The impact on renal function after long-term use of anticoagulants in atrial fibrillation patients

Objective: Long-term oral anticoagulant should be considered or recommended in patients with atrial fibrillation (AF) and CHA2DS2VASc score ≥ 1 for stroke prevention. Warfarin and different direct oral anticoagulants (DOACs) are metabolized differently by the kidney. The impact on renal function after long-term use of anticoagulants in the patients with AF remains unclear. This study aimed to compare DOACs and warfarin’s impact on the decline in renal function from a large cohort with AF. Methods: This study included patients with nonvalvular AF from 2000 to 2018, mainly through the medical history (ICD code) of the Chang Gung Research Database. Baseline estimated glomerular filtration rate (eGFR), follow-up eGFR and the change in eGFR between 2-year eGFR and baseline eGFR were compared between different DOACs and warfarin after propensity score matching. The primary study endpoint was acute kidney injury (AKI). Results: 3657 patients were enrolled in this study and the mean observation time was 3.3 ± 0.9 years. During the observation period, there was a significantly higher incidence of AKI during follow-up in the warfarin group than in the different DOAC groups before and after propensity score matching (before: warfarin vs. DOAC: 9.2% vs. 5.2%, p < 0.001; after: warfarin vs. DOAC: 8.9% vs. 4.4%, p < 0.001). There was no difference in the incidence of AKI between dabigatran group and anti-factor Xa inhibitor group after propensity score matching. The incidence of AKI was similar among rivaroxaban, apixaban and edoxaban groups after propensity score matching. The change in eGFR between 2-year eGFR and baseline eGFR did not differ between the warfarin and DOAC groups after propensity score matching (warfarin vs. DOAC: − 1.27 ± 20.32 vs. -1.94 ± 17.24 mL/min/1.73 m², p = 0.461). Conclusions: During the mean observation time of 3.3 ± 0.9 years, warfarin was associated with a higher incidence of AKI compared with DOACs. The decline in renal function did not differ among warfarin and different DOAC groups.