Predictors of long-term success after high-density mapping-guided substrate ablation procedures for ventricular tachycardia in patients with ischemic cardiomyopathy.

Introduction: High-density (HD) substrate mapping may increase success of catheter ablation targeting ventricular tachycardia (VT). However, despite its use, recurrent VT is not uncommon. We aim to investigate factors that are associated with outcomes after HD mapping-guided substrate ablation procedures for VT in patients with ischemic cardiomyopathy. Methods: Observational cohort study includes patients with ischemic heart disease who underwent HD mapping-guided substrate ablation of VT. Baseline and procedural characteristics were associated with outcomes after VT ablation. Results: VT ablation employing HD mapping was performed in 80 patients. Median follow-up was 2.3 years. VT-free survival at one, two, and five years were 65%, 49%, and 40%. One-, two-, and five-year implantable cardioverter defibrillator (ICD) shock-free survival rates were 90%, 81%, and 70%. Complications occurred in 3 patients (3.8%, 1 vascular, 2 tamponades). Left ventricular ejection fraction (LVEF) and 45 W (vs. 35 W) ablation power were associated with VT-free survival. High ablation power was also associated with shock-free survival. All-cause mortality during follow-up was associated with higher age, the presence of chronic obstructive pulmonary disease (COPD), LVEF, and urgent ablation. Conclusions: In patients with ischemic cardiomyopathy that had HD substrate mapping-guided VT ablation, ablation power was associated with both VT-free and shock-free survival, underlining the importance of effective target elimination. All-cause mortality during follow-up was associated with several factors (age, COPD, LVEF, and urgent vs. elective ablation), which could be used to guide patient selection for VT ablation.