Hemolysis without renal impairment following pulsed field ablation: a comparison of multipolar and large focal catheters

Abstract Background Pulsed field ablation (PFA) is a novel non-thermal technique for the treatment of atrial fibrillation (AF) that enables selective myocardial ablation while sparing surrounding tissue (1). Although hemolysis and renal function during PFA has been reported, data comparing large focal and multipolar PFA catheters, using different PFA waveforms, are still lacking. Purpuse This study aimed to determine the incidence, severity, and clinical consequences of PFA-associated hemolysis and potential renal impairment comparing large focal and multipolar PFA catheters. Methods A total of 122 patients undergoing PFA at the University Hospital were analyzed. Procedures were performed using multipolar and large focal catheter platforms. The ablation strategy consisted of pulmonary vein isolation (PVI) for paroxysmal AF and PVI with additional lesion sets for persistent AF. Venous blood samples were obtained immediately before and 24 hours after ablation. Laboratory testing included standard hemolysis parameters: hemoglobin, haptoglobin, lactate dehydrogenase (LDH), total and direct bilirubin, potassium, creatinine, and estimated glomerular filtration rate (eGFR). All patients received standardized periprocedural hydration (3 L isotonic saline) and diuretics (40 mg furosemide per os 2h after procedure) to mitigate hemolysis-related renal effects. Statistical analysis was conducted using IBM SPSS v30.0. Data was presented with median and interquartile range (IQR). Paired data was compared with paired-samples T-test for normally distributed data and Wilcoxon test for non-normally distributed data. PFA platforms were compared using Student T-test for normally distributed data and Mann-Whitney test for non-normally distributed data. Results Median age of all participants was 64 (IQR 55.5 – 69) years, 64.8% of them were male with median left atrial diameter of 45 (IQR 40 – 49) mm and LVEF of 58 (IQR 53 – 60)%. Median number of PFA lessions was 45.5 (IQR 27 – 88.5) and procedural time was 96 (IQR 78.5 – 109) minutes. PFA was associated with a significant reduction in hemoglobin (P0.001) and haptoglobin (P =0.001), accompanied by marked elevations in LDH (P0.001) and bilirubin (P0.001), consistent with laboratory evidence of intravascular hemolysis. Multipolar PFA catether had much pronounced hemolytic effect, with more significant rise in LDH (P0.001) and bilirubin (P0.001) and more significant decrease in haptoglobin (P=0.002) when compared to large focal PFA catether. Despite these biochemical changes, renal function remained preserved in both groups. The difference in intraprocedural and laboratory parameters between the groups is presented in Table 1. Conclusion Hemolysis was a frequent finding after PFA, more pronounced with the multipolar compared to the large focal catheter. Despite these changes, renal function remained preserved in all patients, likely due to standardized periprocedural hydration and diuretics.Table 1