Management of advanced heart failure: a review

INTRODUCTION

Heart failure (HF) has become a global pandemic. Despite recent developments in both medical and device treatments, HF incidences continues to increase. The current definition of HF restricts itself to stages at which clinical symptoms are apparent. In advanced heart failure (AdHF), it is universally accepted that all patients are refractory to traditional therapies. As the number of HF patients increase, so does the need for additional treatments, with an increased proportion of patients requiring advanced therapies. Areas covered: This review discusses extensive evidence for the effect of medical treatment on HF, although the data on the effect on AdHF is scare. Authors review the relevant literature for treating AdHF patients. Furthermore, mechanical circulatory devices (MCD) have emerged as an alternative to heart transplantation and have been shown to enhance quality of life and reduce mortality therefore authors also review the current literature on the different MCD and technologies. Expert commentary: More patients will need advanced therapies, as the access to heart transplantation is limited by the number of available donors. AdHF patients should be identified timely since the window of opportunities for advanced therapy is narrow as their morbidity is progressive and survival is often short.

Reassessing the Role of Surrogate End Points in Drug Development for Heart Failure

With few notable exceptions, drug development for heart failure (HF) has become progressively more challenging, and there remain no definitively proven therapies for patients with acute HF or HF with preserved ejection fraction. Inspection of temporal trends suggests an increasing rate of disagreement between early-phase and phase III trial end points. Preliminary results from phase II HF trials are frequently promising, but increasingly followed by disappointing phase III results. Given this potential disconnect, it is reasonable to carefully re-evaluate the purpose, design, and execution of phase II HF trials, with particular attention directed toward the surrogate end points commonly used by these studies. In this review, we offer a critical reappraisal of the role of phase II HF trials and surrogate end points, highlighting challenges in their use and interpretation, lessons learned from past experiences, and specific strengths and weaknesses of various surrogate outcomes. We conclude by proposing a series of approaches that should be considered for the goal of optimizing the efficiency of HF drug development. This review is based on discussions between scientists, clinical trialists, industry and government sponsors, and regulators that took place at the Cardiovascular Clinical Trialists Forum in Washington, DC, on December 2, 2016.

Agents with vasodilator properties in acute heart failure

Millions of patients worldwide are admitted for acute heart failure (AHF) each year and physicians caring for these patients are confronted with the short-term challenges of reducing symptoms while preventing end organ dysfunction without causing additional harm, and the intermediate-term challenges of improving clinical outcomes such as hospital readmission and survival. There are limited data demonstrating the efficacy of any currently available therapies for AHF to meet these goals. After diuretics, vasodilators are the most common intravenous therapy for AHF, but neither nitrates, nitroprusside, nor nesiritide have robust evidence supporting their ability to provide meaningful effects on clinical outcomes, except perhaps early symptom improvement. Recently, a number of novel agents with vasodilating properties have been developed for the treatment of AHF. These agents include serelaxin, natriuretic peptides (ularitide, cenderitide), β-arrestin-biased angiotensin II type 1 receptor ligands (TRV120027), nitroxyl donors (CXL-1020, CXL-1427), soluble guanylate cyclase modulators (cinaciguat, vericiguat), short-acting calcium channel blockers (clevidipine), and potassium channel activators (nicorandil). These development programmes range from the stage of early dose-finding studies (e.g. TRV120027, CXL-1427) to large, multicentre mortality trials (e.g. serelaxin, ularitide). There is an urgent need for agents with vasodilating properties that will improve both in-hospital and post-discharge clinical outcomes, and these novel approaches may provide opportunities to address this need.

Rationale and design of a multicentre, randomized, placebo-controlled trial of mirabegron, a Beta3-adrenergic receptor agonist on left ventricular mass and diastolic function in patients with structural heart disease Beta3-left ventricular hypertrophy (Beta3-LVH)

Aims

Progressive left ventricular (LV) remodelling with cardiac myocyte hypertrophy, myocardial fibrosis, and endothelial dysfunction plays a key role in the onset and progression of heart failure with preserved ejection fraction. The Beta3‐LVH trial will test the hypothesis that the β₃ adrenergic receptor agonist mirabegron will improve LV hypertrophy and diastolic function in patients with hypertensive structural heart disease at high risk for developing heart failure with preserved ejection fraction.

Methods and results

Beta3‐LVH is a randomized, placebo‐controlled, double‐blind, two‐armed, multicentre, European, parallel group study. A total of 296 patients will be randomly assigned to receive either mirabegron 50 mg daily or placebo over 12 months. The main inclusion criterion is the presence of LV hypertrophy, that is, increased LV mass index (LVMi) or increased wall thickening by echocardiography. The co‐primary endpoints are a change in LVMi by cardiac magnetic resonance imaging and a change in LV diastolic function (assessed by the E/e′ ratio). Secondary endpoints include mirabegron's effects on cardiac fibrosis, left atrial volume index, maximal exercise capacity, and laboratory markers. Two substudies will evaluate mirabegron's effect on endothelial function by pulse amplitude tonometry and brown fat activity by positron emission tomography using 17F‐fluorodeoxyglucose. Morbidity and mortality as well as safety aspects will also be assessed.

Conclusions

Beta3‐LVH is the first large‐scale clinical trial to evaluate the effects of mirabegron on LVMi and diastolic function in patients with LVH. Beta3‐LVH will provide important information about the clinical course of this condition and may have significant impact on treatment strategies and future trials in these patients.

Patient-reported outcomes in the SOluble guanylate Cyclase stimulatoR in heArT failurE patientS with PRESERVED ejection fraction (SOCRATES-PRESERVED) study

AIMS

Exploratory assessment of the potential benefits of the novel soluble guanylate cyclase stimulator vericiguat on health status in patients with heart failure (HF) with preserved ejection fraction.

