To assess the Usefulness of oral anticoagulation therapy (OAT) in patients with coronary artery aneurysm (CAA).

Data on the most adequate antithrombotic CAA management is lacking.

Patients included in CAAR (Coronary Artery Aneurysm Registry, Clinical Trials.gov: NCT02563626) were selected. Patients were divided in OAT and non-OAT groups, according to anticoagulation status at discharge and 2:1 propensity score matching with replacement was performed. The primary endpoint of the analysis was a composite and mutual exclusive endpoint of myocardial infarction, unstable angina (UA), and aneurysm thrombosis (coronary ischemic endpoint). Net adverse clinical events, major adverse cardiovascular events, their single components, cardiovascular death, re-hospitalizations for heart failure, stroke, aneurysm thrombosis, and bleeding were the secondary ones.

One thousand three hundred thirty-one patients were discharged without OAT and 211 with OAT. In the propensity-matched sample (390 patients in the non-OAT group, 195 patients in the OAT group), after 3 years of median follow-up (interquartile range 1-6 years), the rate of the primary endpoint (coronary ischemic endpoint) was significantly less in the OAT group as compared to non-OAT group (8.7 vs. 17.2%, respectively; p = .01), driven by a significant reduction in UA (4.6 vs. 10%, p < .01) and aneurysm thrombosis (0 vs. 3.1%, p = .03), along with a non-significant reduction in MI (4.1 vs. 7.7%, p = .13). A non-significant increase in bleedings, mainly BARC type 1 (55%), was found in the OAT-group (10.3% in the non-OAT vs. 6.2% in the OAT group, p = .08).

OAT decreases the composite endpoint of UA, myocardial infarction, and aneurysm thrombosis in patients with CAA, despite a non-significant higher risk of bleeding.