Efficacy of catheter ablation for ventricular tachycardia in ischemic cardiomyopathy patients without an ICD implantation

Background Implantable cardioverter defibrillator (ICD) prevents sudden cardiac death (SCD) in patients with ischemic cardiomyopathy (ICM). Catheter ablation has been shown to effectively reduce ventricular tachycardia (VT) recurrence, yet its efficacy in patients without an ICD implantation remains uncertain. Objective We aimed to investigate the outcomes of ablation for VT in ICM patients without a backup ICD. Methods ICM patients received ablation for VT without an ICD implantation were included in this study. Ablation was guided by either activation mapping or substrate mapping. Endocardial ablation was the primary strategy; epicardial access was considered when endocardial ablation failed. The primary endpoint was VT recurrence during follow-up, with secondary endpoints including cardiovascular rehospitalization, all-cause mortality, and a composite of these events. Results A total of 114 patients were included, with the mean age of 58.2 ± 11.1 years, 102 of whom (89.5%) were male.Twelve patients (10.5%) underwent endo-epicardial ablation, while the rest received endocardial ablation. With a median follow-up of 53.8 months (24.8-84.2), VT recurred in 45 patients (39.5%), and 6 patients (5.3%) died, including 2 SCD cases. The recurrence rate of VT was significantly lower in patients undergoing endo-epicardial ablation compared to those with endocardial ablation only (8.3% vs 43.1%, Log-rank P = 0.032). After multivariate adjustment, epicardial ablation remained associated with a reduced risk of VT recurrence (hazard ratio: 0.14, 95% confidential interval: 0.02-0.98, P = 0.048). Conclusion ICM patients undergoing VT ablation without a backup ICD experienced a notably low rate of arrhythmic death, with most recurrences proving non-lethal.