Rivaroxaban Then Aspirin vs. Aspirin Alone after Total Hip or Knee Arthroplasty

Study Summary

Five thousand four hundred twenty-nine patients undergoing elective unilateral primary or revision THA or TKA were randomized and received either aspirin alone (n=2734) or rivaroxaban followed by aspirin (n=2658). Patients in the aspirin-alone group received aspirin 81 mg once daily for the first 5 postoperative days, whereas those in the rivaroxaban–aspirin group received rivaroxaban 10 mg once daily for 5 days; thereafter, all patients received aspirin 81 mg daily for an additional 9 days after TKA or 30 days after THA. The primary effectiveness outcome was symptomatic VTE, defined as proximal deep-vein thrombosis or pulmonary embolism within 90 days. The primary safety outcome was major or clinically relevant nonmajor bleeding. Overall, the results of the study revealed that symptomatic VTE occurred in 0.48% of patients receiving aspirin alone and 0.45% receiving rivaroxaban–aspirin, meeting the prespecified criterion for noninferiority. Bleeding rates were also similar between groups. These findings suggested that aspirin monotherapy provided an effective and comparatively safe thromboprophylaxis strategy for predominantly standard-risk patients following THA or TKA.