Evaluation of Direct Oral Anticoagulant Prescribing in Patients With Moderate to Severe Renal Impairment

Patients with renal impairment require dose adjustments for direct oral anticoagulants (DOACs), though there is uncertainty regarding their use in severe chronic kidney disease. Inappropriately dosed DOACs may increase risk of ischemic events when under-dosed, or risk of bleeding when over-dosed. The purpose of this study was to describe DOAC selection, dosing strategies, and associated clinical outcomes in patients with moderate to severe renal impairment at our institution. This was a single-center retrospective analysis of adult outpatients with moderate to severe renal impairment (estimated creatinine clearance <50 mL/min, including need for hemodialysis) who were prescribed a DOAC by a cardiologist between June 1, 2015 and December 1, 2018. Outcomes evaluated included the percentage of patients who received appropriate and inappropriate DOAC dosing, prescriber reasons for inappropriate DOAC dosing if documented, and incidence of thrombotic and bleeding events. A total of 207 patients were included. Overall, 61 (29.5%) patients received inappropriate dosing, with 43 (70.5%) being under-dosed and 18 (29.5%) being over-dosed as compared to FDA-labeled dosing recommendations for atrial fibrillation or venous thromboembolism (VTE). By a median follow-up duration of 20 months, stroke occurred in 6 (3.3%) patients receiving DOACs for atrial fibrillation, and VTE occurred in 1 (4.3%) patient receiving a DOAC for VTE. International Society on Thrombosis and Haemostasis major or clinically relevant nonmajor bleeding occurred in 25 (12.1%) patients. Direct oral anticoagulants were frequently prescribed at off-label doses in patients with moderate to severe renal impairment, with a tendency toward under-dosing.