Kohki Nakamura, Takehito Sasaki, Taiki Masuyama, Kentaro Minami, Shingo Yoshimura, Suguru Nishiuchi, Akiko Kodama, Kojiro Hattori, Kenichi Kaseno, Shigeto Naito
BACKGROUND: Hemolysis-related acute kidney injury (AKI) is an uncommon but important complication of pulsed-field ablation (PFA) for atrial fibrillation. The role of baseline hypohaptoglobinemia remains unclear. CASE SUMMARY: A 53-year-old woman with persistent atrial fibrillation underwent pulmonary vein and superior vena cava isolation using a pentaspline PFA catheter with 60 applications. Periprocedural hydration of approximately 1,500 mL was administered. Baseline serum haptoglobin was markedly low at 11 mg/dL (reference range: 43-180 mg/dL, lower detection limit: 10 mg/dL). Serum creatinine increased from 0.66 to 2.68 mg/dL on day 1 and peaked at 5.16 mg/dL on day 3, requiring temporary hemodialysis. Renal function subsequently recovered to baseline. DISCUSSION: Markedly low baseline haptoglobin may have contributed to susceptibility to severe hemolysis-related AKI, even without an excessively high number of PFA applications. TAKE-HOME MESSAGE: Preprocedural hypohaptoglobinemia may be associated with increased susceptibility to AKI after PFA and may support closer monitoring in selected patients.