METHODS AND RESULTS

The SOCRATES-PRESERVED trial randomized patients with chronic HF and ejection fraction ≥ 45% within 4 weeks of decompensation to 12 weeks of treatment with titrated doses of vericiguat (1.25, 2.5, 5, and 10 mg once daily) or placebo. Health status was assessed with the disease-specific Kansas City Cardiomyopathy Questionnaire (KCCQ) and the generic health-related quality of life measure EQ-5D. In total, 477 patients were randomized 12.9 ± 9.0 days after hospitalization or if requiring outpatient treatment with intravenous diuretics for HF. Baseline KCCQ clinical summary score (CSS), a combination of symptom and physical function domains, was 52.3 ± 20.4 in the 10 mg arm and 54.1 ± 23.0 in placebo, and EQ-5D US index score was 0.74 ± 0.2 and 0.73 ± 0.2, respectively. A larger proportion of patients treated with vericiguat in the 10 mg arm, compared with placebo, achieved clinically meaningful improvements in KCCQ-CSS (82.0% vs. 59.0%, number needed to treat = 4.35, P = 0.0052). Important domains of the KCCQ as well as EQ-5D scores demonstrated a dose-dependent relationship with vericiguat. In the 10 mg arm, the mean physical limitations domain increased by +17.2 ± 19.1 at 12 weeks, compared with +4.5 ± 21.6 in placebo (P = 0.0009). The EQ-5D US index score increased by +0.064 ± 0.167 in the 10 mg arm, compared with a decrease of -0.009 ± 0.195 in placebo (P = 0.0461). Improvements in KCCQ and EQ-5D scores paralleled physician-assessed NYHA class and clinical congestion.

CONCLUSION

Vericiguat, in exploratory hypothesis-generating analyses, was associated with clinically important improvements in patients' health status, as assessed by the KCCQ and EQ-5D. Further studies should be conducted to test the hypothesis that vericiguat improves physical functioning and health-related quality of life in patients with HF with preserved ejection fraction.

Nitric oxide-sensitive guanylyl cyclase stimulation improves experimental heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) can arise from cardiac and vascular remodeling processes following long-lasting hypertension. Efficacy of common HF therapeutics is unsatisfactory in HFpEF. Evidence suggests that stimulators of the nitric oxide-sensitive soluble guanylyl cyclase (NOsGC) could be of use here. We aimed to characterize the complex cardiovascular effects of NOsGC stimulation using NO-independent stimulator BAY 41-8543 in a double-transgenic rat (dTGR) model of HFpEF. We show a drastically improved survival rate of treated dTGR. We observed less cardiac fibrosis, macrophage infiltration, and gap junction remodeling in treated dTGR. Microarray analysis revealed that treatment of dTGR corrected the dysregulateion of cardiac genes associated with fibrosis, inflammation, apoptosis, oxidative stress, and ion channel function toward an expression profile similar to healthy controls. Treatment reduced systemic blood pressure levels and improved endothelium-dependent vasorelaxation of resistance vessels. Further comprehensive in vivo phenotyping showed an improved diastolic cardiac function, improved hemodynamics, and less susceptibility to ventricular arrhythmias. Short-term BAY 41-8543 application in isolated untreated transgenic hearts with structural remodeling significantly reduced the occurrence of ventricular arrhythmias, suggesting a direct nongenomic role of NOsGC stimulation on excitation. Thus, NOsGC stimulation was highly effective in improving several HFpEF facets in this animal model, underscoring its potential value for patients.

Nitric oxide signalling in cardiovascular health and disease

Nitric oxide (NO) signalling has pleiotropic roles in biology and a crucial function in cardiovascular homeostasis. Tremendous knowledge has been accumulated on the mechanisms of the nitric oxide synthase (NOS)-NO pathway, but how this highly reactive, free radical gas signals to specific targets for precise regulation of cardiovascular function remains the focus of much intense research. In this Review, we summarize the updated paradigms on NOS regulation, NO interaction with reactive oxidant species in specific subcellular compartments, and downstream effects of NO in target cardiovascular tissues, while emphasizing the latest developments of molecular tools and biomarkers to modulate and monitor NO production and bioavailability.

Treatment of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a growing epidemiologic problem affecting more than half of the patients with heart failure (HF). HFpEF has a significant morbidity and mortality and so far no treatment has been clearly demonstrated to improve the outcomes in HFpEF, in contrast to the efficacy of treatment in heart failure with reduced ejection fraction (HFrEF).The failure of proven beneficial drugs in HFrEF to influence the outcome of patients with HFpEF could be related to the heterogeneity of the disease, its various phenotypes and multifactorial pathophysiology, incompletely elucidated yet. The diagnosis of HFpEF could be demanding or even inaccurate. Moreover, the therapeutic strategies were influenced by different cut-offs used to define preserved ejection fraction (EF). From this perspective, the current guidelines have classified HFpEF by an EF ≥ 50%, together with a distinct entity, heart failure with mid-range ejection fraction (HFmrEF), defined by an EF ranging from 41-49%.New therapies have been developed to interfere with the mediator pathways of HFpEF at the cellular and molecular level, including mineralocorticoid receptor antagonists, soluble guanylate cyclase stimulators, or angiotensin receptor-neprilysin inhibitors. A number of antidiabetic drugs, such as sodium/glucose cotransporter 2 inhibitors and dipeptidyl peptidase-4 inhibitors are promising options, being under research in large clinical trials. Until the results of ongoing trials shed light on these therapies, guidelines recommend empirical treatment for established HFpEF, and emphasize the crucial role of addressing cardiovascular comorbidities leading to HFpEF, in particular arterial hypertension.

