Abstract 4368643: Acute Kidney Injury Due to Hemolysis After Pulsed Field Ablation: A Case with Limited Lesion Burden

Background: Pulsed field ablation (PFA) is a novel nonthermal technique for atrial fibrillation that uses high-voltage electrical pulses to achieve myocardial ablation with a favorable safety profile. While hemolysis is a known post-procedural finding, clinically significant acute kidney injury (AKI) remains rare and typically associated with high lesion burdens or pre-existing renal impairment. Case: A 73-year-old man with paroxysmal atrial fibrillation and preserved baseline renal function underwent elective PFA using a Farawave catheter, with a total of 68 ablation applications delivered for pulmonary vein and posterior wall isolation. He initially appeared well post-procedure but presented nine days later with dark urine, anemia, and symptomatic AKI (peak creatinine 10.73 mg/dL). Workup revealed hemoglobinuria, low haptoglobin, elevated LDH, and no alternate cause of AKI. Imaging showed no obstruction, and serologic, autoimmune, and infectious workups were unremarkable. The patient improved with conservative management including intravenous fluids and bicarbonate therapy. Creatinine improved to 1.8 mg/dL within two weeks. Decision-making: Despite a modest lesion burden, hemolysis-induced pigment nephropathy was identified as the etiology of AKI. Prior studies associate such complications with higher lesion counts or pre-existing renal dysfunction, making this a unique presentation in an otherwise low-risk patient. Conclusion: This case highlights that severe hemolysis-related AKI can occur following PFA even with moderate lesion delivery and in patients with preserved renal function. Routine post-procedural monitoring for hemolysis and renal injury should be considered, particularly in elderly or at-risk individuals.