The Myosin Family of Mechanoenzymes: From Mechanisms to Therapeutic Approaches.

Myosins are among the most fascinating enzymes in biology. As extremely allosteric chemomechanical molecular machines, myosins are involved in myriad pivotal cellular functions and are frequently sites of mutations leading to disease phenotypes. Human ß-cardiac myosin has proved to be an excellent target for small-molecule therapeutics for heart muscle diseases, and, as we describe here, other myosin family members are likely to be potentially unique targets for treating other diseases as well. The first part of this review focuses on how myosins convert the chemical energy of ATP hydrolysis into mechanical movement, followed by a description of existing therapeutic approaches to target human ß-cardiac myosin. The next section focuses on the possibility of targeting nonmuscle members of the human myosin family for several diseases. We end the review by describing the roles of myosin in parasites and the therapeutic potential of targeting them to block parasitic invasion of their hosts.

Agonist antibody to guanylate cyclase receptor NPR1 regulates vascular tone.

Heart failure is a leading cause of morbidity and mortality1,2. Elevated intracardiac pressures and myocyte stretch in heart failure trigger the release of counter-regulatory natriuretic peptides, which act through their receptor (NPR1) to affect vasodilation, diuresis and natriuresis, lowering venous pressures and relieving venous congestion3-8. Recombinant natriuretic peptide infusions were developed to treat heart failure but have been limited by a short duration of effect9,10. Here we report that in a human genetic analysis of over 700,000 individuals, lifelong exposure to coding variants of the NPR1 gene is associated with changes in blood pressure and risk of heart failure. We describe the development of REGN5381, an investigational monoclonal agonist antibody that targets the membrane-bound guanylate cyclase receptor NPR1. REGN5381, an allosteric agonist of NPR1, induces an active-like receptor conformation that results in haemodynamic effects preferentially on venous vasculature, including reductions in systolic blood pressure and venous pressure in animal models. In healthy human volunteers, REGN5381 produced the expected haemodynamic effects, reflecting reductions in venous pressures, without obvious changes in diuresis and natriuresis. These data support the development of REGN5381 for long-lasting and selective lowering of venous pressures that drive symptomatology in patients with heart failure.

BET bromodomains mediate transcriptional pause release in heart failure.

Heart failure (HF) is driven by the interplay between regulatory transcription factors and dynamic alterations in chromatin structure. Pathologic gene transactivation in HF is associated with recruitment of histone acetyl-transferases and local chromatin hyperacetylation. We therefore assessed the role of acetyl-lysine reader proteins, or bromodomains, in HF. Using a chemical genetic approach, we establish a central role for BET family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and pathologic cardiac remodeling in vivo. Integrative transcriptional and epigenomic analyses reveal that BET proteins function mechanistically as pause-release factors critical to expression of genes that are central to HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers as essential effectors of transcriptional pause release during HF pathogenesis and identifies BET coactivator proteins as therapeutic targets in the heart.

Semaglutide in Patients with Obesity-Related Heart Failure and Type 2 Diabetes.

BACKGROUND: Obesity and type 2 diabetes are prevalent in patients with heart failure with preserved ejection fraction and are characterized by a high symptom burden. No approved therapies specifically target obesity-related heart failure with preserved ejection fraction in persons with type 2 diabetes. METHODS: We randomly assigned patients who had heart failure with preserved ejection fraction, a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or more, and type 2 diabetes to receive once-weekly semaglutide (2.4 mg) or placebo for 52 weeks. The primary end points were the change from baseline in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS; scores range from 0 to 100, with higher scores indicating fewer symptoms and physical limitations) and the change in body weight. Confirmatory secondary end points included the change in 6-minute walk distance; a hierarchical composite end point that included death, heart failure events, and differences in the change in the KCCQ-CSS and 6-minute walk distance; and the change in the C-reactive protein (CRP) level. RESULTS: A total of 616 participants underwent randomization. The mean change in the KCCQ-CSS was 13.7 points with semaglutide and 6.4 points with placebo (estimated difference, 7.3 points; 95% confidence interval [CI], 4.1 to 10.4; P<0.001), and the mean percentage change in body weight was -9.8% with semaglutide and -3.4% with placebo (estimated difference, -6.4 percentage points; 95% CI, -7.6 to -5.2; P<0.001). The results for the confirmatory secondary end points favored semaglutide over placebo (estimated between-group difference in change in 6-minute walk distance, 14.3 m [95% CI, 3.7 to 24.9; P = 0.008]; win ratio for hierarchical composite end point, 1.58 [95% CI, 1.29 to 1.94; P<0.001]; and estimated treatment ratio for change in CRP level, 0.67 [95% CI, 0.55 to 0.80; P<0.001]). Serious adverse events were reported in 55 participants (17.7%) in the semaglutide group and 88 (28.8%) in the placebo group. CONCLUSIONS: Among patients with obesity-related heart failure with preserved ejection fraction and type 2 diabetes, semaglutide led to larger reductions in heart failure-related symptoms and physical limitations and greater weight loss than placebo at 1 year. (Funded by Novo Nordisk; STEP-HFpEF DM ClinicalTrials.gov number, NCT04916470.).

Multiscale modeling shows how 2'-deoxy-ATP rescues ventricular function in heart failure.

