Background: Over 6 million Americans are prescribed anticoagulation; however, available anticoagulation options for patients with concomitant renal impairment are limited. Until recently, warfarin was the only recommended option because of a lack of data to support the use of alternative agents in such patients. This study evaluates the safety and effectiveness of apixaban, compared with warfarin, in patients with severe renal dysfunction.
Study design: Multicenter retrospective cohort study.
Setting: Seven hospitals in Michigan between January 2013 and December 2015 and including adult patients with CrCl less than 25 cc/min who were newly initiated on apixaban or warfarin.
Synopsis: Patients in the apixaban group (n=128) had a higher rate of heart failure, atrial fibrillation, stent placement, and hyperlipidemia, while the warfarin group (n=733) had a higher rate of prior venous thromboembolism. The primary outcome was time to first bleeding or thrombotic event. Apixaban was associated with a lower risk of thrombotic or bleeding events, compared with warfarin (HR, 0.47). Post-hoc analysis controlling for patient differences showed similar results. There was no statistical difference in the severity of events or overall mortality. Further subgroup analysis showed that 5 mg B.I.D. dosing was not associated with higher risk of bleeding than 2.5 mg B.I.D.
The main limitation is the retrospective observational design, which may have introduced confounding variables that were not accounted for in the analyses. The study also did not account for patient nonadherence to medication.
Bottom line: Apixaban is a reasonable alternative to warfarin in patients with severe renal impairment.
Citation: Hanni C et al. Outcomes associated with apixaban vs. warfarin in patients with renal dysfunction. Blood Adv. 2020;4(11): 2366-71. doi: 10.1182/bloodadvances.2019000972.
Dr. Narayan is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.