Latest pharmaceutical approaches across the spectrum of heart failure

Despite major advances in prevention and medical therapy, heart failure (HF) remains associated with high morbidity and mortality, especially in older and frailer patients. Therefore, a complete, guideline-based treatment is essential, even in HF patients with conditions traditionally associated with a problematic initiation and escalation of the medical HF therapy, such as chronic kidney disease and arterial hypotension, as the potential adverse effects are overcome by the overall decrease of the absolute risk. Furthermore, since the latest data suggest that the benefit of a combined medical therapy (MRA, ARNI, SGLT2i, beta-blocker) may extend up to a LVEF of 65%, further trials on these subgroups of patients (HFmrEF, HFpEF) are needed to re-evaluate the guideline-directed medical therapy across the HF spectrum. In particular, the use of SGLT2i was recently extended to HFpEF patients, as evidenced by the DELIVER and EMPEROR-preserved trials. Moreover, the indication for other conservative treatments in HF patients, such as the intravenous iron supplementation, was accordingly strengthened in the latest guidelines. Finally, the possible implementation of newer substances, such as finerenone, in guideline-directed medical practice for HF is anticipated with great interest.

Precision Cardiology: Phenotype-targeted Therapies for HFmrEF and HFpEF

Heart failure with mid-range ejection fraction (HFmrEF) and preserved ejection fraction (HFpEF) represent over half of heart failure cases but lack proven effective therapies beyond sodium-glucose cotransporter 2 inhibitor and diuretics. HFmrEF and HFpEF are heterogeneous conditions requiring precision phenotyping to enable tailored therapies. This review covers concepts on precision medicine approaches for HFmrEF and HFpEF. Areas discussed include HFmrEF mechanisms, anti-inflammatory and antifibrotic treatments for obesity-related HFpEF, If inhibition for HFpEF with atrial fibrillation, and mineralocorticoid receptor antagonism for chronic kidney disease-HFpEF. Incorporating precision phenotyping and matched interventions in HFmrEF and HFpEF trials will further advance therapy compared to blanket approaches.

The prevalence of coronary microvascular dysfunction (CMD) in heart failure with preserved ejection fraction (HFpEF): a systematic review and meta-analysis

To date, studies on the prevalence of coronary microvascular dysfunction (CMD) in heart failure with preserved ejection fraction (HFpEF) have not been summarized and analyzed as a whole. We conducted this systematic review and meta-analysis to assess the prevalence of CMD in patients with HFpEF. The PubMed, Cochrane, and Embase databases were searched from dates of inception until May 1, 2023. The primary outcome was the prevalence of CMD in patients with HFpEF, and values of CMD prevalence were pooled using a random-effects model. In total, 10 studies involving 1267 patients, including 822 with HFpEF and 445 without HFpEF, were included. The pooled prevalence of CMD in patients with HFpEF was 71% (95% CI, 0.63-0.79). In the subgroup analysis, the prevalence of CMD was 79% (95% CI, 0.71-0.87) by invasive measurement and 66% (95% CI, 0.54-0.77) by noninvasive measurement and 67% (95% CI, 0.52-0.82) with CFR < 2.0 and 75.0% (95% CI, 0.71-0.79) with CFR < 2.5. The prevalence of endothelium-independent CMD and endothelium-dependent CMD was 62% (95% CI, 0.53-0.72) and 50% (95% CI, 0.19-0.81), respectively. The prevalence of CMD was 74% (95% CI = 0.69-0.79) and 66% (95% CI = 0.41-0.90) in prospective and retrospective studies, respectively. Compared with the control group, patients with HFpEF had a significantly lower CFR (MD =  - 1.28, 95% CI =  - 1.82 to - 0.74, P < 0.01) and a higher prevalence of CMD (RR = 2.21, 95% CI = 1.52 to 3.20, P < 0.01). Qualitative analysis demonstrated that CMD might be associated with poor clinical outcomes in patients with HFpEF. In conclusion, this is the first systematic review and meta-analysis of all studies reporting the prevalence of CMD in patients with HFpEF. Our study demonstrates that CMD is common in patients with HFpEF and might be associated with poor clinical outcomes in these patients. Clinicians should attach importance to CMD in the diagnosis and treatment of HFpEF. The number of studies in this field is relatively small. Therefore, more high-quality studies are needed to explore the diagnostic and prognostic value of CMD and the potential role of CMD as a therapeutic target in patients with HFpEF.

Device therapy for patients with atrial fibrillation and heart failure with preserved ejection fraction

Device therapy is a nonpharmacological approach that presents a crucial advancement for managing patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). This review investigated the impact of device-based interventions and emphasized their potential for optimizing treatment for this complex patient demographic. Cardiac resynchronization therapy, augmented by atrioventricular node ablation with His-bundle pacing or left bundle-branch pacing, is effective for enhancing cardiac function and establishing atrioventricular synchrony. Cardiac contractility modulation and vagus nerve stimulation represent novel strategies for increasing myocardial contractility and adjusting the autonomic balance. Left ventricular expanders have demonstrated short-term benefits in HFpEF patients but require more investigation for long-term effectiveness and safety, especially in patients with AF. Research gaps regarding complications arising from left ventricular expander implantation need to be addressed. Device-based therapies for heart valve diseases, such as transcatheter aortic valve replacement and transcatheter edge-to-edge repair, show promise for patients with AF and HFpEF, particularly those with mitral or tricuspid regurgitation. Clinical evaluations show that these device therapies lessen AF occurrence, improve exercise tolerance, and boost left ventricular diastolic function. However, additional studies are required to perfect patient selection criteria and ascertain the long-term effectiveness and safety of these interventions. Our review underscores the significant potential of device therapy for improving the outcomes and quality of life for patients with AF and HFpEF.

Large animal models to study effectiveness of therapy devices in the treatment of heart failure with preserved ejection fraction (HFpEF)

Our understanding of the complex pathophysiology of Heart failure with preserved ejection fraction (HFpEF) is limited by the lack of a robust in vivo model. Existing in-vivo models attempt to reproduce the four main phenotypes of HFpEF; ageing, obesity, diabetes mellitus and hypertension. To date, there is no in vivo model that represents all the haemodynamic characteristics of HFpEF, and only a few have proven to be reliable for the preclinical evaluation of potentially new therapeutic targets. HFpEF accounts for 50% of all the heart failure cases and its incidence is on the rise, posing a huge economic burden on the health system. Patients with HFpEF have limited therapeutic options available. The inadequate effectiveness of current pharmaceutical therapeutics for HFpEF has prompted the development of device-based treatments that target the hemodynamic changes to reduce the symptoms of HFpEF. However, despite the potential of device-based solutions to treat HFpEF, most of these therapies are still in the developmental stage and a relevant HFpEF in vivo model will surely expedite their development process. This review article outlines the major limitations of the current large in-vivo models in use while discussing how these designs have helped in the development of therapy devices for the treatment of HFpEF.

A novel polygenic risk score improves prognostic prediction of heart failure with preserved ejection fraction in the Chinese Han population

AIMS

Mortality risk assessment in patients with heart failure (HF) with preserved ejection fraction (HFpEF) presents a major challenge. We sought to construct a polygenic risk score (PRS) to accurately predict the mortality risk of HFpEF.

METHODS AND RESULTS

We first carried out a microarray analysis of 50 HFpEF patients who died and 50 matched controls who survived during 1-year follow-up for candidate gene selection. The HF-PRS was developed using the independent common (MAF > 0.05) genetic variants that showed significant associations with 1-year all-cause death (P < 0.05) in 1442 HFpEF patients. Internal cross-validation and subgroup analyses were performed to evaluate the discrimination ability of the HF-PRS. In 209 genes identified by microarray analysis, 69 independent variants (r < 0.1) were selected to develop the HF-PRS model. This model yielded the best discrimination capability for 1-year all-cause mortality with an area under the curve (AUC) of 0.852 (95% CI 0.827-0.877), which outperformed the clinical risk score consisting of 10 significant traditional risk factors for 1-year all-cause mortality (AUC 0.696, 95% CI 0.658-0.734, P = 4 × 10-11), with net reclassification improvement (NRI) of 0.741 (95% CI 0.605-0.877; P < 0.001) and integrated discrimination improvement (IDI) of 0.181 (95% CI 0.145-0.218; P < 0.001). Individuals in the medium and the highest tertile of the HF-PRS had nearly a five-fold (HR = 5.3, 95% CI 2.4-11.9; P = 5.6 × 10-5) and 30-fold (HR = 29.8, 95% CI 14.0-63.5; P = 1.4 × 10-18) increased risk of mortality compared to those in the lowest tertile, respectively. The discrimination ability of the HF-PRS was excellent in cross validation and throughout the subgroups regardless of comorbidities, gender, and patients with or without a history of heart failure.

