Cerebrovascular Ischemic Lesions After Pulsed Field Ablation for Atrial Fibrillation Using Variable-Loop Ablation Catheter

BACKGROUND: Pulsed field energy is an increasingly adopted technology for ablation of atrial fibrillation (AF). Although clinical data on pulsed field ablation (PFA) is positive, data on ischemic cerebral lesions (ICLs) after PFA is limited. Because the individual PFA systems differ substantially in pulse characteristics, cerebral safety should be studied separately for each system. OBJECTIVES: This study sought to assess the incidence of ICLs after PFA for AF using a variable-loop circular catheter. METHODS: The study was designed as a prospective, observational, cohort, single-center study. In patients with nonparoxysmal AF, pulmonary vein and left atrial posterior wall isolation were performed. National Institutes of Health Stroke Scale scores were assessed within 24 hours post ablation. Brain magnetic resonance imaging (1.5T, diffusion-weighted imaging included) was conducted 1 day before and 24 hours after the procedure to detect acute ICL. The study initially aimed to enroll 40 patients but was terminated early because of safety concerns. RESULTS: Twenty-one patients were enrolled (age 66.1 ± 9.0 years, 38% women, all with nonparoxysmal AF). ICLs occurred in 14 (66.7%) patients, with a median of 2 (IQR: 0, 3) lesions per patient, and a median cumulative lesion burden of 10.5 mm (6.3, 19.3). Most ICLs (28; 55.8%) were localized in the posterior territory. One patient experienced a transient ischemic attack, and 1 patient suffered a major peri-procedural stroke (National Institutes of Health Stroke Scale = 6; modified Rankin scale = 3 at the day 30 clinical follow-up). CONCLUSIONS: PFA using a variable-loop circular catheter was associated with a high rate of ICLs. More than half of the lesions were in the posterior cerebrovascular territory. (Cerebral Safety After Pulsed-Field Ablation of Atrial Fibrillation; NCT06786988).