Abstract Background Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome comprising multiple pathophysiological phenotypes. HFpEF trials have largely enrolled diverse populations and reported average treatment effects, consistently yielding neutral results that may obscure drug-specific benefits within distinct subgroups. To address this issue, we employ an interaction-based that incorporates treatment-by-variable interactions to uncover drug-specific responses. Methods We leveraged four HFpEF clinical trials (TOPCAT, RELAX, NEAT-HFpEF, INDIE-HFpEF) and developed a framework comprising two complementary approaches. The first employed a prognostic responder model to evaluate whether conventional responder definitions reflect treatment-specific benefit or instead capture favorable clinical trajectories common to both treatment and placebo groups. The second used an interaction-based individual treatment effect (ITE) modeling to identify baseline variables that modify therapy effect, distinguishing drug-specific response from prognostic phenotypes. Results Although the prognostic responder model demonstrated good discrimination, further analisys suggested it primarily captured a prognostic signal associated with favorable clinical trajectories common to both treatment and placebo arms. In contrast, the ITE model identified distinct, drug-specific effect modifiers across trials (cardiorenal-inflammatory for spironolactone (TOPCAT), NO-mediated anti-inflammatory for isosorbide mononitrate (NEAT-HFpEF), afterload-reducing for inorganic nitrite (INDIE-HFpEF), and anti–volume-overload for sildenafil (RELAX). Each ITE model demonstrated significance only within its own trial suggesting drug-specific signal. Conclusions The proposed method identifies mechanism-specific effect modifiers, and uncovers clinically meaningful heterogeneity in treatment response, which is not captured by conventional MCID-based approaches. Although exploratory, these findings support phenotype-guided therapy in HFpEF and argue for phenotype-informed trial design to enhance treatment-effect detection and therapy targeting. Graphical Abstract
Rationale and Design of CARDIO-TTRansform, a Phase 3 Trial of Eplontersen in Transthyretin Amyloid Cardiomyopathy
BACKGROUND: Transthyretin amyloidosis with cardiomyopathy is a progressive, fatal disease characterized by deposition of extracellular misfolded transthyretin (TTR) in the myocardium. Eplontersen is an N-acetylgalactosamine ligand–conjugated antisense oligonucleotide targeting hepatocyte TTR messenger RNA to reduce the production of circulating TTR. METHODS: CARDIO-TTRansform is a Phase 3, randomized, double-blind, placebo-controlled trial to assess the efficacy and safety of eplontersen in transthyretin amyloidosis with cardiomyopathy. Key inclusion criteria include histological evidence of amyloid deposits or grade 2 to 3 cardiac uptake on cardiac scintigraphy in the absence of plasma cell dyscrasia, New York Heart Association class I–III, and end-diastolic interventricular septum thickness >12 millimeters. Participants were randomized 1:1 to receive eplontersen 45 mg or placebo, administered subcutaneously every 4 weeks for up to 140 weeks, followed by a 20-week post-treatment evaluation period or open-label extension. Participants received locally available standard of care, including unrestricted use of TTR stabilizers. The primary end point is a composite of cardiovascular mortality and recurrent clinical cardiovascular events through 140 weeks. Secondary end points, in order of testing hierarchy, include changes from baseline in 6-minute walk distance and Kansas City Cardiomyopathy Questionnaire overall summary score, recurrent cardiovascular events, all-cause mortality, the primary end point in the patient subgroup receiving stabilizers at baseline, and cardiovascular mortality. Echocardiography was performed in all participants, with cardiovascular magnetic resonance imaging and technetium scintigraphy in a subset. CONCLUSIONS: CARDIO-TTRansform is fully enrolled, with 1432 randomized participants who were dosed with study drug or placebo. As the largest transthyretin amyloidosis with cardiomyopathy study to date, it will evaluate whether eplontersen improves cardiovascular outcomes in patients receiving locally available standard of care, including TTR stabilizers. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04136171. URL: http://ClinicalTrialsRegister.eu ; Unique identifier: EudraCT number 2019-002835-27.
