Device-related hemolysis and acute renal injury following pulsed field ablation in atrial fibrillation: insights from pentaspline, large focal, and balloon-in-basket systems

Background Pulsed field ablation (PFA) has recently emerged as a novel non-thermal energy source for the treatment of atrial fibrillation (AF). By inducing irreversible electroporation, PFA enables selective myocardial ablation while minimizing collateral damage to surrounding structures. However, hemolysis has been identified as a unique procedure- related effect of PFA, with its incidence and clinical relevance potentially differing across catheter technologies. Objective This study aimed to evaluate the incidence, severity, and clinical significance of hemolysis and acute kidney injury (AKI) following PFA for AF, comparing three commercially available systems: the pentaspline PFA catheter (FarawaveTM), the large-focal PFA catheter (Sphere-9TM), and the balloon-in-basket PFA catheter. Methods patients undergoing PFA for AF at our institution between September 2022 and August 2025 were prospectively enrolled. Periprocedural blood samples were obtained immediately before the procedure and the following morning to assess hemoglobin (Hb), lactate dehydrogenase (LDH), haptoglobin, bilirubin, creatinine, creatine kinase (CK), troponin, and liver enzymes (AST/GOT, ALT/GPT). AKI was defined according to KDIGO criteria. Results A total of 444 patients were included. Overall, PFA was associated with significant laboratory evidence of hemolysis, with reduced Hb and haptoglobin and increased LDH and bilirubin (all p < 0.001). Creatinine remained stable, confirming preserved renal function. Across devices, hemolysis markers (LDH, bilirubin, haptoglobin) and myocardial injury markers (CK, troponin) were highest with the pentaspline system, intermediate with balloon-in-basket, and lowest with large-focal PFA. AKI occurred in 8 of 404 patients (2.0%), with no significant difference among catheter types and complete recovery within 24 hours. Hemolysis was more frequent with the pentaspline catheter (39.1%), compared with balloon-in-basket (12.0%) and large-focal (0%). None of these laboratory alterations led to clinical symptoms or required medical intervention. Conclusions Different PFA catheters produce distinct biochemical signatures. The pentaspline system was associated with greater subclinical hemolysis and myocardial enzyme elevation followed by balloon-in-basket system. Despite these differences, renal function remained stable, and no clinically relevant complications occurred. These findings confirm the overall safety of PFA and emphasize the impact of catheter design and procedural strategy on its biological footprint.