Aspirin: An Alternative for Pulmonary Embolism Prophylaxis After Arthroplasty?

BACKGROUND: The most effective agent for prophylaxis against venous thromboembolic disease after total joint arthroplasty (TJA) remains unknown. The paucity of literature comparing different methods of pulmonary embolism (PE) prophylaxis and fear of litigation make it difficult for surgeons to abandon the use of aggressive chemical prophylaxis. QUESTIONS/PURPOSES: We compared the (1) overall frequency of symptomatic PE, (2) risk of symptomatic PE after propensity matching that adjusted for potentially confounding variables, and (3) other complications and length of stay before and after propensity matching in patients undergoing TJA at our institution who received either aspirin or warfarin prophylaxis. METHODS: A total of 28,923 patients underwent TJA between January 2000 and June 2012 at our institution, had either aspirin (325 mg twice daily; 2800 patients) or warfarin prophylaxis (26,123 patients), and were registered in our institutional electronic database. The incidence of symptomatic PE, symptomatic deep vein thrombosis (DVT), hematoma formation, infection, wound complications, and mortality up to 90 days postoperatively was collected from the database. We performed multivariate analysis and 3:1 and 5:1 propensity score matching for comorbid and demographic variables. RESULTS: The overall symptomatic PE rate was lower (p < 0.001) in patients receiving aspirin (0.14%) than in the patients receiving warfarin (1.07%). This difference did not change after matching. The aspirin group also had significantly fewer symptomatic DVTs and wound-related problems and shorter hospital stays, which did not change after matching. CONCLUSIONS: After publication of the American Academy of Orthopaedic Surgeons' guidelines, some surgeons have utilized aspirin as thromboprophylaxis after TJA. Based on our findings from a large institutional database, aspirin offers suitable prophylaxis against symptomatic PE in selected patients.