improvements in left ventricular assist devices (LVAD) technology has led to the use of LVAD as a bridge to transplantation (BTT).

AREAS COVERED

The authors provide an overview of the current status of LVAD BTT implantation with special focus ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

EXPERT OPINION

The United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.

Prognostic significance of serum dynamin‑related protein 1 in patients with heart failure: Findings from a prospective observational study

Mitochondrial dysfunction plays a critical role in the development and exacerbation of heart failure (HF). Dynamin-related protein 1 (Drp1), a key regulator of mitochondrial fission, influences cardiac energy metabolism. The present study investigated the relationship between serum Drp1 levels and the prognosis of patients with HF across a broad spectrum. Serum Drp1 concentrations were measured using ELISA. The primary outcome was the risk of composite major adverse cardiac events (MACEs), which included instances of cardiac death and HF-related readmissions. To assess the prognostic significance of serum Drp1, a receiver operating characteristic curve was constructed to predict MACE-free survival. Additionally, an optimal threshold value for Drp1 was determined and was used to stratify patients into different risk categories. A total of 256 HF patients were finally included and categorized into two groups based on their serum Drp1 levels, labeled as the low (Drp1 ≤2.66 ng/ml, n=101) and high group (Drp1 >2.66 ng/ml, n=155). Patients with low serum Drp1 concentrations showed impaired heart structure and function, as assessed by echocardiography. The 6-month follow-up results indicated that patients with reduced Drp1 concentrations faced a substantially increased risk of MACEs (21.1% vs. 2.8%; P<0.001). The present study revealed that diminished serum Drp1 concentrations could potentially act as a predictive marker for the prognosis of HF in a broad patient population.

Heart failure with improved ejection fraction: Beyond diagnosis to trajectory analysis

Left ventricular (LV) systolic dysfunction represents a highly treatable cause of heart failure (HF). A substantial proportion of patients with HF with reduced ejection fraction (EF;HFrEF) demonstrate improvement in LV systolic function (termed HF with improved EF [HFimpEF]), either spontaneously or when treated with guideline-directed medical therapy (GDMT). Although it is a relatively new HF classification, HFimpEF has emerged in recent years as an important and distinct clinical entity. Improvement in LVEF leads to decreased rates of mortality and adverse HF-related outcomes compared to patients with sustained LV systolic dysfunction (HFrEF). While numerous clinical and imaging factors have been associated with HFimpEF, identification of which patients do and do not improve requires further investigation. In addition, patients improve at different rates, and what determines the trajectory of HFimpEF patients after improvement is incompletely characterized. A proportion of patients maintain improvement in LV systolic function, while others experience a recrudescence of systolic dysfunction, especially with GDMT discontinuation. In this review we discuss the contemporary guideline-recommended classification definition of HFimpEF, the epidemiology of improvement in LV systolic function, and the clinical course of this unique patient population. We also offer evidence-based recommendations for the clinical management of HFimpEF and provide a roadmap for future directions in understanding and improving outcomes in the care of patients with HFimpEF.

Phenotype, outcomes and natural history of early-stage non-ischaemic cardiomyopathy

AIMS

To characterize the phenotype, clinical outcomes and rate of disease progression in patients with early-stage non-ischaemic cardiomyopathy (early-NICM).

METHODS AND RESULTS

We conducted a prospective observational cohort study of patients with early-NICM assessed by late gadolinium enhancement cardiovascular magnetic resonance (CMR). Cases were classified into the following subgroups: isolated left ventricular dilatation (early-NICM H-/D+), non-dilated left ventricular cardiomyopathy (early-NICM H+/D-), or early dilated cardiomyopathy (early-NICM H+/D+). Clinical follow-up for major adverse cardiovascular events (MACE) included non-fatal life-threatening arrhythmia, unplanned cardiovascular hospitalization or cardiovascular death. A subset of patients (n = 119) underwent a second CMR to assess changes in cardiac structure and function. Of 254 patients with early-NICM (median age 46 years [interquartile range 36-58], 94 [37%] women, median left ventricular ejection fraction [LVEF] 55% [52-59]), myocardial fibrosis was present in 65 (26%). There was no difference in the prevalence of fibrosis between subgroups (p = 0.90), however fibrosis mass was lowest in early-NICM H-/D+, higher in early-NICM H+/D- and highest in early-NICM H+/D+ (p = 0.03). Over a median follow-up of 7.9 (5.5-10.0) years, 28 patients (11%) experienced MACE. Non-sustained ventricular tachycardia (hazard ratio [HR] 5.1, 95% confidence interval [CI] 2.36-11.00, p < 0.001), myocardial fibrosis (HR 3.77, 95% CI 1.73-8.20, p < 0.001) and diabetes mellitus (HR 5.12, 95% CI 1.73-15.18, p = 0.003) were associated with MACE in a multivariable model. Only 8% of patients progressed from early-NICM to dilated cardiomyopathy with LVEF <50% over a median of 16 (11-34) months.

CONCLUSION

Early-NICM is not benign. Fibrosis develops early in the phenotypic course. In-depth characterization enhances risk stratification and might aid clinical management.

Transmembrane protein 117 knockdown protects against angiotensin-II-induced cardiac hypertrophy

Mitochondrial dysfunction plays a critical role in the pathogenesis of pathological cardiac hypertrophy. Transmembrane protein 117 modulate mitochondrial membrane potential that may be involved in the regulation of oxidative stress and mitochondrial function. However, its role in the development of angiotensin II (Ang-II)-induced cardiac hypertrophy is unclear. Cardiac-specific TMEM117-knockout and control mice were subjected to cardiac hypertrophy induced by Ang-II infusion. Small-interfering RNAs against TMEM117 or adenovirus-based plasmids encoding TMEM117 were delivered into left ventricles of mice or incubated with neonatal murine ventricular myocytes (NMVMs) before Ang-II stimulation. We found that TMEM117 was upregulated in hypertrophic hearts and cardiomyocytes and TMEM117 deficiency attenuated Ang-II-induced cardiac hypertrophy in vivo. Consistently, the in vitro data demonstrated that Ang-II-induced cardiomyocyte hypertrophy significantly alleviated by TMEM117 knockdown. Conversely, overexpression of TMEM117 exacerbated cardiac hypertrophy and dysfunction. An Ang II-induced increase in cardiac (cardiomyocyte) oxidative stress was alleviated by cardiac-specific knockout (knockdown) of TMEM117 and was worsened by TMEM117 supplementation (overexpression). In addition, TMEM117 knockout decreased endoplasmic reticulum stress induced by Ang-II, which was reversed by TMEM117 supplementation. Furthermore, TMEM117 deficiency mitigated mitochondrial injury in hypertrophic hearts and cardiomyocyte, which was abolished by TMEM117 supplementation (overexpression). Taken together, these findings suggest that upregulation of TMEM117 contributes to the development of cardiac hypertrophy and the downregulation of TMEM117 may be a new therapeutic strategy for the prevention and treatment of cardiac hypertrophy.

