The Role of Aspirin and Unfractionated Heparin Combination Therapy Immediately After Total Hip and Knee Arthroplasty.

Aspirin and unfractionated heparin (UH) are accepted options for venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA). The use of aspirin in addition to UH in preventing VTE after TJA has yet to be studied. The primary objective of this study was to determine VTE rates in patients receiving aspirin monotherapy and those receiving aspirin and UH combination therapy immediately following TJA. A TJA database from a single hospital system was retrospectively reviewed to identify all patients who underwent primary hip or knee arthroplasty from 2013 to 2016. Patients were divided into 3 groups based on postoperative VTE chemoprophylaxis: aspirin only, aspirin with 1 dose of UH, and aspirin with multiple doses of UH. There were 5350 patients included: 1024 aspirin only, 1695 aspirin plus 1 dose of UH, and 2631 aspirin plus multiple doses of UH. Deep venous thrombosis and pulmonary embolus rates did not vary significantly between groups (deep venous thrombosis: 1.1%, 0.9%, and 1.2%, respectively, P=.701; pulmonary embolus: 0.3%, 0.3%, and 0.2%, respectively, P=.894). Transfusion rates were significantly greater with 1 dose of UH (1.8%) and multiple doses of UH (4.3%) compared with aspirin only (0.9%) (P<.001). Additionally, the postoperative hemoglobin decreased significantly more postoperatively with the use of UH (P<.001). Aspirin and UH combination therapy did not decrease VTE incidence compared with aspirin monotherapy. Additionally, there was greater perioperative blood loss and an increased rate of blood transfusion in patients receiving UH. On the basis of these findings, the authors do not recommend UH as an additional mode of VTE prophylaxis when prescribing aspirin after elective TJA. [Orthopedics. 2018; 41(3):171-176.]. Copyright 2018, SLACK Incorporated.