Objectives To determine how exercise influences penetrance of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) among patients with desmosomal mutations. Background While animal models and anecdotal evidence suggest exercise is a risk factor for ARVD/C, there have been no systematic human studies. Methods Eighty-seven carriers (46 male, mean age 44±18) were interviewed about regular physical activity from age ten. The relationship of exercise with; 1) sustained ventricular arrhythmia (VT/VF), 2) stage C heart failure (HF), and 3) meeting diagnostic criteria for ARVD/C (TFC) was studied. Results Endurance athletes (n=56) developed symptoms at a younger age (30.1±13.0 vs. 40.6±21.1 years, p=0.05), were more likely to meet TFC at last follow-up (82% vs. 35%, p<0.001), and had a lower lifetime survival free from VT/VF (p=0.013) and HF (p=0.004). Compared to those who did the least (lowest quartile) exercise per year prior to presentation, those in the second (OR=6.64, p=0.013), third (OR=16.7, p=0.001), and top (OR=25.3, p<0.0001) quartiles were increasingly likely to meet TFC. Among 61 who did not present with VT/VF, the 13 subjects experiencing a first VT/VF event over a mean 8.4±6.7 year follow-up were all endurance athletes (p=0.002). Survival from first VT/VF was lowest among those who exercised most (top quartile) both prior to (p=0.036) and after (p=0.005) clinical presentation. Among individuals in the top quartile, a reduction in exercise decreased VT/VF risk (p=0.04). Conclusions Endurance exercise and frequent exercise increase risk of VT/VF, HF, and ARVD/C in desmosomal mutation carriers. These findings support exercise restriction for these patients.

Background— Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a progressive cardiomyopathy. We aimed to define long-term outcome in a transatlantic cohort of 1001 individuals. Methods and Results— Clinical and genetic characteristics and follow-up data of ARVD/C index-patients (n=439, fulfilling of 2010 criteria in all) and family members (n=562) were assessed. Mutations were identified in 276 index-patients (63%). Index-patients presented predominantly with sustained ventricular arrhythmias (268; 61%). During a median follow-up of 7 years, 301 of the 416 index-patients presenting alive (72%) experienced sustained ventricular arrhythmias. Sudden cardiac death during follow-up occurred more frequently among index-patients without an implantable cardioverter-defibrillator (10/63, 16% versus 2/335, 0.6%). Overall, cardiac mortality and the need for cardiac transplantation were low (6% and 4%, respectively). Clinical characteristics and outcomes were similar in index-patients with and without mutations, as well as in those with familial and nonfamilial ARVD/C. ARVD/C was diagnosed in 207 family members (37%). Symptoms at first evaluation correlated with disease expression. Family members with mutations were more likely to meet Task Force Criteria for ARVD/C (40% versus 18%), experience sustained ventricular arrhythmias (11% versus 1%), and die from a cardiac cause (2% versus 0%) than family members without mutations. Conclusions— Long-term outcome was favorable in diagnosed and treated ARVD/C index-patients and family members. Outcome in index-patients was modulated by implantable cardioverter-defibrillator implantation, but not by mutation status and familial background of disease. One third of family members developed ARVD/C. Outcome in family members was determined by symptoms at first evaluation and mutations.

Presentation with SCD/VF occurs at a significantly younger age when compared with sustained monomorphic VT. The genotype of ARVD/C mutation carriers impacts clinical course and disease expression. Male sex negatively modifies phenotypic expression.