The purpose of this study is to evaluate the efficacy and safety of aspirin-free, P2Y12 inhibitor single antiplatelet and colchicine treatment in patients with acute coronary syndrome treated with drug-eluting stents.

After successful drug-eluting stent implantation for acute coronary syndrome, screening for study subject enrollment is performed. For those who submitted written informed consent, aspirin is stopped the day after the intervention, and colchicine 0.6mg once daily is started. The P2Y12 inhibitor, prasugrel or ticagrelor, for single antiplatelet therapy remains. For the duration of hospital stay, platelet reactivity using VerifyNow test and C-reactive protein are measured. Aspirin may be restarted at the discretion of the investigator based on results of the platelet function test. C-reactive protein is remeasured 30 days after the intervention. Clinical follow-up is performed 30 days and 90 days after the intervention.

Inclusion Criteria:

• Successful PCI with drug-eluting stent for NSTE-ACS or STEMI
• Provision of written informed consent

Exclusion Criteria:

• Cardiac arrest or cardiogenic shock
• Age <19 or >90 years old
• Severe liver impairment
• Severe renal impairment (eGFR <30 mL/min/1.73 m2)
• Atrial fibrillation requiring anticoagulation therapy
• Intolerance of prasugrel, ticagrelor, or colchicine
• History of intracranial hemorrhage
• Active bleeding