Hemolysis without clinical sequelae: circular pulsed-field ablation vs high-power short-duration radiofrequency for atrial fibrillation

Background Pulsed-field ablation (PFA) for pulmonary vein isolation (PVI) offers myocardial selectivity and minimizes collateral injury compared with high-power short-duration radiofrequency (HPSD-RF). PFA can transiently disrupt erythrocyte membranes, leading to biochemical hemolysis, but clinical evidence remains limited. Purpose To evaluate acute changes in biochemical markers of hemolysis following circular PFA compared with HPSD-RF ablation. Methods We prospectively enrolled consecutive patients undergoing PVI at a tertiary electrophysiology center. Blood samples were obtained immediately before and 24 hours after ablation. Indirect bilirubin (IB), lactate dehydrogenase (LDH), and haptoglobin were analyzed as percentage variation. Clinical and procedural data were compared between groups. Results Forty patients (median age 59.5 years, 55% male) were included; baseline characteristics were similar. Half had paroxysmal AF and 15% underwent repeat ablation. PFA was performed in 60% and HPSD-RF in 40% of cases. Median applications were 24 (IQR 22–27) for PFA and 60 (IQR 48–67) for HPSD-RF. Compared with HPSD-RF, PFA induced significantly greater biochemical evidence of hemolysis: IB increased by 22.4% versus −0.8% (p=0.046), LDH rose by 21.3% versus −5.7% (p<0.001), and haptoglobin decreased by 40.2% versus 12.6% (p<0.001). Hemoglobin fell similarly in both groups (−1.22 vs −1.47 g/dL, p=0.327). Importantly, no patient developed clinical hemolysis, creatinine elevation, or acute kidney injury (AKI), despite the absence of specific hydration/fluid administration beyond routine intraprocedural perfusions. Conclusion In this prospective cohort, circular PFA was associated with a significantly greater biochemical hemolytic response compared with HPSD-RF. These changes were mild and not accompanied by clinical hemolysis, anemia, or AKI, even without a dedicated hydration protocol. Taken together, these findings reinforce the safety of circular PFA and support its integration into routine workflows.