Safety and Efficacy of Low Dosage of Terazosin in Subjects Undergoing Carotid Artery Stenting

Inclusion Criteria: 1. Symptomatic or asymptomatic carotid artery stenosis. In symptomatic patients the degree of stenosis should more than 50% (Based on NASCET Criteria), in asymptomatic patients the degree of stenosis should more than 70% (Based on NASCET Criteria); 2. Tolerance to any of the study medications, including TZ, clopidogrel, aspirin and statins; 3. Hypertensive patients with or without oral antihypertensive drugs 4. Can cooperate with and complete brain MRI examination; 5. Stable vital signs, cardiopulmonary, liver and kidney function was no obvious abnormalities; 6. Has a negative pregnancy test within 7 days before randomization and no childbearing potential; 7. Stable vital sign, normal renal and hepatic functions; 8. Informed consent. Exclusion Criteria: 1. Evolving stroke; 2. Hemorrhagic tendency； 3. Severe dementia or Prior major ipsilateral stroke, if likely to confound study endpoints; 4. Chronic atrial fibrillation or any other Cardiogenic emboli source disease; 5. Myocardial infarction within previous 30 days; 6. Spontaneous Intracerebral Hemorrhage within the past 180 days, Hemorrhagic conversion of an ischemic stroke within the past 60 days or recent (\<7 days) large area cerebral infarction has a hemorrhagic conversion tendence; 7. Any conditions that hampers proper angiographic assessment or makes percutaneous arterial access unsafe; 8. High risk candidates of CAS defined as the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST); 9. Thiazides taken within 14 days before randomization; 10. Participating in any other clinical trial that has not completed the required protocol follow-up period;