Inclusion Criteria:  Subject must be at least 19 years of age Subject who is able to understand risks, benefits and treatment alternatives and sign informed consent voluntarily. Patients presenting with ACS (ST-elevation myocardial infarction [STEMI], non-ST-elevation myocardial infarction [NSTEMI], or unstable angina) Patients with at least one lesion with equal or greater than 50% diameter stenosis requiring treatment with drug-eluting stents (DES) in native coronary artery or graft  Exclusion Criteria:  Patients unable to provide consent Patients with known intolerance to aspirin, clopidogrel, prasugrel, or major components of drug-eluting stents Patients who have non-cardiac co-morbid conditions with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment) Patients who need chronic anti-coagulation therapy Patients with active pathological bleeding Pregnant or lactating women  Additional Exclusion Criteria for Antiplatelet Comparison Study:  Patients with history of stroke or transient ischemic attack Patients 75 years of age or older Patients weighing less than 60 kg