Long-Term Freedom From Ventricular Arrhythmias in ARVC With Endocardial Only Ablation

Although the epicardial predominance of substrate abnormalities has been well demonstrated in early stages of arrhythmogenic right ventricular cardiomyopathy (ARVC), endocardial (ENDO) ablation may suffice to eliminate ventricular tachycardia (VT) in some patients. We aimed to report the long-term outcomes of ENDO-only ablation in ARVC patients and factors that predict VT-free survival. We included consecutive patients with Task force criteria diagnosis of ARVC undergoing a first ENDO-only VT ablation between 1998 and 2020. Ablation was predominantly guided by activation/entrainment mapping for mappable VTs and pace-mapping/targeting abnormal EGMs for unmappable VTs. The primary endpoint was freedom from any recurrent sustained VT after the last ENDO-only ablation. Seventy-four ARVC patients underwent ENDO-only VT ablation. VT non-inducibility was achieved in 49 patients (66%). During median follow-up of 6.6 years, IQR 3.4 –11.2, 40 patients (54.1%) remained free from any VT recurrence with rare VT ≤ 2 episodes in additional 12.2%. Among patients with non-inducibility, VT-free survival was 75.5% during long-term follow-up. In multivariable analysis, age > 45y at diagnosis (HR = 0.41, 95%CI 0.17-0.98) and VT noninducibility (HR = 0.36, 95%CI 0.16-0.80) were predictors of VT-free survival. Long-term VT-free survival can be achieved in over half of ARVC patients following ENDO-only VT ablation, increasing to over 75% if VT non-inducibility is achieved. Our results support consideration of a stepwise ENDO-only approach before proceeding to epicardial ablation if VT noninducibility can be achieved particularly in older patients.