Assessment of left ventricular tissue mitochondrial bioenergetics in patients with stable coronary artery disease

Recurrent myocardial ischemia can lead to left ventricular (LV) dysfunction in patients with coronary artery disease (CAD). In this observational cohort study, we assessed for chronic metabolomic and transcriptomic adaptations within LV myocardium of patients undergoing coronary artery bypass grafting. During surgery, paired transmural LV biopsies were acquired on the beating heart from regions with and without evidence of inducible ischemia on preoperative stress perfusion cardiovascular magnetic resonance. From 33 patients, 63 biopsies were acquired, compared to analysis of LV samples from 11 donor hearts. The global myocardial adenosine triphosphate (ATP):adenosine diphosphate (ADP) ratio was reduced in patients with CAD as compared to donor LV tissue, with increased expression of oxidative phosphorylation (OXPHOS) genes encoding the electron transport chain complexes across multiple cell types. Paired analyses of biopsies obtained from LV segments with or without inducible ischemia revealed no significant difference in the ATP:ADP ratio, broader metabolic profile or expression of ventricular cardiomyocyte genes implicated in OXPHOS. Differential metabolite analysis suggested dysregulation of several intermediates in patients with reduced LV ejection fraction, including succinate. Overall, our results suggest that viable myocardium in patients with stable CAD has global alterations in bioenergetic and transcriptional profile without large regional differences between areas with or without inducible ischemia.

Prognostic Role of Metabolic Exercise Testing in Heart Failure

Heart failure is a clinical syndrome with significant heterogeneity in presentation and severity. Serial risk-stratification and prognostication can guide management decisions, particularly in advanced heart failure, when progression toward advanced therapies or end-of-life care is warranted. Each currently utilized prognostic marker carries its own set of challenges in acquisition, reproducibility, accuracy, and significance. Left ventricular ejection fraction is foundational for heart failure syndrome classification after clinical diagnosis and remains the primary parameter for inclusion in most clinical trials; however, it does not consistently correlate with symptoms and functional capacity, which are also independently prognostic in this patient population. Utilizing the left ventricular ejection fraction as the sole basis of prognostication provides an incomplete characterization of this condition and is prone to misguide medical decision-making when used in isolation. In this review article, we survey and exposit the important role of metabolic exercise testing across the heart failure spectrum, as a complementary diagnostic and prognostic modality. Metabolic exercise testing, also known as cardiopulmonary exercise testing, provides a comprehensive evaluation of the multisystem (i.e., neurological, respiratory, circulatory, and musculoskeletal) response to exercise performance. These differential responses can help identify the predominant contributors to exercise intolerance and exercise symptoms. Additionally, the aerobic exercise capacity (i.e., oxygen consumption during exercise) is directly correlated with overall life expectancy and prognosis in many disease states. Specifically in heart failure patients, metabolic exercise testing provides an accurate, objective, and reproducible assessment of the overall circulatory sufficiency and circulatory reserve during physical stress, being able to isolate the concurrent chronotropic and stroke volume responses for a reliable depiction of the circulatory flow rate in real time.

Timing of cardiac resynchronization therapy implantation

AIMS

The optimum timing of cardiac resynchronization therapy (CRT) implantation is unknown. We explored long-term outcomes after CRT in relation to the time interval from a first heart failure hospitalization (HFH) to device implantation.

METHODS AND RESULTS

A database covering the population of England (56.3 million in 2019) was used to quantify clinical outcomes after CRT implantation in relation to first HFHs. From 2010 to 2019, 64 968 patients [age: 71.4 ± 11.7 years; 48 606 (74.8%) male] underwent CRT implantation, 57% in the absence of a previous HFH, 12.9% during the first HFH, and 30.1% after ≥1 HFH. Over 4.54 (2.80-6.71) years [median (interquartile range); 272 989 person-years], the time in years from the first HFH to CRT implantation was associated with a higher risk of total mortality [hazard ratio (HR); 95% confidence intervals (95% CI)] (1.15; 95% CI 1.14-1.16, HFH (HR: 1.26; 95% CI 1.24-1.28), and the combined endpoint of total mortality or HFH (HR: 1.19; 95% CI 1.27-1.20) than CRT in patients with no previous HFHs, after co-variate adjustment. Total mortality (HR: 1.67), HFH (HR: 2.63), and total mortality or HFH (HR: 1.92) (all P < 0.001) were highest in patients undergoing CRT ≥2 years after the first HFH.

CONCLUSION

In this study of a healthcare system covering an entire nation, delays from a first HFH to CRT implantation were associated with progressively worse long-term clinical outcomes. The best clinical outcomes were observed in patients with no previous HFH and in those undergoing CRT implantation during the first HFH.

CONDENSED ABSTRACT

The optimum timing of CRT implantation is unknown. In this study of 64 968 consecutive patients, delays from a first heart failure hospitalization (HFH) to CRT implantation were associated with progressively worse long-term clinical outcomes. Each year from a first HFH to CRT implantation was associated with a 21% higher risk of total mortality and a 34% higher risk of HFH. The best outcomes after CRT were observed in patients with no previous HFHs and in those undergoing implantation during their first HFH.

Defining cardiac functional recovery in end-stage heart failure at single-cell resolution

Recovery of cardiac function is the holy grail of heart failure therapy yet is infrequently observed and remains poorly understood. In this study, we performed single-nucleus RNA sequencing from patients with heart failure who recovered left ventricular systolic function after left ventricular assist device implantation, patients who did not recover and non-diseased donors. We identified cell-specific transcriptional signatures of recovery, most prominently in macrophages and fibroblasts. Within these cell types, inflammatory signatures were negative predictors of recovery, and downregulation of RUNX1 was associated with recovery. In silico perturbation of RUNX1 in macrophages and fibroblasts recapitulated the transcriptional state of recovery. Cardiac recovery mediated by BET inhibition in mice led to decreased macrophage and fibroblast Runx1 expression and diminished chromatin accessibility within a Runx1 intronic peak and acquisition of human recovery signatures. These findings suggest that cardiac recovery is a unique biological state and identify RUNX1 as a possible therapeutic target to facilitate cardiac recovery.