2'-deoxy-ATP (dATP) improves cardiac function by increasing the rate of crossbridge cycling and Ca[Formula: see text] transient decay. However, the mechanisms of these effects and how therapeutic responses to dATP are achieved when dATP is only a small fraction of the total ATP pool remain poorly understood. Here, we used a multiscale computational modeling approach to analyze the mechanisms by which dATP improves ventricular function. We integrated atomistic simulations of prepowerstroke myosin and actomyosin association, filament-scale Markov state modeling of sarcomere mechanics, cell-scale analysis of myocyte Ca[Formula: see text] dynamics and contraction, organ-scale modeling of biventricular mechanoenergetics, and systems level modeling of circulatory dynamics. Molecular and Brownian dynamics simulations showed that dATP increases the actomyosin association rate by 1.9 fold. Markov state models predicted that dATP increases the pool of myosin heads available for crossbridge cycling, increasing steady-state force development at low dATP fractions by 1.3 fold due to mechanosensing and nearest-neighbor cooperativity. This was found to be the dominant mechanism by which small amounts of dATP can improve contractile function at myofilament to organ scales. Together with faster myocyte Ca[Formula: see text] handling, this led to improved ventricular contractility, especially in a failing heart model in which dATP increased ejection fraction by 16% and the energy efficiency of cardiac contraction by 1%. This work represents a complete multiscale model analysis of a small molecule myosin modulator from single molecule to organ system biophysics and elucidates how the molecular mechanisms of dATP may improve cardiovascular function in heart failure with reduced ejection fraction.

Ferric Carboxymaltose in Heart Failure with Iron Deficiency.

BACKGROUND: Ferric carboxymaltose therapy reduces symptoms and improves quality of life in patients who have heart failure with a reduced ejection fraction and iron deficiency. Additional evidence about the effects of ferric carboxymaltose on clinical events is needed. METHODS: In this double-blind, randomized trial, we assigned ambulatory patients with heart failure, a left ventricular ejection fraction of 40% or less, and iron deficiency, in a 1:1 ratio, to receive intravenous ferric carboxymaltose or placebo, in addition to standard therapy for heart failure. Ferric carboxymaltose or placebo was given every 6 months as needed on the basis of iron indexes and hemoglobin levels. The primary outcome was a hierarchical composite of death within 12 months after randomization, hospitalizations for heart failure within 12 months after randomization, or change from baseline to 6 months in the 6-minute walk distance. The significance level was set at 0.01. RESULTS: We enrolled 3065 patients, of whom 1532 were randomly assigned to the ferric carboxymaltose group and 1533 to the placebo group. Death by month 12 occurred in 131 patients (8.6%) in the ferric carboxymaltose group and 158 (10.3%) in the placebo group; a total of 297 and 332 hospitalizations for heart failure, respectively, occurred by month 12; and the mean (±SD) change from baseline to 6 months in the 6-minute walk distance was 8±60 and 4±59 m, respectively (Wilcoxon-Mann-Whitney P = 0.02; unmatched win ratio, 1.10; 99% confidence interval, 0.99 to 1.23). Repeated dosing of ferric carboxymaltose appeared to be safe with an acceptable adverse-event profile in the majority of patients. The number of patients with serious adverse events occurring during the treatment period was similar in the two groups (413 patients [27.0%] in the ferric carboxymaltose group and 401 [26.2%] in the placebo group). CONCLUSIONS: Among ambulatory patients who had heart failure with a reduced ejection fraction and iron deficiency, there was no apparent difference between ferric carboxymaltose and placebo with respect to the hierarchical composite of death, hospitalizations for heart failure, or 6-minute walk distance. (Funded by American Regent, a Daiichi Sankyo Group company; HEART-FID ClinicalTrials.gov number, NCT03037931.).

Semaglutide in Patients with Heart Failure with Preserved Ejection Fraction and Obesity.

BACKGROUND: Heart failure with preserved ejection fraction is increasing in prevalence and is associated with a high symptom burden and functional impairment, especially in persons with obesity. No therapies have been approved to target obesity-related heart failure with preserved ejection fraction. METHODS: We randomly assigned 529 patients who had heart failure with preserved ejection fraction and a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or higher to receive once-weekly semaglutide (2.4 mg) or placebo for 52 weeks. The dual primary end points were the change from baseline in the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CSS; scores range from 0 to 100, with higher scores indicating fewer symptoms and physical limitations) and the change in body weight. Confirmatory secondary end points included the change in the 6-minute walk distance; a hierarchical composite end point that included death, heart failure events, and differences in the change in the KCCQ-CSS and 6-minute walk distance; and the change in the C-reactive protein (CRP) level. RESULTS: The mean change in the KCCQ-CSS was 16.6 points with semaglutide and 8.7 points with placebo (estimated difference, 7.8 points; 95% confidence interval [CI], 4.8 to 10.9; P<0.001), and the mean percentage change in body weight was -13.3% with semaglutide and -2.6% with placebo (estimated difference, -10.7 percentage points; 95% CI, -11.9 to -9.4; P<0.001). The mean change in the 6-minute walk distance was 21.5 m with semaglutide and 1.2 m with placebo (estimated difference, 20.3 m; 95% CI, 8.6 to 32.1; P<0.001). In the analysis of the hierarchical composite end point, semaglutide produced more wins than placebo (win ratio, 1.72; 95% CI, 1.37 to 2.15; P<0.001). The mean percentage change in the CRP level was -43.5% with semaglutide and -7.3% with placebo (estimated treatment ratio, 0.61; 95% CI, 0.51 to 0.72; P<0.001). Serious adverse events were reported in 35 participants (13.3%) in the semaglutide group and 71 (26.7%) in the placebo group. CONCLUSIONS: In patients with heart failure with preserved ejection fraction and obesity, treatment with semaglutide (2.4 mg) led to larger reductions in symptoms and physical limitations, greater improvements in exercise function, and greater weight loss than placebo. (Funded by Novo Nordisk; STEP-HFpEF ClinicalTrials.gov number, NCT04788511.).