Effects of Semaglutide in Obesity-Related Heart Failure with Preserved Ejection Fraction Across the Age Spectrum: Findings from the STEP-HFpEF Programme
Abstract Background The prevalence of heart failure with preserved ejection fraction (HFpEF) increases with age, and older adults with HFpEF have worse physical function, quality of life, and clinical outcomes. Semaglutide demonstrated efficacy in the treatment of obesity-related HFpEF in the STEP-HFpEF trials. Some have speculated that older patients may have less to gain from incretin therapies (and perhaps more to lose) than younger patients. Aims In this pre-specified pooled subanalysis of the STEP-HFpEF trials, we evaluated the efficacy of semaglutide across the age spectrum. Methods The STEP-HFpEF and STEP-HFpEF DM trials enrolled participants with obesity-related HFpEF and randomized them to semaglutide 2.4 mg once weekly (n = 573) or placebo (n = 572) for 52 weeks. Dual primary outcomes (change in Kansas City Cardiomyopathy Questionnaire clinical summary score [KCCQ-CSS] and change in body weight) and secondary outcome measures (6-minute walk distance [6MWD], C-reactive protein, hierarchical composite endpoint containing all-cause death, heart failure events, changes in KCCQ-CSS and 6MWD) were compared across specific age groups; <55 years, 55–64 years, 65–74 years and ≥75 years. Results Among 1145 randomized participants, 8.8% (N = 101) were <55, 23.3% (N = 267) were aged between 55–64, 42.4% (N = 485) were between 65–74, and 25.5% (N = 292) were 75 years or over. The efficacy of semaglutide on the dual primary endpoints was consistent across the age spectrum, KCCQ-CSS (p-interaction = 0.80), and body weight (p-interaction = 0.41). Similar benefits were observed for the key secondary endpoints, with no treatment effect heterogeneity across age groups. Moreover, the safety of semaglutide was consistent across age groups. Conclusion In patients with HFpEF enrolled across the STEP-HFpEF and STEP-HFpEF DM trials, treatment with semaglutide improved disease-specific symptoms, physical function and reduced body weight across the age spectrum. The safety profile of semaglutide was consistent in older and younger patients.
Coramitug, a Humanized Monoclonal Antibody for the Treatment of Transthyretin Amyloid Cardiomyopathy: A Phase 2, Randomized, Multicenter, Double-Blind, Placebo-Controlled Trial
BACKGROUND: Transthyretin amyloidosis with cardiomyopathy is a progressive disease caused by the deposition of transthyretin (TTR) as amyloid in the myocardium. Current therapies may slow disease progression but do not clear existing deposits. Coramitug is a humanized monoclonal antibody that targets misfolded transthyretin, designed to promote clearance of transthyretin amyloid through antibody-mediated phagocytosis. METHODS: This phase 2, double-blind, placebo-controlled trial randomized participants with transthyretin amyloidosis with cardiomyopathy to receive infusions every 4 weeks of either coramitug at 2 dosages (10 mg/kg or 60 mg/kg) or placebo in a 1:1:1 ratio for 52 weeks. The primary end points were the change from baseline to week 52 in the 6-minute walk test and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. Safety was assessed for up to 64 weeks by assessing treatment-emergent adverse events, all-cause mortality, and number of cardiovascular events (comprising hospitalization caused by cardiovascular events or urgent heart failure visits). RESULTS: In total, 104 participants (median age, 77 years; 93% men; 84% New York Heart Association class II; 13% with variant transthyretin amyloidosis with cardiomyopathy) were randomized and dosed: 34 to 10 mg/kg of coramitug, 35 to 60 mg/kg of coramitug, and 35 to placebo. Median NT-proBNP was 1985 pg/mL (interquartile range, 1224, 3406). In total, 90% of participants were receiving disease-modifying therapy; 84% were treated with tafamidis and 7 (6.7%) with transthyretin silencers (patisiran, n=4; vutrisiran, n=3). From baseline to week 52, 60 mg/kg of coramitug significantly reduced NT-proBNP levels compared with placebo (–48% [95% CI, –65% to –22%]; P =0.0017). The change in 6-minute walk test from baseline to week 52 was not statistically different from placebo with either dose. Coramitug (60 mg/kg) was associated with improved functional echocardiographic parameters and was well tolerated. CONCLUSIONS: This phase 2 trial showed that coramitug, an antibody targeting misfolded transthyretin in transthyretin amyloidosis with cardiomyopathy, was well tolerated and, at a dose of 60 mg/kg, resulted in a statistically significant reduction in NT-proBNP, a validated marker of disease progression, with no statistically significant effect on 6-minute walk test within 52 weeks. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05442047.
