Clinical Presentation and Long-Term Outcomes of Late-Onset Symptomatic ARVC

Diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) is often made after arrhythmias are detected in the second or third decade but can also present later. The authors sought to compare the phenotypes and the long-term outcome between patients with early- vs late-onset ARVC. Patients with a definite ARVC diagnosis fulfilling the 2010 Task Force criteria and symptomatic arrhythmias at initial presentation were candidates. Based on age of onset of symptoms, patients were divided into 2 groups: early ARVC: ≤40 years (E-ARVC) and late ARVC: >40 years (L-ARVC). Clinical characteristics and outcomes were compared between the groups. Between 2004 and 2024, 76 probands were included. Fifty patients were in the E-ARVC group (median 27.5 years) and 26 in L-ARVC (45.5 years). Gender, genotype, family history, and RV function did not show any statistical differences. Patients with L-ARVC were significantly less likely to present with cardiac arrest or syncope than E-ARVC patients (7.6% vs 40.0%; P = 0.003). During follow-up, patients with L-ARVC had a slower VT cycle length (321.5 ms vs 259.5 ms; P < 0.001), lower incidence of electrical storm (19.2% vs 54.0%; P = 0.004), and fewer ICD therapies (42.3% vs 80.0%; P < 0.001) than patients with E-ARVC. During a mean follow-up of 11.1 years, there was a lower incidence of heart failure in L-ARVC patients (46.0% vs 19.2%; P = 0.028). VT ablation was performed with similar success rates. Clinical onset of ARVC after age 40 years is usually less severe than early-onset disease, despite similar structural phenotype, and is associated with slower VTs and less VT storm, and appears to have a lower risk of progression to clinical heart failure.