Evaluation of dose and contact of a circular pulsed field ablation catheter in a porcine model: Impact on hemolysis and renal function.

Abstract

BACKGROUND: Pulsed field ablation (PFA) is an innovative energy modality for cardiac ablation, but has been increasingly associated with hemolysis. While existing research primarily focuses on basket or flower-shaped catheters, data on circular PFA catheters remain limited. OBJECTIVE: The objective of this study was to evaluate the effects of dose and contact of a circular PFA catheter on hemolysis and renal function in a porcine model. METHODS: In vitro experiments compared suspended and myocardial contact PFA delivery and radiofrequency ablation (RFA). Blood samples were analyzed for free hemoglobin (fHb), haptoglobin, and serum potassium. In vivo, 5 pigs underwent RFA and PFA (100-400 applications) in the right heart, with blood samples collected from immediate post-procedure to 20 days. RESULTS: Myocardial contact PFA delivery reduced hemolysis compared to suspended PFA delivery. PFA caused dose-dependent hemolysis, with fHb peaking immediately post-procedure and recovering within 24 hours, along with haptoglobin and indirect bilirubin. Hemoglobin transiently decreased (24-72 hours) but normalized by day 5. Serum creatinine remained stable, showing no acute renal injury even after 400 PFA applications. CONCLUSION: PFA-induced hemolysis demonstrates dose-dependency and is exacerbated by inadequate tissue contact, yet resolves spontaneously without inducing acute kidney injury. These findings support the safety of circular PFA catheters but highlight the need for further studies in larger cohorts and human subjects for clinical validation.