DYRK1B-STAT3 Drives Cardiac Hypertrophy and Heart Failure by Impairing Mitochondrial Bioenergetics

BACKGROUND

Heart failure is a global public health issue that is associated with increasing morbidity and mortality. Previous studies have suggested that mitochondrial dysfunction plays critical roles in the progression of heart failure; however, the underlying mechanisms remain unclear. Because kinases have been reported to modulate mitochondrial function, we investigated the effects of DYRK1B (dual-specificity tyrosine-regulated kinase 1B) on mitochondrial bioenergetics, cardiac hypertrophy, and heart failure.

METHODS

We engineered DYRK1B transgenic and knockout mice and used transverse aortic constriction to produce an in vivo model of cardiac hypertrophy. The effects of DYRK1B and its downstream mediators were subsequently elucidated using RNA-sequencing analysis and mitochondrial functional analysis.

RESULTS

We found that DYRK1B expression was clearly upregulated in failing human myocardium and in hypertrophic murine hearts, as well. Cardiac-specific DYRK1B overexpression resulted in cardiac dysfunction accompanied by a decline in the left ventricular ejection fraction, fraction shortening, and increased cardiac fibrosis. In striking contrast to DYRK1B overexpression, the deletion of DYRK1B mitigated transverse aortic constriction-induced cardiac hypertrophy and heart failure. Mechanistically, DYRK1B was positively associated with impaired mitochondrial bioenergetics by directly binding with STAT3 to increase its phosphorylation and nuclear accumulation, ultimately contributing toward the downregulation of PGC-1α (peroxisome proliferator-activated receptor gamma coactivator-1α). Furthermore, the inhibition of DYRK1B or STAT3 activity using specific inhibitors was able to restore cardiac performance by rejuvenating mitochondrial bioenergetics.

CONCLUSIONS

Taken together, the findings of this study provide new insights into the previously unrecognized role of DYRK1B in mitochondrial bioenergetics and the progression of cardiac hypertrophy and heart failure. Consequently, these findings may provide new therapeutic options for patients with heart failure.

Relative Prognostic Significance of Positron Emission Tomography Myocardial Perfusion Imaging Markers in Cardiomyopathy

BACKGROUND

Rubidium-82 positron emission tomography myocardial perfusion imaging provides measurements of perfusion, myocardial blood flow and reserve (MBFR), and changes in left ventricular ejection fraction (LVEF) at rest and peak stress. Although all of these variables are known to provide prognostic information, they have not been well studied in patients with heart failure due to reduced LVEF.

METHODS

Between 2010 and 2016, 1255 consecutive unique patients with LVEF≤40% were included in this study who underwent rubidium-82 positron emission tomography myocardial perfusion imaging and did not have subsequent revascularization within 90 days. Perfusion assessment was scored semiquantitatively, and LVEF reserve (stress-rest LVEF) and global MBFR (stress/rest MBF) were quantified using automated software. Cox proportional hazards models adjusted for 14 clinical and 7 test characteristics were used to define the independent prognostic significance of MBFR on all-cause mortality.

RESULTS

Of 1255 patients followed for a mean of 3.2 years, 454 (36.2%) died. After adjusting for clinical variables, the magnitude of fixed and reversible perfusion defects was prognostic of death (P=0.02 and 0.01, respectively), while the rest LVEF was not (P=0.18). The addition of LVEF reserve did not add any incremental value, while the addition of MBFR revealed incremental prognostic value (hazard ratio per 0.1 unit decrease in MBFR=1.08 [95% CI, 1.05-1.11], P<0.001) with fixed and reversible defects becoming nonsignificant (P=0.07 and 0.29, respectively). There was no interaction between MBFR and cause of cardiomyopathy (ischemic versus nonischemic).

CONCLUSIONS

In patients with a known cardiomyopathy who did not require early revascularization, reduced MBFR as obtained by positron emission tomography myocardial perfusion imaging is associated with all-cause mortality while other positron emission tomography myocardial perfusion imaging measures were not.

Left ventricular remodelling and prognosis after discharge in new-onset acute heart failure with reduced ejection fraction

Aims

This study aimed to investigate the left ventricular (LV) remodelling and long‐term prognosis of patients with new‐onset acute heart failure (HF) with reduced ejection fraction who were pharmacologically managed and survived until hospital discharge. We compared patients with ischaemic and non‐ischaemic aetiology.

Methods and results

This cohort study consisted of 111 patients admitted with new‐onset acute HF in the period 2008–2016 [62% non‐ischaemic aetiology, 48% supported by inotropes, vasopressors, or short‐term mechanical circulatory devices, and left ventricular ejection fraction (LVEF) at discharge 28% (interquartile range 22–34)]. LV dimensions, LVEF, and mitral valve regurgitation were used as markers for LV remodelling during up to 3 years of follow‐up. Both patients with non‐ischaemic and ischaemic HF had significant improvement in LVEF (P < 0.001 and P = 0.004, respectively) with significant higher improvement in those with non‐ischaemic HF (17% vs. 6%, P < 0.001). Patients with non‐ischaemic HF had reduction in LV end‐diastolic and end‐systolic diameters (6 and 10 mm, both P < 0.001), but this was not found in those with ischaemic HF [+3 mm (P = 0.09) and +2 mm (P = 0.07), respectively]. During a median follow‐up of 4.6 years, 98 patients (88%) did not reach the composite endpoint of LV assist device implantation, heart transplantation, or all‐cause mortality, with no difference between with ischaemic and non‐ischaemic HF [hazard ratio 0.69 (95% confidence interval 0.19–2.45)].

Conclusions

Patients with new‐onset acute HF with reduced ejection fraction discharged on optimal medical treatment have a good prognosis. We observed a considerable LV remodelling with improvement in LV function and dimensions, starting already at 6 months in patients with non‐ischaemic HF but not in their ischaemic counterparts.

