Relationship between the degree of renal dysfunction and the safety and efficacy outcomes in patients with atrial fibrillation receiving direct oral anticoagulants

Background: The clinical evaluation of a direct oral anticoagulant (DOAC) treatment for atrial fibrillation (AF) patients with renal dysfunction has not been sufficiently studied. This study aimed to evaluate the safety and efficacy of DOACs for patients with a severely impaired renal function. Methods: This was a retrospective and observational study in a single center. We enrolled 894 consecutive AF patients who were prescribed DOACs, and divided them into three groups based on their creatinine clearance (CrCl) value: CrCl >= 50 mL/min group (n = 634), CrCl 30-49 mL/min group (n = 207), and CrCl 15-29 mL/min group (n = 53). We evaluated the occurrence of major bleeding (MB) as the safety outcome and thromboembolic events (TEs) as the efficacy outcome during the follow-up. Results: The incidence of MB in the CrCl 15-29 mL/min group was significantly higher than in the other groups (CrCl >= 50 mL/min group, 0.8/100 person-years; CrCl 30-49 mL/min group, 1.2/100 person-years; CrCl 15-29 mL/min group, 9.0/100 person-years, log rank test, P < .001). On the other hand, there was no significant difference in the incidence of TEs among the three groups. A multivariate analysis using a Cox proportional hazard model adjusted for the age revealed that the CrCl 15-29 mL/min group was significantly associated with increased MB compared to the CrCl >= 50 mL/min group (hazard ratio: 9.76, 95% confidence interval: 2.69-35.5, P < .001). Similar results were observed when adjusting for other multiple clinical factors. Conclusion: This study demonstrated that the degree of renal dysfunction was a significant prognostic factor for MB in AF patients receiving DOACs.