Imaging-Aided VT Ablation. Long-Term Results From a Pilot Study.

Abstract

Background: Ventricular tachycardia (VT) ablation has become a cornerstone of patient care, especially for post-MI VT. Several strategies have proven effective for achieving rhythm control in this population, but the workflow is highly variable and depends on the physician's experience.

Aim: This study describes the initial systematic experience of VT ablation targeting wall thickness heterogeneity on a cardiac computed tomography (CT) scanner used as a surrogate for mapped VT isthmii.

Methods: Consecutive patients with post-MI VT, a CT scan, and a first VT ablation were included from January 2017 to May 2022. Targets were identified based on wall thickness heterogeneity. After image integration, ablation with > 10 grams, 40-50 W was performed with the aim of blocking the CT channels/render them non-capturable. Only then was inducibility tested. Inducible VT, if any, were conventionally mapped and ablated with the aim of reaching non-inducibility.

Results: Thirty-nine patients (97.4% male, age: mean LVEF 35 ± 10%) were included. The mean number of identified CT Channels was 3.6 ± 1.8/patient. Non-inducibility was achieved in 19 (48.7%) of patients after initial imaging-guided ablation, while at least one VT could be induced in 19 (48.7%). Among these patients, 4 had VT related to unblocked or reconnected CT-determined VT channels, and 15 from other areas (border zone), typically with faster cycle length. After further mapping and ablation, 3 (7.7%) patients remained inducible. Mean radiofrequency time was 35 ± 19 min for CT Channels ablation, with an additional 11 ± 8 min for supplementary ablation (global mean RF time 35 ± 19 min). With a mean follow-up of 47.8 ± 24.3 months, 61.9% (95% CI: 44.0%-75.5%) remained VT free.

Conclusion: CT-guided ablation represents a feasible and safe strategy for VT ablation in patients with an ischemic cardiomyopathy.