麻豆传媒

WASHINGTON -- Continuing use of rivaroxaban (Xarelto) at either 20 mg or 10 mg dose appears to reduce the risk of recurrent venous thromboembolism without increasing the risk for bleeding.

"This is a useful and safe clinical pathway for managing these patients," saidof the University of Ottawa, who reported the results from the 3,396-patient EINSTEIN CHOICE study today during a late-breaking clinical trials session at the meeting.

Based on these results, speaking at a press conference Wells said there is "really no role for aspirin in this setting ... I hope these findings will encourage more physicians to prescribe rivaroxaban for these patients."

"Clotting and bleeding have been the focus of so many studies over the years, but those studies are usually focused in the coronary bed, so I am really glad to see these data," said Sandra Lewis, MD, of Oregon Health and Science University in Portland. Lewis, who served as a discussant, added that her patients find it hard to stay on long-term anticoagulation with warfarin due to the need for testing and dietary restrictions.

The decision, she said, often comes down to "equipoise and so we rely on aspirin." The EINSTEIN CHOICE findings suggest that "... we can improve outcome and prevent events in a very safe way."

Patients were randomized to rivaroxaban 20 mg or 10 mg daily or to aspirin 100 mg daily. Prior to study enrollment patients completed 6 to 12 months of anticoagulation therapy and were in equipoise in terms of needing additional anticoagulation.

The study drugs were administered for up to 12 months and the efficacy endpoint was symptomatic recurrent venous thromboembolism (fatal or nonfatal); the safety endpoint was major bleeding.

"We are talking about an area of clinical care that is very challenging," said , who was not involved in the study. "In our own vascular institute we are trying to develop a clinical pathway for this. There are very few guidelines and those that do exist are conflicting," Gardiner, a surgeon, is medical director of Christiana Care's Center for Heart & Vascular Health and executive director of the Value Institute and is a former president of the American Heart Association.

"This looks like it could be the answer, " Gardner said, noting that warfarin is often difficult to manage and "aspirin is just not adequate."

In the U.S. there is a pressing need for a clinical pathway such as Gardner mentioned because recurrent VTE is one of the quality markers used by Medicare.

Wells told 麻豆传媒 that using rivaroxaban as described in the current study is a recognized clinical pathway in Canada, but "little was known about the efficacy of the lower (10 mg) dose."

The study was also simultaneously published online by .

Recurrent VTE occurred in 17 of 1,107 patients taking 20 mg rivaroxaban and in 13 of the 1,127 treated with the 10-mg dose. Among 1,131 patients receiving aspirin, there were 50 VTEs reported. These results translated to a hazard ratio of 0.34 for 20 mg rivaroxaban vs aspirin (95% CI 0.20-0.59); for 10 mg of rivaroxaban vs aspirin, HR 0.26 (95% CI 0.14-0.47).

The major bleeding rate were similar in both rivaroxaban doses (0.5% and 0.4% for 20 mg and 10 mg, respectively). The rate was also low, 0.3%, in the aspirin control group. "The rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. The incidence of adverse events was similar in all three groups," Wells and colleagues wrote.