Abstract 16516: Pulsed Field Ablation Reduces Pulmonary Vein Stenosis Risk: An Advanced Model for Assessment of PV Stenosis

IntroductionPulmonary vein stenosis (PVS) remains a known morbid risk of catheter ablation for pulmonary vein isolation (PVI) to treat atrial fibrillation. Thermal injury from PVI continues to result in PVS with recent incidences as high as 3.4%.HypothesisWe hypothesized that non-thermal pulsed field ablation (PFA) would reduce the risk of PVS compared to irrigated radiofrequency ablation (IRF).MethodsPFA and IRF deliveries were randomized in eight canines with the two superior PVs ablated using one technology and the two inferior PVs ablated using the other technology. Additional branch vessels were used as untreated controls. In addition, energy deliveries targeted PV’s at both PV ostial and distal sites which were typically 1-4 cm into the vein, targeting locations without significant branching. IRF was delivered at 25-30W with 25-30ml/min saline flow, up to 2 min distal and 4 min proximal. Provocative biphasic, bipolar pulsed electric fields capable of deep transmural lesions were applied up to 32 times per PV through a circular intracardiac multi-electrode catheter. Contrast computed tomography (CT) scans were collected at 0, 2, 4, 8, and 12-week time points. Cross-sectional area measurements at each PV ablation site pre- and post-ablation were compared.ResultsThe most severe PVS was due to IRF and found to occur at 2-4 weeks post ablation with normalized measured PV area reductions at two weeks of 40.3% +/-37% for IRF while PFA showed 6.6% +/- 17% PV area reduction (p