Epicardial adipose tissue, functional status, and invasive exercise hemodynamics in heart failure with preserved ejection fraction: Insights from the REDUCE LAP-HF II trial
Abstract Background Obesity is strongly associated with the development of heart failure (HF) with preserved ejection fraction (HFpEF). Beyond increased body mass index (BMI), an abundance of epicardial adipose tissue (EAT) may play a role in its pathophysiology. Purpose To study the associations between increased EAT, functional status and invasive exercise hemodynamics in a large cohort of HFpEF patients. Methods This is a sub-analysis from a large randomized clinical trial that investigated an atrial shunt device in patients with HF with left ventricular ejection fraction ≥40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25mmHg. At baseline, all patients underwent echocardiography, 6-minute walk distance (6-MWD) test, Kansas City Cardiomyopathy Questionnaire (KCCQ) and invasive hemodynamic assessment at rest and during supine ergometry. EAT thickness was measured on the free wall of the right ventricle on echocardiography, expressed in mm and patients were divided according to EAT tertiles. Results In total, 566 patients were examined. Their mean age was 72±8 years, 62% were women, mean BMI was 33±6 kg/m2 and mean EAT thickness was 6.0±2.4 mm, ranging from 1.7 to 17.2 mm. With increasing EAT thickness tertiles, 6-MWD and KCCQ overall summary score were significantly lower (320 vs. 315 vs. 287m, p=.01; 51 vs. 45 vs. 41, p=.003; respectively, Figure 1A-B). The association between increased EAT and lower KCCQ score was independent of BMI (p=.004, β: -2.6), whereas the association with lower 6-MWD was not independent of BMI (p=.1, β: -6.9). At rest, invasive hemodynamics were not different across EAT tertiles. At peak exercise, patients in the highest EAT thickness tertile had higher PCWP and PCWP to right atrial pressure gradient, as compared to patients in the first and second EAT thickness tertiles (36±8 vs. 34±8 mmHg, p=.009; 18±7 vs. 16±7 mmHg, p=.002, respectively, Figure 1C). Conclusion Excess EAT is common in patients with HFpEF and is associated with lower functional status and with higher left-sided filling pressures at peak exercise. These data suggest that EAT plays a significant role in functional status and exercise hemodynamics in HFpEF.Figure 1
SPIROMICS HF: Rationale, Design, and Reproducibility of Measures
BACKGROUND: Although chronic obstructive pulmonary disease (COPD) and heart failure with preserved ejection fraction often coexist with overlapping clinical features, they are usually studied separately. The SPIROMICS HF (Subpopulations and Intermediate Outcome Measures in COPD and Heart Failure Study) is testing hypotheses that new computed tomography emphysema subtypes are associated with specific cardiovascular phenotypes (eg, cor pulmonale , cor pulmonale parvus ), common airway branch variants are associated with right heart dysfunction, and symptomatic tobacco-exposed persons with preserved spirometry have signs of increased left ventricular afterload. METHODS: SPIROMICS is a multicenter observational study of COPD with extensive pulmonary phenotyping of participants with ≥20 pack-years smoking and nonsmoking controls. COPD and COPD severity were defined by standard spirometric criteria and symptomatic tobacco-exposed persons with preserved spirometry by ≥20 pack-years, normal spirometry, and COPD Assessment Test score >10. SPIROMICS HF selected all participants in SPIROMICS visit 5 at major sites. Its comprehensive speckle-tracking echocardiography, which included physiological perturbations of leg raise and low-intensity exercise, was harmonized prospectively with the Multi-Ethnic Study of Atherosclerosis Early Heart Failure and HeartSHARE (Combining Omics, Deep Phenotyping, and Electronic Health Records for Heart Failure Subtypes and Treatment Targets) studies. The cardiopulmonary