Outcomes of Catheter Ablation in Arrhythmogenic Right Ventricular Cardiomyopathy Without Background Implantable Cardioverter Defibrillator Therapy A Multicenter International Ventricular Tachycardia Registry

OBJECTIVES This study sought to determine the long-term outcomes of catheter ablation (CA) of ventricular tachycardia (VT) in a series of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) without background implantable cardioverter-defibrillator (ICD) therapy. BACKGROUND Endo-epicardial CA of VT has been demonstrated to be highly effective in reducing recurrent VT in patients with ARVC. METHODS Thirty-two patients (age 45 +/- 13 years, 72% male) with ARVC and VT underwent CA in the absence of ICD therapy. ICD was recommended in all cases, but implantation was not performed due to patient refusal (63%) or financial hardship (37%). CA was guided by activation/entrainment mapping for mappable VT and pace mapping/targeting of abnormal substrate in cases of unmappable VT. RESULTS Symptoms associated with clinical VT included palpitations (78%), chest pain and shortness of breath (22%), pre-syncope (16%), and syncope (13%). Prior to ablation, 22 patients (69%) failed a mean of 1.3 +/- 0.5 antiarrhythmic drugs. Epicardial mapping and ablation was performed as first-line strategy (20 [63%]) or in case of recurrent VT or persistent inducibility after endocardial-only ablation (3 [9%]-surgical epicardial cryoablation in 1 patient). After a mean of 1.6 (range 1 to 3) procedures, all patients demonstrated noninducibility of sustained VT from at least 2 RV sites; 75% also had stimulation on isoproterenol with no inducible VT. At a median follow-up of 46 months (range 26 to 65 months) following the last ablation, no deaths were observed and freedom from recurrent VT was 81%. CONCLUSIONS In this multicenter international registry of patients with ARVC and VT, CA performed in the absence of background ICD was associated with a low rate of symptomatic VT recurrence (19%) without mortality during 46-month median follow-up. These data suggest that further prospective studies may refine selection of patients with structural heart disease at low risk for SCD, possibly obviating the benefit of ICD therapy. (C) 2019 by the American College of Cardiology Foundation.