The study aims to assess the effectiveness of dual antiplatelet therapy, aspirin alone versus steeply discontinued clopidogrel plus aspirin in preventing clinical MACE events.Our subject is beyond a 12-month period patients receiving sirolimus drug-eluting stent implantation.

It is not clear that dual antiplatelet therapy is better than aspirin beyond 12-months period patients receiving sirolimus drug-eluting stent implantation. If aspirin plus clopidogrel reduced MACE rates without increasing blood events, the investigators will evaluate risk-benefit ratio. The investigators will observe all cause mortality, nonfatal myocardial infarction, or clinical-driven target vessel revascularization TVR in a 1-year trial duration. In addition, strokes, stent thrombosis, cardiac re-hospitalizations, dialysis/hemofiltration, duration of hospitalization and bleeding events will be observed.

Inclusion Criteria:

• Age 18 years of older.
• The latest PCI with DES implantation before 12 months (stents must be one or more sirolimus-eluting stents).
• Angiographically confirmed major epicardial vessels (>=2.5mm in diameter) without significant stenosis or restenosis (>=50%).
• Geographically accessible and willing to come in for required study visits.
• Signed informed consent.

Exclusion Criteria:

• The patient has a known hypersensitivity or contraindication to aspirin and clopidogrel.
• Severe congestive heart failure (class III or IV according to NYHA, or pulmonary edema) at the time of enrollment and within 12 months.
• EF<35% within 12 months.
• Severe cardiac valves disease, or idiopathic cardiomyopathy such as dilated cardiomyopathy, hypotrophic cardiomyopathy. Other severe system diseases.
• Previous ACS within 12 months.
• Previous stroke or transient ischemia attack within 12 months.
• Previous myocardial infarction and clinical-driven target vessel revascularization within 12 months.
• Current enrollment in another clinical trial.
• Suspected pregnancy.
• Big bleeding events within 12 months.
• Planned surgical procedure.
• Previous other type DES implantation or BMS implantation history.
• Extra-cardiac stent implantation history.
• Current or planned dialysis.
• The patient has a known hypersensitivity or contraindication to statins.
• Current or planned high dose and long-term glucocorticoid treatment.
• that is expected to limit survival to less than 1 years.