Mavacamten Treatment for Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis 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-in-class 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 NYHA-FC. 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 1.66-2.67; 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 NYHA-FC and reduces SRT but may be associated with TEAE. Further research is warranted to evaluate the efficacy, safety, and long-term outcomes of mavacamten.