TITLE: Low-dose or full-dose rivaroxaban is superior to aspirin for long-term anticoagulation
CLINICAL QUESTION: Is full or lower intensity rivaroxaban better for extended treatment of venous thromboembolism (VTE) as compared to aspirin?
STUDY DESIGN: Multicenter randomized double-blinded phase III trial.
SETTING: 230 Medical centers worldwide in 20 countries.
SYNOPSIS: 3,365 patients with a history of VTE who had undergone 6-12 months of initial anticoagulation therapy and in whom continuation of therapy was thought to be beneficial were enrolled. Patients were randomly assigned to daily high-dose rivaroxaban (20 mg) or daily low-dose rivaroxaban (10 mg) or aspirin (100 mg). After a median of 351 days, symptomatic recurrent VTE or unexplained death occurred in 17 of the 1,107 patients (1.5%) who were assigned to the high-dose group, in 13 of 1,127 patients (1.2%) who were assigned to the low-dose group, and in 50 of 1,131 patients (4.4%) who were assigned to aspirin. Bleeding rates were not significantly different between the three groups (2%-3%). The major limitation of this study is the short duration of follow-up and the lack of power to demonstrate noninferiority of the low-dose as compared to the high-dose regimen for rivaroxaban.
BOTTOM LINE: In patients with a history of VTE, in whom prolonged anticoagulation could be beneficial, low or high-dose rivaroxaban is superior to aspirin in preventing recurrent VTE without increasing bleeding risk.
CITATION: Weitz JI, Lensing MH, Prins R, et al. Rivaroxaban or aspirin for extended treatment of venous thromboembolism. N Engl J Med. 2017; 376:1211-22.
Dr. Mayasy is assistant professor in the department of hospital medicine at the University of New Mexico.