Novel sGC Stimulators and sGC Activators for the Treatment of Heart Failure

The burden of heart failure (HF) increases worldwide with an aging population, and there is a high unmet medical need in both, heart failure with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). The nitric oxide (NO) pathway is a key regulator in the cardiovascular system and modulates vascular tone and myocardial performance. Disruption of the NO-cyclic guanosine monophosphate (cGMP) signaling axis and impaired cGMP formation by endothelial dysfunction could lead to vasotone dysregulation, vascular and ventricular stiffening, fibrosis, and hypertrophy resulting in a decline of heart as well as kidney function. Therefore, the NO-cGMP pathway is a treatment target in heart failure. Exogenous NO donors such as nitrates have long been used for treatment of cardiovascular diseases but turned out to be limited by increased oxidative stress and tolerance. More recently, novel classes of drugs were discovered which enhance cGMP production by targeting the NO receptor soluble guanylate cyclase (sGC). These compounds, the so-called sGC stimulators and sGC activators, are able to increase the enzymatic activity of sGC to generate cGMP independently of NO and have been developed to target this important signaling cascade in the cardiovascular system.This review will focus on the role of sGC in cardiovascular (CV) physiology and disease and the pharmacological potential of sGC stimulators and sGC activators therein. Preclinical data will be reviewed and summarized, and available clinical data with riociguat and vericiguat, novel direct sGC stimulators, will be presented. Vericiguat is currently being studied in a Phase III clinical program for the treatment of heart failure with reduced ejection fraction (HFrEF).

Vericiguat in patients with worsening chronic heart failure and preserved ejection fraction: results of the SOluble guanylate Cyclase stimulatoR in heArT failurE patientS with PRESERVED EF (SOCRATES-PRESERVED) study

Aims

To determine tolerability and the optimal dose regimen of the soluble guanylate cyclase stimulator vericiguat in patients with chronic heart failure and preserved ejection fraction (HFpEF).

Methods and results

SOCRATES-PRESERVED was a prospective, randomized, placebo-controlled double-blind, Phase 2b dose-finding study in patients with HFpEF (ejection fraction ≥ 45%). Patients received vericiguat once daily at 1.25 or 2.5 mg fixed doses, or 5 or 10 mg titrated from a 2.5 mg starting dose, or placebo for 12 weeks. The two primary endpoints were change from baseline in log-transformed N-terminal pro-B-type natriuretic peptide (NT-ProBNP) and left atrial volume (LAV) at 12 weeks. Patients (N = 477; 48% women; mean age 73 ± 10 years; baseline atrial fibrillation 40%) were randomized within 4 weeks of HF hospitalization (75%) or outpatient treatment with intravenous diuretics for HF (25%) to vericiguat (n = 384) or placebo (n = 93). In the pooled three highest dose arms change in logNT-proBNP (vericiguat: +0.038 ± 0.782 log(pg/mL), n = 195; placebo: -0.098 ± 0.778 log(pg/mL), n = 73; one-sided P = 0.8991, two-sided P = 0.2017), and change in LAV [vericiguat: -1.7 ± 12.8 mL (n = 194); placebo:  -3.4 ± 12.7 mL (n = 67), one-sided P = 0.8156, two-sided P = 0.3688] were not different from placebo. Vericiguat was well tolerated (adverse events: vericiguat 10 mg arm, 69.8%; placebo, 73.1%), with low discontinuation rates in all groups, and no changes in blood pressure at 10 mg compared with placebo. The pre-specified exploratory endpoint of Kansas City Cardiomyopathy Questionnaire Clinical Summary Score improved in the vericiguat 10 mg arm by mean 19.3 ± 16.3 points [median 19.8 (interquartile range 10.4-30.7)] from baseline (mean difference from placebo 9.2 points).

Conclusion

Vericiguat was well tolerated, did not change NT-proBNP and LAV at 12 weeks compared with placebo but was associated with improvements in quality of life in patients with HFpEF. Given the encouraging results on quality of life, the effects of vericiguat in patients with HFpEF warrant further study, possibly with higher doses, longer follow-up and additional endpoints.

Innovative Clinical Trial Designs for Precision Medicine in Heart Failure with Preserved Ejection Fraction

A major challenge in the care of patients with heart failure and preserved ejection fraction (HFpEF) is the lack of proven therapies due to disappointing results from randomized controlled trials (RCTs). The heterogeneity of the HFpEF syndrome and the use of conventional RCT designs are possible reasons underlying the failure of these trials. There are several factors-including the widespread adoption of electronic health records, decreasing costs of obtaining high-dimensional data, and the availability of a wide variety of potential therapeutics-that have evolved to enable more innovative clinical trial designs in HFpEF. Here, we review the current landscape of HFpEF RCTs and present several innovative RCT designs that could be implemented in HFpEF, including enrichment trials, adaptive trials, umbrella trials, basket trials, and machine learning-based trials (including examples for each). Our hope is that the description of the aforementioned innovative trial designs will stimulate new approaches to clinical trials in HFpEF.

Transcatheter Interatrial Shunt Device for the Treatment of Heart Failure: Rationale and Design of the Randomized Trial to REDUCE Elevated Left Atrial Pressure in Heart Failure (REDUCE LAP-HF I)

Heart failure with preserved ejection fraction (HFpEF), a major public health problem with high morbidity and mortality rates, remains difficult to manage because of a lack of effective treatment options. Although HFpEF is a heterogeneous clinical syndrome, elevated left atrial pressure-either at rest or with exertion-is a common factor among all forms of HFpEF and one of the primary reasons for dyspnea and exercise intolerance in these patients. On the basis of clinical experience with congenital interatrial shunts in mitral stenosis, it has been hypothesized that the creation of a left-to-right interatrial shunt to decompress the left atrium (without compromising left ventricular filling or forward cardiac output) is a rational, nonpharmacological strategy for alleviating symptoms in patients with HFpEF. A novel transcatheter interatrial shunt device has been developed and evaluated in patients with HFpEF in single-arm, nonblinded clinical trials. These studies have demonstrated the safety and potential efficacy of the device. However, a randomized, placebo-controlled evaluation of the device is required to further evaluate its safety and efficacy in patients with HFpEF. In this article, we give the rationale for a therapeutic transcatheter interatrial shunt device in HFpEF, and we describe the design of REDUCE Elevated Left Atrial Pressure in Heart Failure (REDUCE LAP-HF I), the first randomized controlled trial of a device-based therapy to reduce left atrial pressure in HFpEF.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02600234.

