The efficacy of aspirin compared to low molecular weight heparin as thromboprophylaxis after orthopedic surgery: A systematic review and meta-analysis

Abstract

Background: Aspirin has increasingly gained attention as a thromboprophylaxis agent for patients undergoing orthopedic surgery; however, the results of recent clinical trials remain controversial. Therefore, in this meta-analysis, we compared the safety and efficacy of aspirin with those of low molecular weight heparin (LMWH) for patients undergoing major orthopedic surgeries leading to significant immobility and necessitating anticoagulants to prevent thromboembolic events. Methods: PubMed, Web of Science, Scopus, and the Cochrane Library were systematically searched from the inception to April 20, 2024, to identify clinical trials and randomized controlled trials comparing the effect of aspirin and LMWH on deep vein thrombosis (DVT), pulmonary thromboembolism (PTE), venous thromboembolism (VTE), major bleeding, short-term postoperative mortality, and adherence to treatment. VTE included DVT and PE in this study. A random-effects model (DerSimonian-Laird) was employed to pool data. Results: In total, 8 randomized controlled trials with 23,540 participants were included in this study. Compared to LMWH, the use of aspirin was associated with a significantly increased risk of DVT (RR 1.56, 95% CI (1.30–1.86), I² = 0.00%), whereas no significant changes were observed in drug adherence (RR 1.04, 95% CI (0.94–1.14), I² = 94.02%) and risk of PTE (RR 1.18, 95% CI (0.64-2.15), I² = 58.64%), VTE (RR 1.51, 95% CI (0.89–2.57), I² = 24.69%), major bleeding (RR 0.96, 95% CI (0.88–1.04), I² = 0.00%), and mortality (RR 1.07, 95% CI (0.89–1.29), I² = 0.00%) after orthopedic surgery. Conclusion: Aspirin is generally as safe as LMWH for preventing thromboembolic events among patients undergoing orthopedic surgery; however, aspirin can increase the risk of DVT