WASHINGTON — In a preliminary study of patients with hypertrophic cardiomyopathy, moderate-intensity exercise modestly improved exercise capacity compared with the usual activity, researchers reported at the American College of Cardiology Scientific Session.
Sara Saberi, MD, MS, assistant professor of medicine at University of Michigan School of Medicine, Ann Arbor, and colleagues randomly assigned 136 patients with hypertrophic cardiomyopathy (mean age, 50 years; 42% women) to 16 weeks of moderate-intensity exercise training or no exercise guidance.
“The primary concern is whether exercise can trigger ventricular arrhythmias,” Saberi said during a presentation.
Those in the exercise-training group participated in a structured but unsupervised exercise program based on data about each patient’s heart rate reserve obtained from a baseline cardiopulmonary exercise test, according to Saberi.
During the program, each patient exercised at least 20 minutes three times per week at a heart rate 60% of heart rate reserve, she said.
The primary outcome was change in peak oxygen consumption (peak VO2).
Before the study, 41% of the usual-activity group and 45% of the exercise-training group reported no habitual exercise, but, during the study, 28% of the non-exercising usual-activity group and 93% of the non-exercising exercise-training group reported habitual exercise, Saberi said.
Overall, 83% of patients completed the study, with a similar rate of attrition in both groups. At 16 weeks, change in mean peak VO2 was 1.35 mL/kg per minute in the exercise-training group (95% CI, 0.5-2.21) vs. 0.08 mL/kg per minute in the usual-activity group (95% CI, –0.62 to 0.79; between-group difference, 1.27 mL/kg per minute; 95% CI, 0.17-2.37; P = .02), according to the researchers.
Neither group had sustained ventricular arrhythmia, sudden cardiac arrest, appropriate defibrillator shock or death during the study period. There were no adverse effects on CV morphology, Saberi said.
Quality-of-life measures did not differ between the groups except for the physical activity component of the 36-item Short Form Health Survey (version 2), which increased 5.7 points in the moderate-exercise group and decreased 2.5 points in the usual-activity group (difference, 8.2 points; 95% CI, 2.6-13.7), according to the findings.
“No previous clinical trial has implemented an exercise intervention in patients with hypertrophic cardiomyopathy,” Saberi said. “The findings support moderate exercise activity as an intervention for improving exercise capacity in hypertrophic cardiomyopathy.”
“The most important implication is that low-to-moderate-intensity aerobic exercise benefits these patients,” researcher Matthew Wheeler, MD, PhD, clinical assistant professor of medicine at Stanford University, told Cardiology Today. “We didn’t see any harm, and it’s been an open question in our field whether moderate-intensity exercise in patients with hypertrophic cardiomyopathy is safe. Our hope is that these data will afford our patients peace of mind in their ability to participate in recreational activity without undue fear of causing harm.”
In a related editorial also published in JAMA, Anjali T. Owens, MD, and Thomas P. Cappola, MD, ScM, both from the Center for Inherited Cardiac Disease, division of cardiovascular medicine, University of Pennsylvania Perelman School of Medicine, noted that although genetic risk for CHD can be mitigated by healthy lifestyle choices, “the genetic basis of hypertrophic cardiomyopathy is far more direct, as evidenced by a mendelian pattern of inheritance. But it remains possible that simple interventions such as recreational exercise might also hold the potential to improve disease course in the long run. Larger studies with longer follow-up will be needed to find out.” – by Erik Swain
Saberi S, et al. Featured Clinical Research I. Presented at: American College of Cardiology Scientific Session; March 17-19, 2017; Washington, D.C.
Owens AT, Cappola TP. JAMA. 2017;doi:10.1001/jama.2017.2584.
Saberi S, et al. JAMA. 2017;doi:10.1001/jama.2017.2503.
Disclosure: Cappola reports serving on a data and safety monitoring board for Novartis. Owens and Saberi report no relevant financial disclosures. Wheeler reports consulting for Array Biopharma and MyoKardia.