Abstract 12248: Dosing of Direct Oral Anticoagulants in Patients With Non-Valvular Atrial Fibrillation and Renal Dysfunction

Abstract

Introduction: Reduced doses of direct oral anticoagulants (DOACs) are approved to prevent bleeding complications in specified populations of patients with non-valvular atrial fibrillation (NVAF). Little is known about the accuracy of DOAC dosing in patients with renal dysfunction. Hypothesis: We hypothesized that NVAF patients with renal dysfunction would be more likely to receive an inappropriate dose of a DOAC compared with patients with normal renal function. Methods: We examined all patients who had at least two claims for NVAF between 2015 and 2017 in the Symphony Health claims dataset. We defined under-dosing as patients treated with a reduced dose without meeting label specified criteria for dose reduction, and excess dosing as patients treated with a full dose despite meeting criteria for dose reduction. We performed a logistic regression model to measure the effect of CrCl on DOAC dosing. Results: Among 86,919 patients with NVAF and CHA 2 DS 2 -VASc > 2, 12.3% were underdosed and 5.0% were excess dosed. Patients who received excess-dosed or under-dosed DOACs were older and more likely to have comorbidities such as heart failure or history of prior stroke (all p<0.001), compared with patients who were appropriately dosed. Among patients with CrCl > 60 ml/min, under-dosing occurred in 9% of patients, highest among patients treated with edoxaban (18%) and rivaroxaban (10.4%). Under-dosing rates were higher among patients with CrCl 30-59 ml/min, especially for apixaban and dabigatran ( Table) . Excess dosing occurred in approximately 1 in 5 patients with CrCl <30 ml/min. For every 10 unit decrease in CrCl, the odds of the patient receiving an inappropriately dosed DOAC increased by 27%. Conclusions: Incorrect DOAC dosing was observed in a substantial number of patients with NVAF in this large national study. Dosing errors occurred more frequently in patients with lower renal function, suggesting the need for efforts to improve effective and safe dosing of DOACs.