Real-world effectiveness, response patterns and clinical implementation of Mavacamten in obstructive hypertrophic cardiomyopathy: Insights from the SWISS-MAVA cohort

INTRODUCTION: Mavacamten has demonstrated efficacy and safety in randomized trials for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM), but detailed real-world data in clinically complex populations remain limited. METHODS: We evaluated the effectiveness, response patterns, safety and implementation challenges of mavacamten in a multicenter cohort (SWISS-MAVA) of adult patients with oHCM treated without CYP2C19 genotyping. The primary outcome was reduction of provocable (Valsalva) left ventricular outflow tract gradient (LVOTGval) ≤ 30 mmHg, or LVOTGval≤50 mmHg with ≥1 NYHA class improvement at last follow-up. RESULTS: (p < 0.001). Mean left ventricular ejection fraction (LVEF) decreased (66.7 ± 5.4% to 62.6 ± 5.8%, (p < 0.001)) but remained preserved overall. The primary endpoint was achieved in 74/82 patients (90%), with 62/82 (76%) responding within 6 months. Twelve patients (15%) showed a super-hemodynamic response requiring protocol-mandated dose reduction, prolonging titration by 3.5 ± 2 months. Transient LVEF