(125) Risk of Acute Kidney Injury with Direct Oral Anticoagulants Compared with Warfarin: Population-based analysis.

Background: Direct oral anticoagulants [DOACs] have emerged as an effective and safe option in the treatment of patients with atrial fibrillation or venous thromboembolism. Case reports have suggested that DOACs may be associated with an increased risk of acute kidney injury [AKI], which led to a potential safety warning from the Food and Drug Administration.

Objectives: To assess the association of DOACs with AKI compared with warfarin.

Methods: Using MarketScan IBM commercial healthcare data in the United States, we conducted a retrospective cohort analysis. We identified individuals 18 years or older who had newly initiated treatment with DOACs or warfarin between January 1, 2014, and December 31, 2021. We included patients who had 12 months of continuous coverage in medical and pharmacy benefits prior to treatment initiation and excluded those with chronic kidney disease. Our primary outcome was hospitalization for AKI defined using the principal position code of the International Classification of Diseases, Ninth and Tenth Revision. Patients in the cohort were followed until the earliest of treatment discontinuation, switch to the comparator drug, outcome, last day of enrollment in health care benefits, or the end of the study period. To adjust for potential baseline differences between DOAC and warfarin users, we calculated propensity scores using logistic regression. Cox proportional hazards regression with a robust variance estimator was used to estimate hazard ratios [HRs] and 95% confidence intervals [CIs]. We conducted a post hoc analysis to examine severe AKI, defined as AKI requiring dialysis, as a secondary outcome.

Results: We identified 215,918 patients who had received a prescription for a DOAC and 147,839 for warfarin. The incidence rate of AKI per 1000 person-years was lower after initiation of a DOAC than warfarin (7.0 vs. 9.9). When compared with warfarin in a propensity score-matched cohort of 234,742 patients (121,871 receiving each drug), DOAC use was associated with a lower rate of AKI (HR 0.79; 95% CI 0.73, 0.87]. Results were similar for severe AKI, but the CI included the null value of 1 (HR 0.62; 95% CI 0.28, 1.41]

Conclusions: In this comparative safety study using real-world data, patients who were newly prescribed DOACs had a lower rate of AKI compared with warfarin.