The available guidelines, endorsed by Surgical Care Improvement Project (SCIP), have advocated that aspirin (ASA) is a safe and effective strategy for venous thromboembolic events (VTE) prophylaxis following total joint arthroplasty (TJA). The optimal dose of aspirin for this purpose is not known. The first guidelines for prevention of VTE that were issued by the American Academy of Orthopedic Surgeons recommended 325 mg Bis in die (twice a day) (bid) for this purpose with the recommendation having a 1C grade (little evidence to support the recommendation). It is known that platelet aggregation inhibition occurs at lower doses. Traditionally, ASA 81mg has been used as a cardioprotective medication. Additionally, all available randomized studies, including the sentinel study on Pulmonary Embolism Prevention (PEP) trial1-4 have used lower doses of ASA. It was our hypothesis that lower dose aspirin is likely to be as effective as higher dose aspirin while reducing the gastrointestinal side effects associated with the higher dose aspirin
