Abstract 4347985: Hypertrophic Cardiomyopathy and Exercise: A Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials

Background: Hypertrophic cardiomyopathy (HCM) is the leading cause of sudden cardiac death (SCD) among young individuals and athletes. Guidelines support individualised exercise prescriptions, due to uncertainties surrounding physical activity's safety. Hypothesis:This meta-analysis evaluates the safety and efficacy of exercise in HCM patients to guide clinical decisions and reduce sedentary behavior. Methods: We systematically reviewed randomized clinical trials comparing exercise interventions versus usual care in HCM patients. Databases included PubMed, Embase, and Cochrane Library. Primary outcome was peak oxygen consumption (pVO2). A random-effects model was used to calculate mean differences (MD) and standardized mean differences (SMD) with 95% confidence intervals (CI). Trial sequential analysis (TSA) assessed evidence robustness. Analyses were performed using R software (v4.2.3). Results: Four RCTs (n=290) were included. Patients were predominantly NYHA I-III, non-obstructive and a mean left ventricular wall thickness (LVWT) of 19.76mm. Exercise improved pVO2 (MD 1.81 mL/kg/min; 95% CI 1.01-2.61; p< 0.01), confirmed by TSA. No significant differences were observed in left ventricular outflow tract gradients or left ventricular ejection fraction. Exercise reduced LVWT (MD -0.56 mm; 95% CI -0.97 to -0.16; p< 0.01) and body mass index (BMI) (MD -0.65 kg/m2; 95% CI -1.05 to -0.25; p<0.01), without increasing in arrhythmias, syncope, SCD or adverse events. Conclusion: In HCM patients with mild phenotypes, structured exercise appears safe and beneficial, improving functional capacity and reducing LVWT and BMI without raising risks.