Aspirin was not found to be superior to other anticoagulants in preventing venous thromboembolism (VTE) after total hip (THR) or knee replacement (TKR), according to a study published in JAMA Internal Medicine.

This was a systematic review and meta-analysis of randomized controlled trials in which the efficacy and safety of aspirin were examined for VTE prophylaxis after THR or TKR and compared with those of other anticoagulants. A total of 13 trials with 6060 adult participants were included. In these studies, aspirin was compared with rivaroxaban, low-molecular-weight heparin (LMWH), and warfarin. The primary outcome of the meta-analysis was postoperative symptomatic or asymptomatic VTE. Secondary outcomes were any adverse event (AE) associated with treatment.

In the pooled analysis, the risk for VTE after THR and TKR was found to be comparable for aspirin and other anticoagulants (relative risk [RR], 1.12; 95% CI, 0.78-1.62). The risk for VTE was similar in patients who received aspirin vs LMWH (RR, 0.76; 95% CI, 0.37-1.56) or rivaroxaban (RR, 1.52; 95% CI, 0.56-4.12). The risks for deep vein thrombosis (RR, 1.04; 95% CI, 0.72-1.51) and pulmonary embolism (RR, 1.01; 95% CI, 0.68-1.48) were comparable in participants receiving aspirin vs other anticoagulants. The risks for any AE, including major bleeding, wound hematoma, and wound infection, were comparable for all anticoagulants examined.

Continue Reading

Study limitations include a small number of included studies, a high risk for bias, and interstudy variability in terms of follow-up durations and outcome reporting.

 “[A]dditional large, well-designed [randomized controlled trials] are needed to validate these findings,” noted the study authors. “Furthermore, these trials must determine whether newer, more expensive anticoagulants (including rivaroxaban and dabigatran) have any clinical benefit over aspirin for VTE prophylaxis after THR and TKR and whether these drugs are cost-effective.”

Related Articles

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Matharu GS, Kunutsor SK, Judge A, Blom AW, Whitehouse MR. Clinical effectiveness and safety of aspirin for venous thromboembolism prophylaxis after total hip and knee replacement: a systematic review and meta-analysis of randomized clinical trials [published online February 3, 2020]. JAMA Intern Med. doi: 10.1001/jamainternmed.2019.6108