Targeting Endothelial Function to Treat Heart Failure with Preserved Ejection Fraction: The Promise of Exercise Training

Although the burden of heart failure with preserved ejection fraction (HFpEF) is increasing, there is no therapy available that improves prognosis. Clinical trials using beta blockers and angiotensin converting enzyme inhibitors, cardiac-targeting drugs that reduce mortality in heart failure with reduced ejection fraction (HFrEF), have had disappointing results in HFpEF patients. A new “whole-systems” approach has been proposed for designing future HFpEF therapies, moving focus from the cardiomyocyte to the endothelium. Indeed, dysfunction of endothelial cells throughout the entire cardiovascular system is suggested as a central mechanism in HFpEF pathophysiology. The objective of this review is to provide an overview of current knowledge regarding endothelial dysfunction in HFpEF. We discuss the molecular and cellular mechanisms leading to endothelial dysfunction and the extent, presence, and prognostic importance of clinical endothelial dysfunction in different vascular beds. We also consider implications towards exercise training, a promising therapy targeting system-wide endothelial dysfunction in HFpEF.

Discovery of the Soluble Guanylate Cyclase Stimulator Vericiguat (BAY 1021189) for the Treatment of Chronic Heart Failure

The first-in-class soluble guanylate cyclase (sGC) stimulator riociguat was recently introduced as a novel treatment option for pulmonary hypertension. Despite its outstanding pharmacological profile, application of riociguat in other cardiovascular indications is limited by its short half-life, necessitating a three times daily dosing regimen. In our efforts to further optimize the compound class, we have uncovered interesting structure-activity relationships and were able to decrease oxidative metabolism significantly. These studies resulting in the discovery of once daily sGC stimulator vericiguat (compound 24, BAY 1021189), currently in phase 3 trials for chronic heart failure, are now reported.

New developments in the pharmacotherapeutic management of heart failure in elderly patients: concerns and considerations

INTRODUCTION

Heart failure (HF) remains a major public health problem worldwide, affecting approximately 23 million patients, and is predominantly a disease of the elderly population. Elderly patients mostly suffer from HF with preserved ejection fraction (HFpEF), which often presents with multiple co-morbidities and they require multiple medical treatments. This, together with the heterogeneous phenotype of HFpEF, makes it a difficult syndrome to diagnose and treat. Areas covered: Although HF is most abundant in the elderly, this group is still underrepresented in clinical trials, which results in the lack of evidence-based medical regimens. The current review has focused on new potential therapies for this poorly studied population. The focus will be on several classes of drugs currently recommended or might be expected soon. These will include sacubitril/valsartan (former LCZ696), Omecamtiv mecarbil, Vericiguat, Ivabradine, mineralocorticoid receptor antagonists (MRAs) and potassium binders. Expert opinion: We discuss promising new treatments and hypothesize that personalized approaches will be needed to treat elderly patients optimally. Medical doctors should not only focus on HF therapy, but comorbidities and polypharmacy should also influence therapeutic decision making. Furthermore, the importance of quality of life as a management endpoint should not be underestimated in the frail elderly.

Silent disease progression in clinically stable heart failure

Heart failure with reduced ejection fraction (HFrEF) is a progressive disorder whereby cardiac structure and function continue to deteriorate, often despite the absence of clinically apparent signs and symptoms of a worsening disease state. This silent yet progressive nature of HFrEF can contribute to the increased risk of death-even in patients who are 'clinically stable', or who are asymptomatic or only mildly symptomatic-because it often goes undetected and/or undertreated. Current therapies are aimed at improving clinical symptoms, and several agents more directly target the underlying causes of disease; however, new therapies are needed that can more fully address factors responsible for underlying progressive cardiac dysfunction. In this review, mechanisms that drive HFrEF, including ongoing cardiomyocyte loss, mitochondrial abnormalities, impaired calcium cycling, elevated LV wall stress, reactive interstitial fibrosis, and cardiomyocyte hypertrophy, are discussed. Additionally, limitations of current HF therapies are reviewed, with a focus on how these therapies are designed to counteract the deleterious effects of compensatory neurohumoral activation but do not fully prevent disease progression. Finally, new investigational therapies that may improve the underlying molecular, cellular, and structural abnormalities associated with HF progression are reviewed.

Advances in the pharmacotherapy of chronic heart failure with preserved ejection fraction: an ideal opportunity for precision medicine

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF), which comprises approximately 50% of all heart failure patients, is a challenging and complex clinical syndrome that is often thought to lack effective treatments. Areas covered: Despite the common mantra that HFpEF has no effective treatments, closer inspection of HFpEF clinical trials reveals that several of the drugs tested are associated with benefits in exercise capacity and quality of life, and reduction in heart failure hospitalization. Here we review major randomized controlled trials in HFpEF, focusing on renin-angiotensin-aldosterone system antagonists, organic nitrates, digoxin, beta-blockers, and phosphodiesterase-5 inhibitors. In addition, we review several classes of drugs currently in development for HFpEF such as neprilysin inhibitors, inorganic nitrates (nitrites), and soluble guanylate cyclase stimulators. Expert opinion: HFpEF should not be viewed as lacking effective treatments. While there have been no breakthrough clinical trials showing a reduction in mortality, several existing medications are likely to benefit specific subgroups of HFpEF patients. HFpEF is now well known to be a heterogeneous syndrome; thus, the clinical management of HFpEF patients and future HFpEF clinical trials will both likely require a nuanced, phenotype-specific approach instead of a one-size-fits-all tactic. Drug development for HFpEF therefore represents an exciting opportunity for personalized medicine.

New pharmacological approaches in heart failure therapy: developments and possibilities

There have been few major breakthroughs in heart failure (HF) drug therapies in recent years yet HF morbidity and mortality remain high, and there is a clear need for further research. Several newer agents that appear promising in Phase I and II trials do not progress to show clinical benefit in later trials. Part of the failure to find new therapies may lie in flawed trial design compounded by the need for ever-increasing patient numbers in order to prove outcome benefit. We summarize some of the most recent and promising medical therapies for HF.

