Safety and efficacy of flecainide in association with beta-blockers in arrhythmogenic right ventricular cardiomyopathy

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy associated with a high risk of ventricular arrhythmia (VA). Current guidelines recommend beta-blockers as first line medical therapy and if ineffective, treatment by sotalol or amiodarone. Purpose To describe our experience as a tertiary centre for ARVC on flecainide effectiveness and tolerance in addition to beta-blockers to prevent ventricular arrhythmia in ARVC. Methods We included one hundred ARVC patients treated with flecainide and beta-blocker diagnosed between May 1999 and November 2017. Ventricular events including sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and ICD therapy were collected retrospectively in patient's medical records. Besides, a 24 hours Holter monitoring and a programmed ventricular stimulation (PVS) before and after introduction of flecainide were performed. Results Tolerance of flecainide was good with 9% discontinuation (6 for VA occurrence, 2 for side effect, 1 for atrial fibrillation). No Brugada-induced ECG pattern on flecainide was reported. PVC burden on 24 hours Holter monitoring (n = 46 patients) was significantly decreased under treatment (2370; IQR1572–3400 versus 415; IQR97–730, P  Proportion of positive PVS was significantly decreased (n = 32 patients) with 94% having positive PVS before treatment compared to 37.5% on flecainide (P  Fig. 1 ). During a median follow-up of 47 (IQR24–74) months, 23 patients had sustained VA (all monomorphic VT) on treatment (5% per patient–year). No sudden death occurred. Conclusion This study suggests that flecainide and beta-blockers association is complementary to ICD and catheter ablation, and is safe to treat ARVC patients with persistent symptomatic VA.