CONCLUSION

The HF-PRS comprising 69 genetic variants provided an improvement of prognostic power over the contemporary risk scores and NT-proBNP in HFpEF patients.

Association of Body Mass Index and Abdominal Obesity with Incidence of Atrial Fibrillation in Heart Failure with Preserved Ejection Fraction

INTRODUCTION

The association between obesity and atrial fibrillation (AF) incidence in heart failure with preserved ejection fraction (HFpEF) patients is currently unclear. Our analyses and results are based on the whole Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial (placebo and spironolactone).

METHOD

A total of 2138 subjects without baseline AF were included in the trial. Kaplan-Meier (K-M) curves and Cox regression with hazard ratios (HRs) and confidence intervals (CIs) were used to assess the incidence of AF with obesity. Of 2138 HFpEF patients without baseline AF, 1165 were obese (body mass index [BMI]≥30 kg/m2).

RESULT

The K-M curve showed obese patients developed AF more than overweight (25≤ BMI ≤29.9 kg/m2) patients (p=0.013), confirmed by multivariable analysis, while there's no statistical difference between overweight and normal weight (18.5≤ BMI ≤24.9 kg/m2) patients. The occurrence of AF increased by 3% for every kg/m2 increase in BMI (adjusted HR, aHR: 1.03; 95% CI: 1.00-1.06), with a positive linear association (p for nonlinear: 0.145). Obesity was associated with AF incidence (aHR: 1.62; 95% CI: 1.05-2.50) compared with non-obesity (including overweight and normal-weight patients).

CONCLUSION

Abdominal obesity was associated with increased AF incidence (aHR: 1.70; 95% CI: 1.04-2.77), and AF incidence rose by 18% per centimeter in circumference (aHR: 1.18; 95% CI: 1.04-1.34). Obesity and abdominal obesity increase the incidence of AF in HFpEF patients. Further studies need to determine whether there is a difference in AF in response to spironolactone across obese HFpEF pheno groups.

Long-term dietary n3 fatty acid prevents aging-related cardiac diastolic and vascular dysfunction

AIMS

The prevalence of left ventricular (LV) diastolic and vascular dysfunction increases with age, eventually leading to heart failure with preserved ejection fraction (HFpEF). A preventive strategy is an unmet medical need. We and others reported previously on the beneficial effects of omega-3 fatty acid alpha linolenic acid (ALA) on cardiovascular disorders in animal models and translational studies. We now investigate whether long-term dietary ALA could prevent LV diastolic dysfunction and vascular aging in a murine model.

METHODS AND RESULTS

Wild-type C57BL/6 J mice were fed a chow or ALA diet for 12 months, starting at 6 months of age. Here, we show that aged (~18 months) mice recapitulate major hallmarks of HFpEF, including LV diastolic dysfunction with preserved ejection fraction, impaired vascular function, cardiac fibrosis, arterial stiffening and inflammation, as well as elevated B-type natriuretic peptide (BNP). Long-term ALA supplementation upregulated the mitochondrial tricarboxylic acid enzyme Idh2 and the antioxidant enzymes SOD1 and Gpx1. It also has been associated with reduced inflammation and ECM remodeling, accompanied by a significant downregulation of fibrosis biomarkers MMP-2 and TGF-β in both cardiac and vascular tissues obtained from aged mice. Our data exhibited the preventive effects of dietary ALA against LV diastolic dysfunction, impaired vasorelaxation, cardiac fibrosis, inflammation and arterial stiffening in aged mice.

CONCLUSIONS

We provide evidence and a simplified mechanistic insight on how long-term ALA supplementation is a successful strategy to prevent the development of age-related diastolic and vascular dysfunction.

Heart failure with preserved ejection fraction in post myocardial infarction patients: a myocardial magnetic resonance (MR) tissue tracking study

Background

This study aimed to explore the value of cardiac magnetic resonance tissue tracking (CMR-TT) technology in evaluating heart failure with preserved ejection fraction (HFpEF) in patients with chronic myocardial infarction (CMI).

Methods

Between June 2016 and March 2022, we included a consecutive series of 92 patients with CMI and 40 healthy controls in this retrospective study. The CMI patients enrolled were divided into different subgroups [HFpEF-CMI group (n=54) and non- heart failure (HF)-CMI group (n=38)] according to the Heart Failure Association (HFA)-PEFF (step 1: P, pre-test assessment; step 2: E, echocardiography and natriuretic peptide score; step 3: F1, functional testing; step 4: F2, final aetiology) diagnostic algorithm. CMR scan was performed at the First Hospital of China Medical University. Quantitative measurements of myocardial damage, such as myocardial strain parameters of both ventricles derived by CMR-TT and infarct size and transmurality by late gadolinium enhancement (LGE), were assessed. One-way analysis of variance, independent samples t-test, and rank sum test were used to compare myocardial impairment among groups. Pearson or Spearman correlation coefficient was used to measure correlations between left ventricular (LV) strains and clinical and functional parameters. Logistic regression analysis and receiver operating characteristic (ROC) curve were performed to identify the best parameter for diagnosing HFpEF-CMI.

Results

HFpEF-CMI patients demonstrated significantly impaired LV strains and strain rates in all of the three directions (radial, circumferential and longitudinal) compared to non-HF-CMI patients and healthy controls (P<0.001 for all), whereas only global longitudinal strain (GLS) was significantly impaired in HFpEF-CMI patients vs. controls for right ventricular strain parameters (P<0.001). LV strains showed moderate correlation with N-terminal pro-brain natriuretic peptide (radial, circumferential and longitudinal strain, R=-0.401, R=0.408, R=0.407, respectively, P<0.001 for all). LV strains in the three directions (radial, circumferential and longitudinal) [area under ROC curve (AUC) =0.707, 95% confidence interval (CI): 0.603-0.797; AUC =0.708, 95% CI: 0.604-0.798; AUC =0.731, 95% CI: 0.628-0.818; respectively, P<0.01 for all] were discriminators for HFpEF-CMI and non-HF-CMI. LV strains and myocardial infarction volume were independent factors in multi-logistic regression analysis after adjusting for body mass index, age, and sex (P<0.05 for all).

Conclusions

CMR-TT provides clinicians with useful additional imaging parameters to facilitate the assessment of CMI patients with HFpEF. LV strain parameters can detect early cardiac insufficiency in patients with HFpEF-CMI and have potential value for discriminating between HFpEF and non-HF patients post-CMI.

Genetic causes of heart failure with preserved ejection fraction: emerging pharmacological treatments

Heart failure with preserved ejection fraction (HFpEF) is a major driver of cardiac morbidity and mortality in developed countries, due to ageing populations and the increasing prevalence of comorbidities. While heart failure with reduced ejection fraction is dominated by left ventricular impairment, HFpEF results from a complex interplay of cardiac remodelling, peripheral circulation, and concomitant features including age, hypertension, obesity, and diabetes. In an important subset, however, HFpEF is subtended by specific diseases of the myocardium that are genetically determined, have distinct pathophysiology, and are increasingly amenable to targeted, innovative treatments. While each of these conditions is rare, they collectively represent a relevant subset within HFpEF cohorts, and their prompt recognition has major consequences for clinical practice, as access to dedicated, disease-specific treatments may radically change the quality of life and outcome. Furthermore, response to standard heart failure treatment will generally be modest for these individuals, whose inclusion in registries and trials may dilute the perceived efficacy of treatments targeting mainstream HFpEF. Finally, a better understanding of the molecular underpinnings of monogenic myocardial disease may help identify therapeutic targets and develop innovative treatments for selected HFpEF phenotypes of broader epidemiological relevance. The field of genetic cardiomyopathies is undergoing rapid transformation due to recent, groundbreaking advances in drug development, and deserves greater awareness within the heart failure community. The present review addressed existing and developing therapies for genetic causes of HFpEF, including hypertrophic cardiomyopathy, cardiac amyloidosis, and storage diseases, discussing their potential impact on management and their broader implications for our understanding of HFpEF at large.