The future of pleiotropic therapy in heart failure. Lessons from the benefits of exercise training on endothelial function

A novel generation of drugs is introduced in the treatment of heart failure (HF). These drugs, including phosphodiesterase-5 inhibitors, guanylate cyclase stimulators and activators, share the feature that their action is either endothelial-mediated or substitutes for endothelial pathways, in particular the nitric oxide-cyclic guanosine monophosphate pathway, thereby influencing homeostatic balances in virtually each organ system in a pleiotropic fashion. Unfortunately, recent clinical trials with some of these drugs have shown disappointing results, at least in the setting of HF with a preserved ejection fraction. This suggests that their clinical use may require approaches that diverge from traditional pharmacological approaches, the latter often titrated on the effects of drugs on haemodynamic parameters or single biomarkers. In this paper we preconize that HF drugs with an endothelial profile should be applied conform to principles of endothelial physiology and systems pharmacology. This type of drug therapy should be viewed as a systems physio-pharmacological intervention and its clinical use accustomed to systems pharmacological principles, comparable to the systemic endothelial-mediated benefits induced by exercise training in HF. We will review the actions of these drugs and define criteria to which trials with these drugs should comply in order to increase chances of success.

Targeting Obesity and Diabetes to Treat Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a major unmet medical need that is characterized by the presence of multiple cardiovascular and non-cardiovascular comorbidities. Foremost among these comorbidities are obesity and diabetes, which are not only risk factors for the development of HFpEF, but worsen symptoms and outcome. Coronary microvascular inflammation with endothelial dysfunction is a common denominator among HFpEF, obesity, and diabetes that likely explains at least in part the etiology of HFpEF and its synergistic relationship with obesity and diabetes. Thus, pharmacological strategies to supplement nitric oxide and subsequent cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling may have therapeutic promise. Other potential approaches include exercise and lifestyle modifications, as well as targeting endothelial cell mineralocorticoid receptors, non-coding RNAs, sodium glucose transporter 2 inhibitors, and enhancers of natriuretic peptide protective NO-independent cGMP-initiated and alternative signaling, such as LCZ696 and phosphodiesterase-9 inhibitors. Additionally, understanding the role of adipokines in HFpEF may lead to new treatments. Identifying novel drug targets based on the shared underlying microvascular disease process may improve the quality of life and lifespan of those afflicted with both HFpEF and obesity or diabetes, or even prevent its occurrence.

Atrial Fibrillation in Heart Failure With Preserved Ejection Fraction: Association With Exercise Capacity, Left Ventricular Filling Pressures, Natriuretic Peptides, and Left Atrial Volume

OBJECTIVES

This study sought to study the association of atrial fibrillation (AF) with exercise capacity, left ventricular filling pressure, natriuretic peptides, and left atrial size in heart failure with preserved ejection fraction (HFpEF).

BACKGROUND

The diagnosis of HFpEF in patients with AF remains a challenge because both contribute to impaired exercise capacity, and increased natriuretic peptides and left atrial volume.

METHODS

We studied 94 patients with symptomatic heart failure and left ventricular ejection fractions ≥45% using treadmill cardiopulmonary exercise testing and right- and/or left-sided cardiac catheterization with simultaneous echocardiography.

RESULTS

During catheterization, 62 patients were in sinus rhythm, and 32 patients had AF. There were no significant differences in age, sex, body size, comorbidities, or medications between groups; however, patients with AF had lower peak oxygen consumption (VO₂) compared with those with sinus rhythm (10.8 ± 3.1 ml/min/kg vs. 13.5 ± 3.8 ml/min/kg; p = 0.002). Median (25th to 75th percentile) N-terminal pro-B-type natriuretic peptide (NT-proBNP) was higher in AF versus sinus rhythm (1,689; 851 to 2,637 pg/ml vs. 490; 272 to 1,019 pg/ml; p < 0.0001). Left atrial volume index (LAVI) was higher in AF than sinus rhythm (57.8 ± 17.0 ml/m² vs. 42.5 ± 15.1 ml/m²; p = 0.001). Invasive hemodynamics showed higher mean pulmonary capillary wedge pressure (PCWP) (19.9 ± 3.7 vs. 15.2 ± 6.8) in AF versus sinus rhythm (all p < 0.001), with a trend toward higher left ventricular end-diastolic pressure (17.7 ± 3.0 mm Hg vs. 15.7 ± 6.9 mm Hg; p = 0.06). After adjusting for clinical covariates and mean PCWP, AF remained associated with reduced peak VO₂ increased log NT-proBNP, and enlarged LAVI (all p ≤0.005).

CONCLUSIONS

AF is independently associated with greater exertional intolerance, natriuretic peptide elevation, and left atrial remodeling in HFpEF. These data support the application of different thresholds of NT-proBNP and LAVI for the diagnosis of HFpEF in the presence of AF versus the absence of AF.

Evolving Concepts of Pulmonary Hypertension Secondary to Left Heart Disease

Pulmonary hypertension associated with left heart disease is the most common form of pulmonary hypertension. Although its pathophysiology remains incompletely understood, it is now well recognized that the presence of pulmonary hypertension is associated with a worse prognosis. Right ventricular failure has independent and additive prognostic value over pulmonary hypertension for adverse outcomes in left heart disease. Recently, several new terminologies have been introduced to better define and characterize the nature and severity of pulmonary hypertension. Several new treatment options including the use of pulmonary arterial hypertension specific therapies are being considered, but there is lack of evidence. Here, we review the recent advances in this field and summarize the diagnostic and therapeutic modalities of use in the management of pulmonary hypertension associated with left heart disease.

Heart failure 2016: still more questions than answers

Heart failure has reached epidemic proportions given the ageing of populations and is associated with high mortality and re-hospitalization rates. This article reviews and summarizes recent advances in the diagnosis, assessment and treatment of the patients with heart failure. Data are discussed based also on the most recent guidelines indications. Open issues and unmet needs are highlighted.

