VTE Recurrence Risk Reduced With Rivaroxaban: Q&A With EINSTEIN CHOICE Investigator

DVT deep vein clot thrombosis
DVT deep vein clot thrombosis
Results from the EINSTEIN CHOICE trial plus an interview with investigator Philip Stephen Wells, MD, FRCP(C), MSc.

WASHINGTON, DC — Rivaroxaban lowered the risk of a recurrent event among patients with venous thromboembolism (VTE) in equipoise for continued anticoagulation, according to results of the EINSTEIN CHOICE trial (Clinicaltrials.gov identifier: NCT02064439) presented at the 66th Annual Scientific Session & Expo of the American College of Cardiology (ACC).1

The findings were simultaneously published in the New England Journal of Medicine.2

EINSTEIN CHOICE (Reduced-dose Rivaroxaban in the Long-term Prevention of Recurrent Symptomatic Venous Thromboembolism) was a randomized, double-blind, phase 3 study that compared the efficacy and safety of 2 doses of rivaroxaban with aspirin for the extended treatment (up to 1 year after the initial 6 to 12 months of therapy) of VTE. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal VTE, and the safety outcome was major bleeding.

A total of 3365 patients were included in the trial. They were assigned in a 1:1:1 ratio to receive rivaroxaban 20 mg, rivaroxaban 10 mg, or aspirin 100 mg, all given once daily with food. Of the patients who received rivaroxaban 20 mg (n=1107), 1.5% experienced a recurrent fatal or nonfatal VTE, and among those who received the 10-mg dose (n=1127), the outcome occurred in 1.2%, compared with 4.4% of patients who received aspirin (hazard ratio [HR] for rivaroxaban 20 mg vs aspirin: 0.34; 95% CI, 0.20-0.59; HR for rivaroxaban 10 mg vs aspirin: 0.26; 95% CI, 0.14-0.47; P <.001 for both comparisons).

The rate of major bleeding among patients who received rivaroxaban 20 mg was 0.5%, which was comparable to the major bleeding rates in the 10-mg (0.4%) and aspirin (0.3%) groups. The rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. Adverse events were also similar among the 3 groups.

The Cardiology Advisor spoke with Philip Stephen Wells, MD, FRCP(C), MSc, to gain more insight on these study results at ACC in Washington.

Dr Wells is the chair and chief of the Department of Medicine at the University of Ottawa in Canada and one of the EINSTEIN CHOICE investigators.

The Cardiology AdvisorYou mentioned that you hope physicians will now prescribe this medication without hesitation. What do you think will unequivocally win them over? And why is it so difficult to get physicians to change their prescribing habits even with evidence?

Dr Wells:
  Change is hard, as they say. Physicians are no different than other people — they develop a comfort level, they develop a kind of anecdotal feeling about a certain medicine. It’s hard to get people to change their practice. 

But the data are unequivocal at this point in terms of patients with VTE. Recurrent risk of VTE is high in patients with unprovoked VTE and they should be on extended therapy.

For provoked VTE, it’s a little trickier. This is a newer thing for physicians, but it’s becoming quite clear that the provoked population that is nonsurgical has a high rate of recurrence — around 4%. Now when it was 4% and you had to use warfarin, it wasn’t really worth it because the major hemorrhage rate per year is around 2%. It is a big nuisance for patients to use warfarin, and so I can understand the reluctance. There is also pretty clear evidence that as you get older, you have a higher risk of bleeding, even when you’re on warfarin.

But now with the DOACs [direct oral anticoagulants], at least 2 of the products, apixaban and rivaroxaban, the bleeding risk is very low and the effectiveness has been maintained. There is no monitoring necessary; they are easy drugs to take. 

And now that we have shown that aspirin has no benefit compared to rivaroxaban and no difference in bleeding, it should be discarded as a treatment option.

Some data, although incomplete, suggest that there is also no difference in the cardiovascular and neurovascular outcomes between the rivaroxaban and aspirin groups. So even those physicians who might say, “Well, aspirin might be better for my patients with known cardiac disease,” this would at least indirectly suggest that is not really the case.