Sodium-glucose co-transporter 2 inhibitors in heart failure with mildly reduced or preserved ejection fraction: an updated systematic review and meta-analysis

OBJECTIVES

Heart failure with mildly reduced ejection fraction (HFmrEF)  or  heart failure with preserved ejection fraction (HFpEF)  are associated with significant morbidity and mortality, as well as growing health and economic burden. Sodium-glucose co-transporter 2 (SGLT2) inhibitors are very promising for the outcome improvement of patients with HFpEF or HFmrEF. The meta-analysis was performed to investigate the effects of SGLT2 inhibitors in HFpEF or  HFmrEF, by pooling data from all clinically randomized controlled trials (RCTs) available to increase power to testify.

METHODS

Studies were searched in electronic databases from inception to November, 2022. We performed a meta-analysis to estimate the effect of SGLT2 inhibitors on clinical endpoints in patients with HFpEF or HFmrEF, using trial-level data with consistent endpoint definitions. The primary outcome was the composite of heart failure (HF) hospitalization or cardiovascular death. Hazard ratio (HR) was pooled with 95% confidence interval (CI) for dichotomous data. This study was registered with INPLASY 2022110095.

RESULTS

Six studies involving 15,989 participants were included into the final analysis. Pooled analyses revealed that SGLT2 inhibitors significantly reduced the composite of HF hospitalization or cardiovascular death [HR: 0.79 (0.72-0.85); I² = 0%; P < 0.00001] and HF hospitalizations [HR: 0.74 (0.67-0.82); I² = 0%; P < 0.00001]. This finding was seen in both HFmrEF trials [HR: 0.76 (0.67-0.87); I² = 49%; P < 0.0001] and HFpEF subgroup studies [HR: 0.70 (0.53-0.93); I² = 0%; P = 0.01]. The incidence of any serious adverse events [OR: 0.89 (0.83-0.96); I² = 0%; P = 0.002] was significantly lower in the SGLT2 inhibitor arm. No significant differences were observed between the two groups with regard to cardiovascular death and all-cause death.

CONCLUSIONS

This meta-analysis of patients with heart failure of left ventricular ejection fraction (LVEF) > 40% showed that SGLT2 inhibitors significantly reduce the risk of  the composite of cardiovascular death and hospitalization for heart failure, but not cardiovascular death and all-cause death. Nevertheless, given that SGLT2 inhibitors may reduce the risk of hospitalization for heart failure, they should be considered the fundamental treatment for all patients with HFpEF or  HFmrEF.

Aortic thoracic neuromodulation in heart failure with preserved ejection fraction

The inadequacy of medical therapies for heart failure with preserved ejection fraction (HFpEF) is driving the development of device-based solutions targeting underlying pathophysiologic abnormalities. The maladaptive autonomic imbalance with a reduction in vagal parasympathetic activity and increased sympathetic signalling contributes to the deterioration of cardiac performance, patient fitness, and the increased overall morbidity and mortality. Thoracic aortic vagal afferents mediate parasympathetic signalling, and their stimulation has been postulated to restore autonomic balance. In this first-in-man experience with chronic stimulation of aortic vagal afferents (Harmony™ System, Enopace, Israel), we demonstrate improved left atrial remodelling and function parallel with improved left ventricular performance. The observed favourable structural and functional cardiac changes remained stable throughout the 1 year follow-up and were associated with improved symptoms and physical fitness. The current experience warrants further validation of the endovascular stimulation of aortic thoracic afferents as a new interventional approach for device-based treatment in HFpEF.

SGLT-2 Inhibitors for Patients with Heart Failure: What Have We Learned Recently?

PURPOSE OF REVIEW

In this review, we discuss the mechanisms of action of sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and the purported protective effects for mitigating heart failure (HF)-related outcomes.

RECENT FINDINGS

Major randomized clinical trials have demonstrated the cardiovascular safety and efficacy of SGLT-2i among patients without known HF and those with established HF with reduced ejection fraction or preserved ejection fraction (HFrEF and HFpEF respectively). Recent HF guidelines have incorporated SGLT-2i in HF treatment algorithms. SGLT-2i have emerged as a novel treatment for both prevention of HF and reduction of cardiovascular morbidity and mortality among patients with existing HFrEF or HFpEF.

Unsupervised Machine Learning for Assessment of Left Ventricular Diastolic Function and Risk Stratification

BACKGROUND

The 2016 American Society of Echocardiography (ASE) guidelines have been widely used to assess left ventricular diastolic function. However, limitations are present in the current classification system. We aimed to develop a data-driven, unsupervised machine learning approach for diastolic function classification and risk stratification using the left ventricular diastolic function parameters recommended by the 2016 ASE guidelines; the guideline grading was used as the reference standard.

METHODS

Baseline demographics, heart failure hospitalization and all-cause mortality data were obtained for all adult patients who underwent transthoracic echocardiography at Mayo Clinic Rochester in 2015. Patients with prior mitral valve intervention, congenital heart disease, cardiac transplant, or cardiac assist device were excluded. Nine left ventricular diastolic function variables (mitral E and A wave peak velocities, E/A, deceleration time, medial and lateral annulus e' and E/e', and tricuspid regurgitation peak velocity) were used for an unsupervised machine learning algorithm to identify different phenotype clusters. The cohort average of each variable was used for imputation. Patients were grouped according to the algorithm-determined clusters for Kaplan-Meier survival analysis.

RESULTS

Among 24,414 patients, age 63.6 ±16.2 years, all-cause mortality occurred in 4,612 (18.9%) patients during median follow-up 3.1 years. The algorithm determined 3 clusters with echocardiographic measurement characteristics corresponding to normal diastolic function (n= 8,312), impaired relaxation (n=11,779) and increased filling pressure (n =4,323), with 3-year cumulative mortality of 11.8%, 19.9% and 33.4%, respectively (p<0.0001). All 10,694 (43.8%) patients classified as indeterminate were reclassified into the 3 clusters (3,324, 5,353, and 2,017, respectively) with 3-year mortality of 16.6%, 22.9% and 34.4%, respectively. The clusters also outperformed guideline-based grade for prognostication (c-index: 0.607 vs. 0.582, p=0.013).

CONCLUSIONS

Unsupervised machine learning identified physiologically and prognostically distinct clusters based on 9 diastolic function Doppler variables. The clusters can be potentially applied in echocardiography laboratory practice and future clinical trials for simple, replicable diastolic function related risk stratification.

Current updates in the pharmacotherapy of heart failure with a preserved ejection fraction

BACKGROUND

Heart failure is the leading cause of morbidity and mortality worldwide. With improved longevity, the incidence and prevalence of heart failure continue to rise with an estimated prevalence of around 26 million worldwide. Heart failure with preserved ejection fraction (HFpEF) constitutes around 50% of the total heart failure cases and is the most common cause of heart failure in the elderly population. The cost of heart failure care continues to rise with care for heart failure hospitalization taking the major bulk. The cost was around 30 billion in the US in 2012 and is projected to reach 70 billion by 2030.

OBJECTIVE

This study aims to provide updated pharmacotherapy of heart failure with a preserved ejection fraction (HFpEF).

METHODS

We performed a comprehensive literature review to examine the available pharmacotherapeutics in the management of heart failure with a preserved ejection fraction using online databases (PubMed and Embase).

RESULTS

We reviewed multiple studies examining pharmacotherapeutics in the management of HFpEF and reducing heart failure hospitalizations in this cohort. Until recently, our management mainly focused on aggressively managing diabetes, hypertension, atrial fibrillation, and coronary artery disease anticipating improving the outcome. Beta-blockers, Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, sildenafil, digoxin, vericiguat, praliciguat, and Ivabradine did not improve heart failure hospitalization in this cohort.

CONCLUSION

EMPEROR-PRESERVED (Empagliflozin) and PRESERVED-HF (Dapagliflozin) results in the management of HFpEF look promising irrespective of diabetes status. Sacubitril-valsartan and Empagliflozon are the only medications approved for its management as per the PARAGON-HF and EMPEROR-PRESERVED studies respectively.