magnetic resonance imaging protocol with gadolinium administration included myocardial fibrosis sequences, pulmonary angiography, time-resolved 3-dimensional cine magnetic resonance imaging (4-dimensional flow) of venous return, and metronome-paced tachypnea to induce dynamic hyperinflation. Coronary artery calcium was assessed on computed tomography scans. The Kansas City Cardiomyopathy Questionnaire was administered. RESULTS: Of the final sample of 753 participants, 57% had COPD (15% mild, 27% moderate, and 15% severe), 18% had symptomatic tobacco-exposed persons with preserved spirometry, 16% were smoking controls, and 8% were nonsmoking controls. Reproducibility of the main measures from speckle-tracking echocardiography (intraclass correlation coefficient, 0.83–0.99), exercise echocardiography (intraclass correlation coefficient, 0.71–0.99) and magnetic resonance imaging (intraclass correlation coefficient, 0.57–0.99) were good-to-excellent, including in severe COPD. CONCLUSIONS: SPIROMICS HF aims to characterize and understand cardiopulmonary interactions in COPD and COPD-related phenotypes to inform targeted treatments for combined cardiopulmonary failure.
Application of a Transthyretin Amyloid Cardiomyopathy Score to Heart Failure with Mildly Reduced or Preserved Ejection Fraction
Importance Excess body fat plays a pivotal role in the pathogenesis of heart failure with preserved ejection fraction (HFpEF). HU6 is a novel, controlled metabolic accelerator that enhances mitochondrial uncoupling resulting in increased metabolism and fat-specific weight loss. Objective To assess efficacy and safety of HU6 in reducing body weight, improving peak volume of oxygen consumption (VO 2 ) and body composition among patients with obesity-related HFpEF. Design, Setting, and Participants The Exploratory Phase 2A, Double-Blind, Placebo-Controlled Dose Escalation Study of Safety, Tolerability, Pharmacodynamics, and Pharmacokinetics of HU6 for Subjects With Obese HFpEF (HuMAIN-HFpEF) trial was a multicenter, dose-escalation randomized clinical trial among patients with chronic stable HFpEF and obesity. Data were analyzed from July to October 2024. Intervention HU6 treatment for 19 weeks, starting at 150 mg per day and potentially up titrated to 450 mg per day based on safety and tolerability vs placebo. Main Outcomes and Measures The primary end point was change in body weight. Results Of 66 participants randomized (mean [SD] age, 64.5 [12] years; 38 female [58%]; mean [SD] weight, 110.9 [22.4] kg), 56 completed the trial. HU6 (vs placebo) significantly decreased weight (between-group difference, −2.86 kg; 95% CI, −4.68 to −1.04 kg; P = .003), total fat mass (between-group difference, −2.96 kg; 95% CI, −4.50 to −1.42 kg; P &lt; .001), and percentage visceral fat (between-group difference,−1.3%; 95% CI, −2.1 to −0.5%; P = .003), with no significant loss of muscle mass. There were no statistically significant changes in peak VO 2 , 6-minute walk distance, Kansas City Cardiomyopathy Questionnaire score, high-sensitivity C-reactive protein level, N-terminal pro–brain natriuretic peptide level, or diastolic function. Serious adverse events were noted in 5 participants (4 in the HU6 group; 1 in the placebo group), including 1 death, all judged unrelated to treatment. Conclusions and Relevance Among patients with obesity-related HFpEF, treatment with HU6 for 19 weeks led to modest but statistically significant weight loss without significant changes in peak VO 2 . Larger trials of longer duration are warranted to determine whether longer-term administration of HU6 can improve exercise function, quality of life, and cardiovascular outcomes in this increasingly common disorder. Trial Registration ClinicalTrials.gov Identifier: NCT05284617
Macitentan for Heart Failure With Preserved or Mildly Reduced Ejection Fraction and Pulmonary Vascular Disease: Results of the SERENADE Randomized Clinical Trial and Open-Label Extension Study
