The Impacts of Oral Anticoagulants on Clinical Outcomes in Patients with Atrial Fibrillation Across Five Stages of Renal Function

Background To analyze the impact of using different renal function equations and stroke prevention strategy in atrial fibrillation (AF) across all chronic kidney disease (CKD) stages. Methods We used the Cockcroft-Gault (CG), Modified Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to classify 39,217 patients into stage 1 to 5 CKD during July 1 st , 2001, and September 30 st , 2018. The endpoint is a composite outcome including ischemic stroke or major bleeding or mortality. Results More patients belonged to stage 1 and 2 CKD using the MDRD and CKD-EPI equations. In subgroups of patients with eGFR-MDRD or eGFR-CKD-EPI ≥ 60 mL/min, a 17-18% increase of event was observed in patients with eGFR-CG < 60 mL/min compared to those ≥ 60 mL/min. Compared to no oral anticoagulant (OAC), OAC use was associated with a significantly lower risk of event across stage 1 to 4 CKD but not in stage 5 CKD. Both warfarin and NOACs exhibited better outcome compared to no OAC across stage 1 to 4 CKD while NOACs was associated with more risk reduction compared to warfarin. Among patients on OACs, there was a trend toward better outcome with NOAC than warfarin across stage 2-4 CKD but not in stage 1 and 5 CKD. Conclusions OAC should be used in stage 1 to 4 CKD with NOAC exhibiting the trend of better outcome through stage 2 to 4 CKD than warfarin. For stage 5 CKD, optimal strategy remains undetermined. Clinical Perspective What Is New? The stages of renal function of AF patients varied significantly with different renal equations, and tthe CG equation remained effective in differentiating clnical outcomes for patients with eGFR-MDRD ≥ 60 mL/min or eGFR-CKD-EPI ≥ 60 mL/min What Are the Clinical Implications? OAC should be used in stage 1 to 4 CKD with NOAC exhibiting the trend of better outcome through stage 2 to 4 CKD than warfarin.