Prognostic Impact of Echocardiographic Diastolic Dysfunction on Outcomes in Patients With Heart Failure With Preserved Ejection Fraction - Insights From the PURSUIT-HFpEF Registry

BACKGROUND

Although diastolic dysfunction is important pathophysiology in heart failure with preserved ejection fraction (HFpEF), its prognostic impact in HFpEF patients, including those with atrial fibrillation (AF), remains to be elucidated.Methods and Results:We included the data for 863 patients (321 patients with AF) registered in a prospective multicenter observational study of patients with HFpEF. Patients were divided into 3 groups according to the 2016 ASE/EACVI recommendations. The primary endpoint was a composite of all-cause death or HF rehospitalization. Median age was 83 years, and 55.5% were female. 196 (22.7%) were classified with normal diastolic function (ND), 253 (29.3%) with indeterminate (ID) and 414 (48.0%) with diastolic dysfunction (DD). The primary endpoint occurred more frequently in patients with DD than in those with ND or ID (log-rank P<0.001 for DD vs. ND, and log-rank P=0.007 for DD vs. ID, respectively). Taking ND as the reference, multivariable Cox regression analysis revealed that DD (hazard ratio (HR): 1.57, 95% confidence interval (CI):1.06-2.32, P=0.024) was independently associated with the composite endpoint, whereas ID (HR: 1.28, 95% CI: 0.84-1.95, P=0.255) was not. DD was associated with the composite endpoint in both patients with and without AF.

CONCLUSIONS

HFpEF patients classified with DD using the 2016 ASE/EACVI recommendations had worse clinical outcomes than those with ND or ID. DD may be considered a prognostic marker in patients with HFpEF regardless of AF.

Current status on the therapeutic strategies for heart failure and diabetic cardiomyopathy

Heart failure (HF) is a leading cause of disease and death from cardiovascular diseases, with cardiovascular diseases accounting for the highest cases of deaths worldwide. The reality is that the quality-of-life survival for those suffering HF remains poor with 45-60% reported deaths within five years. Furthermore, cardiovascular disease is the foremost cause of mortality and disability in people with type 2 diabetes mellitus (T2DM), with T2DM patients having a two-fold greater risk of developing heart failure. The number of T2DM affected persons only continues to surge as there are more than 400 million adults affected by diabetes and an estimated 64.3 million affected by heart failure globally (1). In order to cater to the demands of modern society, the medical field has continuously improved upon the standards for clinical management and its therapeutic approaches. For this purpose, in this review, we aim to provide an overview of the current updates regarding heart failure, to include both heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF) and their respective treatments, while also diving further into heart failure and its correlation with diabetes and diabetic cardiomyopathy and their respective therapeutic approaches.

Mitochondrial bioenergetics and D-ribose in HFpEF: a brief narrative review

Objective

In this review article, we briefly describe the status of treatment options for HFpEF and the role of mitochondrial dysfunction in the pathogenesis of HFpEF as an alternative therapeutic target. We also examine the mechanisms of D-ribose in cellular energy production and discuss the potential disadvantages and benefits of supplemental use of D-ribose in patients with HFpEF.

Background

Heart failure is a major cardiovascular disease that impacts over 6 million Americans and is one of the leading causes for morbidity and mortality. Patients with heart failure often experience shortness of breath and fatigue along with impaired physical capacity, all leading to poor quality of life. As a subtype of heart failure, heart failure with preserved ejection fraction (HFpEF) is characterized with impaired diastolic function. Currently, there are no effective treatments specifically for HFpEF, thus clinicians and researchers are searching for therapies to improve cardiac function. Emerging evidence indicate that mitochondrial dysfunction and impaired cardiac bioenergetics are among the underlying mechanisms for HFpEF. There is increased interest in investigating the use of supplements such as D-ribose to enhance mitochondrial function and improve production of adenosine triphosphate (ATP).

Methods

For this narrative review, more than 100 relevant scientific articles were considered from various databases (e.g., PubMed, Web of Science, CINAHL, and Google Scholar) using the keywords “Heart Failure”, “HFpEF”, “D-ribose”, “ATP”, “Mitochondria”, Bioenergetics”, and “Cellular Respiration”.

Conclusions

It is essential to find potential targeted therapeutic treatments for HFpEF. Since there is evidence that the HFpEF is related to impaired myocardial bioenergetics, enhancing mitochondrial function could augment cardiac function. Using a supplement such as D-ribose could improve mitochondrial function by increasing ATP and enhancing cardiac performance for patients with HFpEF. There is a recently completed clinical trial with HFpEF patients that indicates D-ribose increases ATP production and improves cardiac ejection fraction.

Cardiac mesh morphing method for finite element modeling of heart failure with preserved ejection fraction

Numerical modeling of heart biomechanics can realistically capture morphological variations in diseases and has been helpful in advancing our understanding of the physiology. Subject-specific models require anatomic representation of medical images, and it is desirable to have a consistently repeatable models for any given morphology. In this study, we propose a novel and easily adaptable cardiac reconstruction algorithm by morphing an existing discretized mesh of an advanced finite element (FE) model, to match anatomies acquired from porcine cardiac magnetic resonance imaging (cMRI) scans. The morphing algorithm involves iterative FE simulations with visco-hyperelastic material properties. The living heart porcine model (LHPM) was chosen as the input baseline FE mesh, in order to preserve detailed anatomical features that cannot be captured in routine scans such as myofiber orientations and conduction pathways. The algorithm was demonstrated for the recreation of porcine hearts of a healthy subject and of a subject induced with heart failure with preserved ejection fraction (HFpEF) conditions, where there were substantial hypertrophy and anatomical alterations. We further used the morphed meshes for FE modeling of cardiac contraction and relaxation, thus demonstrating the applicability of the proposed algorithm in producing viable meshes. The results show that our algorithm can recreate the characteristic anatomical changes of cardiac remodeling, including heart muscle thickening, as well as replicate the reduction in ventricular volume. This algorithm allows for the creation of subject-specific models with the same mesh connectivity, thus enabling spatial comparison and analysis of pathologic progress.

Changes in clinical biochemical indexes of patients with heart failure with preserved ejection fraction or patients with hypertensive heart disease before and after treadmill exercise

BACKGROUND

The incidence of hypertension is continuously increasing. This study aimed to investigate the changes in clinical biochemical indexes of patients with heart failure with preserved ejection fraction (HFpEF), or patients with hypertensive heart disease (HHD) before and after treadmill exercise.

METHODS

Seventy-eight patients with HFpEF and 78 patients with HHD who were admitted to our hospital between February 2020 and February 2021 were selected to take a treadmill exercise test. All patients continued to exercise for 1 month. Clinical biochemical indexes [hemoglobin A1c (HbA1c), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), total cholesterol (TC), N-segment pro-brain natriuretic peptide (NT-proBNP), and cardiac troponin I (cTnI)] were measured before and after the treadmill exercise test and compared between the two groups. Receiver operating characteristic (ROC) curves were drawn to analyze the optimal cutoff values of the clinical biochemical indexes in the diagnosis of HFpEF. The positive diagnostic rates of the biochemical indicators for HFpEF before and after treadmill exercise were compared using the optimal cut-off value of ROC as the positive standard.

RESULTS

Before exercise, there was no significant difference in HbA1c, LDL-C, HDL-C, or TC between the two groups (P>0.05), but NT-proBNP and cTnI were significantly higher in the HFpEF group than in the HHD group (P<0.05). ROC curve analysis showed that before exercise, the best cutoff values for plasma NT-proBNP and cTnI in the diagnosis of HFpEF were 2,248.24 pg/mL and 1.14 ng/mL, respectively. After exercise, no significant difference was found in HbA1c, LDL-C, HDL-C, or TC between the two groups (P>0.05). However, the levels of NT-proBNP and cTnI in both groups were higher after exercise, with more significant increases seen in the HFPEF group (P<0.05). The positive rates of plasma NT-proBNP and cTnI in HFpEF group were statistically higher after exercise than before exercise (P<0.05).

CONCLUSIONS

The changes in plasma NT-proBNP and cTnI in patient after treadmill exercise can be used as sensitive indicators for the diagnosis and differentiation of HFpEF and HHD.

