Strength-Based Exercise Is Not Associated With Ventricular Arrhythmia in Arrhythmogenic Cardiomyopathy-Towards Safer...

Arrhythmogenic cardiomyopathy (ACM) is a genetic heart disorder characterized by fibrofatty replacement of ventricular myocardium, sustained ventricular arrhythmia (VA), and elevated risk of sudden death. Current guidelines restrict high-intensity aerobic exercise and competitive sports in individuals with ACM or at risk due to pathogenic/likely-pathogenic (P/LP) gene variants; however, the impact of strength-based exercise is poorly understood.

This study sought to evaluate the risk of VA in individuals with ACM and/or P/LP ACM gene variants exposed to strength-based exercise.

Participants were from the Johns Hopkins ARVC Registry. Exercise exposure was assessed via telephone from age 10 through follow-up. Participants were stratified into 4 groups: dual athlete, endurance athlete, strength athlete, and sedentary. Kaplan-Meier curves visualized the impact of endurance vs strength exercise on VA risk. Cox proportional hazards regression tested independent associations between strength exercise and VA.

355 individuals were enrolled, with median age 34 years; 55% were dual athletes, 26% sedentary, 12% endurance athletes, and 7% strength athletes. Overall lifetime risk of VA was higher with increased aerobic exercise (dual + endurance) than without (strength + sedentary). There was no difference between dual vs endurance athletes, nor strength athletes vs sedentary. A multivariable Cox regression showed no association of VA with strength training, whereas risk of endurance exercise was significant.

Our study found no association between strength exercise and risk of sustained VA. These findings support individualized risk stratification and shared decision-making in ACM care and show the need for additional studies to guide recommendations.