[EINSTEIN CHOICE: Comparison of rivaroxaban treatment and prophylactic doses with aspirin in the extended treatment of patients with venous thromboembolism].

Although many patients with venous thromboembolism (VTE) may need extended treatment, efficacy and safety issues of full- or lower-intensity anticoagulation over acetyl salicylic acid (ASA) treatment have remained to be determined. EINSTEIN CHOICE is a randomized, double-blind and phase 3 study, and compared either once-daily rivaroxaban (at doses of 20 mg or 10 mg) and 100 mg of ASA in patients with VTE who were in equipoise regarding the need for extended anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal VTE and the principal safety outcome was major bleeding. A total of 3365 patients were included in the intentionto-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 1.5% of patients receiving 20 mg of rivaroxaban and in 1.2% of patients receiving 10 mg of rivaroxaban, in comparison to 4.4% of those receiving aspirin (hazard ratio for 20 mg of rivaroxaban vs. ASA, 0.34; 95% confidence interval [CI] 0.20 to 0.59; hazard ratio for 10 mg of rivaroxaban vs. ASA, 0.26; 95% CI 0.14 to 0.47; P<0.001 for both comparisons). Rates of major bleeding and adverse events were comparable among three treatment groups. In conclusion, in patients with VTE in equipoise for extended anticoagulation, either a treatment dose (20 mg) or a prophylactic dose (10 mg) of rivaroxaban compared with ASA significantly reduced the risk of VTE recurrence without a significant increase in bleeding risk.