Catheter Ablation Versus Non-Ablative Strategies for Ventricular Tachycardia in Patients with Ischemic Cardiomyopathy on Implantable Cardioverter-Defibrillator: A Systematic Review and Meta-Analysis

Abstract

Background: Ventricular tachycardia (VT) is an abnormal rapid rhythm originating from the lower ventricles occurring commonly in patients with cardiomyopathic hearts. Three treatment options are available: implantable cardioverter defibrillator (ICD), antiarrhythmic medications or catheter ablation (or a combination of these options). This systematic review aimed to compare the efficacy of catheter ablation vs non-ablative techniques as treatment for VT in patients with ischemic cardiomyopathy. Methods: This was a systematic review and meta-analysis of prospective studies that compared ablative vs non-ablative strategies in patients with ischemic heart disease and depressed left ventricular ejection fraction (LVEF). Outcomes of interest included the post-treatment rate of recurrent VT, appropriate ICD shocks and mortality. Results: Pooled findings of five studies showed a non-significant difference in the odds of VT post-treatment between the ablation arm and the non-ablation arm (OR 0.61; 95% CI 0.34-1.10; p=0.10). Heterogeneity was high (I2=55%). Sensitivity analysis excluding one pilot study contributing to the heterogeneity revealed a statistically significant reduction in the odds of recurrent VT (OR 0.54; 95% CI 0.31-0.94; p=0.0.03). Pooled findings of four studies showed that ablation resulted in a lower rate of appropriate shocks post-treatment compared with the non-ablative group (OR 0.51; 95% CI 0.30-0.87; p=0.01. There was no significant difference in the mortality rate between catheter ablation and non-ablative strategies (OR 0.77; 95% CI 0.47-1.25; p=0.29). Conclusion: Catheter ablation on top of ICD placement reduced the risk of post-treatment VT and appropriate shocks. However, these did not translate into a reduction in mortality. KEYWORDS: catheter ablation, non-ablative strategies, implantable cardioverter defibrillator, ischemic cardiomyopathy.