Abstract 16668: Long-term Outcomes After Endo-epicardial Catheter Ablation of Ventricular Tachycardia in Nonischemic Cardiomyopathy

Abstract

Introduction: Endo-epicardial catheter ablation of ventricular tachycardia (VT) in patients (pts) with nonischemic cardiomyopathy (NICM) has been reported to have satisfactory results at the short- and mid-term follow-up. We sought to determine the outcomes at the long-term follow-up of endo-epicardial ablation of VT in NICM. Hypothesis: Catheter ablation provides satisfactory long term outcome Methods: We prospectively enrolled 128 pts (age 59±13 years, 116 [91%] males) with NICM who underwent endo-epicardial radiofrequency catheter ablation at our Institution. After substrate mapping, all critical sites for the clinical or induced VT(s), identified with activation, entrainment or pace-mapping, together with late, split and fractionated potentials were targeted with focal and/or linear ablation. The procedural endpoint was noninducibility of sustained monomorphic VT. Pts were followed with ICD interrogation. Results: A total of 108 (73%) pts had idiopathic dilated NICM. The remaining 20 (14%) pts had hypertrophic CM (n=11), suspected inflammatory CM (n=6), or valvular CM (n=3). The mean LV ejection fraction was 33±15%. After a mean follow-up of 19 months (max 97 months), a total of 36 (28%) pts died and 17 (13%) underwent heart transplant. Cumulative survival free from any recurrent VT was 53% (68/128 patients) (Figure A). In the remaining 60 (47%) patients with VT recurrences, catheter ablation still resulted in a significant beneficial clinical impact on VT burden, with 25/60 (42%) having only isolated (1-2) VT episodes over follow-up, and a striking reduction of VT storm in the remaining pts (Figure B). Conclusions: In patients with NICM and VT, endo-epicardial substrate-based ablation is effective in achieving long-term freedom from any VT in 53% of patients, with a substantial improvement in VT burden in many of the remaining patients.