BackgroundAdvancing age, decreasing renal function, and atrial fibrillation are strongly associated. Real-world evidence of direct oral anticoagulant (DOAC) use among elderly patients ≥75 years of age with nonvalvular atrial fibrillation and renal dysfunction is limited.ObjectivesThis study sought to assess 2-year outcomes and anticoagulant treatment, stratified by renal function.MethodsEnrolled patients were divided into 4 subgroups by creatinine clearance (CrCl) to determine the impact of renal dysfunction on clinical outcomes.ResultsOf 32,275 patients, 26,202 with CrCl data were analyzed (median follow-up 2.00 [IQR: 1.92-2.00] years); 1.3% of patients had CrCl <15 mL/min, 10.7% had CrCl 15 to <30 mL/min, 33.4% had CrCl 30 to <50 mL/min, 35.8% had CrCl ≥50 mL/min, and 18.9% had unknown CrCl. Cumulative incidences of stroke/systemic embolic events, major bleeding, major plus clinically relevant nonmajor bleeding, cardiovascular death, all-cause death, and net clinical outcomes increased with decreasing CrCl. In multivariable Cox regression analysis, lower CrCl emerged as an independent risk factor for these clinical outcomes, except for major bleeding, compared with CrCl ≥50 mL/min. The effectiveness and safety of DOACs over warfarin were similar or better across 3 CrCl subgroups with CrCl 15 mL/min or more. DOAC use was associated with a lower risk of stroke/systemic embolic events, major bleeding, cardiovascular death, all-cause death, and net clinical outcome compared with warfarin in patients with CrCl 30 to <50 mL/min.ConclusionsIncidences of major clinical outcomes increased with decreasing renal function in elderly nonvalvular atrial fibrillation patients. DOACs were effective and safe even in patients with renal dysfunction (CrCl 15-<50 mL/min). (Prospective Observational Study in Late-Stage Elderly Patients with Non-Valvular Atrial Fibrillation: All Nippon AF In Elderly Registry [ANAFIE Registry];UMIN000024006)