Comparison of Alcohol Septal Ablation With Mavacamten in Obstructive Hypertrophic Cardiomyopathy

Obstructive hypertrophic cardiomyopathy (HCM) is associated with significant morbidity attributed to left ventricular outflow tract (LVOT) obstruction. Although alcohol septal ablation (ASA) is an established interventional treatment, mavacamten, a novel cardiac myosin inhibitor, has emerged as a noninvasive pharmacologic alternative. Understanding the comparative efficacy of these 2 treatments is important for optimizing patient care. This single-center retrospective study assessed the hemodynamic and functional changes in adult patients with obstructive HCM treated with ASA (n = 58) or mavacamten (n = 36) from July 2012 to May 2024. Outcomes, including changes in LVOT gradient, left ventricular ejection fraction, mitral regurgitation (MR) severity, and New York Heart Association (NYHA) class, were collected at baseline, 16 weeks, and after 32 weeks of treatment. ASA and mavacamten were associated with over 70% reductions in Valsalva-induced LVOT gradient and MR after 32 weeks. The maximal effect of ASA on LVOT gradient was observed at 16 weeks, whereas mavacamten's peak effect was noted after 32 weeks. MR severity improved similarly in both cohorts (p <0.01). Patients who underwent ASA had a poorer baseline NYHA functional class than their counterparts; however, each treatment significantly improved LVOT gradients (p <0.001) and average NYHA class after 32 weeks (p <0.001). The average left ventricular ejection fraction was comparable at baseline and after 32 weeks between the 2 groups. Patients treated with ASA were older than those treated with mavacamten (68.5 vs 60.8 years, p <0.001). In patients with obstructive HCM, ASA and mavacamten yield significant and comparable improvements in hemodynamics and functional status after 32 weeks.