Baseline and Dynamic Risk Predictors of Appropriate Implantable Cardioverter Defibrillator Therapy

Background Current approaches fail to separate patients at high versus low risk for ventricular arrhythmias owing to overreliance on a snapshot left ventricular ejection fraction measure. We used statistical machine learning to identify important cardiac imaging and time-varying risk predictors. Methods and Results Three hundred eighty-two cardiomyopathy patients (left ventricular ejection fraction ≤35%) underwent cardiac magnetic resonance before primary prevention implantable cardioverter defibrillator insertion. The primary end point was appropriate implantable cardioverter defibrillator discharge or sudden death. Patient characteristics; serum biomarkers of inflammation, neurohormonal status, and injury; and cardiac magnetic resonance-measured left ventricle and left atrial indices and myocardial scar burden were assessed at baseline. Time-varying covariates comprised interval heart failure hospitalizations and left ventricular ejection fractions. A random forest statistical method for survival, longitudinal, and multivariable outcomes incorporating baseline and time-varying variables was compared with (1) Seattle Heart Failure model scores and (2) random forest survival and Cox regression models incorporating baseline characteristics with and without imaging variables. Age averaged 57±13 years with 28% women, 66% white, 51% ischemic, and follow-up time of 5.9±2.3 years. The primary end point (n=75) occurred at 3.3±2.4 years. Random forest statistical method for survival, longitudinal, and multivariable outcomes with baseline and time-varying predictors had the highest area under the receiver operating curve, median 0.88 (95% CI, 0.75-0.96). Top predictors comprised heart failure hospitalization, left ventricle scar, left ventricle and left atrial volumes, left atrial function, and interleukin-6 level; heart failure accounted for 67% of the variation explained by the prediction, imaging 27%, and interleukin-6 2%. Serial left ventricular ejection fraction was not a significant predictor. Conclusions Hospitalization for heart failure and baseline cardiac metrics substantially improve ventricular arrhythmic risk prediction.

The role of Asprosin in patients with dilated cardiomyopathy

Background

Asprosin is a novel fasting glucogenic adipokine discovered in 2016. Asprosin induces rapid glucose releases from the liver. However, its molecular mechanisms and function are still unclear. Adaptation of energy substrates from fatty acid to glucose is recently considered a novel therapeutic target in heart failure treatment. We hypothesized that the asprosin is able to modulate cardiac mitochondrial functions and has important prognostic implications in dilated cardiomyopathy (DCM) patients.

Methods

We prospectively enrolled 50 patients (86% male, mean age 55 ± 13 years) with DCM and followed their 5-year major adverse cardiovascular events from 2012 to 2017. Comparing with healthy individuals, DCM patients had higher asprosin levels (191.2 versus 79.7 ng/mL, P < 0.01).

Results

During the 5-year follow-up in the study cohort, 16 (32.0%) patients experienced adverse cardiovascular events. Patients with lower asprosin levels (< 210 ng/mL) were associated with increased risks of adverse clinical outcomes with a hazard ratio of 7.94 (95% CI 1.88–33.50, P = 0.005) when compared patients with higher asprosin levels (≥ 210 ng/mL). Using cardiomyoblasts as a cellular model, we showed that asprosin prevented hypoxia-induced cell death and enhanced mitochondrial respiration and proton leak under hypoxia.

Conclusions

In patients with DCM, elevated plasma asprosin levels are associated with less adverse cardiovascular events in five years. The underlying protective mechanisms of asprosin may be linked to its functions relating to enhanced mitochondrial respiration under hypoxia.

Systolic function recovery in Heart Failure: Frequency, prognostic impact and predictors

BACKGROUND

Systolic function recovery in patients with Heart failure (HF) with reduced ejection fraction (EF) is well recognized but not completely understood. We aimed to characterize HF patients with systolic function recovery, its prognostic impact and predictors.

METHODS

We analysed patients followed in a HF clinic (2006-2015) with 2 echocardiograms performed. Partial recovery: EF recovery without attaining EF ≥ 50%; total recovery: patients reached EF ≥ 50%. Median follow-up from first echocardiogram: 69 months. Multivariate logistic regression models to determine recovery predictors.

RESULTS

We analysed 304 patients with at least mild left ventricular dysfunction. During a median 34 months between echocardiogram re-evaluation 150 (49.3%) patients showed no EF recovery; 55 (18.1%) had partial recovery and 99 (32.6%) totally recovered. Mean patients age: 66; 71.1% men, high comorbidity burden; ischemic HF: 35.5%. Non-recovered patients were mostly men (80.7% vs 61.8% in partially; 61.6% in fully-recovered) with ischemic HF (46.0% vs 32.5% in partially; 21.2% in fully-recovered). Comorbidity burden, NYHA class and therapy were similar. During follow-up, 156 patients (46.7%) died. Patients with total recovery had a multivariate-adjusted 54% lower risk of dying when compared to non-recovered. Partially-recovered patients showed a non-significant adjusted 8% mortality reduction. Independent predictors of systolic function recovery were female gender(OR: 2.17, 95% CI 1.11-4.35), non-ischemic aetiology (OR: 2.78, 95% CI 1.35-5.56), and end diastolic left ventricular diameter < 60 mm (OR: 3.12, 95% CI 1.56-6.25).

CONCLUSIONS

HF-recovered patients were mainly women with non-ischemic HF and smaller left ventricles. These patients had significantly better prognosis than those with persistently reduced EF.

Baseline Longitudinal Strain Predicts Recovery of Left Ventricular Ejection Fraction in Hospitalized Patients With Nonischemic Cardiomyopathy

Background

Heart failure (HF) with “recovered” ejection fraction (HFrecEF) is an emerging phenotype, but no tools exist to predict ejection fraction (EF) recovery in acute HF. We hypothesized that indices of baseline cardiac structure and function predict HFrecEF in nonischemic cardiomyopathy and reduced EF.

Methods and Results

We identified a nonischemic cardiomyopathy cohort with EF<40% during the first HF hospitalization (n=166). We performed speckle‐tracking echocardiography to measure longitudinal, circumferential, and radial strain, and the average of these measures (myocardial systolic performance). HFrecEF was defined as follow‐up EF ≥40% and ≥10% improvement from baseline EF. Fifty‐nine patients (36%) achieved HFrecEF (baseline EF 26±7%; follow‐up EF 51±7%) within a median of 135 (interquartile range 58‐239) days after the first HF hospitalization. Baseline demographics, biomarker profiles, and comorbid conditions (except lower chronic kidney disease in HFrecEF) were similar between HFrecEF and persistent reduced‐EF groups. HFrecEF patients had smaller baseline left ventricular end‐systolic dimension (3.6 versus 4.8 cm; P<0.01), higher baseline myocardial systolic performance (9.2% versus 8.1%; P=0.02), and improved survival (adjusted hazard ratio 0.27, 95% confidence interval 0.11, 0.62). We found a significant interaction between baseline left ventricular end‐systolic dimension and absolute longitudinal strain. Among patients with left ventricular end‐systolic dimension >4.35 cm, higher absolute longitudinal strain (≥8%) was associated with HFrecEF (unadjusted odds ratio=3.9, 95% CI)confidence interval 1.2, 12.8). Incorporation of baseline indices of cardiac mechanics with clinical variables resulted in a predictive model for HFrecEF with c‐statistic=0.85.

