Pulsed field ablation in cavotricuspid isthmus does not induce significant neointimal hyperplasia - results from prospective angiography assessment

The efficacy and safety of pulmonary vein isolation (PVI) using pulsed field ablation (PFA) have been well demonstrated (1). However, concerns have been raised regarding the use of the PFA in the proximity of the coronary arteries, specifically about potential acute (spasm) and chronic arterial wall changes (neointimal hyperplasia) (2).

This study investigated the safety of PFA during CTI ablation, with a specific focus on chronic coronary lesion assessment through computed tomography (CT) angiography at 3 months after the index procedure. The primary outcome was a composite measure that included the occurrence of coronary spasm during ablation or a reduction in the cross-sectional area of the distal right coronary artery (RCA), as observed on CT angiography follow up.

Patient population consisted of subjects enrolled under the 3 different first in human studies with PFA platforms. All study protocols included mandatory CT angiography before and 3 months after the index ablation procedure. Focal (Faraflex large focal platform and PFA through commercially available solid tip, force-sensing catheters with CENTAURI generator), as well as multipolar (Arga Medtech) PFA platforms were used. CTI ablation and bidirectional CTI block check were performed in accordance with a standard clinical practice. Only a multipolar subset of patients received bolus of nitroglycerin intravenously prior to the first PFA application. A continuous twelve-lead ECG monitoring was used to track ST-segment changes. Baseline and three months post-procedure CT angiography (per CT coronary angiography protocol) were conducted to assess distal RCA changes. Significant neointimal hyperplasia was defined as a decrease of more than 50% in the cross-sectional area of the distal part of RCA.

A total of 24 patients were included (age 64 [standard deviation (SD) 7] years; ejection fraction 60% [SD 6%]; left atrial size 45 [SD 4] mm). Of these, 14 patients were in the focal PFA group (Faraflex 7, CENTAURI 7) and 10 were in the multipolar group. Acute bidirectional conduction block of CTI was achieved in all patients. There was one clinicaly overt case of coronary spasm with ST elevation in the focal group, which resolved after an intravenous nitroglycerin injection. Significant neointimal hyperplasia in the distal part of the RCA was not observed in any of the subjcts at 3 months CT angiography follow up.

Neointimal hyperplasia at 3 months post PFA in CTI was not observed in the subject teated with differente PFA platforms/waveform configurations. Safety profile of CTI ablation with the PFA platforms observed in our study should be further validated in larger patient cohorts.