Aspirin is no different than other anticoagulants for VTE prevention after joint replacement surgery

Reference

Matharu GS, Kunutsor S, Judge A, Blom AW, Whitehouse MR. Clinical effectiveness and safety of aspirin for venous thromboembolism prophylaxis after total hip and knee replacement. JAMA Intern Med 2020;180(3):376-384.

Synopsis

Patients who have joint replacement surgery are at high risk for postoperative VTE, but guidelines differ on how they should be treated to prevent this complication. In this study, investigators searched multiple databases, including MEDLINE, EMBASE, and the Cochrane Library, for randomized controlled trials that evaluated the effectiveness and safety of aspirin compared with another anticoagulant for VTE prophylaxis after either TKR or THR. The primary outcome was any postoperative VTE event. Two investigators independently selected studies and extracted data. Bias assessment of the individual studies was performed using the Cochrane Collaboration's risk of bias tool. Overall, 13 studies were included (N = 6060 patients) and 11 of them had a high risk of bias. The studies differed in the populations assessed, the dosage of aspirin (range = 81 mg - 1200 mg daily), the duration of therapy, reporting of outcomes and adverse events, and follow-up duration. The most common comparators were low-molecular-weight heparin and rivaroxaban; other comparators included warfarin, heparin, and dipyridamole. The largest study started with an initial 5 days of rivaroxaban for both study groups, followed by either aspirin or rivaroxaban. The pooled risk of VTE for patients who received aspirin after TKR or THR was not significantly different than the risk for patients who received other anticoagulants (relative risk 1.12; 95% CI 0.78 - 1.62). There was evidence of moderate heterogeneity among studies. Subgroup analysis by type of surgery (TKR or THR) or comparator anticoagulant (low-molecular-weight heparin or rivaroxaban) did not change the effect result. The pooled risk of adverse events, including bleeding, wound infection, wound complications, myocardial infarction, and death, was also not different in patients who received aspirin versus other anticoagulants. There was no evidence of publication bias.