Platelet Resistance With Ticagrelor or Standard-Dose Clopidogrel Among CKD and ACS Patients

Inclusion Criteria: 1. Provision of informed consent prior to any study specific procedures 2. Female and male, age between 20-75 years 3. Stage 3-5 chronic kidney disease (eGFR\<60ml/min) patients or ESRD 4. Taking standard treatment dose of clopidogrel (75mg/day) for more than 1 week 5. Patients were eligible for enrollment if they were hospitalized for an acute coronary syndrome, with or without ST-segment elevation, with an onset of symptoms during the past 6 months. 6. For patients who had an acute coronary syndrome without ST-segment elevation, at least two of the following three criteria had to be met: ST-segment changes on electrocardiography, indicating ischemia; a positive test of a biomarker, indicating myocardial necrosis; or one of several risk factors (age ≥60 years; previous myocardial infarction or coronary-artery bypass grafting \[CABG\]; coronary artery disease with stenosis of ≥50% in at least two vessels; previous ischemic stroke, transient ischemic attack, carotid stenosis of at least 50%, or cerebral revascularization; diabetes mellitus; peripheral arterial disease). 7. For patients who had an acute coronary syndrome with ST-segment elevation, the following two inclusion criteria had to be met: persistent ST-segment elevation of at least 0.1 mV in at least two contiguous leads or a new left bundle-branch block. Exclusion Criteria: 1. Oral anticoagulation therapy that cannot be stopped 2. Increased risk of bradycardia 3. Concomitant use of strong CYP3A inhibitor/inducers 4. Unwilling to sign inform consent 5. Allergic or contraindicated to any study medications