Effect of Ejection Fraction on Clinical Outcomes in Patients Treated With Omecamtiv Mecarbil in GALACTIC-HF

Representativeness of the GALACTIC-HF Clinical Trial in Patients Having Heart Failure With Reduced Ejection Fraction

Background

Randomized clinical trials in populations with heart failure with reduced ejection fraction may not be reflective of the general population with heart failure with reduced ejection fraction. Our study assessed the representativeness of the GALACTIC‐HF (Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure) patient population in Kaiser Permanente Southern California.

Methods and Results

We identified 9770 patients with a diagnosis of heart failure with reduced ejection fraction from 2014 to 2018 using electronic health records. Four mutually exclusive cohorts were created, including GALACTIC‐HF–ineligible cohorts: (1) not taking guideline‐directed medical therapy (GDMT) and (2) taking GDMT; and GALACTIC‐HF–eligible cohorts with: (3) ejection fraction (EF) ≤28% and (4) EF 29% to 35%. Patients were followed for 30‐day and 1‐year mortality and 30‐day, 180‐day, and 1‐year hospitalization. Overall, 3626 (37.1%) met GALACTIC‐HF inclusion criteria with EF ≤35%, and 2367 (65.3%) of those individuals had EF ≤28%. The risk of 1‐year mortality was lower among all cohorts versus the GALACTIC‐HF–ineligible cohort not taking GDMT (hazard ratio, 0.80 [95% CI, 0.70–0.91], 0.84 [95% CI, 0.72–0.98], and 0.62 [95% CI, 0.51–0.75] for the GALACTIC‐HF–ineligible cohort taking GDMT and GALACTIC‐HF‐eligible cohorts with EF ≤28% and 29%–35%, respectively). Compared with the GALACTIC‐HF–ineligible cohort not taking GDMT, the short‐term hospitalization risk at 30 and 180 days were similar for both GALACTIC‐HF–eligible cohorts and the hospitalization risk at 1 year was similar for the GALACTIC‐HF–eligible cohort with EF ≤28%.

Conclusions

A large portion of patients with heart failure with reduced ejection fraction with low EF met inclusion criteria for the GALACTIC‐HF trial and, despite being on GDMT, had hospitalization rates similar to those not taking GDMT, suggesting potential benefits from other innovative treatments.

Influence of atrial fibrillation on efficacy and safety of omecamtiv mecarbil in heart failure: the GALACTIC-HF trial

AIMS

In GALACTIC-HF, the cardiac myosin activator omecamtiv mecarbil compared with placebo reduced the risk of heart failure events or cardiovascular death in patients with heart failure with reduced ejection fraction. We explored the influence of atrial fibrillation or flutter (AFF) on the effectiveness of omecamtiv mecarbil.

METHODS AND RESULTS

GALACTIC-HF enrolled patients with New York Heart Association (NYHA) Class II-IV heart failure, left ventricular ejection fraction ≤35%, and elevated natriuretic peptides. We assessed whether the presence or absence of AFF, a pre-specified subgroup, modified the treatment effect for the primary and secondary outcomes, and additionally explored effect modification in patients who were or were not receiving digoxin. Patients with AFF (n = 2245, 27%) were older, more likely to be randomized as an inpatient, less likely to have a history of ischaemic aetiology or myocardial infarction, had a worse NYHA class, worse quality of life, lower estimated glomerular filtration rate, and higher N-terminal pro-B-type natriuretic peptide. The treatment effect of omecamtiv mecarbil was modified by baseline AFF (interaction P = 0.012), with patients without AFF at baseline deriving greater benefit. The worsening of the treatment effect by baseline AFF was significantly more pronounced in digoxin users than in non-users (interaction P = 0.007); there was minimal evidence of effect modification in those patients not using digoxin (P = 0.47) or in digoxin users not in AFF.

CONCLUSION

Patients in AFF at baseline were less likely to benefit from omecamtiv mecarbil than patients without AFF, although the attenuation of the treatment effect was disproportionally concentrated in patients with AFF who were also receiving digoxin.Clinical Trial Registration: NCT02929329.

