Difference in Cerebral Microembolization With Multielectrode Pentaspline or Variable-Loop Circular PFA Systems

Pulsed field ablation (PFA) is a largely nonthermal modality with myocardial selectivity and collateral damage sparing. Cerebrovascular safety remains an important consideration as catheter design and pulse parameters may influence embolic risk. Microembolic signals (MES), detected by transcranial Doppler (TCD) ultrasonography, may offer a sensitive real-time surrogate for procedural-related embolic activity.

We prospectively compared MES burden between two PFA systems: a multielectrode Pentaspline catheter (Farawave, Boston Scientific) and a more recently introduced variable-loop circular catheter (VLCC) (Varipulse, Biosense Webster). Consecutive patients undergoing first-time pulmonary vein isolation for AF were included. ACT targets were > 300 s (Pentaspline) and > 350 s (VLCC), and ablation was delivered according to manufacturer-recommended workflows.

Among 23 patients (16 Pentaspline, 7 VLCC), ACT was maintained above respective targets in all, and left atrial dwell time was comparable. The total number of PFA deliveries was significantly higher in the Pentaspline group compared to the VLCC group (51 [46-66] vs. 22 [22-25], p < 0.001). The MES burden was significantly higher with VLCC during ablation time (919 [154-2302] vs. 102 [52-248], p = 0.005). This difference was even higher when normalized by the delivered-to-recommended PFA deliveries ratio (p = 0.005). In addition, MES burden with VLCC displayed markedly greater inter-patient variability, whereas Pentaspline results were more reproducible (IQR 2148 vs. 196, p < 0.001).

VLCC PFA was associated with higher and more variable cerebral microembolization compared with the Pentaspline system. These findings underscore the impact of catheter design and energy delivery on embolic load and highlight the need for dedicated cerebrovascular safety evaluation.