Exercise Training and Cardiac Remodeling in Hypertrophic Cardiomyopathy: A Systematic Review and Meta-Analysis.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and a leading cause of sudden cardiac death in young individuals and athletes. Historically, exercise restrictions were advised because of concerns about arrhythmias, left ventricular outflow tract (LVOT) obstruction, and adverse remodeling; however, emerging evidence challenges these recommendations. OBJECTIVE: To systematically evaluate the effects of structured and habitual exercise on cardiac structure, function, biomarkers, functional capacity, and safety in individuals with HCM. METHODS: We performed a systematic review and meta-analysis in accordance with PRISMA 2020 guidelines. Randomized and observational studies including patients ≥12 years with confirmed HCM participating in structured exercise or habitual physical activity were eligible. Comparators included usual care, lower-intensity exercise, or sedentary controls. Outcomes included cardiac remodeling parameters (wall thickness, chamber volumes, LVOT gradient, diastolic function), left ventricular ejection fraction (LVEF), B-type natriuretic peptide (BNP), peak oxygen consumption (VO₂ peak), body mass index (BMI), and major adverse clinical events. Random-effects models were used for pooled analyses. RESULTS: Eleven studies (1,457 participants) were included. Exercise was not associated with adverse changes in wall thickness, chamber volumes, LVEF, LVOT gradient, diastolic indices, BNP, or BMI. VO₂ peak changes were heterogeneous, with some trials demonstrating individualized functional improvement. No study reported excess adverse events, including sudden cardiac death, ventricular arrhythmias, syncope, or appropriate ICD therapy. CONCLUSIONS: Structured and habitual exercise appear safe in HCM, without evidence of adverse remodeling or increased arrhythmic risk. Functional benefits vary, supporting individualized, supervised exercise prescriptions and more patient-centered counseling.