Risk of Stroke, Bleeding, and Death in Patients with Nonvalvular Atrial Fibrillation and Chronic Kidney Disease

Introduction: Atrial fibrillation (AF) and chronic kidney disease (CKD) are both associated with increased risk of stroke, and CKD carries a higher bleeding risk. Oral anticoagulation (OAC) treatment is used to reduce the risk of stroke in patients with nonvalvular AF (NVAF); however, the risk versus benefit of OAC for advanced CKD is continuously debated. We aim to assess the management and outcomes of NVAF patients with impaired renal function within a population-based cohort. Methods: We conducted a retrospective observational cohort study using ICD-9 healthcare coding. Patients with incident NVAF between 2004 and 2015 were identified stratified by CKD stage. We compared treatment strategies and estimated risks of stroke, death, or any major bleeding based on CKD stages and OAC treatment. Results: We identified 85,116 patients with incident NVAF. Patients with impaired renal function were older and had more comorbidities. OAC was most common among stage 2 CKD patients (49%) and least in stages 4-5 CKD patients (27.6%). Higher CKD stages were associated with worse outcomes. Stroke rates increased from 1.04 events per 100 person-years (PY) in stage 1 CKD to 3.72 in stages 4-5 CKD. Mortality increased from 3.42 to 32.95 events/100 PY, and bleeding rates increased from 0.89 to 4.91 events/100 PY. OAC was associated with reduced stroke and intracranial bleeding risk regardless of CKD stage, and with a reduced mortality risk in stages 1-3 CKD. Conclusion: Among NVAF patients, advanced renal failure is associated with higher risk of stroke, death, and bleeding. OAC was associated with reduced stroke and intracranial bleeding risk, and with improved survival in stages 1-3 CKD.