Quantification of reversible electroporation area following pentaspline vs balloon-in-basket pulsed-field ablation in patients undergoing systematic remapping

Background / Introduction Pulsed-field ablation (PFA) can induce reversible or irreversible electroporation. Acute remapping may overestimate durable lesions, influencing decisions such as completing posterior wall (PW) ablation. Comparative data on lesion reversibility across PFA systems are lacking. Purpose To evaluate PFA lesion reversibility by comparing acute and chronic electroanatomical mapping (EAM) findings in patients undergoing scheduled systematic remapping after index PFA. Methods Prospective single-centre study including consecutive patients treated with pentaspline PFA (P-PFA) or balloon-in-basket PFA (B-PFA) for paroxysmal or persistent AF. Acute remapping was performed with the ablation catheter; chronic remapping (≥30 days) with a high-density catheter. PW ablated area was defined as bipolar voltage <0.1 mV. Primary endpoint: regression of PW ablated area (acute–chronic difference). Results Fifty-three patients were included (30 P-PFA, 23 B-PFA). Baseline clinical characteristics are listed in Table 1 and were comparable between groups. Time to remapping was similar (38.0 [34.0–51.2] vs 36.0 [32.5–40.0] days; p = 0.273). B-PFA had shorter total procedure time (60.9 ± 11.7 vs 69.6 ± 14.6 min; p = 0.020) and shorter left atrial time (40.8 ± 10.0 vs 53.4 ± 14.0 min; p < 0.001). Fluoroscopy time was shorter with B-PFA (4.4 min [2.25–5.55] vs 8.15 min [6.13–9.44]; p < 0.001) with fewer applications (15.0 [15.0–16.0] vs 58.0 [51.8–68.5]; p < 0.001). Electrogram density in the left atrium did not differ significantly between systems (1441.1 ± 553.9 vs 1248.6 ± 334.4 points; p = 0.136), whereas chronic point density was substantially higher in the P-PFA group (5554.0 [4342.0–6932.0] vs 3215.0 [2648.5–4221.5] points; p < 0.001) Lesion reversibility (acute vs chronic PW ablation area) was significantly greater with P-PFA (median 6.8 [4.6–11.2] cm² vs −0.3 [−1.8–2.0] cm²; p < 0.001), indicating a greater reduction in ablated area over time Acute posterior wall (PW) ablation area was larger with P-PFA (12.6 ± 4.3 vs 6.2 ± 5.0 cm²; p < 0.001). However, chronic PW ablation area was comparable between systems (5.6 [3.8–7.6] vs 5.0 [3.0–8.7] cm²; p = 0.77). Chronic minimum non-ablated PW corridor did not differ significantly between systems (19.5 [15.35–22.15] vs 18.0 [9.25–23.00] mm; p =0.46). The chronic percentage of non-ablated PW surface was also similar (65.6 % [47.7–71.3] with P-PFA vs 70.5 % [58.0–83.4] with B-PFA; p = 0.12). Conclusion P-PFA produces significantly larger acute PW ablation but exhibits substantial lesion reversibility, resulting in chronic PW surfaces comparable to B-PFA. In contrast, B-PFA maintains stable PW lesion proportions. These findings highlight distinct patterns of lesion behavior across two PFA technologies.