Effect of Semaglutide on Cardiac Structure and Function in Patients With Obesity-Related Heart Failure

Background: Obesity is associated with adverse cardiac remodeling and is a key driver for the development and progression of heart failure (HF). Once-weekly semaglutide (2.4 mg) has been shown to improve HF-related symptoms and physical limitations, body weight, and exercise function in patients with obesity-related heart failure with preserved ejection fraction (HFpEF), but the effects of semaglutide on cardiac structure and function in this population remain unknown. Objectives: In this echocardiography substudy of the STEP-HFpEF Program, we evaluated treatment effects of once-weekly semaglutide (2.4 mg) vs placebo on cardiac structure and function. Methods: Echocardiography at randomization and 52 weeks was performed in 491 of 1,145 participants (43%) in the STEP-HFpEF Program (pooled STEP-HFpEF [Semaglutide Treatment Effect in People with Obesity and HFpEF] and STEP-HFpEF DM [Semaglutide Treatment Effect in People with Obesity, HFpEF, and Type 2 Diabetes] trials). The prespecified primary outcome was change in left atrial (LA) volume, with changes in other echocardiography parameters evaluated as secondary outcomes. Treatment effects of semaglutide vs placebo were assessed using analysis of covariance stratified by trial and body mass index, with adjustment for baseline parameter values. Results: Overall, baseline clinical and echocardiographic characteristics were balanced among those receiving semaglutide (n = 253) and placebo (n = 238). Between baseline and 52 weeks, semaglutide attenuated progression of LA remodeling (estimated mean difference [EMD] in LA volume, −6.13 mL; 95% CI: −9.85 to −2.41 mL; P = 0.0013) and right ventricular (RV) enlargement (EMD in RV end-diastolic area: −1.99 cm²; 95% CI: −3.60 to −0.38 cm²; P = 0.016; EMD in RV end-systolic area: −1.41 cm²; 95% CI: −2.42 to −0.40] cm²; P = 0.0064) compared with placebo. Semaglutide additionally improved E-wave velocity (EMD: −5.63 cm/s; 95% CI: −9.42 to −1.84 cm/s; P = 0.0037), E/A (early/late mitral inflow velocity) ratio (EMD: −0.14; 95% CI: −0.24 to −0.04; P = 0.0075), and E/e′ (early mitral inflow velocity/early diastolic mitral annular velocity) average (EMD: −0.79; 95% CI: −1.60 to 0.01; P = 0.05). These associations were not modified by diabetes or atrial fibrillation status. Semaglutide did not significantly affect left ventricular dimensions, mass, or systolic function. Greater weight loss with semaglutide was associated with greater reduction in LA volume (P_interaction = 0.033) but not with changes in E-wave velocity, E/e′ average, or RV end-diastolic area. Conclusions: In the STEP-HFpEF Program echocardiography substudy, semaglutide appeared to improve adverse cardiac remodeling compared with placebo, further suggesting that treatment with semaglutide may be disease modifying among patients with obesity-related HFpEF.