Phase 1 Trial of Antibody NI006 for Depletion of Cardiac Transthyretin Amyloid.

BACKGROUND: Transthyretin amyloid (ATTR) cardiomyopathy is a progressive and fatal disease caused by misfolded transthyretin. Despite advances in slowing disease progression, there is no available treatment that depletes ATTR from the heart for the amelioration of cardiac dysfunction. NI006 is a recombinant human anti-ATTR antibody that was developed for the removal of ATTR by phagocytic immune cells. METHODS: In this phase 1, double-blind trial, we randomly assigned (in a 2:1 ratio) 40 patients with wild-type or variant ATTR cardiomyopathy and chronic heart failure to receive intravenous infusions of either NI006 or placebo every 4 weeks for 4 months. Patients were sequentially enrolled in six cohorts that received ascending doses (ranging from 0.3 to 60 mg per kilogram of body weight). After four infusions, patients were enrolled in an open-label extension phase in which they received eight infusions of NI006 with stepwise increases in the dose. The safety and pharmacokinetic profiles of NI006 were assessed, and cardiac imaging studies were performed. RESULTS: The use of NI006 was associated with no apparent drug-related serious adverse events. The pharmacokinetic profile of NI006 was consistent with that of an IgG antibody, and no antidrug antibodies were detected. At doses of at least 10 mg per kilogram, cardiac tracer uptake on scintigraphy and extracellular volume on cardiac magnetic resonance imaging, both of which are imaging-based surrogate markers of cardiac amyloid load, appeared to be reduced over a period of 12 months. The median N-terminal pro-B-type natriuretic peptide and troponin T levels also seemed to be reduced. CONCLUSIONS: In this phase 1 trial of the recombinant human antibody NI006 for the treatment of patients with ATTR cardiomyopathy and heart failure, the use of NI006 was associated with no apparent drug-related serious adverse events. (Funded by Neurimmune; NI006-101 ClinicalTrials.gov number, NCT04360434.).

Targeting Cyclophilin A in the Cardiac Microenvironment Preserves Heart Function and Structure in Failing Hearts.

BACKGROUND: Cardiac hypertrophy is characterized by remodeling of the myocardium, which involves alterations in the ECM (extracellular matrix) and cardiomyocyte structure. These alterations critically contribute to impaired contractility and relaxation, ultimately leading to heart failure. Emerging evidence implicates that extracellular signaling molecules are critically involved in the pathogenesis of cardiac hypertrophy and remodeling. The immunophilin CyPA (cyclophilin A) has been identified as a potential culprit. In this study, we aimed to unravel the interplay between eCyPA (extracellular CyPA) and myocardial dysfunction and evaluate the therapeutic potential of inhibiting its extracellular accumulation to improve heart function. METHODS: Employing a multidisciplinary approach encompassing in silico, in vitro, in vivo, and ex vivo experiments we studied a mouse model of cardiac hypertrophy and human heart specimen to decipher the interaction of CyPA and the cardiac microenvironment in highly relevant pre-/clinical settings. Myocardial expression of CyPA (immunohistology) and the inflammatory transcriptome (NanoString) was analyzed in human cardiac tissue derived from patients with nonischemic, noninflammatory congestive heart failure (n=187). These analyses were paralleled by a mouse model of Ang (angiotensin) II-induced heart failure, which was assessed by functional (echocardiography), structural (immunohistology, atomic force microscopy), and biomolecular (Raman spectroscopy) analyses. The effect of inhibiting eCyPA in the cardiac microenvironment was evaluated using a newly developed neutralizing anti-eCyPA monoclonal antibody. RESULTS: We observed a significant accumulation of eCyPA in both human and murine-failing hearts. Importantly, higher eCyPA expression was associated with poor clinical outcomes in patients (P=0.043) and contractile dysfunction in mice (Pearson correlation coefficient, -0.73). Further, myocardial expression of eCyPA was critically associated with an increase in myocardial hypertrophy, inflammation, fibrosis, stiffness, and cardiac dysfunction in vivo. Antibody-based inhibition of eCyPA prevented (Ang II)-induced myocardial remodeling and dysfunction in mice. CONCLUSIONS: Our study provides strong evidence of the pathogenic role of eCyPA in remodeling, myocardial stiffening, and dysfunction in heart failure. The findings suggest that antibody-based inhibition of eCyPA may offer a novel therapeutic strategy for nonischemic heart failure. Further research is needed to evaluate the translational potential of these interventions in human patients with cardiac hypertrophy.