Developments in Exercise Capacity Assessment in Heart Failure Clinical Trials and the Rationale for the Design of METEORIC-HF

Heart failure with reduced ejection fraction (HFrEF) is a highly morbid condition for which exercise intolerance is a major manifestation. However, methods to assess exercise capacity in HFrEF vary widely in clinical practice and in trials. We describe advances in exercise capacity assessment in HFrEF and a comparative analysis of how various therapies available for HFrEF impact exercise capacity. Current guideline-directed medical therapy has indirect effects on cardiac performance with minimal impact on measured functional capacity. Omecamtiv mecarbil is a novel selective cardiac myosin activator that directly increases cardiac contractility and in a phase 3 cardiovascular outcomes study significantly reduced the primary composite end point of time to first heart failure event or cardiovascular death in patients with HFrEF. The objective of the METEORIC-HF trial (Multicenter Exercise Tolerance Evaluation of Omecamtiv Mecarbil Related to Increased Contractility in Heart Failure) is to assess the effect of omecamtiv mecarbil versus placebo on multiple components of functional capacity in HFrEF. The primary end point is to test the effect of omecamtiv mecarbil compared with placebo on peak oxygen uptake as measured by cardiopulmonary exercise testing after 20 weeks of treatment. METEORIC-HF will provide state-of-the-art assessment of functional capacity by measuring ventilatory efficiency, circulatory power, ventilatory anaerobic threshold, oxygen uptake recovery kinetics, daily activity, and quality-of-life assessment. Thus, the METEORIC-HF trial will evaluate the potential impact of increased myocardial contractility with omecamtiv mecarbil on multiple important measures of functional capacity in ambulatory patients with symptomatic HFrEF. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT03759392.

Contemporary Drug Treatment of Advanced Heart Failure with Reduced Ejection Fraction

The introduction of multiple new pharmacological agents over the past three decades in the field of heart failure with reduced ejection fraction (HFrEF) has led to reduced rates of mortality and hospitalizations, and consequently the prevalence of HFrEF has increased, and up to 10% of patients progress to more advanced stages, characterized by high rates of mortality, hospitalizations, and poor quality of life. Advanced HFrEF patients often show persistent or progressive signs of severe HF symptoms corresponding to New York Heart Association class III or IV despite being on optimal medical, surgical, and device therapies. However, a subpopulation of patients with advanced HF, those with the most advanced stages of disease, were often insufficiently represented in the major trials demonstrating efficacy and tolerability of the drugs used in HFrEF due to exclusion criteria such as low BP and kidney dysfunction. Consequently, the results of many landmark trials cannot necessarily be transferred to patients with the most advanced stages of HFrEF. Thus, the efficacy and tolerability of guideline-directed medical therapies in patients with the most advanced stages of HFrEF often remain unsettled, and this knowledge is of crucial importance in the planning and timing of consideration for referral for advanced therapies. This review discusses the evidence regarding the use of contemporary drugs in the advanced HFrEF population, covering components such as guideline HFrEF drugs, diuretics, inotropes, and the use of HFrEF drugs in LVAD recipients, and provides suggestions on how to manage guideline-directed therapy in this patient group.

Drug Treatment of Heart Failure in Children: Gaps and Opportunities

Medical therapy for pediatric heart failure is based on a detailed mechanistic understanding of the underlying causes, which are diverse and unlike those encountered in most adult patients. Diuresis and improved perfusion are the immediate goals of care in the child with acute decompensated heart failure. Conversion to maintenance oral therapy for heart failure is based on the results of landmark studies in adults, as well as recent pediatric clinical trials and heart failure guidelines. There will continue to be an important role for newer drugs, some of which are in active trials in adults, and some of which are already approved for use in children. The need to plan for clinical trials in children during drug development for heart failure is emphasized.

Clinical trajectory of patients with a worsening heart failure event and reduced ventricular ejection fraction

BACKGROUND

Recent data suggest that patients with heart failure with reduced ejection fraction (HFrEF) and worsening heart failure (WHF) have potential for greater benefit from newer HF therapies. We investigated characteristics and outcomes of patients with HFrEF and WHF by severity of left ventricular dysfunction.

METHODS

We identified patients with chronic symptomatic HFrEF (left ventricular ejection fraction [LVEF] ≤35%) and evidence of WHF (emergency department visit or hospitalization for acute HF within 12 months of index echocardiogram) treated at Duke University between 1/2009 and 12/2018. Patients were stratified by LVEF≤25% or 26% to35%. Cox models were used to estimate cause-specific hazard ratios and 5-year event incidence of death and hospitalization across the range of LVEF.

