Evaluation of Pharmacologic Strategies for Prevention of Venous Thromboembolism in Elective Orthopedic Surgery

Background: Venous thromboembolism (VTE) is a common postoperative complication in orthopedic surgery and warrants the use of pharmacologic thromboprophylaxis. The purpose of this study was to analyze current prescribing practices at our institution and to assess outcomes of pharmacologic strategies used for VTE prophylaxis following major orthopedic surgery. Methods: This was a single center, retrospective analysis at a tertiary academic medical center. Patients were included if they were admitted for total hip or knee arthroplasties and received pharmacologic thromboprophylaxis (warfarin INR goal 1.8-2.3, aspirin at variable doses, low molecular weight heparin (LMWH), DOAC) post-operatively from January 2017 to June 2017. Patients were excluded if they had a history of VTE or were on long-term anticoagulation. Major endpoints included incidence of thrombotic and bleeding events within 30 days post-surgery. Results: A total of 476 patients were screened; 89 were excluded and 387 were included (warfarin = 183, aspirin = 201, LMWH = 2, apixaban = 1). Two patients in the warfarin group experienced a deep vein thrombosis compared with one patient in the aspirin group (p = 0.51). Major bleeding occurred in one patient in the warfarin group and none in the aspirin group. Total bleeding rates occurred in 2.7% and 1.0% in the warfarin and aspirin groups, respectively. Conclusion: There has been an increase in the use of aspirin at our facility in postoperative orthopedic surgery patients without an increase in DOAC use. No difference was detected in safety and efficacy endpoints in our warfarin versus aspirin patients.