Left atrial volume and left ventricular mass indices in heart failure with preserved and reduced ejection fraction

AIMS

Two key echocardiographic parameters that are currently used to diagnose heart failure (HF) with preserved ejection fraction (HFpEF) are left atrial volume index (LAVi) and left ventricular mass index (LVMi). We investigated whether patients' characteristics, biomarkers, and co-morbidities are associated with these parameters and whether the relationships differ between patients with HFpEF or HF with reduced ejection fraction (HFrEF).

METHODS

We consecutively enrolled 831 outpatients with typical signs and symptoms of HF and elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels and categorized patients based upon left ventricular ejection fraction (LVEF): LVEF < 40% (HFrEF), LVEF between 40% and 50% (HF with mid-range ejection fraction), and LVEF ≥ 50% (HFpEF). The study includes consecutively enrolled HF patients from an HF outpatient clinic at a tertiary medical centre in the Netherlands. All patients underwent baseline characterization, laboratory measurements, and echocardiography.

RESULTS

Four hundred sixty-nine patients had HFrEF, 189 HF with mid-range ejection fraction, and 173 HFpEF. The patients with HFrEF were rather male [HFrEF: 323 (69%); HFpEF: 80 (46%); P < 0.001], and the age was comparable (HFrEF 67 ± 13; HFpEF 70 ± 14; P = 0.069). In HFpEF, more patients had hypertension [190 (40.5%); 114 (65.9%); P < 0.001], higher body mass indices (27 ± 8; 30 ± 7; P < 0.001), and atrial fibrillation [194 (41.4); 86 (49.7); P = 0.029]. The correlation analyses showed that in HFrEF patients, LAVi was significantly associated with age (β 0.293; P < 0.001), male gender (β 0.104; P = 0.042), body mass index (β -0160; P = 0.002), diastolic blood pressure (β -0.136; P < 0.001), New York Heart Association (β 0.174; P = 0.001), atrial fibrillation (β 0.381; P < 0.001), galectin 3 (β 0.230; P < 0.001), NT-proBNP (β 0.183; P < 0.001), estimated glomerular filtration rate (β -0.205; P < 0.001), LVEF (β -0.173; P = 0.001), and LVMi (β 0.337; P < 0.001). In HFpEF patients, only age (β 0.326; P < 0.001), atrial fibrillation (β 0.386; P < 0.001), NT-proBNP (β 0.176; P = 0.036), and LVMi (β 0.213; P = 0.013) were associated with LAVi.

CONCLUSIONS

Although LVMi and LAVi are hallmark parameters to diagnose HFpEF, they only correlate with a few characteristics of HF and mainly with atrial fibrillation. In contrast, in HFrEF patients, LAVi relates strongly to several other HF parameters. These findings underscore the complexity in visualizing the pathophysiology of HFpEF and question the relation between cardiac structural remodeling and the impact of co-morbidities.

Treating heart failure in patients with diabetes: The view of the cardiologist

Diabetes is a very important comorbidity in patients with heart failure. When both diseases coexist cardiovascular morbidity and mortality is greatly increased. Therefore, it is of clinical importance to treat both diseases as early as possible with an optimal therapy. Hitherto, heart failure therapy did not differ if a patient had concomitant diabetes. However, with SGLT-2 inhibitors having demonstrated to reduce hospitalization of heart failure independent of diabetes state and expected to be included into the ESC heart failure treatment guidelines in 2021 coexisting diabetes potentially will make a difference when to start therapy. In this article we provide an overview of current recommendations and also provide clinical considerations for the therapy of heart failure with concomitant diabetes.

Effects of Left Ventricular Hypertrophy and Myocardial Stiffness on Myocardial Strain Under Preserved Ejection Fraction

Despite numerous experimental observations regarding heart failure with preserved ejection fraction (HFpEF), which is characterized mainly by left ventricular hypertrophy and a left ventricular ejection fraction over 50%, myocardial dynamics under HFpEF have not yet been fully clarified, particularly regarding the relationship between myocardial strain distribution and myocardial work. To address this issue, we numerically investigated radial distribution of myocardial strain during a cardiac cycle with fixed internal volume at the end of the systolic and diastolic phases under different mechanical conditions, such as those involving myocardial thickness and elasticity of myocardial fibers. The myocardium was a modeled as a visco-hyperelastic continuous material. This model was taken into account that active contractile stress along the myocardial fiber direction depends on membrane potential change. Our numerical results showed that both radial and circumferential strains decreased as wall thickness increased, which reflected cardiac hypertrophy, but that myocardial work became larger than that observed with thin ventricular walls. Further, the change in left ventricular diastolic internal pressure caused circumferential strain, while fiber stiffness contributed to radial strain. Since peak circumferential strain was well estimated by the maximum difference between total internal and myocardial volumes, measuring the epicardial contraction rate should be helpful in understanding patients with HFpEF.

Atrial Fibrillation and Heart Failure: Epidemiology, Pathophysiology, Prognosis, and Management

Atrial fibrillation (AF) and heart failure (HF) have similar risk factors, frequently coexist, and potentiate each other in a vicious cycle. Evidence suggests the presence of AF in both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) increases the risk of all-cause mortality and stroke, particularly when AF is incident. Catheter ablation may be an effective strategy in controlling symptoms and improving quality of life in AF-HFrEF. Strong data guiding management of AF-HFpEF are lacking largely due to its challenging diagnosis. Improving outcomes associated with these coexistent conditions requires further careful investigation.

Heart failure with preserved ejection fraction in coronavirus disease 2019 patients: the promising role of diuretic therapy in critically ill patients

The impact of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) on diastolic function is less known. We describe a 46‐year‐old man with a history of mild hypertension who presented to the emergency department with fever, cough, and myalgia for 2 days. The patient was tested positive for SARS‐CoV‐2. He was admitted and started on a combination of antiviral and antimicrobial therapy. He developed respiratory distress 2 days later, and O₂ saturation declined. Blood tests showed an increased N‐terminal pro‐B type natriuretic peptide (NT‐proBNP) level, and echocardiography showed normal left ventricular ejection fraction and E/e′ ratio of 16. Computed tomography scan showed interstitial pulmonary oedema and prominent peripheral pulmonary vascular markings. Given these findings, heart failure with preserved ejection fraction (HFpEF) was considered. Low‐dose diuretic was started, and fluid administration was restricted, resulting in a decrease in NT‐proBNP level, clinical and haemodynamic stabilization, and improved oxygenation. This case highlights the occurrence of HFpEF in coronavirus disease 2019.

Mechanics of right ventricular dysfunction in pulmonary arterial hypertension and heart failure with preserved ejection fraction

Right ventricular (RV) dysfunction is the most important determinant of survival in patients with pulmonary hypertension (PH). The manifestations of RV dysfunction not only include changes in global RV systolic function but also abnormalities in the pattern of contraction and synchrony. The effects of PH on the right ventricle have been mainly studied in patients with pulmonary arterial hypertension (PAH). However, with the demographic shift towards an aging population, heart failure with preserved ejection fraction (HFpEF) has become an important etiology of PH in recent years. There are significant differences in RV mechanics, function and adaptation between patients with PAH and HFpEF (with or without PH), which are related to different patterns of remodeling and dysfunction. Due to the unique features of the RV chamber, its connection with the main pulmonary artery and the pulmonary circulation, an understanding of the mechanics of RV function and its clinical significance is mandatory for both entities. In this review, we describe the mechanics of the pressure overloaded right ventricle. We review the different mechanical components of RV dysfunction and ventricular dyssynchrony, followed by insights via analysis of pressure-volume loop, energetics and novel blood flow patterns, such as vortex imaging. We conduct an in-depth comparison of prevalence and characteristics of RV dysfunction in HFpEF and PAH, and summarize key outcome studies. Finally, we provide a perspective on needed and expected future work in the field of RV mechanics.

Confirmation of the Cardioprotective Effect of MitoGamide in the Diabetic Heart

Purpose

HFpEF (heart failure with preserved ejection fraction) is a major consequence of diabetic cardiomyopathy with no effective treatments. Here, we have characterized Akita mice as a preclinical model of HFpEF and used it to confirm the therapeutic efficacy of the mitochondria-targeted dicarbonyl scavenger, MitoGamide.

