A Study to Compare the Safety of Rivaroxaban Versus Acetylsalicylic Acid in Addition to Either Clopidogrel or Ticagrelor Therapy in Participants With Acute Coronary Syndrome

Inclusion Criteria: * Participants, 18 years or older, must have symptoms suggestive of acute coronary syndrome (ACS) (angina, or symptoms thought to be equivalent) within 48 hours of hospital presentation, or developed ACS while being hospitalized, and has a diagnosis of: a) ST segment elevation myocardial infarction (STEMI); b) non-ST-segment elevation acute coronary syndrome (NSTE-ACS). However, participant who is 54 years of age or younger must also have either diabetes mellitus or a history of a prior myocardial infarction (MI), in addition to the presenting ACS event * Participant must be randomized within the screening window of 10 days after hospital admission for the index ACS event. Participant should have received acute phase treatment for the index ACS, such as intravenous anticoagulant or antiplatelet, and are receiving maintenance dual antiplatelet therapy (DAPT) with either clopidogrel plus acetyl salicylic acid (ASA), or ticagrelor plus ASA, with the intent to continue the treatment with a platelet adenosine diphosphate P2Y12 receptor antagonist (P2Y12 inhibitor) after randomization * Participants must agree to provide a pharmacogenomics deoxyribonucleic acid (DNA) sample Exclusion Criteria: * Participant has any conditions that, in the opinion of the investigator, contraindicates anticoagulant therapy or would have an unacceptable risk * Participant with a prior stroke of any etiology or transient ischemic attack (TIA) * Participant who received thrombolytic therapy as treatment for the index ACS event cannot be enrolled in the ticagrelor stratum * Participant has anticipated need for chronic administration of omeprazole or esomeprazole concomitantly with clopidogrel * Participant has known allergy or intolerance to ASA or rivaroxaban