Glucagon Receptor Antagonist for Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is an emerging major unmet need and one of the most significant clinic challenges in cardiology. The pathogenesis of HFpEF is associated with multiple risk factors. Hypertension and metabolic disorders associated with obesity are the 2 most prominent comorbidities observed in patients with HFpEF. Although hypertension-induced mechanical overload has long been recognized as a potent contributor to heart failure with reduced ejection fraction, the synergistic interaction between mechanical overload and metabolic disorders in the pathogenesis of HFpEF remains poorly characterized. METHOD: We investigated the functional outcome and the underlying mechanisms from concurrent mechanic and metabolic stresses in the heart by applying transverse aortic constriction in lean C57Bl/6J or obese/diabetic B6.Cg-Lepob/J (ob/ob) mice, followed by single-nuclei RNA-seq and targeted manipulation of a top-ranked signaling pathway differentially affected in the 2 experimental cohorts. RESULTS: In contrast to the post-transverse aortic constriction C57Bl/6J lean mice, which developed pathological features of heart failure with reduced ejection fraction over time, the post-transverse aortic constriction ob/ob mice showed no significant changes in ejection fraction but developed characteristic pathological features of HFpEF, including diastolic dysfunction, worsened cardiac hypertrophy, and pathological remodeling, along with further deterioration of exercise intolerance. Single-nuclei RNA-seq analysis revealed significant transcriptome reprogramming in the cardiomyocytes stressed by both pressure overload and obesity/diabetes, markedly distinct from the cardiomyocytes singularly stressed by pressure overload or obesity/diabetes. Furthermore, glucagon signaling was identified as the top-ranked signaling pathway affected in the cardiomyocytes associated with HFpEF. Treatment with a glucagon receptor antagonist significantly ameliorated the progression of HFpEF-related pathological features in 2 independent preclinical models. Importantly, cardiomyocyte-specific genetic deletion of the glucagon receptor also significantly improved cardiac function in response to pressure overload and metabolic stress. CONCLUSIONS: These findings identify glucagon receptor signaling in cardiomyocytes as a critical determinant of HFpEF progression and provide proof-of-concept support for glucagon receptor antagonism as a potential therapy for the disease.

Lifestyle Walking Intervention for Patients With Heart Failure With Reduced Ejection Fraction: The WATCHFUL Trial.

BACKGROUND: Physical activity is pivotal in managing heart failure with reduced ejection fraction, and walking integrated into daily life is an especially suitable form of physical activity. This study aimed to determine whether a 6-month lifestyle walking intervention combining self-monitoring and regular telephone counseling improves functional capacity assessed by the 6-minute walk test (6MWT) in patients with stable heart failure with reduced ejection fraction compared with usual care. METHODS: The WATCHFUL trial (Pedometer-Based Walking Intervention in Patients With Chronic Heart Failure With Reduced Ejection Fraction) was a 6-month multicenter, parallel-group randomized controlled trial recruiting patients with heart failure with reduced ejection fraction from 6 cardiovascular centers in the Czech Republic. Eligible participants were ≥18 years of age, had left ventricular ejection fraction <40%, and had New York Heart Association class II or III symptoms on guidelines-recommended medication. Individuals exceeding 450 meters on the baseline 6MWT were excluded. Patients in the intervention group were equipped with a Garmin vívofit activity tracker and received monthly telephone counseling from research nurses who encouraged them to use behavior change techniques such as self-monitoring, goal-setting, and action planning to increase their daily step count. The patients in the control group continued usual care. The primary outcome was the between-group difference in the distance walked during the 6MWT at 6 months. Secondary outcomes included daily step count and minutes of moderate to vigorous physical activity as measured by the hip-worn Actigraph wGT3X-BT accelerometer, NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity C-reactive protein biomarkers, ejection fraction, anthropometric measures, depression score, self-efficacy, quality of life, and survival risk score. The primary analysis was conducted by intention to treat. RESULTS: Of 218 screened patients, 202 were randomized (mean age, 65 years; 22.8% female; 90.6% New York Heart Association class II; median left ventricular ejection fraction, 32.5%; median 6MWT, 385 meters; average 5071 steps/day; average 10.9 minutes of moderate to vigorous physical activity per day). At 6 months, no between-group differences were detected in the 6MWT (mean 7.4 meters [95% CI, -8.0 to 22.7]; P=0.345, n=186). The intervention group increased their average daily step count by 1420 (95% CI, 749 to 2091) and daily minutes of moderate to vigorous physical activity by 8.2 (95% CI, 3.0 to 13.3) over the control group. No between-group differences were detected for any other secondary outcomes. CONCLUSIONS: Whereas the lifestyle intervention in patients with heart failure with reduced ejection fraction improved daily steps by about 25%, it failed to demonstrate a corresponding improvement in functional capacity. Further research is needed to understand the lack of association between increased physical activity and functional outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03041610.

Effects of Semaglutide on Symptoms, Function, and Quality of Life in Patients With Heart Failure With Preserved Ejection Fraction and Obesity: A Prespecified Analysis of the STEP-HFpEF Trial.

