Differential subclinical hemolysis after pulsed field ablation using the FARAPULSE pentaspline catheter vs the PulseSelect circular multi-electrode array catheter.

Background: Pulsed field ablation (PFA) is a nonthermal ablation method characterized by favorable tissue selectivity and a low complication rate. However, hemolysis has recently emerged as a PFA-specific concern, particularly associated with the FARAPULSE system. Objective: To assess the incidence and clinical relevance of hemolysis following atrial fibrillation (AF) ablation using the PulseSelect system, in comparison with FARAPULSE and conventional radiofrequency (RF) ablation. Methods: This retrospective study included 120 consecutive patients who underwent AF ablation between October 2024 and February 2025 (RF: n = 15; FARAPULSE: n = 39; PulseSelect: n = 66). Hemolysis markers-free plasma hemoglobin, haptoglobin, lactate dehydrogenase (LDH), total bilirubin, and creatinine-were measured before and after ablation. Results: PFA was associated with significantly higher the post-/pre-ablation ratio of free plasma hemoglobin, LDH, and total bilirubin, whereas the ratio of haptoglobin were significantly lower than with RF. The PulseSelect system resulted in less hemolysis than the FARAPULSE system, as evidenced by smaller increases in free plasma hemoglobin, LDH, and total bilirubin, and by higher haptoglobin. Notably, although free plasma hemoglobin increased after ablation with both the PulseSelect and FARAPULSE systems, in contrast to FARAPULSE, no correlation was observed between the number of PulseSelect applications and free plasma hemoglobin. No cases of acute kidney injury occurred in any group. Conclusion: The PulseSelect system induced only mild, subclinical hemolysis-comparable to that seen with FARAPULSE-without any clinically significant anemia or acute kidney injury, even in the absence of a limit on the number of applications. These findings support the safe and flexible use of PulseSelect, not only for pulmonary vein isolation, but also for additional lesion sets in more complex ablation procedures.