Net Clinical Benefit of Rivaroxaban for Thrombosis Prevention in ACS Patients

SAN FRANCISCO, CA—After reports of having met the primary endpoints in the ATLAS-ACS TIMI-52 study, rivaroxaban 2.5mg and 5mg demonstrated a benefit over placebo in terms of cardiac mortality and bleeding risk as presented at ACC.13, the American College of Cardiology's 62nd Annual Scientific Session.

Recent studies have examined the impact of rivaroxaban and other factor Xa inhibitors in the prevention of thrombosis related to pulmonary embolism, stroke, and acute coronary syndromes (ACS).  However, there is uncertainty regarding the use of rivaroxaban as adjunctive therapy in patients with ACS, especially taking into consideration the bleeding risk.

Rohit R. Arora, MD, from Chicago Medical School, in North Chicago, IL and colleagues studied the safety and efficacy of rivaroxaban by conducting a Bayesian net-benefit analysis using reported information from the ATLAS-ACS TIMI-52 Study. Data was obtained regarding primary endpoint as well as MI, stroke, mortality, stent thrombosis, and bleeding results. In addition, researchers calculated probabilities benefit, along with a magnitude of therapeutic effect calculation. Net clinical benefit was derived from overall combined efficacy endpoints and safety endpoints.

A benefit probability of 87.3% was observed for both dosages using posterior probabilities for the primary endpoint. Similar efficacy was seen for both doses of rivaroxaban vs. placebo regarding stent thrombosis. The 2.5mg dose has a differential benefit in cardiac and all-cause mortality, along with slightly lower bleeding. A 63.2% benefit for the 2.5mg dose and a 52.7% benefit for the 5mg dose vs. placebo were indicated by a net clinical benefit calculation.

Rivaroxaban 2.5mg and 5mg doses performed better than placebo in regards to a significant benefit in cardiac mortality, especially with the 2.5mg dose, coupled with significant increase in bleeding risk, especially with the 5mg dose. Dr. Arora commented, “Overall, there are trends toward clinically important benefits for the primary endpoint and reduction in cardiovascular death/MI.” Further investigation regarding the elevated bleeding risk in these patients on other anticoagulants is warranted.