Preprocedural substrate visualization and image integration based on late enhancement computed tomography for ventricular tachycardia ablation in non-ischemic cardiomyopathy

Abstract Background Catheter ablation is an established treatment for ventricular tachycardia (VT). Outcomes for VT ablation in non-ischemic cardiomyopathy (NICM) patients (pts) remain limited and might be improved using preprocedural visualization und mapping integration of the complex underlying substrates. In this context, late iodine enhancement computed tomography (LIE-CT) has emerged as a promising alternative to cardiac MRI for preprocedural substrate assessment. Purpose Data regarding LIE-CT guided VT ablation is scarce especially in NICM pts. Present study sought to assess procedural parameters and outcomes of LIE-CT guided VT ablation in direct comparison with a matched cohort of NICM pts undergoing VT ablation with a conventional mapping (CM) approach. Methods Consecutive patients with NICM undergoing VT ablation between 01/2022 and 08/2024 were included in this registry. For LIE-CT guided VT ablation the CT images were uploaded to an online platform and processed using a dedicated software. A propensity score was used to match NICM pts undergoing VT ablation with CM in a 1:1 fashion according to baseline characteristics, presence of electrical storm and number of prior VT ablations extracted from our specifically designed database. Results A total of 46 pts (age 59±16.4 years, 74% male) were included. Of those 23 pts underwent LIE-CT guided and 23 pts CM VT ablation. An additional voltage map was acquired in all LIE-CT pts. At comparable procedure durations (LIE-CT: 231.5±74.2 min, CV: 220.2±70.2 min, p=0.5) mapping times were shorter in the LIE-CT group: LIE-CT: 35.9±15.3 min, CM: 54±5 min, p=<0.001. An epicardial access was obtained in 12/23 pts (52%) in the LIE-CT group and in 6/23 patients (26%) in the CM group (p=<0.001). Bipolar ablation due to intramural scar detected by LIE-CT was performed in 4/23 pts (17%). No bipolar ablation was performed in the CM group. There was no difference in manifestation of acute kidney injury (LIE-CT: 2/23 pts (9%) vs. CM: 4/23 pts (17%), p=0.9). In one patient in the LIE-CT group a coronary artery stenosis requiring revascularization after bipolar ablation, and in one patient in the CM group a third-degree AV-block during septal ablation occurred. No other complications were observed. After a median follow-up of 138 days (IQR 65-340 days) 15/23 pts (65%) after LIE-CT guided and 13/23 pts (53%) after CM VT ablation were free from VT (logrank p=0.3). Three patients died in each group respectively from terminal heart failure after a median of 60 days (IQR 18-171 days). 30-days mortality was 6%. Conclusion LIE-CT guided preprocedural substrate visualization can be applied safely without additional risk of contrast agent-induced kidney injuries. LIE-CT-model integration resulted in shorter mapping times and identified complex intramural and epicardial scar, leading to bipolar and epicardial ablation.