Evaluation of the pharmacoDYNAMIC effects of riociguat in subjects with pulmonary hypertension and heart failure with preserved ejection fraction : Study protocol for a randomized controlled trial

Background

The presence of pulmonary hypertension (PH) severely aggravates the clinical course of heart failure with preserved ejection fraction (HFPEF) resulting in substantial morbidity and mortality. So far, neither established heart failure therapies nor pulmonary vasodilators have proven to be effective for this condition. Riociguat (Adempas®, BAY 63-2521), a stimulator of soluble guanylate cyclase, is a novel pulmonary and systemic vasodilator that has been approved for the treatment of precapillary forms of PH. With regard to postcapillary PH, the DILATE-1 study was a multicenter, double-blind, randomized, placebo-controlled single-dose study in subjects with PH associated with HFPEF. Although there was no significant change in the primary outcome measure, peak decrease in mean pulmonary artery pressure with riociguat versus placebo, riociguat significantly increased stroke volume without changing heart rate, pulmonary artery wedge pressure, transpulmonary pressure gradient or pulmonary vascular resistance. The present study is designed to test the efficacy of long-term treatment with riociguat in patients with PH associated with HFPEF.

Methods/study design

The DYNAMIC study is a randomized, double-blind, placebo-controlled, parallel-group, multicenter clinical phase IIb trial evaluating the efficacy, safety and kinetics of riociguat in PH-HFPEF patients. The drug will be given over 26 weeks to evaluate the effects of riociguat versus placebo. The primary efficacy variable will be the change from baseline in cardiac output at rest, measured by right heart catheter after 26 weeks of study drug treatment. Additional efficacy variables will be changes from baseline in further hemodynamic parameters, changes in left and right atrial area, right ventricular volume, as well as right ventricular ejection fraction measured by cardiac magnetic resonance imaging, and changes from baseline in World Health Organization (WHO) class and N‑terminal prohormone B‑type natriuretic peptide (NT-proBNP).

The trial was registered on 25 August 2014 (EudraCT Number: 2014-003055-60; www.clinicaltrialsregister.eu).

Heart failure-potential new targets for therapy

INTRODUCTION/BACKGROUND

Heart failure is a major cause of cardiovascular morbidity and mortality. This review covers current heart failure treatment guidelines, emerging therapies that are undergoing clinical trial, and potential new therapeutic targets arising from basic science advances.

SOURCES OF DATA

A non-systematic search of MEDLINE was carried out. International guidelines and relevant reviews were searched for additional articles.

AREAS OF AGREEMENT

Angiotensin-converting enzyme inhibitors and beta-blockers are first line treatments for chronic heart failure with reduced left ventricular function.

AREAS OF CONTROVERSY

Treatment strategies to improve mortality in heart failure with preserved left ventricular function are unclear.

GROWING POINTS

Many novel therapies are being tested for clinical efficacy in heart failure, including those that target natriuretic peptides and myosin activators. A large number of completely novel targets are also emerging from laboratory-based research. Better understanding of pathophysiological mechanisms driving heart failure in different settings (e.g. hypertension, post-myocardial infarction, metabolic dysfunction) may allow for targeted therapies.

AREAS TIMELY FOR DEVELOPING RESEARCH

Therapeutic targets directed towards modifying the extracellular environment, angiogenesis, cell viability, contractile function and microRNA-based therapies.

Novel Therapies for Heart Failure - Where Do They Stand?

Despite advances in therapy, patients with heart failure (HF) continue to experience unacceptably high rates of hospitalization and death, as well as poor quality of life. As a consequence, there is an urgent need for new treatments that can improve the clinical course of the growing worldwide population of HF patients. Serelaxin and ularatide, both based on naturally occurring peptides, have potent vasodilatory as well as other effects on the heart and kidneys. For both agents, phase 3 studies that are designed to determine whether they improve outcomes in patients with acute HF have completed enrollment. TRV027, a biased ligand for the type 1 angiotensin receptor with effects that extend beyond traditional angiotensin-receptor blockers is also being studied in the acute HF population. Omecamtiv mecarbil, an inotropic agent that improves myocardial contractility by a novel mechanism, and vericiguat, a drug that stimulates soluble guanylate cyclase, are both being developed to treat patients with chronic HF. Finally, despite the negative results of the CUPID study, gene transfer therapy continues to be explored as a means of improving the function of the failing heart. The basis for the use of these drugs and their current status in clinical trials are discussed. (Circ J 2016; 80: 1882-1891).

Guanylate cyclase stimulators for pulmonary hypertension

BACKGROUND

Pulmonary hypertension is a condition of complex aetiology that culminates in right heart failure and early death. Soluble guanylate cyclase (sGC) stimulators are a promising class of agents that have recently gained approval for use.

OBJECTIVES

To evaluate the efficacy of sGC stimulators in pulmonary hypertension.

SEARCH METHODS

We searched CENTRAL (Cochrane Central Register of Controlled Trials), MEDLINE, EMBASE and the reference lists of articles. Searches are current as of 12 February 2016.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) involving participants with pulmonary hypertension of all ages, severities and durations of treatment.

DATA COLLECTION AND ANALYSIS

AW, MS and RW independently selected studies, assessed evidence quality and extracted data. This process was overseen by RT and SG. All included studies were sponsored by the drug manufacturer.

