The purpose of this study is to evaluate optimal duration of antiplatelet therapy after Bioresorbable Vascular Scaffold implantation to reduce late coronary arterial thrombotic events.

Inclusion Criteria:

1. Men or women at least 19 years of age
2. Patients undergoing dual- or triple-antiplatelet therapy at least 12-14 months after PCI with BVS
3. Among the participants underwent PCI with BVS, event-free patients who survived the first 12 months without death, serious MI, stroke, repeat revascularization or major bleeding (except non-significant peri-procedural MI)
4. The patient or guardian agrees to the study protocol and the schedule of clinical follow-up, and provides informed, written consent, as approved by the appropriate Institutional Review Board/Ethical Committee of the respective clinical site.

Exclusion Criteria:

1. Contraindication to antiplatelet therapy
2. If the physician believes that the patient need continuation of dual anti-platelet therapy because of comorbidities (ACS, peripheral vascular disease, significant carotid disease, etc.)
3. Continuous administration of clopidogrel is impossible due to comorbidities of the patient (major bleeding history, bleeding diathesis)
4. Cardiac co-morbid conditions are present with life expectancy <1 year or that may result in protocol non-compliance (per site investigator's medical judgment).
5. Pregnancy test positive (hCG test is performed before randomization in all fertile women)