Abstract Body: Background: The identification of ventricular tachycardia (VT) substrate is crucial for optimizing the success of VT ablation. Recently, multi-modality imaging has gained interest in VT substrate identification before ablation.
Objective: This study aims to compare VT recurrence and all-cause mortality in patients undergoing MRI-guided versus MRI-aided VT ablation.
Methods: A systematic literature review was conducted from inception until November 30, 2024, following PRISMA guidelines. Two independent reviewers screened studies meeting the following inclusion criteria: VT due to ischemic (ICM) or non-ischemic cardiomyopathy (NICM), MRI-guided ablation (MRI data integrated with electroanatomic mapping), or MRI-aided ablation (MRI reviewed by radiologists and electrophysiologists), age >18 years, and clinical trials or observational studies. Primary endpoints included VT recurrence and all-cause mortality. A stratified subgroup analysis for ICM and NICM was performed. Event rates were estimated using a generic variance random-effects model (CMA IV), with heterogeneity assessed via Cochrane’s Q-statistic (I2>75% indicating high heterogeneity) and study quality evaluated using the Newcastle-Ottawa Scale.
Results: Fifteen studies (N=565, MRI-guided: n=238; MRI-aided: n=327) were included, with a mean follow-up of 24 months. VT recurrence was 25% (CI: 15%-38%, I2=41%, p=0.012) and all-cause mortality was 5.7% (CI: 2.5%-13%, I2=0%, p=0.64) in the MRI-guided group. Subgroup analysis showed VT recurrence rates of 27% in ICM (CI: 17%-40%, I2=11%, p=0.342) and 35% in NICM (CI: 18%-56%, I2=0%, p=0.963). In the MRI-aided group, VT recurrence was 29% (CI: 18%-45%, I2=69%, p=0.04) and all-cause mortality was 4.2% (CI: 1.5%-11%, I2=0%, p=0.669). Subgroup analysis showed VT recurrence of 46.5% in ICM (CI: 29%-65%, I2=37%, p=0.205) and 41% in NICM (CI: 23%-63%, I2=74%, p=0.004). Study quality ranged from moderate to high.
Conclusion: MRI-guided VT ablation is associated with lower VT recurrence rates compared to MRI-aided VT ablation, while all-cause mortality remains similar between both techniques. Stratified analysis suggests that MRI-guided VT ablation may be particularly beneficial in reducing VT recurrence in the ICM subgroup.