Impact of physical activity intensity on peak oxygen consumption and adverse outcomes in hypertrophic cardiomyopathy: a systematic review and meta-analysis

Abstract Introduction Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by left ventricular hypertrophy and often associated with an elevated risk of sudden cardiac death. Due to concerns about potential adverse events, patients are frequently advised to avoid strenuous exercise, resulting in a scarcity of data on its safety and potential benefits. Consequently, the impact of physical activity on individuals with HCM remains uncertain. Purpose This research aims to systematically review studies, evaluating the effects, safety and efficacy of different exercise intensities on HCM patients. Methods We systematically searched PubMed, Embase, and Cochrane databases and identified studies comparing different levels of physical activity in patients with HCM. Physical activity was categorized into three groups: high-intensity physical activity (HIPA), moderate-intensity physical activity (MIPA) and usual activity/sedentary lifestyle. The primary outcome was change in peak oxygen consumption (VO2), while secondary outcomes included the incidence of syncope, non-sustained ventricular tachycardia (NSVT), and atrial fibrillation during or immediately after the intervention. Heterogeneity was assessed using the I² statistic, and a random-effects model was used for outcomes with high heterogeneity. Results Seven studies (3 RCTs, 4 observational) with 1,882 patients were included. Two RCTs showed a significantly greater increase in peak VO₂ in the MIPA group versus usual activity (MD: 1.60, 95% CI: 0.73–2.46, p = 0.0003, I² = 0%). Adverse events included syncope in 15 (6.4%) usual activity/sedentary, 21 (2.4%) MIPA, and 23 (3.0%) HIPA patients. NSVT occurred in 37 (15.7%) usual activity/sedentary, 39 (4.5%) MIPA, and 21 (2.7%) HIPA patients, while atrial fibrillation was reported in 23 (9.7%) usual activity/sedentary, 5 (0.6%) MIPA, and 8 (1.0%) HIPA patients. The pooled risk ratio for syncope in MIPA group compared to the sedentary group was 0.64 (95% CI: 0.27–1.50, p = 0.15, I² = 0%), and for NSVT in HIPA compared to MIPA group was 0.66 (95% CI: 0.06–7.13, p = 0.53, I² = 54%), both showing no significant difference in risk. Conclusion Moderate-intensity physical activity (MIPA) significantly improved peak VO₂ compared to usual activity, without a significant increase in syncope risk. High-intensity physical activity (HIPA) did not result in a significantly higher risk of non-sustained ventricular tachycardia (NSVT) compared to MIPA.