Bleeding Risk Is Associated Inversely with Kidney Function in Patients Taking Warfarin for Atrial Fibrillation

Risk for bleeding during warfarin treatment is higher in patients with end-stage kidney disease than in those without kidney disease. Whether the same is true for patients with less-severe kidney disease is unclear. In this retrospective study, investigators assessed kidney function and risk for major bleeding (e.g., intracranial, gastrointestinal) in >12,000 older adults (mean age, 77) with atrial fibrillation who received first prescriptions for warfarin. Participants were stratified by baseline kidney function into six groups: The groups ranged from estimated glomerular filtration rate (eGFR) ≥90 mL/minute/1.73 m² to eGFR <15 mL/minute/1.73 m².

During median follow-up of 2 years, 12% of participants experienced major bleeding episodes. Ri…