Genotype-Guided Abbreviated DAPT Versus Un-Guided De-escalation Therapy in Patients With ACS and HBR

Inclusion Criteria: * Patients must be at least 19 years of age * Patients who is able to understand risks, benefits and treatment alternatives and sign informed consent voluntarily. * Patients presenting with ACS (ST-elevation myocardial infarction \[STEMI\] or non-ST-elevation \[NSTE\] ACS). * Patients with at least one lesion with equal or greater than 50% diameter stenosis requiring treatment with drug-eluting stents in native coronary artery or graft. * Patients with high bleeding risk (by ARC-HBR definition or PRECISE-DAPT score 25 or more) Exclusion Criteria: * Patients unable to provide consent. * Patients who need chronic anti-coagulation therapy. * Patients suffering from cardiogenic shock or cardiac arrest * Patients with known intolerance to aspirin, all P2Y12 inhibitors, or components of drug-eluting stents. * Clinically significant out of range values for platelet count (\< 50,000/mm3) or hemoglobin (\<8 g/dL) at screening * Non-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). * Pregnant or lactating women.