Background: Pulsed field ablation (PFA) is a new myocardial-specific ablation technology for atrial fibrillation (AF). Direct current electric energy is applied to cells and disrupts cell membranes by creating pores. Data regarding midterm outcome are sparse. 

Objectives:  The aim of this single-center study was to report midterm clinical outcomes following PFA-based pulmonary vein isolation (PVI).

Methods:  Consecutive patients with symptomatic AF were enrolled to undergo PFA-PVI based on the “5S Study” ablation strategy. Procedures were done between March 2021 and January 2022. A dedicated catheter with five splines delivering bipolar energy with a voltage of 1.8-2.0 kV was used. Arrhythmia recurrence was defined as documented AF/atrial tachycardia (AT) lasting more than 30 seconds after a 90 days blanking period (BP). Procedural and demographic data were analysed.

Results: 231 patients (42% female, age 69±12, 55% paroxysmal atrial fibrillation [PAF]) were included in this preliminary analysis. 901 pulmonary veins (PV) were identified, and all PVs could be isolated using solely the PFA device. 895 (99.3 %) PVs were isolated with the first application. 32±4 applications per patient were delivered. The overall complication rate was 3.5% (vascular access complication: 2.2%, stroke: 0.9%, tamponade: 0.4%). Median follow-up time was 323 days. 22% of patients experienced a recurrence during the BP after a median of 23 days. Kaplan Meier estimated freedom of AF/AT out of the BP was 75% at one year, 83% for PAF and 64% for persistent atrial fibrillation (persAF, p< 0.0036). In a multivariate analysis blanking recurrence (p<0.001) and female sex (p=0.002) were the only independent predictors for late recurrence. 

Conclusions:  This study indicates high acute efficacy of PFA based PVI. 75% of patients are free of AF at one year. Blanking recurrence is an independent predictor for late recurrence after PFA-PVI: further studies are required to better define the duration of the BP after PFA PVI.