Conclusions

Factors associated with achieving HFrecEF were specific to cardiac structure and indices of cardiac mechanics. Higher baseline absolute longitudinal strain is associated with HFrecEF among nonischemic cardiomyopathy patients with reduced EF and larger left ventricular dimensions.

Nonocclusive multivessel intracoronary infusion of allogeneic cardiosphere-derived cells early after reperfusion prevents remote zone myocyte loss and improves global left ventricular function in swine with myocardial infarction

Intracoronary cardiosphere-derived cells (icCDCs) infused into the infarct-related artery reduce scar volume but do not improve left ventricular (LV) ejection fraction (LVEF). We tested the hypothesis that this reflects the inability of regional delivery to prevent myocyte death or promote myocyte proliferation in viable myocardium remote from the infarct. Swine (n = 23) pretreated with oral cyclosporine (200 mg/day) underwent a 1-h left anterior descending coronary artery (LAD) occlusion, which reduced LVEF from 61.6 ± 1.0 to 45.3 ± 1.5% 30 min after reperfusion. At that time, animals received global infusion of allogeneic icCDCs (n = 8), regional infusion of icCDCs restricted to the LAD using the stop-flow technique (n = 8), or vehicle (n = 7). After 1 mo, global icCDCs increased LVEF from 44.8 ± 1.9 to 60.8 ± 3.8% (P < 0.05) with no significant change after LAD stop-flow icCDCs (44.8 ± 3.6 to 50.9 ± 3.1%) or vehicle (46.5 ± 2.5 to 47.7 ± 2.6%). In contrast, global icCDCs did not alter infarct volume (%LV mass) assessed at 2 days (11.2 ± 2.3 vs. 12.6 ± 2.3%), whereas it was reduced after LAD stop-flow icCDCs (7.1 ± 1.1%, P < 0.05). Histopathological analysis of remote myocardium after global icCDCs demonstrated a significant increase in myocyte proliferation (147 ± 32 vs. 14 ± 10 nuclei/10⁶ myocytes, P < 0.05) and a reduction in myocyte apoptosis (15 ± 9 vs. 46 ± 10 nuclei/10⁶ myocytes, P < 0.05) that increased myocyte nuclear density (1,264 ± 39 vs. 1,157 ± 33 nuclei/mm², P < 0.05) and decreased myocyte diameter (13.2 ± 0.2 vs. 14.5 ± 0.3 μm, P < 0.05) compared with vehicle-treated controls. In contrast, remote zone changes after regional LAD icCDCs were no different from vehicle. These data indicate that changes in global LVEF after icCDCs are dependent upon preventing myocyte loss and hypertrophy in myocardium remote from the infarct. These arise from stimulating myocyte proliferation and reducing myocyte apoptosis indicating the importance of directing cell therapy to viable remote regions.NEW & NOTEWORTHY Administration of allogeneic cardiosphere-derived cells to the entire heart via global intracoronary infusion shortly after myocardial infarction favorably influenced left ventricular ejection fraction by preventing myocyte death and promoting myocyte proliferation in remote, noninfarcted myocardium in swine. In contrast, regional intracoronary cell infusion did not significantly affect remote zone myocyte remodeling. Global cell administration targeting viable myocardium remote from the infarct may be an effective approach to prevent adverse ventricular remodeling after myocardial infarction.

Effect of coenzyme Q10 in Europeans with chronic heart failure: A sub-group analysis of the Q-SYMBIO randomized double-blind trial

BACKGROUND

Geographical differences in patient characteristics, management and outcomes in heart failure (HF) trials are well recognized. The aim of this study was to assess the consistency of the treat- ment effect of coenzyme Q10 (CoQ10) in the European sub-population of Q-SYMBIO, a randomized double-blind multinational trial of treatment with CoQ10, in addition to standard therapy in chronic HF.

METHODS

Patients with moderate to severe HF were randomized to CoQ10 300 mg daily or placebo in addition to standard therapy. At 3 months the primary short-term endpoints were changes in New York Heart Association (NYHA) functional classification, 6-min walk test, and levels of N-terminal pro-B type natriuretic peptide. At 2 years the primary long-term endpoint was major adverse cardiovascular events (MACE).

RESULTS

There were no significant changes in short-term endpoints. The primary long-term endpoint of MACE was reached by significantly fewer patients in the CoQ10 group (n = 10, 9%) compared to the placebo group (n = 33, 27%, p = 0.001). The following secondary endpoints were significantly improved in the CoQ10 group compared with the placebo group: all-cause and cardiovascular mortality, NYHA classification and left ventricular ejection fraction (LVEF). In the European sub-population, when compared to the whole group, there was greater adherence to guideline directed therapy and similar results for short- and long-term endpoints. A new finding revealed a significant improvement in LVEF.

CONCLUSIONS

The therapeutic efficacy of CoQ10 demonstrated in the Q-SYMBIO study was confirmed in the European sub-population in terms of safely reducing MACE, all-cause mortality, cardiovascular mortality, hospitalization and improvement of symptoms.

Myocardial recovery after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy

BACKGROUND

Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) are unknown.

METHODS

A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post-CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events.

RESULTS

In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT-defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17-0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48-0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88-0.99; p = 0.04). Subjects with post-CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate anti-tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow-up of 75.9 months (HR, 0.38; 95% CI, 0.16-0.88; p = 0.02).

CONCLUSION

In LBBB-associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.

A new educational program in heart failure drug development: the Brescia international master program

: Despite recent advances in chronic heart failure treatment, prognosis of acute heart failure patients remains poor with a heart failure rehospitalization rate or death reaching approximately 25% during the first 6 months after discharge. In addition, about half of these patients have preserved ejection fraction for which there are no evidence-based therapies. Disappointing results from heart failure clinical trials over the past 20 years emphasize the need for developing novel approaches and pathways for testing new heart failure drugs and devices. Indeed, many trials are being conducted without matching the mechanism and action of the drug with the clinical event. The implementation of these novel approaches should be coupled with the training of a new generation of heart failure physicians and scientists in the art and science of clinical trials. Currently, drug development is led by opinion leaders and experts who, despite their huge personal experience, were never trained systematically on drug development. The aim of this article is to propose a training program of 'drug development in Heart Failure'. A physician attending this course would have to be trained with a major emphasis on heart failure pathophysiology to better match mechanisms of death and rehospitalization with mechanism of action of the drug. Applicants will have to prove their qualifications and special interest in heart failure drug development before enrollment. This article should serve as a roadmap on how to apply emerging general principles in an innovative drug-development-in-heart-failure-process as well as the introduction of a new educational and mentorship program focusing on younger generations of researchers.

