Background and Aims: Obesity is a major risk factor for heart failure (HF) with preserved ejection fraction (HFpEF). To date, there are no approved therapies specifically targeting the obesity phenotype of HFpEF. STEP-HFpEF (NCT04788511) is a phase 3a trial investigating the effects of semaglutide on disease burden in people with HFpEF and obesity.
Methods: In this 52-week, double-blind trial, adults with HFpEF and body mass index (BMI) ≥30 kg/m2 were randomised 1:1 to once-weekly subcutaneous semaglutide 2.4 mg or placebo. Eligible participants had left ventricular ejection fraction (LVEF) ≥45%, New York Heart Association functional (NYHA) class II–IV, Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) <90 points and ≥1 elevated filling pressure; or HF hospitalisation (within past year) plus ongoing diuretic use and/or structural echo abnormalities. Key exclusion criteria were prior/planned bariatric surgery, >5 kg change in body weight, recent (<30 days) cardiovascular event or recent HF hospitalisation, systolic blood pressure >160 mmHg and diabetes. Dual primary endpoints are change from baseline to 52 weeks in KCCQ-CSS and body weight.
Results: 529 participants (56.1% female, 95.8% White, median age 69 years) were randomised (83 sites, 13 countries). Median body weight was 105.1 kg, BMI 37.0 kg/m2; 66.0% (n=349) of participants had a BMI ≥35. Median baseline measurements were KCCQ-CSS 58.9 points, 6-minute walk distance 320 meters, high-sensitivity C-reactive protein 3.8 mg/L, LVEF 57% and N-terminal pro B-type natriuretic peptide 451 pg/mL. Overall, 52% had history of atrial fibrillation, 15.3% were hospitalised for HF, and 66.2% and 33.8% were in NYHA class II and III–IV, respectively. The majority of patients were treated with beta-blockers, diuretics and angiotensin enzyme/receptor inhibitors or blockers.
Conclusions: STEP-HFpEF will determine whether semaglutide 2.4 mg can improve symptoms, physical limitations and exercise function, plus weight loss, in patients with unmet need for additional therapies.