BACKGROUND: Despite favorable hemodynamic and neurohormonal effects, endothelin receptor antagonists have not improved outcomes in patients with heart failure (HF), possibly because they cause fluid retention. METHODS: In this randomized, double-blind, multicenter trial (SERENADE [Macitentan in Heart Failure With Preserved Ejection Fraction and Pulmonary Vascular Disease]), we evaluated the effects of an endothelin receptor antagonist, macitentan, in patients with HF, left ventricular ejection fraction ≥40%, and pulmonary vascular disease. After a 4-week placebo run-in (to ensure clinical stability), followed by a 5-week single-blind macitentan run-in, patients who did not exhibit fluid retention were randomized to macitentan or placebo. The primary end point was change in NT-proBNP (N-terminal pro-B-type natriuretic peptide; baseline to 24 weeks); secondary end points included change in KCCQ (Kansas City Cardiomyopathy Questionnaire) clinical summary score (baseline to 24 weeks) and time to worsening HF by 52 weeks. RESULTS: Of 230 patients enrolled, 28 were excluded during the placebo run-in, 60 excluded during the macitentan run-in, and 142 were randomized. Macitentan had no effect on change in NT-proBNP (geometric mean ratio [macitentan/placebo], 1.02 [90% CI, 0.88–1.19]; P =0.79) or on secondary end points (placebo-corrected change in KCCQ clinical summary score, −3.5 [90% CI, −8.2 to +1.2]; P =0.22). Worsening HF occurred in 20 (28%) patients assigned to macitentan and 13 (18%) assigned to placebo (hazard ratio, 1.48 [90% CI, 0.83–2.67]; P =0.24). More macitentan-treated patients developed fluid retention (16 [23%] versus 10 [14%]) and cardiac adverse events (33 [46%] versus 22 [31%]) versus placebo. CONCLUSIONS: Despite a novel enrichment trial design to target pulmonary vascular disease and exclude treatment-related fluid retention in patients with HF and preserved/mildly reduced left ventricular ejection fraction, macitentan neither lowered NT-proBNP nor improved HF outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifiers: NCT03153111 and NCT03714815.
Baseline Kidney Function and the Effects of Dapagliflozin On Health Status in Heart Failure in DEFINE-HF and PRESERVED-HF
Abstract Aims Sodium–glucose co-transporter-2 (SGLT2) inhibitors improve health status and outcomes in the setting of heart failure (HF) across the range of ejection fraction (EF). Baseline kidney disease is common in HF, complicates HF management and is strongly linked to worse health status. This study aimed to assess whether the treatment effects of dapagliflozin on health status vary based on estimated glomerular filtration rate (eGFR). Methods and Results We conducted a pooled participant-level analysis of two double-blind, randomized trials, DEFINE-HF (n = 236) and PRESERVED-HF (n = 324), which evaluated dapagliflozin versus placebo. Both multicentre studies enrolled adults with HF, New York Heart Association Class II or higher, elevated natriuretic peptides, and an EF < 40% in DEFINE-HF or >45% in PRESERVED-HF. The primary exposure was eGFR. The main outcome was the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) at 12 weeks. Across both trials, there were 583 (99.3%) participants with a baseline eGFR. The median (25th, 75th) eGFR was 59 (46, 77) mL/min/1.73 m2. Dapagliflozin improved KCCQ-CSS at 12 weeks [placebo-adjusted difference, +5.0 points, 95% confidence interval (CI) 2.6–7.5; P < 0.001], and this was consistent in participants with an eGFR ≥ 60 (+6.0 points, 95% CI 2.4–9.7; P = 0.001) and eGFR < 60 (+4.1 points, 95% CI 0.5–7.7; P = 0.025) (P interaction = 0.46). The benefits of dapagliflozin on KCCQ-CSS remained robust across eGFR when modelled as a continuous variable (P interaction = 0.48). Conclusions Dapagliflozin led to early and clinically meaningful improvements in health status in HF patients, regardless of EF or baseline eGFR.