Redefining biomarkers in heart failure

Heart failure (HF) is the end result of many different cardiac and non-cardiac abnormalities leading to a complex clinical entity. In this view, the use of biomarkers in HF should be deeply reconsidered; indeed, the same biomarker may carry a different significance in patients with preserved or reduced EF. The aim of this review is to reconsider the role of biomarkers in HF, based on the different clinical characteristics of this syndrome. The role of cardiac and non-cardiac biomarkers will be reviewed with respect of the different clinical manifestations of this syndrome.

MitoQ improves mitochondrial dysfunction in heart failure induced by pressure overload

Heart failure remains a major public-health problem with an increase in the number of patients worsening from this disease. Despite current medical therapy, the condition still has a poor prognosis. Heart failure is complex but mitochondrial dysfunction seems to be an important target to improve cardiac function directly. Our goal was to analyze the effects of MitoQ (100 µM in drinking water) on the development and progression of heart failure induced by pressure overload after 14 weeks. The main findings are that pressure overload-induced heart failure in rats decreased cardiac function in vivo that was not altered by MitoQ. However, we observed a reduction in right ventricular hypertrophy and lung congestion in heart failure animals treated with MitoQ. Heart failure also decreased total mitochondrial protein content, mitochondrial membrane potential in the intermyofibrillar mitochondria. MitoQ restored membrane potential in IFM but did not restore mitochondrial protein content. These alterations are associated with the impairment of basal and stimulated mitochondrial respiration in IFM and SSM induced by heart failure. Moreover, MitoQ restored mitochondrial respiration in heart failure induced by pressure overload. We also detected higher levels of hydrogen peroxide production in heart failure and MitoQ restored the increase in ROS production. MitoQ was also able to improve mitochondrial calcium retention capacity, mainly in the SSM whereas in the IFM we observed a small alteration. In summary, MitoQ improves mitochondrial dysfunction in heart failure induced by pressure overload, by decreasing hydrogen peroxide formation, improving mitochondrial respiration and improving mPTP opening.

Lessons learned in acute heart failure

Acute heart failure (HF) is a global pandemic with more than one million admissions to hospital annually in the US and millions more worldwide. Post-discharge mortality and readmission rates remain unchanged and unacceptably high. Although recent drug development programmes have failed to deliver novel therapies capable of reducing cardiovascular morbidity and mortality in patients hospitalized for worsening chronic HF, hospitalized HF registries and clinical trial databases have generated a wealth of information improving our collective understanding of the HF syndrome. This review will summarize key insights from clinical trials in acute HF and hospitalized HF registries over the last several decades, focusing on improving the management of patients with HF and reduced ejection fraction.

P2y12 Receptor Promotes Pressure Overload-Induced Cardiac Remodeling via Platelet-Driven Inflammation in Mice

Inflammation plays a critical role in adverse cardiac remodeling and heart failure. The P2y12 receptor is one of the predominant activating receptors for platelets, thus initiating inflammatory responses under various diseases. In this study, we investigated the functional significance of P2y12-mediated platelet activation in pressure overload-induced cardiac remodeling. Notably, P2y12 knockout (P2y12^-/-) mice exhibited suppressed transverse aortic constriction-induced changes in cardiac hypertrophy, collagen synthesis, inflammatory cell recruitment, and cardiac dysfunction. Activated platelets and platelet-leukocyte aggregates were markedly downregulated in P2y12 knockout mice compared with wild-type counterparts after transverse aortic constriction. Moreover, bone marrow chimera experiments revealed that wild-type recipients of P2y12 knockout bone marrow markedly improved cardiac function and attenuated cardiac remodeling, reversed by wild-type platelets reinjection. Platelet depletion and P-selectin inhibition mimicked these protective effects by limiting the interaction between activated platelets and leukocytes. Furthermore, activated wild-type platelets directly induced cardiomyocyte hypertrophy and collagen synthesis via α-granule exocytosis, vanished in P2y12 knockout platelets or those administered anti-NSF (N-ethlymalimide-sensitive factor) antibodies. The results suggest that P2y12-mediated platelet activation promotes cardiac remodeling by triggering a series of inflammatory changes and interacting with leukocytes and endotheliocytes.

Sudden Cardiac Death Substrate Imaged by Magnetic Resonance Imaging: From Investigational Tool to Clinical Applications

Sudden cardiac death (SCD) is a devastating event afflicting 350 000 Americans annually despite the availability of life-saving preventive therapy, the implantable cardioverter defibrillator. SCD prevention strategies are hampered by over-reliance on global left ventricular ejection fraction <35% as the most important criterion to determine implantable cardioverter defibrillator candidacy. Annually in the United States alone, this results in ≈130 000 implantable cardioverter defibrillator placements at a cost of >$3 billion but only a 5% incidence per year of appropriate firings. This approach further fails to identify individuals who experience the majority, as many as 80%, of SCD events, which occur in the setting of more preserved left ventricular ejection fraction. Better risk stratification is needed to improve care and should be guided by direct pathophysiologic markers of arrhythmic substrate, such as specific left ventricular structural abnormalities. There is an increasing body of literature to support the prognostic value of cardiac magnetic resonance imaging with late gadolinium enhancement in phenotyping the left ventricular to identify those at highest risk for SCD. Cardiac magnetic resonance has unparalleled tissue characterization ability and provides exquisite detail about myocardial structure and composition, abnormalities of which form the direct, pathophysiologic substrate for SCD. Here, we review the evolution and the current state of cardiac magnetic resonance for imaging the arrhythmic substrate, both as a research tool and for clinical applications.

