HFSA 25 - Aficamten improves excercise capacity compared to metoprolol in patients with obstructive hypertrophic cardiomyopathy in a prespecified analysis of the MAPLE-HCM study.

Dr Gregory Lewis joins us to discuss findings from a prespecified cardiopulmonary exercise testing analysis of the MAPLE-HCM trial, which reveals divergent effects between aficamten and metoprolol on exercise performance in patients with symptomatic obstructive hypertrophic cardiomyopathy.

This international, double-blind, double-dummy trial enrolled 175 adults with symptomatic obstructive HCM, randomized 1:1 to receive either the cardiac myosin inhibitor aficamten or standard beta-blocker therapy with metoprolol. The prespecified CPET substudy rigorously evaluated maximal effort exercise testing, requiring patients to achieve a peak respiratory exchange ratio above 1.05. Investigators assessed changes in exercise capacity as the primary endpoint, alongside secondary measures including LVOT gradients, functional class, quality of life scores, and echocardiographic parameters over 24 weeks.

Results demonstrated significant differences between treatment arms, with aficamten producing improvements across all physiologic markers of exercise adaptation while metoprolol showed neutral or detrimental effects on several key metrics.

Interview Questions:
1. What is the current treatment landscape for obstructive HCM?
2. What prompted the MAPLE-HCM investigators to conduct this CPET substudy, and what were the aims?
3. What are the key findings?
4. How might these findings influence treatment decisions for clinicians managing patients with oHCM?
5. What are your key take-home messages?

Recorded remotely from Portland, 2025.

Editor: Jordan Rance
Video Specialist: David Ben-Harosh
Support: This is an independent interview produced by Radcliffe Cardiology.