MAIN RESULTS

Five trials involving 962 participants are included in this review. All trials were of relatively short duration (< 16 weeks). Due to the heterogenous aetiology of pulmonary hypertension in participants, results are best considered according to each pulmonary hypertension subtype.Pooled analysis shows a mean difference (MD) increase in six-minute walking distance (6MWD) of 30.13 metres (95% CI 5.29 to 54.96; participants = 659; studies = 3). On subgroup analysis, for pulmonary arterial hypertension (PAH) there was no effect noted (6MWD; MD 11.91 metres, 95% CI -44.92 to 68.75; participants = 398; studies = 2), and in chronic thromboembolic pulmonary hypertension (CTEPH) sGC stimulators improved 6MWD by an MD of 45 metres (95% CI 23.87 to 66.13; participants = 261; studies = 1). Data for left heart disease-associated PH was not available for pooling. Importantly, when participants receiving phosphodiesterase inhibitors were excluded, sGC stimulators increased 6MWD by a MD of 36 metres in PAH. The second primary outcome, mortality, showed no change on pooled analysis against placebo (Peto odds ratio (OR) 0.57, 95% CI 0.18 to 1.80).Pooled secondary outcomes include an increase in World Health Organization (WHO) functional class (OR 1.53, 95% CI 0.87 to 2.72; participants = 858; studies = 4), no effect on clinical worsening (OR 0.45, 95% CI 0.17 to 1.14; participants = 842; studies = 3), and a reduction in mean pulmonary artery pressure (MD -2.77 mmHg, 95% CI -4.96 to -0.58; participants = 744; studies = 5). There was no significant difference in serious adverse events on pooled analysis (OR 1.12, 95% CI 0.66 to 1.90; participants = 818; studies = 5) or when analysed at PAH (MD -3.50, 95% CI -5.54 to -1.46; participants = 344; studies = 1), left heart disease associated subgroups (OR 1.56, 95% CI 0.78 to 3.13; participants = 159; studies = 2) or CTEPH subgroups (OR 1.29, 95% CI 0.65 to 2.56; participants = 261; studies = 1).It is important to consider the results for PAH in the context of a person who is not also receiving a phosphodiesterase-V inhibitor, a contra-indication to sGC stimulator use. It should also be noted that CTEPH results are applicable to inoperable or recurrent CTEPH only.Evidence was rated according to the GRADE scoring system. One outcome was considered high quality, two were moderate, and eight were of low or very low quality, meaning that for many of the outcomes the true effect could differ substantially from our estimate. There were only minor concerns regarding the risk of bias in these trials, all being RCTs largely following the original protocol. Most trials employed an intention-to-treat analysis.

AUTHORS' CONCLUSIONS

sGC stimulators improve pulmonary artery pressures in people with PAH (who are treatment naive or receiving a prostanoid or endothelin antagonist) or those with recurrent or inoperable CTEPH. In these settings this can be achieved without notable complication. However, sGC stimulators should not be taken by people also receiving phosphodiestase-V inhibitors or nitrates due to the risks of hypotension, and there is currently no evidence supporting their use in pulmonary hypertension associated with left heart disease. There is no evidence supporting their use in children. These conclusions are based on data with limitations, including unavailable data from two of the trials.

Pharmacology of heart failure: From basic science to novel therapies

Chronic heart failure is one of the leading causes for hospitalization in the United States and Europe, and is accompanied by high mortality. Current pharmacological therapy of chronic heart failure with reduced ejection fraction is largely based on compounds that inhibit the detrimental action of the adrenergic and the renin-angiotensin-aldosterone systems on the heart. More than one decade after spironolactone, two novel therapeutic principles have been added to the very recently released guidelines on heart failure therapy: the HCN-channel inhibitor ivabradine and the combined angiotensin and neprilysin inhibitor valsartan/sacubitril. New compounds that are in phase II or III clinical evaluation include novel non-steroidal mineralocorticoid receptor antagonists, guanylate cyclase activators or myosine activators. A variety of novel candidate targets have been identified and the availability of gene transfer has just begun to accelerate translation from basic science to clinical application. This review provides an overview of current pharmacology and pharmacotherapy in chronic heart failure at three stages: the updated clinical guidelines of the American Heart Association and the European Society of Cardiology, new drugs which are in clinical development, and finally innovative drug targets and their mechanisms in heart failure which are emerging from preclinical studies will be discussed.

Heart Failure: Diagnosis, Management and Utilization

Despite the advancement in medicine, management of heart failure (HF), which usually presents as a disease syndrome, has been a challenge to healthcare providers. This is reflected by the relatively higher rate of readmissions along with increased mortality and morbidity associated with HF. In this review article, we first provide a general overview of types of HF pathogenesis and diagnostic features of HF including the crucial role of exercise in determining the severity of heart failure, the efficacy of therapeutic strategies and the morbidity/mortality of HF. We then discuss the quality control measures to prevent the growing readmission rates for HF. We also attempt to elucidate published and ongoing clinical trials for HF in an effort to evaluate the standard and novel therapeutic approaches, including stem cell and gene therapies, to reduce the morbidity and mortality. Finally, we discuss the appropriate utilization/documentation and medical coding based on the severity of the HF alone and with minor and major co-morbidities. We consider that this review provides an extensive overview of the HF in terms of disease pathophysiology, management and documentation for the general readers, as well as for the clinicians/physicians/hospitalists.

After TOPCAT: What to do now in Heart Failure with Preserved Ejection Fraction

Although patients with heart failure and preserved ejection fraction (HF-PEF) represent nearly half of the population with chronic heart failure, few evidence-based medical therapies are available. The neutral overall results of the TOPCAT trial of spironolactone in HF-PEF leave clinicians who treat heart failure with an ongoing clinical dilemma. In this review, we outline an approach to the clinical management of the patient with HF-PEF synthesizing data from available clinical trials and expert consensus.

Myocardial reverse remodeling: how far can we rewind?

