LAUSR

Direct oral anticoagulants (DOACs) are as effective as warfarin, with a favorable safety profile, and improved ease of use. Guidelines recommend DOACs as first line management for non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE) [1, 2]. The proportion of Medicare anticoagulant claims for DOACs increased from 0.2% in 2010 to 46.5% in 2017 [3]. Despite the advantages that DOACs offer, warfarin remains the best evidence-based treatment option for select indications and specific patient populations such as patients with triple positive antiphospholipid syndrome (APLS), durable ventricular assist devices (VAD), mechanical heart valves with or without AF, or left ventricular thrombi where warfarin was found to be superior to DOACs [4–7]. Additionally, some patient populations were underrepresented in the DOAC landmark trials (i.e. severe renal insufficiency, morbid obesity, and cancer), resulting in limited data regarding their efficacy and safety. This report evaluates the indications for new patient referrals to the Brigham and Women’s Hospital (BWH) Anticoagulation Management Service (AMS) for warfarin management as well as the referring provider rationale for selecting warfarin over a DOAC. Methods