Pulsed field ablation (PFA) has emerged as a novel modality for atrial fibrillation (AF) treatment, though concerns regarding procedure-related hemolysis persist. This study, published in the Heart Rhythm, compared hemolysis and acute kidney injury (AKI) following microsecond PFA (microPFA), nanosecond PFA (nanoPFA), and radiofrequency ablation (RFA) in patients undergoing AF ablation.

A total of 323 patients treated at a high-volume center were included, comprising microPFA (n=186), nanoPFA (n=65), and RFA (n=72) groups. Pulmonary vein isolation was performed with or without adjunctive ablation. 

Hemolysis markers and renal parameters were assessed at baseline, at the end of the procedure, and 24 hours post-procedure. Patients undergoing AF ablation during the study period were included, while specific exclusion criteria were not detailed in the abstract.
PFA modalities were associated with evident hemolysis, which was not observed with RFA. Increases in bilirubin, lactate dehydrogenase (LDH), and free hemoglobin, along with reduced haptoglobin, were noted following PFA. 

After adjustment, LDH (229.0±50.6 vs 198.4±33.8 IU/L; P<0.001) and free hemoglobin (289.3±45.1 vs 263.7±55.0 ng/mL; P=0.043) were higher with microPFA compared with nanoPFA. Hemoglobin reduction and declines exceeding 20 g/L occurred more frequently with microPFA than nanoPFA or RFA. AKI events were infrequent across groups.

PFA was associated with hemolysis, with greater effects observed in microPFA. NanoPFA showed lower hemolysis indices, while severe anemia and AKI remained uncommon.