Preprocedural imaging for VT ablation: enhancing procedure times and ablation success

J. Müller (Bad Krozingen)¹, K. Nentwich (Bad Neustadt a. d. Saale)², A. Berkovitz (Bad Neustadt a. d. Saale)², L. Lehmkuhl (Bad Neustadt a. d. Saale)³, H. Lehrmann (Bad Krozingen)⁴, T. Deneke (Nürnberg)^5
1Universitäts-Herzzentrum Freiburg / Bad Krozingen Klinik für Kardiologie und Angiologie Bad Krozingen, Deutschland; ²RHÖN-KLINIKUM AG Campus Bad Neustadt Klinik für Kardiologie II / Interventionelle Elektrophysiologie Bad Neustadt a. d. Saale, Deutschland; ³RHÖN-KLINIKUM AG Campus Bad Neustadt Radiologie Bad Neustadt a. d. Saale, Deutschland; ⁴Universitäts-Herzzentrum Freiburg / Bad Krozingen Klinik für Kardiologie und Angiologie II Bad Krozingen, Deutschland; ⁵Klinikum Nürnberg Süd Kardiologie Nürnberg, Deutschland

Background:
Preprocedural imaging can facilitate procedural planning of complex electrophysiological procedures including ablation of monomorphic ventricular tachycardia (VT). Computed tomography (CT) and magnetic resonance imaging (MRI) represent cornerstones of high-resolution imaging techniques. Computer-assisted analysis and segmentation of data can help streamline procedures, however, comparison with conventional techniques are scarce. 

Methods:
Consecutive patients with preprocedural imaging (CT or MRI) for first VT ablation from February 2018 to April 2021 were identified. Patients with preprocedural imaging and imaging-aided ablation (electroanatomical data was collected and used to select ablation targets) were compared to patients with conventional electroanatomical mapping. A 1:1 propensity score matching from our institutional database during the same period was performed to identify the conventional ablation group. Procedural data, acute and long-term follow-up was compared between both groups. 

Results:
A total of 214 patients (107 imaging-aided, 107 conventional) undergoing a first VT ablation were included (64 ± 14 years; 88% male; 60% ischemic cardiomyopathy (ICM)). Patients with ICM and preprocedural imaging had in 59% CT (40/68) and in 41% MRI (28/68). Patients with non-ischemic cardiomyopathy (NICM) CT in 10% (4/39) and MRI in 90% (35/39). Major complications occurred in 10% of all patients. Patients with imaging had significantly reduced overall procedure time (136 ± 32 min vs. 149 ± 46 min; p=0.015) and numerically lower fluoroscopy (12.8 ± 7.9 min vs. 13.7 ± 9.4 min; p=0.505) and ablation times (25.9 ± 15.3 min vs. 36.4 ± 56.6 min; p=0.074). Non-inducibility of the clinical VT was achieved in 92% of all patients with higher rates among patients with preprocedural imaging (98% vs. 86%; p=0.014; OR 5.210, 95% CI 1.063-25.522; p=0.042). Non-inducibility of any VT was achieved in 83% with comparable rates among both groups (86% vs. 80%; p=0.273). Especially in patients with ICM preprocedural imaging was associated with successful elimination of the clinical VT (OR 10.353, 95% CI 1.254-85.456; p=0.030). After 21 ± 10 months overall VT recurrences occurred in 39% of all patients with comparable rates between both groups (40% imaging-aided vs. 37% conventional; log rank p=0.705), irrespective of ICM/NICM. All-cause mortality occurred in 25 patients (12%); patients with conventional ablation died significantly more often (18% vs. 6%; log-rank p=0.003).

Conclusions:
Imaging-aided VT ablation is feasible and safe and can help to streamline complex EP procedures. It reduces the procedural, fluoroscopy, and radiofrequency times and is associated with higher non-inducibility rates of the clinical VT.