Original title: Rivaroxaban in Patients Stabilized After a ST-Segment Elevation Myocardial Infarction. Results From the ATLAS ACS-2–TIMI-51 Trial. Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects with Acute Coronary Syndrome Thrombolysis In Myocardial Infarction-51. Reference: Jessica L. Mega et al. J Am Coll Cardiol 2013;61:1853–9.

Morbidity and mortality rates following AMI have progressively declined in the last decades due to the use of new drug strategies. However, even now with the long term treatments based on the double scheme anticoagulant and anti ischemic therapies, patients that have suffered a coronary event still have a high risk of adverse cardiovascular events, including death, in the short and long term. This is the reason behind the renewed interest in proving how effective would be to add an anticoagulant, in this case, an anti-Xa, to the treatment with AAS and one thienopyridine. 

The study ATLAS ACS 2-TIMI 51, published in NEJM in 2011, 15 526 patients with acute coronary syndrome were analyzed, and within 1 to 7 days from the event they were randomized to Rivaroxaban 2.5 mg twice a day, Rivaroxaban 5 mg twice a day or placebo. The study showed benefits in favor of the use of Rivaroxaban in this kind of patients. However, the authors showed particular interest in STEMI patients. This pre specified analysis of the subgroup showed the use of Rivaroxaban after patient stabilization in addition to the regular AMI treatment reduces the combined primary end point of cardiovascular death, AMI and stoke, compared to placebo (8.4% vs. 10.6%, HR 0.81; p=0.019) at the expense of increasing non surgical bleeding (2.2% vs. 0.6%; p<0.001) and intra cranial bleeding (0.6% vs. 0.1%; p= 0.015), with no significant difference in fatal bleeding (0.2% vs. 0.1%, p =0.51).

In analyzing the two Rivaroxaban doses used in the study, it was seen that the twice a day 2.5 mg dose reduce cardiovascular death significantly compared to placebo, but not the 5 mg dose. This could be explained by the fact that the authors included as cardiovascular death, death associated to bleeding events. There was also a significant difference in the three types of bleeding (major, intra cranial and fatal) in favor of the 2.5 mg dose.

Conclusion: 

In patients with acute coronary syndrome with STEMI, Rivaroxaban reduces cardiovascular events. This benefit is obtained in the early phase of treatment, at treatment start, and continues with the association of anticoagulants. Rivaroxaban increases major bleeding but was not significant as regards fatal bleeding.

Editorial Comment: 

Apparently, from these substudy ATLAS ACS 2-TIMI 51 data, it would be beneficial to use Rivaroxaban after an AMI with STEMI in 2.5 mg twice a day doses. However, we have to take into account that no patient was being treated with Prasugrel or Ticagrelor (more and more used as a post STEMI treatment) and that the original study excluded those patients with increased bleeding risk. Therefore, despite the conclusive results, we need more information to be able to offer the anticoagulant benefit to our patients without increasing their bleeding risk. 

Courtesy of Dra. María Sol Andrés.
Hospital Universitario
Fundación Favaloro. Argentina.

Dra. María Sol Andrés.