Cardiorenal Outcomes of Treatment with Direct Oral Anticoagulants and Warfarin in Patients with Atrial Fibrillation

Background: Life-long oral anticoagulation therapy with warfarin or direct oral anticoagulants (DOACs) is the mainstay for stroke prevention in patients with non-valvular atrial fibrillation (AF). The DOACs might potentially have lower risk on decline in renal function than warfarin. The aim of this study was to examine the renal outcomes among rivaroxaban, edoxaban, dabigatran and warfarin. Method Using a clinical database from a single-center, this cohort study identified 2203 adults with AF who started anticoagulation therapy between July 1, 2013 and December 31, 2020. Inverse probability of treatment weighting was adopted to balance baseline characteristics among four groups. The primary outcome was a composite of cardiorenal outcomes, involving ≥ 30% decline in estimated glomerular filtration rate (eGFR), renal failure, cardiovascular death, and renal death. Other renal outcomes of interest including ≥ 30% decline in eGFR, doubling of serum creatinine, the incidence of acute kidney injury (AKI) and renal failure, were analyzed. Result We studied 595 patients on warfarin, who were compared to 244, 1070 and 289 patients on dabigatran, rivaroxaban and edoxaban, respectively. After propensity score weighting, dabigatran was associated with significantly lower risk of ≥ 30% decline in eGFR (hazard ratio [HR]: 0.69; 95% confidence interval [CI]: 0.497 to 0.951; p = 0.0237), doubling of serum creatinine (HR:0.49; 95% CI: 0.259 to 0.927; p = 0.0282), and the composite of cardiorenal outcomes (HR:0.67; 95% CI: 0.485 – 0.913; p = 0.0115) compared with warfarin. Rivaroxaban and edoxaban did not show statistically significant protective effects on any renal outcomes, compared to warfarin. Conclusion In this retrospective, single center study, patients treated with dabigatran had significantly reduced risk of decline in renal function and cardiorenal events, when compared to those treated with warfarin. In contrast, rivaroxaban and edoxaban were not associated with lower risk of AKI and renal failure when compared to warfarin.