Myocardial infarction is defined according to icd-10 using the data base of South korea National Health Insurance Corporation, where personal identification information has already been removed, and detailed results are derived for each drug category.

The purpose of this study is to compare the prognosis of patients with clopidogrel after early discontinuation of ticagrelor/prasugrel with patients who maintained aspirin and ticagrelor/prasugrel as standard therapy in patients with acute myocardial infarction who underwent percutaneous coronary intervention.

Inclusion Criteria:

• Patients who have a diagnosis code for acute myocardial infarction indicated in the National Health Insurance data and data for drugs that have used ticagrelor/prasugrel for 30-90 days when hospitalized for the relevant disease.
• Patients who switched to clopidogrel after 30-90 days.
• Patients with a diagnosis code for Venus myocardial infarction and a prescription code for percutaneous cardiovascular intervention in the National Health Insurance data.
• Adults 18 years of age or older

Exclusion Criteria:

• A person who has data for requesting blood transfusion during the period of hospitalization in the National Health Insurance data
• Those who have data for oral anticoagulants (warfarin, Coumadin, apixaban, edoxaban, dabigatran, rivaroxaban) in the National Health Insurance data
• Those who have a diagnosis code for malignant tumor in the National Health Insurance data
• Those who have end-stage renal failure code in the National Health Insurance data or those who have data for hemo/peritoneal dialysis
• A person who has a request for blood transfusion during the period of using Ticagrelor/prasugrel

Prognostic data of patients who maintained aspirin and ticagreolor/prasugrel as standard therapy in patients with acute myocardial infarction who underwent percutaneous coronary intervention, and patients with clopidogrel after early discontinuation of ticagrerol/prasugrel