Extended therapy with rivaroxaban was more effective than aspirin in reducing the risk of recurrent venous thromboembolism (VTE) with no significant increase in bleeding risk, according to data from the EINSTEIN CHOICE* study presented at the ACC.17 Scientific Session in Washington, DC, US.
"Although extended anticoagulation therapy prevents recurrent VTE, concerns about bleeding often lead to reluctance to continue treatment beyond 6 to 12 months," said Dr Philip Wells of the University of Ottawa in Ontario, Canada. "Our findings show that it’s [a safe option] and ... that practitioners can safely prescribe rivaroxaban for patients at risk for a recurrent VTE without being concerned that doing so will increase risk for bleeding side effects.”
The multicentre, double-blind, phase III randomized trial enrolled 3,396 patients (mean age 59, 55 percent male) with VTE, who had previously completed 6-12 months of anticoagulant therapy and were uncertain whether to continue with longer-term therapy. They were randomized to receive rivaroxaban (10 or 20 mg once-daily) or aspirin 100 mg for up to 12 months. [N Engl J Med 2017;doi:10.1056/NEJMoa1700518]
After following up for a median of 351 days, recurrent VTE (symptomatic fatal or nonfatal) occurred less commonly in rivaroxaban-treated patients than aspirin-treated patients (1.5 and 1.2 percent, respectively for rivaroxaban 20 and 10 mg vs 4.4 percent for aspirin, hazard ratio [HR], 0.34 and 0.26 for each respective comparison; p<0.001 for both).
The secondary efficacy endpoint comprising a composite of recurrent VTE-related deaths or all-cause mortality was also significantly lower with rivaroxaban compared with aspirin (2.1 and 1.3 percent, respectively vs 4.9 percent; p<0.001). Similarly, the combined rates of recurrent VTE/myocardial infarction/systemic embolism/ischaemic stroke were significantly reduced in patients receiving rivaroxaban than aspirin (2.0 and 1.9 percent, respectively vs 5.6 percent; p<0.001).
There were no significant differences in major bleeding rates (0.5 and 0.4 percent, respectively for 20 and 10 mg rivaroxaban, vs 0.3 percent for aspirin) and clinically relevant nonmajor bleeding rates (2.7 and 2.0 percent, vs 1.8 percent) between the three groups.
"Rivaroxaban 10 mg once daily provides an additional option for extended VTE treatment," said Wells, although he noted that patients requiring full-dose anticoagulant therapy, such as rivaroxaban 20 mg, were excluded in the current study, which was also not powered to detect noninferiority of the 10 mg vs 20 mg treatment regimen.
Whether low-dose rivaroxaban is as effective as the established therapeutic dose in other patient populations, and whether treatment should be continued beyond 12 months require further study, he added.