Benefits and risks of extended treatment of venous thromboembolism with rivaroxaban or with aspirin

Background: Full- or lower-dose anticoagulant therapy or aspirin can be used for extended therapy in patients with venous thromboembolism (VTE), but information on their relative benefit-risk profiles is limited. Methods: Data from the EINSTEIN-CHOICE trial were used to compare the benefit-risk profiles of extended treatment with rivaroxaban (20 or 10 mg once daily) and aspirin (100 mg once daily) in VTE patients who had completed 6 to 12 months of anticoagulation therapy. One-year cumulative incidences of recurrent VTE and major bleeding were estimated and benefits and risks were calculated by determining the between group differences in a hypothetical population of 10,000 VTE patients treated for 1 year. Findings: A total of 1107 patients were treated with 20 mg of rivaroxaban, 1127 with 10 mg of rivaroxaban, and 1131 with aspirin. The cumulative incidences of recurrent VTE in the rivaroxaban 20-mg, rivaroxaban 10-mg and aspirin groups were 1.9%, 1.6%, and 5.0%, respectively, whereas the cumulative incidences of major bleeding were 0.7%, 0.4% and 0.5%, respectively. The incidences of the combined outcome of recurrent VTE and major bleeding were 2.8% and 3.4% lower in the rivaroxaban 20-mg and 10-mg groups than in the aspirin group. For 10,000 patients treated for 1 year, there would be 284 (95% confidence interval [CI] 106 to 462) and 339 (95% CI 165 to 512) fewer events with rivaroxaban 20 mg or 10 mg than with aspirin. Interpretation: Compared with aspirin, extended anticoagulation with once daily rivaroxaban reduces recurrent VTE with a favourable benefit-risk profile.