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

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. 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. 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. 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.