Abstract
BACKGROUND AND AIMS: Pulsed Field Ablation (PFA) can establish pulmonary vein isolation via irreversible electroporation and is believed to reduce overall complications; however, periprocedural stroke has also been reported after PFA procedures. Assessment of microembolic signals (MES) measured by transcranial doppler (TCD) allows to monitor cerebral embolization during the procedure and to identify higher risk procedural steps. This study was designed to compare the incidence of MES during different procedural steps between two different PFA systems and radiofrequency ablation (RFA). METHODS AND RESULTS: Pulmonary vein isolation was performed either using either high-power short-duration radiofrequency ablation (HPSD RFA), or PFA using a variable loop circular catheter (VLCC) or a circular multielectrode array catheter (CMAC). MES were compared during transseptal puncture, ablation, left atrial mapping, and introduction/retraction of catheters. Neurological examination was performed pre and post ablation for all patients including the National Institutes of Health Stroke Scale (NIHSS). Fifty-six consecutive patients (19 female (34%), average age 70 years) were included: 28 in the HPSD RFA group and 14 patients each in the VLCC and CMAC groups. Total MES count was higher for both PFA systems compared to HPSD RFA (VLCC 1402 (IQR 973), CMAC 449 (IQR 193) vs. HPSD RFA 131 (IQR 250); p < 0.001). MES count was higher in VLCC than in CMAC (p < 0.001). In all groups, MES were most frequently detected during ablation (87% of overall MES). Postprocedural NIHSS did not differ between groups (median NIHSS 0 [IQR 0] in all groups), yet two patients experienced new focal neurological deficits after PFA. CONCLUSION: Pulsed field ablation was associated with a higher cerebral MES count than high-power short-duration radiofrequency ablation, with marked differences between catheter systems. Transcranial doppler indicates ablation as the most embolic step in both PFA and high-power short duration ablation.