Methods and Results

A longitudinal echocardiographic analysis confirmed that Akita mice develop diastolic dysfunction with reduced E peak velocity, E/A ratio and extended isovolumetric relaxation time (IVRT), while the systolic function remains comparable with wild-type mice. The myocardium of Akita mice had a decreased ATP/ADP ratio, elevated mitochondrial oxidative stress and increased organelle density, compared with that of wild-type mice. MitoGamide, a mitochondria-targeted 1,2-dicarbonyl scavenger, exhibited good stability in vivo, uptake into cells and mitochondria and reactivity with dicarbonyls. Treatment of Akita mice with MitoGamide for 12 weeks significantly improved the E/A ratio compared with the vehicle-treated group.

Conclusion

Our work confirms that the Akita mouse model of diabetes replicates key clinical features of diabetic HFpEF, including cardiac and mitochondrial dysfunction. Furthermore, in this independent study, MitoGamide treatment improved diastolic function in Akita mice.

Electronic supplementary material

The online version of this article (10.1007/s10557-020-07086-7) contains supplementary material, which is available to authorized users.

Ventricular-vascular coupling in heart failure with preserved ejection fraction: A systematic review and meta-analysis

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is a complex disease underlined by impaired ventricular-vascular coupling (VVC).

OBJECTIVES

To evaluate the VVC ratio in HFpEF patients at rest and during exercise and compare it to the healthy and heart failure with reduced ejection fraction (HFrEF) controls.

METHODS

PubMed and EMBASE databases were searched for trials that matched the inclusion criteria. Random-effects models were used to estimate the pooled mean difference with 95% confidence interval using Open Meta[Analyst] software.

RESULTS

A total of 13 trials met the inclusion criteria. Although VVC ratio was comparable between HFpEF and healthy controls at rest, it was significantly lower in HFrEF compared to HFpEF. During exercise, there was a significant decline in VVC ratio in HFpEF (-0.119, 95% CI (-0.183 to -0.055), p<0.001).

CONCLUSION

VVC ratio, although 'preserved' at rest in HFpEF patients, was overtly impaired during exercise highlighting the importance of dynamic testing.

Factors Associated With Elevated N-Terminal Pro B-Type Natriuretic Peptide Concentrations at the Convalescent Stage and 1-Year Outcomes in Patients With Heart Failure With Preserved Ejection Fraction

Background: Little is known about factors associated with elevated N-terminal pro B-type natriuretic peptide (NT-proBNP) at the convalescent stage and their effects on 1-year outcomes in patients with heart failure with preserved ejection fraction (HFpEF). Methods and Results: This study included 469 patients with HFpEF. Elevated NT-proBNP was defined as the highest quartile. The first 3 quartiles (Q1-Q3) were combined together for comparison with the fourth quartile (Q4). Median NT-proBNP concentrations in Q1-Q3 and Q4 were 669 and 3,504 pg/mL, respectively. Multivariate logistic regression analysis revealed that low albumin (odds ratio [OR] 2.44; 95% confidence interval [CI] 1.35-4.39; P=0.003), low estimated glomerular filtration rate (OR 5.83; 95% CI 3.46-9.83; P<0.001), high C-reactive protein (OR 2.09; 95% CI 1.21-3.63; P=0.009), and atrial fibrillation at discharge (OR 2.33; 95% CI 1.40-3.89; P=0.001) were associated with elevated NT-proBNP. Cumulative rates of all-cause mortality and heart failure rehospitalization were significantly higher in Q4 than in Q1-Q3 (P=0.001 and P<0.001, respectively). Incidence and hazard ratios of these adverse events increased when the number of associated factors for elevated NT-proBNP clustered together (P<0.001 and P=0.002, respectively). Conclusions: In addition to atrial fibrillation, extracardiac factors (malnutrition, renal impairment and inflammation) were associated with elevated NT-proBNP at the convalescent stage, and led to poor prognosis in patients with HFpEF.

Amyloidosis in Heart Failure

PURPOSE

Amyloidosis represents an increasingly recognized but still frequently missed cause of heart failure. In the light of many effective therapies for light chain (AL) amyloidosis and promising new treatment options for transthyretin (ATTR) amyloidosis, awareness among caregivers needs to be raised to screen for amyloidosis as an important and potentially treatable differential diagnosis. This review outlines the diversity of cardiac amyloidosis, its relation to heart failure, the diagnostic algorithm, and therapeutic considerations that should be applied depending on the underlying type of amyloidosis.

RECENT FINDINGS

Non-biopsy diagnosis is feasible in ATTR amyloidosis in the absence of a monoclonal component resulting in higher detection rates of cardiac ATTR amyloidosis. Biomarker-guided staging systems have been updated to facilitate risk stratification according to currently available biomarkers independent of regional differences, but have not yet prospectively been tested. Novel therapies for hereditary and wild-type ATTR amyloidosis are increasingly available. The complex treatment options for AL amyloidosis are improving continuously, resulting in better survival and quality of life. Mortality in advanced cardiac amyloidosis remains high, underlining the importance of early diagnosis and treatment initiation. Cardiac amyloidosis is characterized by etiologic and clinical heterogeneity resulting in a frequently delayed diagnosis and an inappropriately high mortality risk. New treatment options for this hitherto partially untreatable condition have become and will become available, but raise challenges regarding their implementation. Referral to specialized centers providing access to extensive and targeted diagnostic investigations and treatment initiation may help to face these challenges.

H2FPEF Score for the Prediction of Exercise Intolerance and Abnormal Hemodynamics in Japanese - Evaluation by Exercise Stress Echocardiography Combined With Cardiopulmonary Exercise Testing

BACKGROUND

Both the H₂FPEF-score and nomogram-score, which consist of simple clinical parameters, can assist in diagnosing "early" heart failure with preserved ejection fraction (HFpEF) and only exertional dyspnea, but their these usefulness in Japanese remains unclear. We sought to investigate the correlation between these scores and exercise response, including the peak oxygen uptake (V̇O₂), the pulmonary artery systolic pressure (PASP), the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e') and stroke volume (SV) using exercise stress echocardiography (ESE) combined with cardiopulmonary exercise testing (CPET).Methods and Results:In this single-center, retrospective cross-sectional study the H₂FPEF-score and nomogram-score were calculated in a total of 139 patients who underwent ESE combined with CPET. The scores correlated with peak V̇O₂(r=-0.48, r=-0.44), PASP (r=0.23, r=0.29) and SV (r=-0.32, r=-0.19) at peak exercise. The nomogram-score correlated with E/e' (r=0.24). The prevalence of exercise intolerance (percent predicted peak V̇O₂<75% and <50%) increased as the H₂FPEF-score increased and reached 88.9% and 22.2% among the patients with high H₂FPEF-score (6-9 points).

CONCLUSIONS

The H₂FPEF-score may be useful as the initial step to diagnosing 'early' HFpEF. The nomogram-score may be more useful in Japanese because of its more universal association with exercise response than the H₂FPEF-score.

Effects of Sodium-Glucose Cotransporter 2 Inhibitor on Vascular Endothelial and Diastolic Function in Heart Failure With Preserved Ejection Fraction - Novel Prospective Cohort Study

Background: Pathogenesis of heart failure with preserved ejection fraction (HFpEF) may involve endothelial dysfunction and abnormal vascular structure. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial cardiovascular effects and may improve vascular function in patients with HFpEF. Methods and Results: We recruited 184 patients with type 2 diabetes and HFpEF (mean age, 66.0±14.4 years) who were scheduled for treatment with SGLT2 inhibitors, had transthoracic echocardiogram to identify diastolic function, and flow-mediated dilation (FMD) to evaluate endothelial function, and assessed cardio-ankle vascular index (CAVI) and carotid intima-media thickness as indices of vascular function and vascular structure, respectively. Body weight, systolic blood pressure, diastolic blood pressure, triglycerides, remnant lipoprotein cholesterol, fasting plasma glucose, hemoglobin A1c, urinary albumin/creatinine ratio, and insulin resistance (IR) decreased, hematocrit and FMD increased significantly, and CAVI decreased significantly, after 12-week treatment (P<0.05). Short-term SGLT2 inhibitors improved diastolic function, significantly reducing the mitral ratios of septal E/early septal annular tissue Doppler velocity (P=0.003) and lateral E/early lateral e' (P=0.044). On multiple regression statistically significant associations were seen between ∆mean E/e' and ∆FMD, ∆CAVI, and ∆IR. Conclusions: SGLT2 inhibitors can improve diastolic function in patients with type 2 diabetes, suggesting that current treatment policies for diabetes should be re-examined. Further prospective studies with larger sample sizes could provide mechanistic insights into the benefits of SGLT2 inhibitors.