RESULTS

Of 2823 patients with HFrEF and WHF, 1620 (57.4%) had an LVEF≤25% and 1203 (42.6%) had an LVEF 26% to35%. Compared to patients with LVEF 26% to35%, those with LVEF≤25% were younger and more commonly men with a lower cardiovascular comorbidity burden. Patients with LVEF≤25% were less commonly on beta blockers (85.9% vs 90.5%) but more commonly treated with mineralocorticoid receptor antagonists (49.3% vs 41.1%) and implantable defibrillators (41.3% vs 28.2%). Patients with LVEF≤25% had significantly higher hazards for death (HR 1.24 [95% CI 1.11 - 1.38]), all-cause hospitalization (HR 1.21 [95% CI 1.10 - 1.33]), and HF hospitalization (HR 1.25 [95% CI 1.1 - 1.38]) through 5-years.

CONCLUSIONS

More than half of patients with chronic HFrEF and WHF have severe LV dysfunction. Important differences in comorbidities, HF therapies, and outcomes exist between those with LVEF≤25% and those with LVEF 26% to35%.

Myosin modulators: emerging approaches for the treatment of cardiomyopathies and heart failure

Myosin modulators are a novel class of pharmaceutical agents that are being developed to treat patients with a range of cardiomyopathies. The therapeutic goal of these drugs is to target cardiac myosins directly to modulate contractility and cardiac power output to alleviate symptoms that lead to heart failure and arrhythmias, without altering calcium signaling. In this Review, we discuss two classes of drugs that have been developed to either activate (omecamtiv mecarbil) or inhibit (mavacamten) cardiac contractility by binding to β-cardiac myosin (MYH7). We discuss progress in understanding the mechanisms by which the drugs alter myosin mechanochemistry, and we provide an appraisal of the results from clinical trials of these drugs, with consideration for the importance of disease heterogeneity and genetic etiology for predicting treatment benefit.

Editor-in-Chief's Top Picks From 2021

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16M+), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Artificial Intelligence & Machine Learning (NEW section), Basic & Translational Research, Biomarkers (NEW section), Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Cardiovascular Disease in Women, Coronary Disease & Interventions, Congenital Heart Disease, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Vascular Medicine, and Valvular Heart Disease.^1-100.

The year in cardiovascular medicine 2021: heart failure and cardiomyopathies

In the year 2021, the universal definition and classification of heart failure (HF) was published that defines HF as a clinical syndrome with symptoms and/or signs caused by a cardiac abnormality and corroborated by elevated natriuretic peptide levels or objective evidence of cardiogenic congestion. This definition and the classification of HF with reduced ejection fraction (HFrEF), mildly reduced, and HF with preserved ejection fraction (HFpEF) is consistent with the 2021 ESC Guidelines on HF. Among several other new recommendations, these guidelines give a Class I indication for the use of the sodium-glucose co-transporter 2 (SGLT2) inhibitors dapagliflozin and empagliflozin in HFrEF patients. As the first evidence-based treatment for HFpEF, in the EMPEROR-Preserved trial, empagliflozin reduced the composite endpoint of cardiovascular death and HF hospitalizations. Several reports in 2021 have provided novel and detailed analyses of device and medical therapy in HF, especially regarding sacubitril/valsartan, SGLT2 inhibitors, mineralocorticoid receptor antagonists, ferric carboxymaltose, soluble guanylate cyclase activators, and cardiac myosin activators. In patients hospitalized with COVID-19, acute HF and myocardial injury is quite frequent, whereas myocarditis and long-term damage to the heart are rather uncommon.

Medical management of acute heart failure

Despite recent advances in the treatment of chronic heart failure, therapeutic options for acute heart failure (AHF) remain limited. AHF admissions are associated with significant multi-organ dysfunction, especially worsening renal failure, which results in significant morbidity and mortality. There are several aspects of AHF management: diagnosis, decongestion, vasoactive therapy, goal-directed medical therapy initiation and safe transition of care. Effective diagnosis and prognostication could be very helpful in an acute setting and rely upon biomarker evaluation with noninvasive assessment of fluid status. Decongestive strategies could be tailored to include pharmaceutical options along with consideration of utilizing ultrafiltration for refractory hypervolemia. Vasoactive agents to augment cardiac function have been evaluated in patients with AHF but have shown to only have limited efficacy. Post stabilization, initiation of quadruple goal-directed medical therapy—angiotensin receptor-neprilysin inhibitors, mineral receptor antagonists, sodium glucose type 2 (SGLT-2) inhibitors, and beta blockers—to prevent myocardial remodeling is being advocated as a standard of care. Safe transition of care is needed prior to discharge to prevent heart failure rehospitalization and mortality. Post-discharge close ambulatory monitoring (including remote hemodynamic monitoring), virtual visits, and rehabilitation are some of the strategies to consider. We hereby review the contemporary approach in AHF diagnosis and management.

