Inclusion Criteria:
* All four conditions below must be met.
1. Patients who are 20 years of age or older, have undergone coronary artery stent implantation for coronary artery disease, and require dual antiplatelet therapy for 6 months or longer.
2. Patients are considered to be at high bleeding risk if at least 1 criteria are met (Based on clinical recommendations (6,7,10,14-16) and expert consensus documents (17-19)) 1) Age ≥65 y 2) Low body weight (\<55 Kg for men, \<50 Kg for women) 3)Hemoglobin \<11g/dL 4) Platelet count \<100×109/L 5) Severe CKD: eGFR \<30mL/min/1.73m2,5 or on hemodialysis 6) Anticipated use of long-term oral anticoagulation (warfarin or direct-acting oral anticoagulants) 7) Long-term use of oral NSAIDs or steroids 8) Heart failure 9) A history of previous gastric or duodenal ulcer. 10) A history of previous gastrointestinal bleeding. 11)Previous or confirmed Helicobacter pylori infection
3. A voluntary participant in this clinical trial who has provided written consent, or a legal guardian who has provided written consent on behalf of the participant.
4. Those who agree to use a medically valid method of contraception\* (including conditions in which pregnancy is medically impossible) during the clinical trial period Women who are medically unable to become pregnant can participate in this clinical trial: women who have undergone menopause (amenorrhea for more than 24 months), hysterectomy, salpingectomy, or bilateral oophorectomy, etc.
* Medically valid contraceptive methods: intrauterine device (Loop, Mirena), physical barrier method (male condom, female condom (femidom)), subcutaneous contraception (Implanon, etc.), long-acting contraceptive injection, or tubectomy and ligation, vasectomy, etc. ( However, oral contraceptives cannot be used during this clinical trial, and it is recommended to use double contraception to prevent pregnancy while participating in this trial.)
Exclusion Criteria:
1. Patients who have a hypersensitivity reaction to the components of this clinical trial drug or benzimidazole-based drugs or have a history of clinically significant hypersensitivity reaction
2. Patients with contraindications to antiplatelet agents, such as allergies.
3. Genetic blood coagulation disorders
4. Cases in which the investigator determines that the use of dual antiplatelet therapy is difficult due to severe liver cirrhosis, thrombocytopenia, or other medical conditions.
5. Hemodynamically unstable at the time of randomization (cardiogenic shock, uncontrolled arrhythmia, severe heart failure: NYHA Class IV).
6. Patients with warning symptoms suspected of digestive malignancy (unintentional significant weight loss, recurrent vomiting, dysphagia, hematemesis, melena, etc.) within the past 3 months
7. Patients with malignancy or serious illnesses with an expected survival of less than 1 year.
8. Severe anemia (hemoglobin \< 8 g/dL) or blood transfusion within 4 weeks of randomization.
9. Active liver disease or impaired liver function (AST or ALT greater than three times the upper limit of normal).
10. Advanced renal dysfunction: eGFR less than 30 mLmin/1.73m2 or patients receiving dialysis
11. Patients taking drugs contraindicated for this clinical trial drug (e.g., patients taking atazanavir, nelfinavir, or rilpivirine-containing preparations)
12. Patients with genetic problems such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption
13. Concurrently taking CYP 3A4 and p-glycoprotein (P-GP) inhibitors.
14. Dementia or individuals unable to understand the trial procedures or comply with the trial requirements
15. Pregnant or breastfeeding women, or women planning to become pregnant
16. Individuals with active infections, significant hematologic, renal, metabolic, gastrointestinal, endocrine disorders, or any other reason the investigator deems the subject unsuitable for participation in the clinical trial
