Inclusion Criteria:  Age ≥50 years old History of drug-eluting stent implantation due to acute myocardial infarction 12 to 24 months ago High-risk for ischemic events (at least one of the following) 1) Age >65 years old 2) Medical treatments for diabetes mellitus 3) Multi-vessel coronary artery disease 4) More than 2 episodes of myocardial infarction 5) Chronic kidney disease (stage III or IV)  Exclusion Criteria:  Age ≥85 years old Pregnant women or women with potential childbearing Life expectancy < 1 year Inability to understand or read the informed consent Need for long-term anticoagulation therapy