Abstract 13189: Clinical Presentation, Long-Term Follow-Up, and Disease Penetrance of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy in 1001 Patients and Family Members

Abstract

Introduction: Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) is a hereditary progressive cardiomyopathy. We aimed to define long-term outcome in a transatlantic ARVD/C cohort of 1001 individuals. Methods: Clinical/genetic characteristics and follow-up data of ARVD/C index patients (n=439, fulfillment of 2010 criteria in all) and family members (n=562) were assessed. Genetic screening of desmosomal and TMEM43 and PLN genes was performed in index patients. Results: Mutations, predominantly in PKP2, were identified in 276/439 (63%). Index patients presented mostly with sustained ventricular arrhythmias (VA) (268/439, 61%). Recurrent sustained VA (in 301/416 (72%) patients presenting alive) characterized follow-up (median 7 years) with 10/63 (16%) sudden cardiac deaths (SCD) in patients without implantable cardioverter-defibrillators (ICDs) versus 2/335 (0.6%) in those with ICDs. Overall, cardiac mortality during follow-up (6%) and cardiac transplantation rate (4%) were low. Although disease onset was significantly earlier in index patients with mutations (first presentation 34 vs.38 years old, p<0.001), disease burden was similar in index patients with and without identified mutations. No phenotypic differences were found between index patients with familial and isolated ARVD/C. Of family members, 37% (207/562) had ARVD/C. Symptoms at presentation correlated with disease expression. Nonetheless, even 103/324 (32%) initially asymptomatic mutation-carrying family members, developed ARVD/C. Family members with mutations more often had ARVD/C (40 vs. 18%, p<0.001), sustained VA (11 vs. 1.3%, p<0.001), and cardiac death (2 vs. 0%) than those without. Conclusions: Long-term outcome in ARVD/C index patients was favorable when diagnosed and treated. Prognosis in family members was determined by symptoms and mutation status. One in three family members, including asymptomatic mutation carriers, developed ARVD/C.