Efficacy and safety of Mavacamten for symptomatic Hypertrophic cardiomyopathy - an updated Meta-Analysis of randomized controlled trials

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disorder with risk of sudden cardiac death (SCD) in children and adolescents. Mavacamten, also referred to as MYK-461, a myosin inhibitor of cardiac myocytes is studied in symptomatic HCM. The safety and efficacy of this medication is not well studied in pooled metaanalysis. Online database search was performed from inception to September 2023. We selected randomized clinical trials that compared Mavacamten with placebo/guideline medical treatment for HCM. We studied safety outcomes (Serious adverse events (SAEs), treatment emergent adverse events (TEAs) and Atrial fibrillation). Functional status of patients was assessed as New York Heart Association (NYHA) Classification improvement of at least + 1 grade, Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) change from baseline). Relative risk ratios were used in randomized model using Review Manager Version 5.4 statistical software. A total of 4 RCTs comprising 503 patients were included in meta-analysis. On random effect model, we found that HCM patients that received Mavacamten had significant symptomatic improvement as depicted by improvement in NYHA class by at least + 1 grade (RR = 2.15; P < 0.0001) and KCCQ CSS score improvement (MD = 8.38; P < 0.00001) as compared to placebo arm. There was no statistically significant difference in SAEs (RR = 0.87; P = 0.69) and atrial fibrillation onset (RR = 0.80; P = 0.73) between HCM and placebo arm. The studies had low heterogeneity/publication bias. Mavacamten can improve symptoms in HCM patients, and can be additive to other alternative regimen in HCM patients with no statistical significance of risk of SAE or atrial fibrillation onset as compared to placebo.