Aspirin Matches Rivaroxaban for Post-Surgery Clot Prevention
A large trial found low-dose aspirin is non-inferior to rivaroxaban for preventing blood clots after hip or knee replacement surgery.
Updated on Nov. 4, 2026 in Stroke
The EPCAT III trial, published in The New England Journal of Medicine, found once-daily 81mg aspirin non-inferior to 10mg rivaroxaban for venous thromboembolism prevention after hip or knee arthroplasty. The study randomised 5429 patients with a mean age of 66.5 years.
Why it matters
Aspirin is a low-cost, widely available drug, so a non-inferior alternative to rivaroxaban could ease access to effective post-surgical clot prevention. The trial extends earlier EPCAT II findings to a larger patient population.
The randomised controlled trial enrolled 5429 patients with a mean age of 66.5 years, comparing 81mg daily aspirin against 10mg daily rivaroxaban, with no clinically relevant difference in bleeding. Exact clot-event rates and confidence intervals for the non-inferiority margin were not included in the extraction.
The players
EPCAT III trial
The EPCAT III trial is an extension of the EPCAT II study, which previously showed extended low-dose aspirin was non-inferior to continued rivaroxaban after joint replacement.
The details
Patients received once-daily aspirin or rivaroxaban for five days after surgery, with rivaroxaban recipients then switching to aspirin. Knee patients continued aspirin for nine more days and hip patients for 30 days, and VTE prevention was assessed over the 90-day postoperative period.
Timeline
Five days postoperatively: initial once-daily thromboprophylaxis period.
Nine additional days: aspirin continuation after knee arthroplasty.
30 days: aspirin continuation after hip arthroplasty.
90-day postoperative period: window for assessing VTE prevention.
Health Landscape
The EPCAT III trial extends the EPCAT II study, which showed extended low-dose aspirin was non-inferior to continued rivaroxaban after hip or knee arthroplasty. Its larger randomised cohort reinforces aspirin as a potential alternative in post-surgical thromboprophylaxis.
Patients undergoing hip or knee replacement may be prescribed aspirin rather than rivaroxaban for post-surgical clot prevention, which is typically less expensive. Patients should discuss the appropriate option with their surgeon, as bleeding risk was similar between the two drugs in this trial.
The takeaway
Low-dose aspirin may offer a lower-cost option for preventing post-surgery blood clots without a clinically relevant increase in bleeding. Patients should review options with their surgical team.
Further reading
For broader context on related vascular risks, explore our Stroke coverage.
Source note: This article includes information reported by AusDoc.
