Cerebral safety of two different pulsed field ablation systems for pulmonary vein isolation: the TWOSOME MRI substudy

Abstract Background The TWOSOME trial randomized paroxysmal atrial fibrillation (AF) patients to either single-tip or single shot pulsed field ablation (PFA) for pulmonary vein isolation (PVI). Only few data investigating silent cerebral lesions (SCL) after novel PFA technology exist. Purpose In this substudy, patients underwent cerebal magnetic resonance imaging (cMRI) to detect SCL after PFA using two different ablation systems. Methods In this single-center trial, AF patients were prospectively enrolled and 1:1 randomized in the single-tip or single-shot PFA group. Single-tip PVI was performed using a PFA generator and a 3.5mm contact-force enabled ablation catheter guided by 3D mapping system. In the single-shot PVI group, a pentaspline PFA catheter was used for fluoroscopy-guided PVI. Neurological symptoms of the entire cohort were assessed using NIHSS score. A subset of consecutive patients of each group received cMRI (1.5-T MRI scanning using diffusion-weighted imaging and fluid–attenuated inversion recovery sequences) on the day after the procedure irrespectively of clinical symptoms. Results One hundred patients underwent successful PVI in conscious sedation (50 single-tip, 50 single-shot PFA, 64 ± 10 years, 44% female, CHA2DS2-VA 2 [0-2]). There were no differences in baseline characteristics. Cerebral MRI was performed in 50 patients (25 in each group). In total, 4/50 patients (8%) showed a single cerebral lesion in cMRI (2 in each group, p=1.0). Of these, a punctate SLC was detected in 2/25 patients (8%) in the single-tip group and in 1/25 patients (4%) in the single shot PFA group, respectively (p=0.56), and one patient of the single-shot PFA cMRI group experienced neurological symptoms following air embolization after transseptal puncture, but before the insertion of the PFA system. Cerebral MRI showed focal ischemia in the area of the left middle cerebral artery. Acute NIHSS score was 1, but symptoms resolved completely after 6 weeks, and follow-up cMRI showed continuous lesion demarcation. No permanent sequelae occurred. Conclusions In patients treated with two different PFA systems the rate of cerebral lesions was similar in both groups. SCL occurred in one patient (4%) of the single-shot PFA group and in two patients (8%) of the single-tip PFA group without demonstrating statistical significance.