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

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.