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%).
Keywords: Catheter ablation; Heart failure; Ischemic cardiomyopathy; Ventricular tachycardia.
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