Outcomes and predictive value of the 2MACE score in patients with atrial fibrillation treated with rivaroxaban in a prospective, multicenter observational study: The EMIR study.

Background: The aim of the study was to evaluate the performance of the 2MACE in patients with atrial fibrillation (AF) treated with rivaroxaban and to improve the accuracy of 2MACE.

Methods: This was a post-authorization and observational study of AF adults treated with rivaroxaban for ≥ 6 months. The primary endpoint was any of the major adverse cardiac events (MACE), namely, cardiovascular death, non-fatal myocardial infarction, and myocardial revascularization. The area under the curve (AUC) was calculated to evaluate the performance of 2MACE, and a new score, 2MACER to predict MACE.

Results: A total of 1433 patients were included (74.2 ± 9.7 years, CHA₂DS₂-VASc 3.5 ± 1.5, 26.9% 2MACE ≥ 3). The annual event rates (follow-up 2.5 years) were 1.07% for MACE, 0.66% for thromboembolic events and 1.04% for major bleeding. Patients with 2MACE ≥ 3 (vs. < 3) had higher risk of stroke/systemic embolism/transient ischemic attack (odds ratio [OR] 5.270; 95% CI 2.216-12.532), major bleeding (OR 4.624; 95% CI 2.163-9.882), MACE (OR 3.202; 95% CI 1.548-6.626) and cardiovascular death (OR 3.395; 95% CI 1.396-8.259). 2MACE was recalculated giving 1 more point to patients with baseline a glomerular filtration rate < 50 mL/min/1.73 m² (2MACER); 2MACER vs. 2MACE: IDI 0.1%, p = 0.126; NRI 23.9%, p = 0.125; AUC: 0.651 (95% CI 0.547-0.755) vs. 0.638 (95% CI 0.534-0.742), respectively; p = 0.361.

Conclusions: In clinical practice, AF patients anticoagulated with rivaroxaban exhibit a low risk of events. 2MACE score acts as a modest predictor of a higher risk of adverse outcomes in this population. 2MACER did not significantly increase the ability of 2MACE to predict MACE.