High intensity exercise programme in patients with hypertrophic cardiomyopathy: a randomized trial

Background and Aims The feasibility and impact of high intensity exercise programmes in patients with hypertrophic cardiomyopathy (HCM) are unknown. This study was conducted to determine the feasibility of a high intensity exercise programme and explore safety and efficacy outcomes in patients with HCM. Methods Participants were randomized to a 12-week supervised exercise programme (n = 40) in addition to usual care, or usual care alone (n = 40). All participants underwent assessment at baseline and 12 weeks. The exercise group was re-evaluated 6 months post-programme. Feasibility was assessed by (i) recruitment, adherence, and retention rates; (ii) staffing ratios; (iii) logistics; and (iv) acceptability of the intervention. The primary exploratory safety outcome was a composite of arrhythmia-related events. Exploratory secondary outcomes included changes in (i) cardiorespiratory fitness; (ii) cardiovascular risk factors; and (iii) quality of life, anxiety, and depression scores. Results Overall, 67 (84%) participants completed the study (n = 34 and n = 33 in the exercise and usual care groups, respectively). Reasons for non-adherence included travel, work, and family commitments. Resource provision complied with national cardiac rehabilitation standards. There was no difference between groups for the exploratory safety outcome (P = .99). At 12 weeks, the exercise group had a greater increase in peak oxygen consumption (VO2) [+4.1 mL/kg/min, 95% confidence interval (CI) 1.1, 7.1] and VO2 at anaerobic threshold (+2.3 mL/kg/min, 95% CI 0.4, 4.1), lower systolic blood pressure (−7.3 mmHg, 95% CI −11.7, −2.8) and body mass index (−0.8 kg/m2, 95% CI −1.1, −0.4), and greater improvement in hospital anxiety (−3, 95% CI −4.3, −1.7) and depression (−1.7, 95% CI −2.9, −0.5) scores, compared to the usual care group. Most exercise gains dissipated at 6 months. Conclusions A high intensity exercise programme is feasible in patients with HCM, with apparent cardiovascular and psychological benefits, and no increase in arrhythmias. A large-scale study is required to substantiate findings and assess long-term safety of high intensity exercise in HCM.