Po-05-042 combined endocardial-epicardial versus endocardial catheter ablation alone as first-line therapy for ventricular tachycardia in structural heart disease: an updated systematic review and meta-analysis

Limited single-center studies suggest that a combined endocardial-epicardial (endo-epi) ablation strategy may be superior to endocardial ablation (endo) alone in patients with recurrent ventricular tachycardia (VT). However, small sample size impedes determining the precise impact, as well as the risks, associated with a combined strategy. To compare safety and acute and long-term clinical outcomes of combined endo-epi ablation to endo ablation alone in patients with scar-related VT. A systematic review of studies comparing outcomes between endo-epi vs. endo VT ablation from January 1996 to December 2022 in PubMed, Cochrane, and Embase was performed. Two independent reviewers assessed the studies to determine eligibility and manually extracted the information. Differences were solved by consensus, and the references of selected studies were examined to search for additional studies not initially included. The primary outcomes of this study were individual endpoints of all-ventricular arrhythmia recurrence and all-cause mortality during follow-up after ablation. Secondary endpoints were acute procedural success (non-inducibility of any VT at the end of the procedure) and acute procedural complications. Twenty-four studies comprising 1643 patients were included (mean age 54.8 ± 10.8 years; 80% male; ICM in 47.2%; NICM in 21.3%; and ARVC in 31.5%). After a mean follow-up of 30.9 ± 20.4 months, endo-epi VT ablation was associated with a 38% relative risk reduction of all-ventricular arrhythmia recurrence compared with endo ablation alone (risk ratio [RR]: 0.62; 95% confidence interval [CI]: 0.53 to 0.72; p < 0.001). Secondary outcomes by subgroups showed a lower risk of all-ventricular arrhythmia recurrence in ICM (RR: 0.51; 95% CI: 0.37 to 0.70; p < 0.00001) and ARVC (RR: 0.56; 95% CI: 0.43 to 0.72; p < 0.00001), with a non-significant trend in NICM (RR: 0.82; 95% CI: 0.67 to 1.00; p = 0.06). Overall, endo-epi, compared with endo ablation, was associated with a significant reduction of all-cause mortality (RR: 0.56; 95% CI: 0.34 to 0.94; p = 0.03). The endo-epi approach had a non-significant trend towards higher acute procedural complications (RR: 1.67; 95% CI: 0.99 to 2.82; p = 0.05). This meta-analysis suggests that combined endo-epi ablation as first-line therapy in patients with scar-related VT is associated with a lower risk of all-ventricular arrhythmia recurrence and all-cause mortality than endo-only ablation.