Pathophysiological and therapeutic implications in patients with atrial fibrillation and heart failure

Heart failure and atrial fibrillation are common and responsible for significant mortality of patients. Both share the same risk factors like hypertension, ischemic heart disease, diabetes, obesity, arteriosclerosis, and age. A variety of microscopic and macroscopic changes favor the genesis of atrial fibrillation in patients with preexisting heart failure, altered subcellular Ca²⁺ homeostasis leading to increased cellular automaticity as well as concomitant fibrosis that are induced by pressure/volume overload and altered neurohumoral states. Atrial fibrillation itself promotes clinical deterioration of patients with preexisting heart failure as atrial contraction significantly contributes to ventricular filling. In addition, atrial fibrillation induced tachycardia can even further compromise ventricular function by inducing tachycardiomyopathy. Even though evidence has been provided that atrial functions significantly and independently of confounding ventricular pathologies, correlate with mortality of heart failure patients, rate and rhythm controls have been shown to be of equal effectiveness in improving mortality. Yet, it also has been shown that cohorts of patients with heart failure benefit from a rhythm control concept regarding symptom control and hospitalization. To date, amiodarone is the most feasible approach to restore sinus rhythm, yet its use is limited by its extensive side-effect profile. In addition, other therapies like catheter-based pulmonary vein isolation are of increasing importance. A wide range of heart failure-specific therapies are available with mixed impact on new onset or perpetuation of atrial fibrillation. This review highlights pathophysiological concepts and possible therapeutic approaches to treat patients with heart failure at risk for or with atrial fibrillation.

Therapeutic potential of phosphodiesterase type 5 inhibitors in heart failure with preserved ejection fraction and combined post- and pre-capillary pulmonary hypertension

OBJECTIVE

Heart failure with preserved ejection fraction (HFpEF) is frequently associated with pulmonary hypertension (PH), which substantially impacts survival. Based on pulmonary vascular resistance (PVR) and the diastolic pressure gradient (DPG), current guidelines distinguish between isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH). However, the therapeutic consequences of this sub-classification remain entirely unclear. We specifically investigated the efficacy and safety of PDE5i in patients with HFpEF and CpcPH.

METHODS

In 40 hemodynamically precisely characterized patients with HFpEF and Cpc-PH who were treated with a PDE5i for at least 12 months, the therapeutic effect on 6-minute walk distance (6MWD), WHO functional class (FC), NTproBNP levels, right ventricular function, and hospitalization rates was evaluated.

RESULTS

Patients' mean age was 73 ± 9 years, and comorbidities were frequent (78% hypertension, 58% atrial fibrillation, 35% diabetes). Initially, 38 patients (95%) were in WHO-FC III and 2 patients (5%) in WHO-FC II. Prior to PDE5i initiation, mean PAPm was 46.2 ± 10.3 mmHg, PAWP 21.2 ± 4.7 mmHg, DPG 5.5 ± 7.2 mmHg, and PVR 6.2 ± 3.0 WU. After 12 months of PDE5i therapy, the 6MWD increased from initially 277 ± 17 to 340 ± 18 m (p < 0.001), and the proportion of patients in WHO-FC I/II increased from 5% to 37.5%. NTproBNP levels decreased by 33% (p = 0.004), and TAPSE improved from 16.8 ± 0.7 mm at baseline to 18.2 ± 0.6 mm (p = 0.01). The rate of HF-associated hospitalizations was substantially lower in the 12 months post PDE5i initiation compared to the prior 12 months. The DPG had no impact on the response to therapy. No deaths occurred, and typical side effects of PDE5i were observed.

CONCLUSION

These data indicate that at least a subset of precisely characterized patients with HFpEF and CpcPH who tolerate PDE5i may benefit from targeted therapy. A randomized study in this particular sub-population is warranted.

Renal function, N-terminal Pro-B-Type natriuretic peptide, propeptide big-endothelin and patients with heart failure and preserved ejection fraction

Renal dysfunction may limit the clinical application of NT-proBNP in the diagnosis of heart failure. In general practice, where echocardiography is not readily available, a biomarker for the diagnosis of a heart failure with preserved ejection fraction (HFpEF) would be useful. Since cardiac diseases frequently coincide with renal disease, there is a high need of valid risk stratification methods in patients affected with both. We therefore examined NT-proBNP and another biomarker, Big-Endothelin-1, as a marker of HFpEF in patients with CKD. NT-proBNP and Big-ET-1 were determined in 439 patients with HFpEF in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. NT-proBNP plasma level has shown an exponential increase with declining GFR, while Big-ET-1 plasma level increased only in a moderate and linear fashion. In patients without CKD, a NT-proBNP cut-off point at 250 pg/mL was suitable for the discrimination between HFpEF and patients without HF. When the GFR was less than 60 mL/min/1.73m², the NT-proBNP cut-off point should be raised to 750 pg/mL. At a cutoff point at 0.85 fmol/L, Big-ET-1 allowed to distinguish patients with HFpEF from persons without HF, independently of GFR. In general, NT-proBNP is a good indicator of suspected heart failure. While for NT-proBNP different cut-off points have to be considered in the diagnosis of HFpEF, a single cut-off point of Big-ET-1 was appropriate in the diagnosis of HFpEF, regardless of the presence or absence of CKD. An additional measurement of Big-ET-1 improves the diagnosis of HFpEF in patients with chronic kidney disease.

Effect of the peptides Relaxin, Neuregulin, Ghrelin and Glucagon-like peptide-1, on cardiomyocyte factors involved in the molecular mechanisms leading to diastolic dysfunction and/or heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) represents an important cardiac condition because of its increasing prevalence, resistance to treatment and high associated morbidity and mortality. Two of the major mechanisms responsible for HFpEF are impaired cardiomyocyte sarcoplasmic reticulum (SR) Ca²⁺ ATPase (SERCA2a), which is responsible for calcium reuptake into the SR, and cardiac fibroblasts/myofibroblasts that produce collagen or myocardial fibrosis. Phospholamban (PLB), in the SR and endoplasmic reticulum, is the primary regulator of SERCA2a in the heart and acts as a reversible inhibitor of SERCA2a. Glucagon-like peptide-1, a 30 amino acid peptide, improves diastolic function through increasing SERCA2a expression and activity as well as by decreasing phosphorylation of Ryanodine receptors. It also enhances collagen production through enhanced procollagen IalphaI/IIIalphaI, connective tissue growth factor, fibronectin, TGF-β3 as well as Interleukin -10, -1beta, and -6 gene expression. Relaxin-2, a two chain, 53 amino acid peptide, increases Ser16- and Thr17-phosphorylation levels of PLB, thereby relieving SERCA2a of its inhibition. H3 Relaxin inhibits TGF-β1-stimulated collagen deposition through H3 relaxin-induced increases in pSmad2. Neuregulin-1, an epidermal growth factor, induces nitric oxide and PI-3 kinase activation that enhance SERCA2 activity. Neuregulin-1 was associated with less myocardial macrophage infiltration and cytokine expression reducing collagen deposition. Ghrelin, a 28 amino acid peptide, improves SERCA2a function by inducing PLB phosphorylation. Ghrelin also reduces cardiac fibrosis. In summary, Glucagon-like peptide-1, Relaxin-2, Neuregulin-1, and Ghrelin each modify calcium dynamics, collagen expression, and myocardial fibrosis through attenuation of deleterious signaling cascades, and induction of adaptive pathways, representing potential therapeutic targets for HFpEF.

A Valveless Pulsatile Pump for the Treatment of Heart Failure with Preserved Ejection Fraction: A Simulation Study

PURPOSE

Effective treatment of patients with terminal heart failure and preserved ejection fraction (HFpEF) is an unmet medical need. The aim of this study was to investigate a novel valveless pulsatile pump as a therapeutic option for the HFpEF population through comprehensive in silico investigations.