BACKGROUND: Patients with heart failure (HF) with preserved ejection fraction (HFpEF) and obesity experience a high burden of symptoms and functional impairment, and a poor quality of life. In the STEP-HFpEF trial (Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity), once-weekly semaglutide 2.4 mg improved symptoms, physical limitations, and exercise function, and reduced inflammation and body weight. This prespecified analysis investigated the effects of semaglutide on the primary and confirmatory secondary end points across the range of the Kansas City Cardiomyopathy Questionnaire (KCCQ) scores at baseline and on all key summary and individual KCCQ domains. METHODS: STEP-HFpEF randomly assigned 529 participants with symptomatic HF, an ejection fraction of ≥45%, and a body mass index of ≥30 kg/m2 to once-weekly semaglutide 2.4 mg or placebo for 52 weeks. Dual primary end points change in KCCQ-Clinical Summary Score (CSS) and body weight. Confirmatory secondary end points included change in 6-minute walk distance, a hierarchical composite end point (death, HF events, and change in KCCQ-CSS and 6-minute walk distance) and change in C-reactive protein. Patients were stratified by KCCQ-CSS tertiles at baseline. Semaglutide effects on the primary, confirmatory secondary, and select exploratory end points (N-terminal pro-brain natriuretic peptide) were examined across these subgroups. Semaglutide effects on additional KCCQ domains (Total Symptom Score [including symptom burden and frequency], Physical Limitations Score, Social Limitations Score, Quality of Life Score, and Overall Summary Score) were also evaluated. RESULTS: Baseline median KCCQ-CSS across tertiles was 37, 59, and 77 points, respectively. Semaglutide consistently improved primary end points across KCCQ tertiles 1 to 3 (estimated treatment differences [95% CI]: for KCCQ-CSS, 10.7 [5.4 to 16.1], 8.1 [2.7 to 13.4], and 4.6 [-0.6 to 9.9] points; for body weight, -11 [-13.2 to -8.8], -9.4 [-11.5 to -7.2], and -11.8 [-14.0 to -9.6], respectively; Pinteraction=0.28 and 0.29, respectively); the same was observed for confirmatory secondary and exploratory end points (Pinteraction>0.1 for all). Semaglutide-treated patients experienced improvements in all key KCCQ domains (estimated treatment differences, 6.7-9.6 points across domains; P≤0.001 for all). Greater proportion of semaglutide-treated versus placebo-treated patients experienced at least 5-, 10-, 15-, and 20-point improvements in all KCCQ domains (odds ratios, 1.6-2.9 across domains; P<0.05 for all). CONCLUSIONS: In patients with HFpEF and obesity, semaglutide produced large improvements in HF-related symptoms, physical limitations, exercise function, inflammation, body weight, and N-terminal pro-brain natriuretic peptide, regardless of baseline health status. The benefits of semaglutide extended to all key KCCQ domains. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04788511.

Effect of Dapagliflozin Versus Placebo on Symptoms and 6-Minute Walk Distance in Patients With Heart Failure: The DETERMINE Randomized Clinical Trials.

BACKGROUND: Sodium-glucose cotransporter 2 inhibitors reduce the risk of worsening heart failure (HF) and cardiovascular death in patients with HF irrespective of left ventricular ejection fraction. It is important to determine whether therapies for HF improve symptoms and functional capacity. METHODS: The DETERMINE (Dapagliflozin Effect on Exercise Capacity Using a 6-Minute Walk Test in Patients With Heart Failure) double-blind, placebo-controlled, multicenter trials assessed the efficacy of the sodium-glucose cotransporter 2 inhibitor dapagliflozin on the Total Symptom Score (TSS) and Physical Limitation Scale (PLS) of the Kansas City Cardiomyopathy Questionnaire (KCCQ) and 6-minute walk distance (6MWD) in 313 patients with HF with reduced ejection fraction (DETERMINE-Reduced) and in 504 patients with HF with preserved ejection fraction (DETERMINE-Preserved) with New York Heart Association class II or III symptoms and elevated natriuretic peptide levels. The primary outcomes were changes in the KCCQ-TSS, KCCQ-PLS, and 6MWD after 16 weeks of treatment. RESULTS: Among the 313 randomized patients with HF with reduced ejection fraction, the median placebo-corrected difference in KCCQ-TSS from baseline at 16 weeks was 4.2 (95% CI, 1.0, 8.2; P=0.022) in favor of dapagliflozin. The median placebo-corrected difference in KCCQ-PLS was 4.2 (95% CI, 0.0, 8.3; P=0.058). The median placebo-corrected difference in 6MWD from baseline at 16 weeks was 3.2 meters (95% CI, -6.5, 13.0; P=0.69). In the 504 patients with HF with preserved ejection fraction, the median placebo-corrected 16-week difference in KCCQ-TSS and KCCQ-PLS was 3.2 (95% CI, 0.4, 6.0; P=0.079) and 3.1 (-0.1, 5.4; P=0.23), respectively. The median 16-week difference in 6MWD was 1.6 meters (95% CI, -5.9, 9.0; P=0.67). In an exploratory post hoc analysis of both trials combined (DETERMINE-Pooled), the median placebo-corrected difference from baseline at 16 weeks was 3.7 (1.5, 5.9; P=0.005) for KCCQ-TSS, 4.0 (0.3, 4.9; P=0.036) for KCCQ-PLS, and 2.5 meters (-3.5, 8.4; P=0.50) for 6MWD. CONCLUSIONS: Dapagliflozin improved the KCCQ-TSS in patients with HF with reduced ejection fraction but did not improve KCCQ-PLS or 6MWD. Dapagliflozin did not improve these outcomes in patients with HF with preserved ejection fraction. In a post hoc analysis including all patients across the full spectrum of ejection fraction, there was a beneficial effect of dapagliflozin on KCCQ-TSS and KCCQ-PLS but not 6MWD. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT03877237 and NCT03877224.

