Endo-epicardial homogenization of the scar versus limited substrate ablation for the treatment of electrical storms in patients with ischemic cardiomyopathy

Objectives: This study investigated the impact on recurrences of 2 different substrate approaches for the treatment of these arrhythmias. Background: Catheter ablation of electrical storms (ES) for ventricular arrhythmias (VAs) has shown moderate long-term efficacy in patients with ischemic cardiomyopathy. Methods: Ninety-two consecutive patients (81% male, age 62 ± 13 years) with ischemic cardiomyopathy and ES underwent catheter ablation. Patients were treated either by confining the radiofrequency lesions to the endocardial surface with limited substrate ablation (Group 1, n = 49) or underwent endocardial and epicardial ablation of abnormal potentials within the scar (homogenization of the scar, Group 2, n = 43). Epicardial access was obtained in all Group 2 patients, whereas epicardial ablation was performed in 33% (14) of these patients. Results: Mean ejection fraction was 27 ± 5. During a mean follow-up of 25 ± 10 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 47% (23 of 49 patients) in Group 1 and 19% (8 of 43 patients) in Group 2 (log-rank p = 0.006). One patient in Group 1 and 1 patient in Group 2 died at follow-up for noncardiac reasons. Conclusions: Our study demonstrates that ablation using endo-epicardial homogenization of the scar significantly increases freedom from VAs in ischemic cardiomyopathy patients.