Assessment of Omecamtiv Mecarbil for the Treatment of Patients With Severe Heart Failure: A Post Hoc Analysis of Data From the GALACTIC-HF Randomized Clinical Trial

Importance

Heart failure with reduced ejection fraction is a progressive clinical syndrome, and many patients' condition worsen over time despite treatment. Patients with more severe disease are often intolerant of available medical therapies.

Objective

To evaluate the efficacy and safety of omecamtiv mecarbil for the treatment of patients with severe heart failure (HF) enrolled in the Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure (GALACTIC-HF) randomized clinical trial.

Design, Setting, and Participants

The GALACTIC-HF study was a global double-blind, placebo-controlled phase 3 randomized clinical trial that was conducted at multiple centers between January 2017 and August 2020. A total of 8232 patients with symptomatic HF (defined as New York Heart Association symptom class II-IV) and left ventricular ejection fraction of 35% or less were randomized to receive omecamtiv mecarbil or placebo and followed up for a median of 21.8 months (range, 15.4-28.6 months). The current post hoc analysis evaluated the efficacy and safety of omecamtiv mecarbil therapy among patients classified as having severe HF compared with patients without severe HF. Severe HF was defined as the presence of all of the following criteria: New York Heart Association symptom class III to IV, left ventricular ejection fraction of 30% or less, and hospitalization for HF within the previous 6 months.

Interventions

Participants were randomized at a 1:1 ratio to receive either omecamtiv mecarbil or placebo.

Main Outcomes and Measures

The primary end point was time to first HF event or cardiovascular (CV) death. Secondary end points included time to CV death and safety and tolerability.

Results

Among 8232 patients enrolled in the GALACTIC-HF clinical trial, 2258 patients (27.4%; mean [SD] age, 64.5 [11.6] years; 1781 men [78.9%]) met the specified criteria for severe HF. Of those, 1106 patients were randomized to the omecamtiv mecarbil group and 1152 to the placebo group. Patients with severe HF who received omecamtiv mecarbil experienced a significant treatment benefit for the primary end point (hazard ratio [HR], 0.80; 95% CI, 0.71-0.90), whereas patients without severe HF had no significant treatment benefit (HR, 0.99; 95% CI, 0.91-1.08; P = .005 for interaction). For CV death, the results were similar (HR for patients with vs without severe HF: 0.88 [95% CI, 0.75-1.03] vs 1.10 [95% CI, 0.97-1.25]; P = .03 for interaction). Omecamtiv mecarbil therapy was well tolerated in patients with severe HF, with no significant changes in blood pressure, kidney function, or potassium level compared with placebo.

Conclusions and Relevance

In this post hoc analysis of data from the GALACTIC-HF clinical trial, omecamtiv mecarbil therapy may have provided a clinically meaningful reduction in the composite end point of time to first HF event or CV death among patients with severe HF. These data support a potential role of omecamtiv mecarbil therapy among patients for whom current treatment options are limited.

Trial Registration

ClinicalTrials.gov Identifier: NCT02929329.

[Decompensated heart failure with reduced ejection fraction: overcoming barriers to improve prognosis in the "vulnerable" period after discharge]

Frequency of hospitalizations for decompensated heart failure (HF) and associated costs are steadily increasing worldwide. An episode of HF is a risk marker, reflects a change in the course of disease, a high probability of adverse events, and requirement for using all options to improve the prognosis. This article discusses barriers and ways to overcome them in managing HF patients with low ejection fraction. An evidence-based, disease-modifying therapy exists for this HF phenotype. Administration of the therapy along with additional, novel drugs that improve outcomes, and organization of medical care are essential during the "vulnerable period" after discharge from the hospital.

The myosin activator: is another step forward in heart failure therapy?