Sex Disparities in Longitudinal Use and Intensification of Guideline-Directed Medical Therapy Among Patients With Newly Diagnosed Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Guideline-directed medical therapies (GDMTs) are the mainstay of treatment for heart failure with reduced ejection fraction (HFrEF), but they are underused. Whether sex differences exist in the initiation and intensification of GDMT for newly diagnosed HFrEF is not well established. METHODS: Patients with incident HFrEF were identified from the 2016 to 2020 Optum deidentified Clinformatics Data Mart Database, which is derived from a database of administrative health claims for members of large commercial and Medicare Advantage health plans. The primary outcome was the use of optimal GDMT within 12 months of HFrEF diagnosis. Consistent with the guideline recommendations during the time period of the study, optimal GDMT was defined as ≥50% of the target dose of evidence-based beta-blocker plus ≥50% of the target dose of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, or any dose of angiotensin receptor neprilysin inhibitor plus any dose of mineralocorticoid receptor antagonist. The probability of achieving optimal GDMT on follow-up and predictors of optimal GDMT were evaluated with time-to-event analysis with adjusted Cox proportional hazard models. RESULTS: The study cohort included 63 759 patients (mean age, 71.3 years; 15.2% non-Hispanic Black race; 56.6% male). Optimal GDMT use was achieved by 6.2% of patients at 12 months after diagnosis. Female (compared with male) patients with HFrEF had lower use across every GDMT class and lower use of optimal GDMT at each time point at follow-up. In an adjusted Cox model, female sex was associated with a 23% lower probability of achieving optimal GDMT after diagnosis (hazard ratio [HR], 0.77 [95% CI, 0.71-0.83]; P<0.001). The sex disparities in GDMT use after HFrEF diagnosis were most pronounced among patients with commercial insurance (females compared with males; HR, 0.66 [95% CI, 0.58-0.76]) compared with Medicare (HR, 0.85 [95% CI, 0.77-0.92]); Pinteraction sex×insurance status=0.005) and for younger patients (age <65 years: HR, 0.65 [95% CI, 0.58-0.74]) compared with older patients (age ≥65 years: HR, 87 [95% CI, 80-96]) Pinteraction sex×age=0.009). CONCLUSIONS: Overall use of optimal GDMT after HFrEF diagnosis was low, with significantly lower use among female (compared with male) patients. These findings highlight the need for implementation efforts directed at improving GDMT initiation and titration.

Tadalafil for Treatment of Combined Postcapillary and Precapillary Pulmonary Hypertension in Patients With Heart Failure and Preserved Ejection Fraction: A Randomized Controlled Phase 3 Study.

BACKGROUND: We assessed the efficacy and safety of tadalafil, a phosphodiesterase type 5 inhibitor, in patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension. METHODS: In the double-blind PASSION study (Phosphodiesterase-5 Inhibition in Patients With Heart Failure With Preserved Ejection Fraction and Combined Post- and Pre-Capillary Pulmonary Hypertension), patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension were randomized 1:1 to receive tadalafil at a target dose of 40 mg or placebo. The primary end point was the time to the first composite event of adjudicated heart failure hospitalization or all-cause death. Secondary end points included all-cause mortality and improvements in New York Heart Association functional class or ≥10% improvement in 6-minute walking distance from baseline. RESULTS: Initially targeting 372 patients, the study was terminated early because of disruption in study medication supply. At that point, 125 patients had been randomized (placebo: 63; tadalafil: 62,). Combined primary end-point events occurred in 20 patients (32%) assigned to placebo and 17 patients (27%) assigned to tadalafil (hazard ratio, 1.02 [95% CI, 0.52-2.01]; P=0.95). There was a possible signal of higher all-cause mortality in the tadalafil group (hazard ratio, 5.10 [95% CI, 1.10-23.69]; P=0.04). No significant between-group differences were observed in other secondary end points. Serious adverse events occurred in 29 participants (48%) in the tadalafil group and 35 (56%) in the placebo group. CONCLUSIONS: The PASSION trial, terminated prematurely due to study medication supply disruption, does not support tadalafil use in patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension, with potential safety concerns and no observed benefits in primary and secondary end points. REGISTRATION: URL: https://www.clinicaltrialsregister.eu/; Unique identifier: 2017-003688-37. URL: https://drks.de; Unique identifier: DRKS -DRKS00014595.

Cardiovascular Outcomes in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study).

BACKGROUND: Cardiovascular disease is a major cause of morbidity and mortality in patients with type 2 diabetes. The effects of glucose-lowering medications on cardiovascular outcomes in individuals with type 2 diabetes and low cardiovascular risk are unclear. We investigated cardiovascular outcomes by treatment group in participants randomly assigned to insulin glargine, glimepiride, liraglutide, or sitagliptin, added to baseline metformin, in GRADE (Glycemia Reduction Approaches in Type 2 Diabetes: A Comparative Effectiveness Study). METHODS: A total of 5047 participants with a mean±SD age of 57.2±10.0 years, type 2 diabetes duration of 4.0±2.7 years, and low baseline prevalence of cardiovascular disease (myocardial infarction, 5.1%; cerebrovascular accident, 2.0%) were followed for a median of 5 years. Prespecified outcomes included between-group time-to-first event analyses of MACE-3 (composite of major adverse cardiovascular events: cardiovascular death, myocardial infarction, and stroke), MACE-4 (MACE-3+unstable angina requiring hospitalization or revascularization), MACE-5 (MACE-4+coronary revascularization), MACE-6 (MACE-5+hospitalization for heart failure), and the individual components. MACE outcomes and hospitalization for heart failure in the liraglutide-treated group were compared with the other groups combined using Cox proportional hazards models. MACE-6 was also analyzed as recurrent events using a proportional rate model to compare all treatment groups. RESULTS: We observed no statistically significant differences in the cumulative incidence of first MACE-3, MACE-4, MACE-5, or MACE-6, or their individual components, by randomized treatment group. However, when compared with the other treatment groups combined, the liraglutide-treated group had a significantly lower risk of MACE-5 (adjusted hazard ratio, 0.70 [95% CI, 0.54-0.91]; P=0.021), MACE-6 (adjusted hazard ratio, 0.70 [95% CI, 0.55-0.90]; P=0.021), and hospitalization for heart failure (adjusted hazard ratio, 0.49 [95% CI, 0.28-0.86]; P=0.022). Compared with the liraglutide group, significantly higher rates of recurrent MACE-6 events occurred in the groups treated with glimepiride (rate ratio, 1.61 [95% CI, 1.13-2.29]) or sitagliptin (rate ratio 1.75; [95% CI, 1.24-2.48]). CONCLUSIONS: This comparative effectiveness study of a contemporary cohort of adults with type 2 diabetes, largely without established cardiovascular disease, suggests that liraglutide treatment may reduce the risk of cardiovascular events in patients at relatively low risk compared with other commonly used glucose-lowering medications. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01794143.