Heart failure (HF) is a systemic disease that can be divided into HF with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). HFpEF accounts for over 50% of all HF patients and is typically associated with high prevalence of several comorbidities, including hypertension, diabetes mellitus, pulmonary hypertension, obesity, and atrial fibrillation. Myocardial remodeling occurs both in HFrEF and HFpEF and it involves changes in cardiac structure, myocardial composition, and myocyte deformation and multiple biochemical and molecular alterations that impact heart function and its reserve capacity. Understanding the features of myocardial remodeling has become a major objective for limiting or reversing its progression, the latter known as reverse remodeling (RR). Research on HFrEF RR process is broader and has delivered effective therapeutic strategies, which have been employed for some decades. However, the RR process in HFpEF is less clear partly due to the lack of information on HFpEF pathophysiology and to the long list of failed standard HF therapeutics strategies in these patient's outcomes. Nevertheless, new proteins, protein-protein interactions, and signaling pathways are being explored as potential new targets for HFpEF remodeling and RR. Here, we review recent translational and clinical research in HFpEF myocardial remodeling to provide an overview on the most important features of RR, comparing HFpEF with HFrEF conditions.

Is enhancing cGMP-PKG signalling a promising therapeutic target for heart failure with preserved ejection fraction?

Heart failure with preserved ejection fraction, i.e. HFpEF, is highly prevalent in ageing populations, accounting for more than 50 % of all cases of heart failure in Western societies, and is closely associated with comorbidities such as obesity, diabetes and arterial hypertension. However, all large multicentre trials of potential HFpEF treatments conducted to date have failed to produce positive outcomes. These disappointing results suggest that a 'one size fits all' strategy may be ill-suited to HFpEF and support the use of tailored, personalised therapeutic approaches with specific treatments designed for specific comorbidity-related HFpEF phenotypes. The accumulation of a multitude of cardiovascular comorbidities over time leads to increased systemic inflammation, oxidative stress and coronary microvascular endothelial inflammation, eventually resulting in degradation of cyclic guanosine monophosphate (cGMP) via multiple pathways, thereby reducing protein kinase G (PKG) activity. The importance of cGMP-PKG pathway modulation is supported by growing evidence that suggests that this pathway may be a promising therapeutic target, evidence that is mainly based on its role in the phosphorylation of the giant cytoskeletal protein titin. This review will focus on the preclinical and early clinical evidence in the field of cGMP-enhancing therapies and PKG activation.

Advances in the pathophysiology and treatment of heart failure with preserved ejection fraction

PURPOSE OF REVIEW

With the failure of multiple trials to identify a successful therapy for heart failure with preserved ejection fraction (HFpEF), attention has shifted to defining specific phenotypes within the HFpEF spectrum in an effort to develop a targeted approach to treatment. Here we summarize the most recent studies investigating the pathophysiology and clinical features of HFpEF, and discuss recent clinical trials in the context of developing treatments that look toward the underlying cause of this disorder.

RECENT FINDINGS

Advances in basic science and clinical research have further characterized HFpEF, identifying multiple pathophysiological mechanisms that ultimately lead to exercise intolerance and volume overload. The success of small studies focused on specific subsets of the HFpEF population has promoted the concept that there may not be one treatment strategy that can universally be applied to HFpEF.

SUMMARY

HFpEF is associated with significant morbidity and mortality and accounts for approximately half of patients with chronic heart failure. HFpEF is a complex disease, encompassing a diverse cohort of patients and marked by the presence of multiple etiological mechanisms. The failure to develop successful therapies for the management of HFpEF may be because of inadequate standardization of the HFpEF diagnosis, overly broad inclusion criteria and inadequate differentiation of disease subtypes. Given the heterogeneity among patients with HFpEF, much of the current research is focused on understanding of pathophysiology and identifying disease phenotypes that may respond to a targeted treatment approach. Several newer approaches, including neprilysin inhibition and device therapy, offer promise for a new era of HFpEF treatment.

Spectrum of epidemiological and clinical findings in patients with heart failure with preserved ejection fraction stratified by study design: a systematic review

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) represents a major global and economic burden, but its epidemiological, clinical, and outcome data have varied according to study design.

METHODS AND RESULTS

We conducted a systematic review of published HFpEF clinical trials and observational studies (community-based studies and registries) from August 1998 to July 2013 using PubMed and EMBASE databases. Two independent investigators manually screened and extracted relevant data. We included 62 articles (19 describing clinical trials, 12 describing community-based observational studies, and 31 describing registries). The ejection fraction (EF) cut-off values ranged widely for HFpEF from >40% to >55%. However, differences in EF cut-offs were not clearly associated with incidence and prevalence data across studies. Of all patients with heart failure in community studies, 33-84% had HFpEF, which tended to be higher than reported in registries. The HFpEF patients in included studies were primarily older, white (>70%) patients with hypertension (∼50-90%) and coronary artery disease (up to 60%). All-cause mortality and all-cause hospitalizations ranged from 13% to 23% (26-50 months follow-up) and 55% to 67% (37-50 months follow-up), respectively, in clinical trials; cardiovascular causes accounted for 70% of both outcomes. All-cause mortality tended to be higher in registries than in clinical trials and community-based observational studies up to 5 years into follow-up.

CONCLUSIONS

Important differences in EF thresholds, epidemiological indices, clinical profiles, treatment patterns, and outcomes exist across contemporary HFpEF clinical trials, observational studies, and registries. Precision in definition and inclusion of more uniform populations may facilitate improved profiling of HFpEF patients.

Reactive Oxygen-Related Diseases: Therapeutic Targets and Emerging Clinical Indications

SIGNIFICANCE

Enhanced levels of reactive oxygen species (ROS) have been associated with different disease states. Most attempts to validate and exploit these associations by chronic antioxidant therapies have provided disappointing results. Hence, the clinical relevance of ROS is still largely unclear.

RECENT ADVANCES

We are now beginning to understand the reasons for these failures, which reside in the many important physiological roles of ROS in cell signaling. To exploit ROS therapeutically, it would be essential to define and treat the disease-relevant ROS at the right moment and leave physiological ROS formation intact. This breakthrough seems now within reach.

CRITICAL ISSUES

Rather than antioxidants, a new generation of protein targets for classical pharmacological agents includes ROS-forming or toxifying enzymes or proteins that are oxidatively damaged and can be functionally repaired.

FUTURE DIRECTIONS

Linking these target proteins in future to specific disease states and providing in each case proof of principle will be essential for translating the oxidative stress concept into the clinic.