Comparing outcomes using low-dose apixaban and anti-Xa monitoring and vitamin K antagonists in patients with renal replacement therapy.

BACKGROUND: Guidelines recommend oral anticoagulation for stroke prevention in atrial fibrillation and secondary prevention of venous thromboembolism. Outside the United States, apixaban is unlicensed for use in patients with end-stage renal disease (ESRD) receiving renal replacement therapy (RRT). AIM: To compare thrombotic and safety outcomes in patients receiving either vitamin K antagonists (VKAs) or apixaban 2.5 mg twice daily in the context of ESRD and RRT. METHOD: Retrospective service evaluation comparing bleeding and thrombotic outcomes in patients treated with apixaban 2.5 mg BD or VKA in a tertiary anticoagulation clinic. Trough anti-Xa levels of apixaban patients were reviewed. Clinical features and outcomes were reviewed using electronic patient records. RESULTS: Fifty-five VKA and 33 apixaban patients were included in the analysis. There were no major bleeds in the apixaban cohort compared with 4 (7.3%) in the VKA cohort (χ2 = 2.667, p = 0.102). No difference in time to major or clinically relevant non-major bleeding (CRNMB) was found (χ2 = 1.252, p = 0.263). Rates of thrombotic events (all stroke) were 1 vs. 3 (1.1 and 7.1 events/100 patient-years) for VKA and apixaban, respectively (χ2 = 3.291, p = 0.070). Only one stroke was related to AF. Eighty-four of 85 trough anti-Xa levels analysed were below the upper limit of normal of the reference range for the general population. DISCUSSION: Our results suggest similar outcomes with VKA and apixaban in those receiving RRT, indicating apixaban may be a viable second-line treatment option in those for whom VKA may not be appropriate. Further investigation into the safety of the apixaban 5-mg regimen is warranted.