Catheter Design Matters: Hemolysis and Renal Function after Pulsed Field Ablation with Balloon-in-Basket vs. Pentaspline Systems

BACKGROUND: Pulsed field ablation (PFA) is a non-thermal modality for pulmonary vein isolation (PVI) in atrial fibrillation (AF). While effective, hemolysis and renal effects may occur, potentially modulated by catheter design. METHODS: In this prospective, non-randomized, single-center study, patients underwent PFA-based PVI using either a balloon-in-basket catheter or a pentaspline catheter. Hemolysis (LDH, bilirubin, haptoglobin, myoglobin) and renal markers (creatinine, eGFR) were assessed immediately before and the morning after ablation. RESULTS: Eighty-one patients were included (balloon-in-basket: n=35; pentaspline: n=46), with comparable baseline characteristics. Both groups achieved acute 100% first-pass PVI. The pentaspline group received more PFA applications (32 [32-40] vs. 16 [16-18], p<0.001). Hemolytic markers increased significantly in both groups but were more pronounced in the pentaspline group: LDH Δ+99 [76-121] vs. +59 [43-69] U/L, bilirubin Δ+5.2 [2.4-8.5] vs. +2.4 [0.2-5.1] µmol/L, haptoglobin Δ-28 [-39 to -18] vs. -6 [-17 to +5] mg/dL (all p<0.001). Myoglobin increased modestly in both groups: Δ+12.0 [0-26.0] vs. +11.0 [0-21.5] ng/mL (p=0.696). Only the pentaspline group exhibited a significant renal function decline: creatinine Δ+6.0 [2.2-11.5] vs. +2.0 [-4.0-4.4] µmol/L (p=0.009); eGFR Δ-4.5 [-10.8 to -1.3] vs. -1.0 [-3.5-5.0] mL/min (p=0.002). CONCLUSION: The pentaspline catheter induced more hemolysis and a measurable decline in renal function. Myoglobin increases were similar in both groups and unlikely to explain the renal findings. Catheter design and energy delivery appear to shape the systemic impact profile of PFA.