Mavacamten Treatment for Hypertrophic Cardiomyopathy: A Systematic Review and MetaAnalysis of Randomized Controlled Trials

Hypertrophic cardiomyopathy (HCM) is the most common heritable cardiomyopathy, yet pharmacological therapy has been unchanged for decades until the recent introduction of mavacamten, a first-inclass cardiac myosin inhibitor. We assessed the efficacy and safety of mavacamten in HCM. To date, only 3 randomized controlled trials (RCTs) compared the outcomes of mavacamten vs placebo for HCM. We used a fixed effects model to calculate risk ratios (RRs) with 95% confidence intervals (CIs). The primary composite endpoint (PCE) was defined as either >= 1.5 mL/kg/min increase in peak oxygen consumption (pVO2) with >= 1 New York Heart Association functional class (NYHA-FC) improvement or >= 3.0 mL/kg/ min increase in pVO2 without worsening of NYHAFC. Secondary outcomes included >= 1 NYHA-FC improvement, septal reduction therapy (SRT) or guideline eligible for SRT, >= 1 serious adverse event (SAE), >= 1 treatment emergency adverse event (TEAE), atrial fibrillation (AF), and nonsustained ventricular tachycardia (NSVT). Three RCTs (n = 422, mean follow-up 24 weeks) were included. Compared to placebo, mavacamten achieved higher rates of PCE (RR 1.92; 95% CI 1.28-2.88; P = 0.002) and >= 1 NYHA-FC improvement (RR 2.10; 95% CI 1.662.67; P < 0.00001) and lower rates of SRT or guideline eligible for SRT (RR 0.29; 95% CI 0.22-0.39; P < 0.00001). There were no differences between both groups in >= 1 SAE, AF, and NSVT, however mavacamten had higher rates of >= 1 TEAE. In patients with HCM, mavacamten helps improve pVO2 and NYHAFC and reduces SRT but may be associated with TEAE. Further research is warranted to evaluate the efficacy, safety, and long-term outcomes of mavacamten. (Curr Probl Cardiol 2023;48:101429.)