Ertugliflozin for Functional Mitral Regurgitation Associated With Heart Failure: EFFORT Trial.

BACKGROUND: The morbidity and mortality rates of patients with heart failure (HF) and functional mitral regurgitation (MR) remain substantial despite guideline-directed medical therapy for HF. We evaluated the efficacy of ertugliflozin for reduction of functional MR associated with HF with mild to moderately reduced ejection fraction. METHODS: The EFFORT trial (Ertugliflozin for Functional Mitral Regurgitation) was a multicenter, double-blind, randomized trial to examine the hypothesis that the sodium-glucose cotransporter 2 inhibitor ertugliflozin is effective for improving MR in patients with HF with New York Heart Association functional class II or III, 35%≤ejection fraction<50%, and effective regurgitant orifice area of chronic functional MR >0.1 cm2 on baseline echocardiography. We randomly assigned 128 patients to receive either ertugliflozin or placebo in addition to guideline-directed medical therapy for HF. The primary end point was change in effective regurgitant orifice area of functional MR from baseline to the 12-month follow-up. Secondary end points included changes in regurgitant volume, left ventricular (LV) volume indices, left atrial volume index, LV global longitudinal strain, and NT-proBNP (N-terminal pro-B-type natriuretic peptide). RESULTS: The treatment groups were generally well-balanced with regard to baseline characteristics: mean age, 66±11 years; 61% men; 13% diabetes; 51% atrial fibrillation; 43% use of angiotensin receptor-neprilysin inhibitor; ejection fraction, 42±8%; and effective regurgitant orifice area, 0.20±0.12 cm2. The decrease in effective regurgitant orifice area was significantly greater in the ertugliflozin group than in the placebo group (-0.05±0.06 versus 0.03±0.12 cm2; P<0.001). Compared with placebo, ertugliflozin significantly reduced regurgitant volume by 11.2 mL (95% CI, -16.1 to -6.3; P=0.009), left atrial volume index by 6.0 mL/m2 (95% CI, -12.16 to 0.15; P=0.005), and LV global longitudinal strain by 1.44% (95% CI, -2.42% to -0.46%; P=0.004). There were no significant between-group differences regarding changes in LV volume indices, ejection fraction, or NT-proBNP levels. Serious adverse events occurred in one patient (1.6%) in the ertugliflozin group and 6 (9.2%) in the placebo group (P=0.12). CONCLUSIONS: Among patients with functional MR associated with HF, ertugliflozin significantly improved LV global longitudinal strain and left atrial remodeling, and reduced functional MR. Sodium-glucose cotransporter 2 inhibitors may be considered for patients with functional MR. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04231331.

Cardiovascular Effects of Oral Ketone Ester Treatment in Patients With Heart Failure With Reduced Ejection Fraction: A Randomized, Controlled, Double-Blind Trial.

BACKGROUND: Heart failure triggers a shift in myocardial metabolic substrate utilization, favoring the ketone body 3-hydroxybutyrate as energy source. We hypothesized that 14-day treatment with ketone ester (KE) would improve resting and exercise hemodynamics and exercise capacity in patients with heart failure with reduced ejection fraction. METHODS: In a randomized, double-blind cross-over study, nondiabetic patients with heart failure with reduced ejection fraction received 14-day KE and 14-day isocaloric non-KE comparator regimens of 4 daily doses separated by a 14-day washout period. After each treatment period, participants underwent right heart catheterization, echocardiography, and blood sampling at plasma trough levels and after dosing. Participants underwent an exercise hemodynamic assessment after a second dosing. The primary end point was resting cardiac output (CO). Secondary end points included resting and exercise pulmonary capillary wedge pressure and peak exercise CO and metabolic equivalents. RESULTS: We included 24 patients with heart failure with reduced ejection fraction (17 men; 65±9 years of age; all White). Resting CO at trough levels was higher after KE compared with isocaloric comparator (5.2±1.1 L/min versus 5.0±1.1 L/min; difference, 0.3 L/min [95% CI, 0.1-0.5), and pulmonary capillary wedge pressure was lower (8±3 mm Hg versus 11±3 mm Hg; difference, -2 mm Hg [95% CI, -4 to -1]). These changes were amplified after KE dosing. Across all exercise intensities, KE treatment was associated with lower mean exercise pulmonary capillary wedge pressure (-3 mm Hg [95% CI, -5 to -1] ) and higher mean CO (0.5 L/min [95% CI, 0.1-0.8]), significantly different at low to moderate steady-state exercise but not at peak. Metabolic equivalents remained similar between treatments. In exploratory analyses, KE treatment was associated with 18% lower NT-proBNP (N-terminal pro-B-type natriuretic peptide; difference, -98 ng/L [95% CI, -185 to -23]), higher left ventricular ejection fraction (37±5 versus 34±5%; P=0.01), and lower left atrial and ventricular volumes. CONCLUSIONS: KE treatment for 14 days was associated with higher CO at rest and lower filling pressures, cardiac volumes, and NT-proBNP levels compared with isocaloric comparator. These changes persisted during exercise and were achieved on top of optimal medical therapy. Sustained modulation of circulating ketone bodies is a potential treatment principle in patients with heart failure with reduced ejection fraction. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05161650.

