CMR-guided vs CMR-aided catheter ablation for ventricular tachycardia: a meta-analysis of prospective studies

Abstract Background Catheter ablation for ventricular tachycardia (VT) in structural heart disease is often limited by challenges in accurately identifying arrhythmogenic substrates. Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) enables detailed scar visualization and may improve ablation targeting. In CMR-guided ablation, imaging data are directly integrated into electroanatomical mapping systems, allowing precise scar-based ablation. In contrast, CMR-aided ablation uses CMR data qualitatively to inform but not guide ablation. The comparative effectiveness of these two strategies remains uncertain. Purpose This meta-analysis aims to evaluate clinical outcomes of CMR-guided versus CMR-aided VT ablation. Methods PubMed, Scopus and Cochrane databases were searched for randomized controlled trials and observational studies comparing CMR-guided versus CMR-aided VT ablation in patients with ischemic and non-ischemic cardiomyopathy. Outcomes assessed were: (1) recurrent ventricular tachyarrhythmias at 12 months of follow-up; (2) residual VT after first substrate ablation; (3) complete and partial procedural success; and (4) radiofrequency ablation time and fluoroscopy time. A random-effects model was applied. Risk ratios (RR) with 95% confidence intervals (CI) were calculated for each outcome. Across all analysed variables, Tau² was 0.00 and I² showed 0% heterogeneity with a non-significant Cochran’s Q test result. This strongly reinforces that our results will be consistent with the larger population. Results Three prospective non-randomized studies comprising 386 patients were included, of whom 145 (37.6%) underwent CMR-guided ablation. Mean follow-up ranged from 12 to 20 months. Recurrence of VT at 12 months of follow-up (RR 0.41; 95% CI: 0.32-0.52; Figure 2) was significantly lower in the CMR-guided group and complete procedural success favored CMR-guided ablation (RR 1.13; 95% CI: 1.05-1.21; Figure 3). Residual VT after first substrate ablation (RR 0.54; 95% CI: 0.30-0.99; Figure 4) was also reduced in CMR-guided ablation. Partial procedural success (RR 0.71; 95% CI 0.30-1.66) and unsuccessful procedure (RR 0.54; 95% CI: 0.04-7.67) were not significantly different between groups. Conclusion CMR-guided VT ablation is associated with significantly lower arrhythmia recurrence and higher procedural success compared to aided-CMR. These findings support the integration of CMR in pre-ablation planning for patients with both ischemic and non-ischemic cardiomyopathy.Figure 1.PRISMA flow diagram Figure 2.Forest Plots of Outcomes