APERITIF is a prospective randomized open-label, blinded end-point (PROBE) trial, nested in the ongoing the "FRENCHIE" registry, a French multicenter prospective observational study granted by "ANR-RHU Grand Emprunt", in which all consecutive patients admitted within 48 hours after symptom onset in a cardiac Intensive Care Unit (ICU) for an acute myocardial infarction (AMI) are included (NCT04050956). Among them, eligible Patients for "APERITIF" will be randomized into two groups: Dual Anti-Platelet Therapy (DAPT) alone or DAPT plus rivaroxaban 2.5mg twice daily for 4 weeks, prescribed as soon as possible after admission and completion of the initial percutaneous coronary intervention/angiography procedure.

Inclusion Criteria:

• Age ≥ 18 years;
• Anterior STEMI (e.g., ST elevation above the J-point of ≥0.1 millivolt in ≥two contiguous leads or left bundle branch block) or very high-risk NSTEMI (e.g., dynamic ECG changes or ongoing chest pain or acute heart failure or hemodynamic instability independent of ECG changes or life-threatening ventricular arrhythmias) with echographic evidence of anterior wall motion abnormalities and, with a culprit lesion of the proximal or mid portion of the left anterior descending (LAD) on the coronary angiography;
• No contraindication to CMR (e.g., claustrophobia, pacemaker or defibrillator not compatible);
• Ability to provide written informed consent and willing to participate in 1-month follow-up period.
• Affiliation of social security regime.

Exclusion Criteria:

• Patients with cardiogenic shock (systolic blood pressure <90 mmHg with clinical signs of low output or patients requiring inotropic agents);
• Patients referred to surgery for coronary artery bypass grafting (CABG) or treatment of acute complications (e.g. ventricular septal rupture);
• Patients treated with fibrinolytic therapy;
• LV thrombus diagnosed before randomization using a transthoracic echocardiography;
• Active major bleeding or major surgery within the last 30 days;High bleeding risk (patients considered at increased risk of bleeding during DAPT; e.g. PRECISE-DAPT score >25; severe liver failure or Child Pugh class C);
• Known history of intracranial hemorrhagic stroke or intra-cranial aneurysm;
• Known history of peptic ulcer;
• Known stroke (any type) within the last 30 days;
• Known intolerance to aspirin, P2Y12 inhibitors, rivaroxaban and their excipients;
• Patients with presence of malignant neoplasms at high risk of bleeding
• Patients with hepatic impairment
• According to the SmPC any contraindication to rivaroxaban, aspirin, clopidogrel, ticagrelor
• Known intolerance to gadolinium chelates;
• Chronic kidney disease (creatinine clearance (ClCr) <30 mL/min);
• Indication for anticoagulation (e.g. atrial fibrillation, mechanical valves, LV thrombus…);
• Life expectancy <1 month;
• Known pregnancy at time of randomization (pregnancy test done) or breastfeeding women;
• Currently participating in another trial
• Protected adults (including individual under guardianship by court order)
• Persons deprived of their liberty by judicial or administrative decision