Developing New Treatments for Heart Failure: Focus on the Heart

Compared with heart failure (HF) care 20 to 30 years ago, there has been tremendous advancement in therapy for ambulatory HF with reduced ejection fraction with the use of agents that block maladaptive neurohormonal pathways. However, during the past decade, with few notable exceptions, the frequency of successful drug development programs has fallen as most novel therapies have failed to offer incremental benefit or raised safety concerns (ie, hypotension). Moreover, no therapy has been approved specifically for HF with preserved ejection fraction or for worsening chronic HF (including acutely decompensated HF). Across the spectrum of HF, preliminary results from many phase II trials have been promising but are frequently followed by unsuccessful phase III studies, highlighting a disconnect in the translational process between basic science discovery, early drug development, and definitive clinical testing in pivotal trials. A major unmet need in HF drug development is the ability to identify homogeneous subsets of patients whose underlying disease is driven by a specific mechanism that can be targeted using a new therapeutic agent. Drug development strategies should increasingly consider therapies that facilitate reverse remodeling by directly targeting the heart itself rather than strictly focusing on agents that unload the heart or target systemic neurohormones. Advancements in cardiac imaging may allow for more focused and direct assessment of drug effects on the heart early in the drug development process. To better understand and address the array of challenges facing current HF drug development, so that future efforts may have a better chance for success, the Food and Drug Administration facilitated a meeting on February 17, 2015, which was attended by clinicians, researchers, regulators, and industry representatives. The following discussion summarizes the key takeaway dialogue from this meeting.

Reassessing Phase II Heart Failure Clinical Trials: Consensus Recommendations

The increasing burden and the continued suboptimal outcomes for patients with heart failure underlines the importance of continued research to develop novel therapeutics for this disorder. This can only be accomplished with successful translation of basic science discoveries into direct human application through effective clinical trial design and execution that results in a substantially improved clinical course and outcomes. In this respect, phase II clinical trials play a pivotal role in determining which of the multitude of potential basic science discoveries should move to the large and expansive registration trials in humans. A critical examination of the phase II trials in heart failure reveals multiple shortcomings in their concept, design, execution, and interpretation. To further a dialogue on the challenges and potential for improvement and the role of phase II trials in patients with heart failure, the Food and Drug Administration facilitated a meeting on October 17, 2016, represented by clinicians, researchers, industry members, and regulators. This document summarizes the discussion from this meeting and provides key recommendations for future directions.

Employing Extracellular Volume Cardiovascular Magnetic Resonance Measures of Myocardial Fibrosis to Foster Novel Therapeutics

Quantifying myocardial fibrosis (MF) with myocardial extracellular volume measures acquired during cardiovascular magnetic resonance promises to transform clinical care by advancing pathophysiologic understanding and fostering novel therapeutics. Extracellular volume quantifies MF by measuring the extracellular compartment depicted by the myocardial uptake of contrast relative to plasma. MF is a key domain of dysfunctional but viable myocardium among others (eg, microvascular dysfunction and cardiomyocyte/mitochondrial dysfunction). Although anatomically distinct, these domains may functionally interact. MF represents pathological remodeling in the heart associated with cardiac dysfunction and adverse outcomes likely mediated by interactions with the microvasculature and the cardiomyocyte. Reversal of MF improves key measures of cardiac dysfunction, so reversal of MF represents a likely mechanism for improved outcomes. Instead of characterizing the myocardium as homogenous tissue and using important yet still generic descriptors, such as thickness (hypertrophy) and function (diastolic or systolic), which lack mechanistic specificity, paradigms of cardiac disease have evolved to conceptualize myocardial disease and patient vulnerability based on the extent of disease involving its various compartments. Specifying myocardial compartmental involvement may then implicate cellular/molecular disease pathways for treatment and targeted pharmaceutical development and above all highlight the role of the cardiac-specific pathology in heart failure among myriad other changes in the heart and beyond. The cardiology community now requires phase 2 and 3 clinical trials to examine strategies for the regression/prevention of MF and eventually biomarkers to identify MF without reliance on cardiovascular magnetic resonance. It seems likely that efficacious antifibrotic therapy will improve outcomes, but definitive data are needed.

Circulating microRNA-150-5p as a novel biomarker for advanced heart failure: A genome-wide prospective study

BACKGROUND

Circulating microRNAs (miRs) are promising biomarkers for heart failure (HF). Previous studies have provided inconsistent miR "signatures." The phenotypic and pathophysiologic heterogeneity of HF may have contributed to this inconsistency. In this study we assessed whether advanced HF (AHF) patients present a distinct miR signature compared with healthy subjects (HS) and mild to moderate HF (MHF) patients.

METHODS

The study consisted of 2 phases: a screening phase and a validation phase. In the screening phase, 752 miRs were profiled in HS and MHF and AHF patients (N = 15), using the real-time quantitative polymerase chain reaction (RT-qPCR) technique and global mean normalization. In the validation phase, the miRs found to be significantly dysregulated in AHF patients compared with both HS and MHF patients were validated in 15 HS, 25 patients with MHF and 29 with AHF, using RT-qPCR, and normalizing to exogenous (cel-miR-39) and endogenous controls.

RESULTS

In the screening phase, 5 miRs were found to be significantly dysregulated: -26a-5p; -145-3p; -150-5p; -485-3p; and -487b-3p. In the validation phase, miR-150-5p was confirmed to be significantly downregulated in AHF patients when compared with both HS and MHF patients, irrespective of the normalization method used. miR-26a-5p was confirmed to be significantly dysregulated only when normalized to cell-miR-39. Dysregulation of the other miRs could not be confirmed. miR-150-5p was significantly associated with maladaptive remodeling, disease severity and outcome.

CONCLUSIONS

Our data suggest miR-150-5p as a novel circulating biomarker for AHF. The association of miR-150-5p with maladaptive remodeling, disease severity and outcome supports the pathophysiologic relevance of downregulated miR-150-5p expression to AHF.

Expert consensus document: Mitochondrial function as a therapeutic target in heart failure

Heart failure is a pressing worldwide public-health problem with millions of patients having worsening heart failure. Despite all the available therapies, the condition carries a very poor prognosis. Existing therapies provide symptomatic and clinical benefit, but do not fully address molecular abnormalities that occur in cardiomyocytes. This shortcoming is particularly important given that most patients with heart failure have viable dysfunctional myocardium, in which an improvement or normalization of function might be possible. Although the pathophysiology of heart failure is complex, mitochondrial dysfunction seems to be an important target for therapy to improve cardiac function directly. Mitochondrial abnormalities include impaired mitochondrial electron transport chain activity, increased formation of reactive oxygen species, shifted metabolic substrate utilization, aberrant mitochondrial dynamics, and altered ion homeostasis. In this Consensus Statement, insights into the mechanisms of mitochondrial dysfunction in heart failure are presented, along with an overview of emerging treatments with the potential to improve the function of the failing heart by targeting mitochondria.

Intravenous Allogeneic Mesenchymal Stem Cells for Nonischemic Cardiomyopathy: Safety and Efficacy Results of a Phase II-A Randomized Trial

RATIONALE

Potential benefits of mesenchymal stem cell (MSC) therapy in heart failure may be related to paracrine properties and systemic effects, including anti-inflammatory activities. If this hypothesis is valid, intravenous administration of MSCs should improve outcomes in heart failure, an entity in which excessive chronic inflammation may play a pivotal role.

