Catheter ablation versus medical therapy for treatment of ventricular tachycardia associated with structural heart disease: Systematic review and meta-analysis of randomized controlled trials and comparison with observational studies

Abstract

Catheter ablation (CA) is an established therapeutic modality for ventricular tachycardia (VT). We compared the clinical outcomes of CA for VT vs medical therapy from all previously performed randomized controlled trials (RCTs) and compared these to contemporary observational studies. A comprehensive database search through to August 2018 identified 8 eligible studies enrolling 797 patients. In RCTs, VT recurrence and electrical VT storm were significantly reduced in the CA group vs medical therapy group (relative risk [RR] 0.78, 95% confidence interval [CI] 0.64-0.95, P = .01; RR 0.70, 95% CI 0.51-0.94, P = .02, respectively) at a mean follow-up of 22 months. All-cause or cardiac-specific mortality did not differ significantly (RR 0.92, 95% CI 0.67-1.27, P = .62; RR 0.82, 95% CI 0.54-1.26, P = .37, respectively). In 4 observational studies, including 3065 patients with a mean follow-up of 18.2 months, VT recurrence and mortality were significantly lower as compared to the RCTs (28.6% vs 39%, P < .001; 13.2% vs 18%, P= .01, respectively) despite greater incidence of electrical storm (33.2% vs 17%, P < .001), higher prevalence of nonischemic substrate (46.4% vs 3.6%, P < .001), and lower rate of implanted ICDs (68% vs 94.7%, P < .001). Meta-analysis of RCT data shows that CA is superior to medical therapy for predominantly postinfarct, scar-related VT in terms of VT recurrence and electrical VT storm, with no reduction in mortality. Real-world observational studies also demonstrate significant reduction in VT recurrence and mortality, despite a sicker cohort, demonstrating replicability and translation of RCT data in the real world.