METHODS

The pump was simulated in a numerical model of the cardiovascular system of four HFpEF phenotypes and compared to a typical case of heart failure with reduced ejection fraction (HFrEF). The proposed pump, which was modeled as being directly connected to the left ventricle, features a single valveless inlet and outlet cannula and is driven in co-pulsation with the left ventricle. We collected hemodynamics for two different pump volumes (30 and 60 mL).

RESULTS

In all HFpEF conditions, the 30 mL pump improved the cardiac output by approximately 1 L/min, increased the mean arterial pressure by > 11% and lowered the mean left atrial pressure by > 30%. With the larger (60 mL) stroke volume, these hemodynamic improvements were more pronounced. In the HFrEF condition however, these effects were three times less in magnitude.

CONCLUSIONS

In this simulation study, the valveless pulsatile device improves hemodynamics in HFpEF patients by increasing the total stroke volume. The hemodynamic benefits are achieved with a small device volume comparable to implantable rotary blood pumps.

Cardiac metabolism - A promising therapeutic target for heart failure

Both heart failure with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF) are associated with high morbidity and mortality. Although many established pharmacological interventions exist for HFrEF, hospitalization and death rates remain high, and for those with HFpEF (approximately half of all heart failure patients), there are no effective therapies. Recently, the role of impaired cardiac energetic status in heart failure has gained increasing recognition with the identification of reduced capacity for both fatty acid and carbohydrate oxidation, impaired function of the electron transport chain, reduced capacity to transfer ATP to the cytosol, and inefficient utilization of the energy produced. These nodes in the genesis of cardiac energetic impairment provide potential therapeutic targets, and there is promising data from recent experimental and early-phase clinical studies evaluating modulators such as carnitine palmitoyltransferase 1 inhibitors, partial fatty acid oxidation inhibitors and mitochondrial-targeted antioxidants. Metabolic modulation may provide significant symptomatic and prognostic benefit for patients suffering from heart failure above and beyond guideline-directed therapy, but further clinical trials are needed.

Measures of Ventricular-Arterial Coupling and Incident Heart Failure With Preserved Ejection Fraction: A Matched Case-Control Analysis

BACKGROUND

Evidence continues to demonstrate increasing prevalence, cost, and mortality implications of heart failure with preserved ejection fraction (HFpEF), but clearly defined parameters that distinguish between control subjects and HFpEF have not been established.

OBJECTIVES

This study was designed to detect differences in markers associated with Ventricular-arterial coupling and HFpEF when comparing matched case and control groups.

METHODS

A study cohort of case (incident patients with HFpEF; n = 155) and matched control (patients with no prior heart failure; n = 155) groups was retrospectively identified. Matching criteria included race, sex, age, and date of echocardiography (within 1 year). Physiologic and echocardiographic markers were collected from previously acquired transthoracic echocardiograms. These echocardiographic images were reanalyzed, and measures of ventricular-arterial coupling were calculated. Using conditional logistic regression and controlling for covariates, models were fitted to detect differences in HFpEF markers between case and control subjects.

RESULTS

Statistically significant differences in markers that reflect ventricular elastance (Ees; P = .007) and left atrial diameter (LAdiam; P = .04) were detected when comparing the case and control groups. Conditional logistic regression analyses suggested a 40% higher odds of being in the case group with every 1-unit increase in Ees (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.10-1.79) and a 2.92 times higher odds of being in the case group for every 1 cm increase in LAdiam (OR 2.92, 95% CI 1.064-7.994).

CONCLUSIONS

Ees and LAdiam are easily measurable echocardiographic markers that may have a role in identifying and tracking the progression toward incident HFpEF without increasing cost or risk to the patient. Prospective studies are indicated to explore the use of Ees and LAdiam as predictors of impending HFpEF.

ω3-Polyunsaturated fatty acids for heart failure: Effects of dose on efficacy and novel signaling through free fatty acid receptor 4

Heart failure (HF) affects 5.7 million in the U.S., and despite well-established pharmacologic therapy, the 5-year mortality rate remains near 50%. Furthermore, the mortality rate for HF has not declined in years, highlighting the need for new therapeutic options. Omega-3 polyunsaturated fatty acids (ω3-PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are important regulators of cardiovascular health. However, questions of efficacy and mechanism of action have made the use of ω3-PUFAs in all cardiovascular disease (CVD) controversial. Here, we review recent studies in animal models of HF indicating that ω3-PUFAs, particularly EPA, are cardioprotective, with the results indicating a threshold for efficacy. We also examine clinical studies suggesting that ω3-PUFAs improve outcomes in patients with HF. Due to the relatively small number of clinical studies of ω3-PUFAs in HF, we discuss EPA concentration-dependency on outcomes in clinical trials of CVD to gain insight into the perceived questionable efficacy of ω3-PUFAs clinically, with the results again indicating a threshold for efficacy. Ultimately, we suggest that the main failing of ω3-PUFAs in clinical trials might be a failure to reach a therapeutically effective concentration. We also examine mechanistic studies suggesting that ω3-PUFAs signal through free fatty acid receptor 4 (Ffar4), a G-protein coupled receptor (GPR) for long-chain fatty acids (FA), thereby identifying an entirely novel mechanism of action for ω3-PUFA mediated cardioprotection. Finally, based on mechanistic animal studies suggesting that EPA prevents interstitial fibrosis and diastolic dysfunction, we speculate about a potential benefit for EPA-Ffar4 signaling in heart failure preserved with ejection fraction.

Non-Invasive Assessment of Pulmonary Vascular Resistance in Pulmonary Hypertension: Current Knowledge and Future Direction

Pulmonary Hypertension (PHT) is relatively common, dangerous and under-recognised. Pulmonary hypertension is not a diagnosis in itself; it is caused by a number of differing diseases each with different treatments and prognoses. Therefore, timely and accurate recognition of the underlying cause for PHT is essential for appropriate management. This is especially true for patients with Pulmonary Arterial Hypertension (PAH) in the current era of disease-specific drug therapy. Measurement of Pulmonary Vascular Resistance (PVR) helps separate pre-capillary from post-capillary PHT, and is measured with right heart catheterisation (RHC). Echocardiography has been used to derive a number of non-invasive surrogates for PVR, with varying accuracy. Ultimately, the goal of non-invasive assessment of PVR is to separate PHT due to left heart disease from PHT due to increased PVR, to help streamline investigation and subsequent treatment. In this review, we summarise the physiology and pathophysiology of pulmonary blood flow, the various causes of pulmonary hypertension, and non-invasive surrogates for PVR.

Concomitant coronary and renal revascularization improves left ventricular hypertrophy more than coronary stenting alone in patients with ischemic heart and renal disease

Percutaneous transluminal renal artery stenting (PTRAS) has been proved to have no more benefit than medication alone in treating atherosclerotic renal artery stenosis (ARAS). Whether PTRAS could improve left ventricular hypertrophy (LVH) and reduce adverse events when based on percutaneous coronary intervention (PCI) for patients with coronary artery disease (CAD) and ARAS is still unclear. A retrospective study was conducted, which explored the effect of concomitant PCI and PTRAS versus PCI alone for patients with CAD and ARAS complicated by heart failure with preserved ejection fraction (HFpEF). A total of 228 patients meeting inclusion criteria were divided into two groups: (1) the HFpEF-I group, with PCI and PTRAS; (2) the HFpEF-II group, with PCI alone. Both groups had a two-year follow-up. The left ventricular mass index (LVMI) and other clinical characteristics were compared between groups. During the follow-up period, a substantial decrease in systolic blood pressure (SBP) was observed in the HFpEF-I group, but not in the HFpEF-II group. There was marked decrease in LVMI in both groups, but the HFpEF-I group showed a greater decrease than the HFpEF-II group. Regression analysis demonstrated that PTRAS was significantly associated with LVMI reduction and fewer adverse events after adjusting for other factors. In HFpEF patients with both CAD and ARAS, concomitant PCI and PTRAS can improve LVH and decrease the incidence of adverse events more than PCI alone. This study highlights the beneficial effect of ARAS revascularization, as a new and more aggressive revascularization strategy for such high-risk patients.