Progression of myocardial dysfunction and prediction of arrhythmic events in patients with exercise-induced arrhythmogenic cardiomyopathy

Background

Several reports exist of an acquired exercise-induced arrhythmogenic cardiomyopathy. Little is known about myocardial disease progression and arrhythmia prediction in this population.

Objective

The study sought to explore the evolution of myocardial function and structure and its relation to incident life-threatening ventricular arrhythmias (VA), to identify markers of impending events.

Methods

We included athletes (individuals with exercise doses >24 metabolic equivalent of task hours per week, >6 consecutive years, participating in organized and competitive sports) who had VA, absence of family history and known genetic variants associated with cardiac disease, and no other identified etiology, in a tertiary referral single-center, longitudinal cohort study of patients with exercise-induced arrhythmogenic cardiomyopathy (EiAC). Evolution of myocardial function and structure was assessed by repeated echocardiographic examinations during long-term follow-up. Life-threatening VA were assessed at baseline and during long-term follow-up.

Results

Forty-one EiAC patients (15% women, age 45 ± 13 years) were followed for 80 (interquartile range 48–115) months. There were no changes in myocardial function or structure in the overall population during follow-up. We observed high incidence rate and high recurrence rate of life-threatening VA in EiAC patients. Subtle deterioration of right ventricular function was strongly associated with subsequent first-time VA (odds ratio 1.12, 95% confidence interval 1.01–1.25, P = .031, per 1% deterioration of right ventricular free wall longitudinal strain).

Conclusion

There were no clear changes in myocardial function or structure during follow-up in the overall population, but there was a high incidence rate and high recurrence rate of life-threatening VA. Subtle right ventricular deterioration by free wall longitudinal strain was a strong predictor of impending first-time life-threatening VA during follow-up.