A Study of Milvexian in Participants After a Recent Acute Coronary Syndrome

Inclusion Criteria: * Participants must have an index event that meets all 3 of the following criteria within 7 days prior to randomization: a) clinical syndrome consistent with spontaneous cardiac ischemia, b) diagnosis of acute coronary syndrome (ACS) (that is, ST-elevation myocardial infarction \[STEMI\], non-STEMI, or unstable angina \[UA\]), c) cardiac biomarker elevation (example, troponin I, troponin T, creatine kinase-MB \[CK-MB\]) above the upper limit of normal as determined by the local laboratory * Participants must have at least 2 of the following risk factors:a) age 65 or older, b) diabetes mellitus, c) history of a prior myocardial infarction (MI) (other than index ACS event), d) multivessel coronary artery disease (CAD), e) history of coronary artery bypass graft (CABG) surgery prior to index ACS event, f) history of peripheral artery disease (PAD) or cerebrovascular disease (example, carotid atherosclerosis, intracranial artery stenosis, g) conservative management (that is, no percutaneous intervention \[PCI\] or CABG after index ACS event), h) Any one or more of the following high-risk angiographic features i) total stent length of greater than (\>) 30 millimeters (mm), ii) thrombotic target lesion, iii) bifurcation lesion treated with more than one stent, iv) calcified target lesion treated with atherectomy, v) treatment of obstructive left main or proximal left anterior descending artery for index ACS (or clinical diagnosis of an anterior STEMI) * All fem…