OBJECTIVE

To assess the safety and preliminary efficacy of intravenously administered ischemia-tolerant MSCs (itMSCs) in patients with nonischemic cardiomyopathy.

METHODS AND RESULTS

This was a single-blind, placebo-controlled, crossover, randomized phase II-a trial of nonischemic cardiomyopathy patients with left ventricular ejection fraction ≤40% and absent hyperenhancement on cardiac magnetic resonance imaging. Patients were randomized to intravenously administered itMSCs (1.5×10⁶ cells/kg) or placebo; at 90 days, each group received the alternative treatment. Overall, 22 patients were randomized to itMSC (n=10) and placebo (n=12) at baseline. After crossover, data were available for 22 itMSC patients. No major differences in death, hospitalization, or serious adverse events were noted between the 2 treatments. Change from baseline in left ventricular ejection fraction and ventricular volumes was not significantly different between therapies. Compared with placebo, itMSC therapy increased 6-minute walk distance (+36.47 m, 95% confidence interval 5.98-66.97; P=0.02) and improved Kansas City Cardiomyopathy clinical summary (+5.22, 95% confidence interval 0.70-9.74; P=0.02) and functional status scores (+5.65, 95% confidence interval -0.11 to 11.41; P=0.06). The data demonstrated MSC-induced immunomodulatory effects, the magnitude of which correlated with improvement in left ventricular ejection fraction.

CONCLUSIONS

In this pilot study of patients with nonischemic cardiomyopathy, itMSC therapy was safe, caused immunomodulatory effects, and was associated with improvements in health status and functional capacity.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02467387.

Utility of positron emission tomography for drug development for heart failure

Only about 1 in 5,000 investigational agents in a preclinical stage acquires Food and Drug Administration approval. Among many reasons for this includes an inefficient transition from preclinical to clinical phases, which exponentially increase the cost and the delays the process of drug development. Positron emission tomography (PET) is a nuclear imaging technique that has been used for the diagnosis, risk stratification, and guidance of therapy. However, lately with the advance of radiochemistry and of molecular imaging technology, it became evident that PET could help novel drug development process. By using a PET radioligand to report on receptor occupancy during novel agent therapy, it may help assess the effectiveness, efficacy, and safety of such a new medication in an early preclinical stage and help design successful clinical trials even at a later phase. In this article, we explore the potential implications of PET in the development of new heart failure therapies and review PET's application in the respective pathophysiologic pathways such as myocardial perfusion, metabolism, innervation, inflammation, apoptosis, and cardiac remodeling.

Associations between scar characteristics by cardiac magnetic resonance and changes in left ventricular ejection fraction in primary prevention defibrillator recipients

BACKGROUND

Left ventricular ejection fraction (LVEF) improves over time in 25%-40% of patients with cardiomyopathy with primary prevention implantable cardioverter-defibrillator (ICD). The determinants of LVEF improvement, however, are not well characterized.

OBJECTIVES

We sought to examine the associations of clinical risk factors and cardiac imaging markers with changes in LVEF after ICD implantation.

METHODS

We conducted a retrospective analysis of cardiac magnetic resonance images in 202 patients who underwent primary prevention ICD implantation to quantify the amount of heterogeneous myocardial tissue (gray zone), dense core, and total scar. LVEF was reassessed at least once after ICD implantation.

RESULTS

Over a mean follow-up of 3 years, LVEF decreased in 43 (21.3%), improved in 88 (43.6%), and was unchanged in 71 (35.1%) of the patients. Baseline LVEF and myocardial scar characteristics were the strongest determinants of LVEF trajectory with high scar burden and increasing lack of myocardial viability associated with a greater decline in LVEF. There was a trend toward an association between both changes in LVEF and scar extent with subsequent appropriate ICD shock. Changes in LVEF were also strongly associated with heart failure hospitalizations.

CONCLUSION

Scar burden and characteristics were strong determinants, independent of baseline LVEF and other traditional cardiovascular risk factors, of changes in LVEF. Both worsened LVEF and high scar extent were associated with a trend toward increased risk of appropriate shock. These findings suggest that baseline cardiac magnetic resonance imaging of the myocardial substrate may provide important prognostic information on subsequent left ventricular remodeling and adverse events.

Stem cell therapy for heart failure: Ensuring regenerative proficiency

Patient-derived stem cells enable promising regenerative strategies, but display heterogenous cardiac reparative proficiency, leading to unpredictable therapeutic outcomes impeding practice adoption. Means to establish and certify the regenerative potency of emerging biotherapies are thus warranted. In this era of clinomics, deconvolution of variant cytoreparative performance in clinical trials offers an unprecedented opportunity to map pathways that segregate regenerative from non-regenerative states informing the evolution of cardio-regenerative quality systems. A maiden example of this approach is cardiopoiesis-mediated lineage specification developed to ensure regenerative performance. Successfully tested in pre-clinical and early clinical studies, the safety and efficacy of the cardiopoietic stem cell phenotype is undergoing validation in pivotal trials for chronic ischemic cardiomyopathy offering the prospect of a next-generation regenerative solution for heart failure.

Prognostication in Different Heart Failure Phenotypes: The Role of Circulating Biomarkers

Heart failure (HF) is multifactorial syndrome with high cardiovascular (CV) morbidity and mortality rates associated with an increasing prevalence worldwide. Measuring plasma levels of circulating biomarkers, i.e., natriuretic peptides, cardiac-specific troponins, metabolomic intermediates, Galectin-3, ST2, cardiotrophin-1, soluble endoglin and growth differentiation factor 15, may assist in the prognostication of HF development. However, the role of biomarker models in the prediction of an early stage of HF with a preserved ejection fraction (HFpEF) and HF with a reduced ejection fraction (HFrEF) is not still understood. This review explores the knowledge regarding the utility of cardiac biomarkers, aiming to reclassify patients with different phenotypes of HF. The review reports that several biomarkers reflected on subsequently alter collagen turnover, cardiac fibrosis and inflammation, which might have diagnostic and predictive value in HFpEF and HFrEF. The best candidates for determining the early stage of HF development were sST2, Galectin-3, CT-1 and GDF-15. However, increased plasma concentrations of these biomarkers were not specific to a distinct disease group of HFpEF and HFrEF. Finally, more investigations are required to determine the role of novel biomarkers in the prediction of HF and the determination of the early stages of HFpEF and HFrEF development.