The Elderly ACS II Trial

Inclusion Criteria: \- Patients \>74 years of age hospitalized for an ACS, with or without STE, with an onset of symptoms during the previous 72 hours, and candidates to an early PCI. * STEMI patients may be randomized upon first diagnosis, provided they do not meet any exclusion criteria. STEMI patients should not exceed 50 percent of the global population of the study * Eligible NSTEACS patients may be randomized after coronary angiography. To be eligible, NSTEACS patients must have at least one of the following characteristics: * elevated troponin levels; * diabetes mellitus; * prior MI; * at least one new ischemic episode while on standard treatment during the index hospitalization; * ACS due to stent thrombosis. Exclusion Criteria: * History of stroke or transient ischemic attack (TIA) * Gastrointestinal or genitourinary bleeding of clinical significance within 6 weeks prior to randomization. * Hemoglobin level on admission \<10 g/dl, unless this is considered to be secondary to renal dysfunction or known myelodysplasia. * Secondary causes of acute myocardial ischemia. * Known current platelet count \< 90,000 cells/mL. * Ongoing oral anticoagulant treatment or an INR known to be \>1.5 at the time of screening. * Concomitant severe obstructive lung disease, malignancy or neurologic deficit limiting follow-up or adherence to the study protocol. * Participation in any phase of another clinical research study involving the evaluation of another investigational drug or device within 30 days prior to randomization * Inability to give at least verbal informed consent to the study. * Contraindications to the use of clopidogrel or prasugrel as per package leaflet.