Effect of Empagliflozin on Heart Failure Outcomes After Acute Myocardial Infarction: Insights From the EMPACT-MI Trial.

BACKGROUND: Empagliflozin reduces the risk of heart failure (HF) events in patients with type 2 diabetes at high cardiovascular risk, chronic kidney disease, or prevalent HF irrespective of ejection fraction. Whereas the EMPACT-MI trial (Effect of Empagliflozin on Hospitalization for Heart Failure and Mortality in Patients With Acute Myocardial Infarction) showed that empagliflozin does not reduce the risk of the composite of hospitalization for HF and all-cause death, the effect of empagliflozin on first and recurrent HF events after myocardial infarction is unknown. METHODS: EMPACT-MI was a double-blind, randomized, placebo-controlled, event-driven trial that randomized 6522 patients hospitalized for acute myocardial infarction at risk for HF on the basis of newly developed left ventricular ejection fraction of <45% or signs or symptoms of congestion to receive empagliflozin 10 mg daily or placebo within 14 days of admission. In prespecified secondary analyses, treatment groups were analyzed for HF outcomes. RESULTS: Over a median follow-up of 17.9 months, the risk for first HF hospitalization and total HF hospitalizations was significantly lower in the empagliflozin compared with the placebo group (118 [3.6%] versus 153 [4.7%] patients with events; hazard ratio, 0.77 [95% CI, 0.60, 0.98]; P=0.031, for first HF hospitalization; 148 versus 207 events; rate ratio, 0.67 [95% CI, 0.51, 0.89]; P=0.006, for total HF hospitalizations). Subgroup analysis showed consistency of empagliflozin benefit across clinically relevant patient subgroups for first and total HF hospitalizations. The need for new use of diuretics, renin-angiotensin modulators, or mineralocorticoid receptor antagonists after discharge was less in patients randomized to empagliflozin versus placebo (all P<0.05). CONCLUSIONS: Empagliflozin reduced the risk of HF in patients with left ventricular dysfunction or congestion after acute myocardial infarction. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04509674.

Dapagliflozin Enhances Arterial and Venous Compliance During Exercise in Heart Failure With Preserved Ejection Fraction: Insights From the CAMEO-DAPA Trial.

BACKGROUND: Systemic arterial compliance and venous capacitance are typically impaired in patients with heart failure with preserved ejection fraction (HFpEF), contributing to hemodynamic congestion with stress. Sodium-glucose cotransporter-2 inhibitors reduce hemodynamic congestion and improve clinical outcomes in patients with HFpEF, but the mechanisms remain unclear. This study tested the hypothesis that Dapagliflozin would improve systemic arterial compliance and venous capacitance during exercise in patients with HFpEF. METHODS: In this secondary analysis from the CAMEO-DAPA trial (Cardiac and Metabolic Effects of Dapagliflozin in Heart Failure With Preserved Ejection Fraction Trial), 37 patients with HFpEF (mean age 68 ± 9 years, women 65%) underwent invasive hemodynamic exercise testing with simultaneous echocardiography at baseline and following treatment for 24 weeks with Dapagliflozin or placebo. Radial artery pressure (BP) was measured continuously using a fluid-filled catheter with transformation to aortic pressure, central hemodynamics were measured using high-fidelity micromanometers, and stressed blood volume was estimated from hemodynamic indices fit to a comprehensive cardiovascular model. RESULTS: There was no statistically significant effect of Dapagliflozin on resting BP, but Dapagliflozin reduced systolic BP during peak exercise (estimated treatment difference [ETD], -18.8 mm Hg [95% CI, -33.9 to -3.7] P=0.016). Reduction in BP was related to improved exertional total arterial compliance (ETD, 0.06 mL/mm Hg/m2 [95% CI, 0.003-0.11] P=0.039) and aortic root characteristic impedance (ETD, -2.6 mm Hg/mL*sec [95% CI: -5.1 to -0.03] P=0.048), with no significant effect on systemic vascular resistance. Dapagliflozin reduced estimated stressed blood volume at rest and during peak exercise (ETD, -292 mm Hg [95% CI, -530 to -53] P=0.018), and improved venous capacitance evidenced by a decline in ratio of estimated stressed blood volume to total blood volume (ETD, -7.3% [95% CI, -13.3 to -1.3] P=0.020). Each of these effects of Dapagliflozin at peak exercise were also observed during matched 20W exercise intensity. Improvements in total arterial compliance and estimated stressed blood volume were correlated with decreases in body weight, and reduction in systolic BP with treatment was correlated with the change in estimated stressed blood volume during exercise (r=0.40, P=0.019). Decreases in BP were correlated with reduction in pulmonary capillary wedge pressure during exercise (r=0.56, P<0.001). CONCLUSIONS: In patients with HFpEF, treatment with Dapagliflozin improved systemic arterial compliance and venous capacitance during exercise, while reducing aortic characteristic impedance, suggesting a reduction in arterial wall stiffness. These vascular effects may partially explain the clinical benefits with sodium-glucose cotransporter-2 inhibitors in HFpEF. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04730947.