First-line ablation of ventricular tachycardia in ischemic cardiomyopathy: stratification of outcomes by left ventricular function

Purpose: First-line catheter ablation of ventricular tachycardia/ventricular fibrillation (VT/VF) in patients with ischemic cardiomyopathy (ICM) has been associated with improved outcomes; however, most benefit seems to be in patients with moderately depressed left ventricular ejection fraction (LVEF). Herein, outcomes were stratified based on LVEF. Methods: A meta-analysis of randomized controlled trials (RCTs) evaluating first-line ablation versus medical therapy in patients with VT and ICM was performed. Risk estimates and 95% confidence intervals (CI) were measured. Results: Four RCTs with a total of 505 patients (mean age 66 ± 9 years, 89% male, 80% with previous revascularization) were included. Mean LVEF was 35 ± 8%. At a mean follow-up of 24 ± 9 months, a significant benefit in survival-free from appropriate implantable cardioverter-defibrillator (ICD) therapies was observed in all patients undergoing first-line catheter ablation compared with medical management (RR 0.70, 95% CI 0.56–0.86). In patients with moderately depressed LVEF (> 30–50%), first-line VT ablation was associated with a statistically significant reduction in the composite endpoint of survival free from VT/VF and appropriate ICD therapies (HR 0.52, 95% CI 0.36–0.76), whereas there was no difference in patients with severely depressed LVEF (≤30%) (HR 0.56, 95% CI 0.24–1.32). Funnel plots did not show asymmetry suggesting lack of bias. Conclusions: Patients with ICM and VT undergoing first-line ablation have a significantly lower rate of appropriate ICD therapies without a mortality difference compared with patients receiving an initial approach based on medical therapy. The beneficial effect of a first-line ablation approach was only observed in patients with moderately depressed LVEF (> 30–50%).