Optimizing the Anticoagulation Regimen of Enoxaparin During Percutaneous Coronary Intervention (OPTIENOX-PCI)

Inclusion Criteria: 1. Provision of written informed consent. 2. Aged 18 years or older, male or female. 3. Documented stable coronary artery disease (SCAD) or non-ST-segment elevation acute coronary syndromes (NSTE-ACS). 4. Plan to undergo elective trans-radial coronary angiography with or without subsequent PCI. 5. No fibrinolytic, or anticoagulant, or parenteral antiplatelet therapy within 7 days of screening. 6. Negative cardiac troponin test within 7 days of screening. 7. Trans-radial approach successfully established. 8. Females who are either post-menopausal \> 1 year or surgically sterile. Exclusion Criteria: 1. Recent (within 30 days of screening) acute myocardial infarction, including ST-segment elevation myocardial infarction or non-ST-segment elevation myocardial infarction. 2. The aim of the index coronary angiography is to undergo primary PCI or early PCI for acute coronary syndromes. 3. Any indications other than coronary artery disease (e.g., atrial fibrillation, prosthetic heart valve, venous thromboembolism, ventricular thrombosis, et al) for fibrinolytic or anticoagulant treatment during study period. 4. Planned use of any fibrinolytic or antithrombotic agents, with the exception of enoxaparin, aspirin, clopidogrel, and ticagrelor during study period. 5. Planned coronary artery bypass graft (CABG) during study period. 6. Increased bleeding risk, including * any history of intracranial, intraocular, retroperitoneal, or spinal bleeding; * recent (within 30 days of screening) gastrointestinal (GI) bleeding; * recent (within 30 days of screening) major trauma or major surgery; * planned surgery or other invasive procedure during study period; * sustained uncontrolled hypertension (systolic blood pressure \[SBP\] \> 180 mmHg or diastolic blood pressure \[DBP\] \> 100 mmHg) within 7 days of screening; * history of hemorrhagic disorders, e.g., haemophilia, von Willebrand's disease; * inability to discontinue non-steroidal anti-inflammatory drugs (NSAIDs) during study period; * platelet count less than 100,000/mm3 or hemoglobin \< 10 g/dL within 7 days of screening. 7. Contraindications for enoxaparin, e.g., hypersensitivity, active bleeding, bleeding diathesis, coagulation disorders, acute infectious endocarditis, thrombocytopenia (including heparin-induced thrombocytopenia), cerebral hemorrhage, severe liver of kidney diseases, severe hypertension, stroke, retinopathy, et al. 8. History of intolerance to enoxaparin. 9. Patient requires dialysis or has a creatinine clearance \< 30 mL/min as calculated by the Cockcroft-Gault equation: Clcr = (140 - Age) × WT / (72 × Scr) (× 0.85 for females), where WT is weight in kg, Scr is serum creatinine in mg/dL measured within 7 days of screening. 10. Any acute or chronic unstable conditions in the past 30 days which, in the opinion of the investigator, may either put the patient at risk or influence the result of the study, e.g., active cancer, et al. 11. Any condition that may increase the risk of non-compliance to study protocol or follow-up, e.g., history of drug addiction or alcohol abuse, et al. 12. Patients who has previously been randomized in this study. 13. Participation in another investigational drug or device study within 30 days of screening. 14. Involvement in the planning and conduct of the study (applies to investigators, contract research organization staff, and study site staff). 15. Known pregnancy, breast-feeding, or intend to become pregnant during the study period. 16. Any condition which in the opinion of the investigator would make it unsafe or unsuitable for the patient to participate in this study.