Redefining the Standard: Insights from the MAPLE Trial in Obstructive HCM

In this episode of In the Thick of It, Dr. Floridian Rader and Dr. Ahmad Masri discuss the transformative results of the MAPLE trial, a head-to-head study comparing aficamten—a cardiac myosin inhibitor—to metoprolol in patients with symptomatic obstructive hypertrophic cardiomyopathy1. The trial utilized a rigorous "double-dummy" design to ensure blinding while testing both medications at therapeutic doses2. Dr. Masri highlights unexpected findings, including the significant reduction in peak $VO_2$ and the worsening of cardiac biomarkers like NT-proBNP in the metoprolol group3. The conversation explores how these results challenge decades of reliance on beta-blockers as a first-line therapy and demonstrate the efficacy of aficamten as a potent upfront monotherapy for improving patient function and cardiac remodeling4.