Selective cardiac myosin activators constitute a new class of drugs capable of increasing cardiac contractility independently of intracellular calcium concentrations. In the GALACTIC-HF study, the first of this class of molecules, omecamtiv mercabil, was compared with the standard of care according to current guidelines, showing a significant reduction in the composite endpoint of first episode of heart failure or mortality due to cardiovascular causes in patients exposed to treatment compared with placebo. In particular, the effect was more pronounced for decreasing ejection fraction values, suggesting a potential further benefit of selective cardiac myosin activators in this category of patients.

Contemporary Pillars of Heart Failure with Reduced Ejection Fraction Medical Therapy

Heart failure with reduced ejection fraction (HFrEF) is a clinical condition associated with cardiac contractility impairment. HFrEF is a significant public health issue with a high morbidity and mortality burden. Pathological left ventricular (LV) remodeling and progressive dilatation are hallmarks of HFrEF pathogenesis, ultimately leading to adverse clinical outcomes. Therefore, cardiac remodeling attenuation has become a treatment goal and a standard of care over the last three decades. Guideline-directed medical therapy mainly targeting the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) has led to improved survival and a reduction in HF hospitalization in this population. More recently, novel pharmacological therapies targeting other pathways implicated in the pathophysiology of HFrEF have emerged at an exciting rate, with landmark clinical trials demonstrating additive clinical benefits in patients with HFrEF. Among these novel therapies, angiotensin receptor-neprilysin inhibitors (ARNI), sodium-glucose cotransporter-2 inhibitors (SGLT2i), vericiguat (a novel oral guanylate cyclase stimulator), and omecamtiv mecarbil (a selective cardiac myosin activator) have shown improved clinical benefit when added to the traditional standard-of-care medical therapy in HFrEF. These new comprehensive data have led to a remarkable change in the medical therapy paradigm in the setting of HFrEF. This article will review the pivotal studies involving these novel agents and present a suggestive paradigm of pharmacological therapy representing the 2021 European Society of Cardiology (ESC) guidelines for the treatment of chronic HFrEF.

Women and Diabetes: Preventing Heart Disease in a New Era of Therapies

Despite major advances in cardiovascular research over the past decade, women with type 2 diabetes have a high risk of cardiovascular events. Several factors contribute to the poor prognosis for women, including higher levels of frailty and comorbidities, but their cardiovascular risk is underestimated and there is suboptimal implementation and uptitration of new evidence-based therapies, leading to high morbidity and mortality. Recent studies highlight the need for better management of diabetes in women that can be pursued and achieved in light of recent results from randomised controlled trials demonstrating evidence of the benefits of new therapeutic strategies in improving cardiovascular outcomes and quality of life of women covering the entire cardiovascular continuum. This review critically discusses the multiple benefits for women of new pharmacological treatments, such as glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter type 2 inhibitors (SGLT2i), proprotein convertase subtilisin/kexin type 9 inhibitors, inclisiran, icosapent ethyl and bempedoic acid in preventing cardiovascular events, and treatments, such as angiotensin receptor neprilysin inhibitors, SGLT2i, vericiguat and omecamtiv mecarbil, for preventing heart failure.

Recent and Upcoming Drug Therapies for Pediatric Heart Failure

Pediatric heart failure (HF) is an important clinical condition with high morbidity, mortality, and costs. Due to the heterogeneity in clinical presentation and etiologies, the development of therapeutic strategies is more challenging in children than adults. Most guidelines recommending drug therapy for pediatric HF are extrapolated from studies in adults. Unfortunately, even using all available treatment, progression to cardiac transplantation is common. The development of prospective clinical trials in the pediatric population has significant obstacles, including small sample sizes, slow recruitment rates, challenging endpoints, and high costs. However, progress is being made as evidenced by the recent introduction of ivabradine and of sacubitril/valsartan. In the last 5 years, new drugs have also been developed for HF with reduced ejection fraction (HFrEF) in adults. The use of well-designed prospective clinical trials will be fundamental in the evaluation of safety and efficacy of these new drugs on the pediatric population. The aim of this article is to review the clinical presentation and management of acute and chronic pediatric heart failure, focusing on systolic dysfunction in patients with biventricular circulation and a systemic left ventricle. We discuss the drugs recently approved for children and those emerging, or in use for adults with HFrEF.