Cerebral Safety of Two Pulsed Field Ablation Workflows for Pulmonary Vein Isolation: Results From the Randomized TWOSOME MRI Study

Background Data on silent cerebral events/lesions (SCE/SCL) following pulsed field ablation (PFA) for pulmonary vein isolation (PVI) are limited. This study aimed to assess the incidence of SCE/SCL using cerebral magnetic resonance imaging (cMRI) in atrial fibrillation (AF) patients undergoing PVI with two distinct PFA systems and workflows. Methods In this prospective, single‐center TWOSOME MRI substudy, patients with paroxysmal AF were randomized 1:1 to single‐shot or single‐tip PFA. Single‐shot PVI was performed using a pentaspline PFA catheter (single‐transseptal access, PV‐angiography, no 3D mapping) and single‐tip PVI using a PFA generator with a focal ablation catheter (double‐transseptal access, 3D mapping). A predefined consecutive cohort underwent 1.5‐T cMRI 24 h after the procedure. SCE were defined as acute cMRI‐detected lesions resolving on 6‐week follow‐up cMRI, and SCL as persistent lesions. Baseline characteristics, neurological symptoms, procedural data, and cMRI findings were assessed. Results Fifty patients underwent cMRI (25 per group). Acute SCE were detected in 3/50 patients (6%; 95% CI 1.3–16.5), with 1/25 (4%) in the single‐shot group and 2/25 (8%) in the single‐tip group ( p = 1.00). All SCE resolved on follow‐up imaging, with no evidence of persistent SCL. One symptomatic stroke occurred in the single‐shot group, unrelated to PFA, and was attributed to air embolization during transseptal puncture. No permanent neurological deficits occurred. Conclusions In this exploratory cMRI study, both PFA workflows showed a low incidence of SCE without evidence of SCL or PFA‐related neurological complications. Larger studies are required to compare cerebral safety profiles of PFA technologies. Trial Registration: NCT07175727 ( clinicaltrials.gov ).