Pre-operative Antihypertension Strategies-Carotid Artery Stenting

Inclusion Criteria: * age ≥ 18 * have a history of TIA or nondisabling ischemic stroke within the past 6 months (symptomatic) with ipsilateral initial part of EICA stenosis ≥ 50 % or asymptomatic with initial part of EICA stenosis ≥ 70%, and the cause of stenosis was atherosclerosis * have hypertension requiring hypertensives * modified Rankin scale (mRS) before stenting \< 3 Exclusion Criteria: * with ipsilateral tandem stenosis * with history of operation in contralateral carotid artery, like stenting, endarterectomy and bypass. * requiring operation in contralateral carotid artery in the same admission. * requiring general anesthesia in the same operation (stenting) * with contraindication to carotid stenting, such as Inability to tolerate surgery due to organ dysfunction, cerebral aneurism, cerebral hemorrhage in 3 months, myocardial infraction or large-area cerebral infraction within 2 weeks, extreme tortuosity of the vessel * allergic to Calcium channel blockers, angiotensin receptor blockers or hydrochlorothiazide * pregnancy * with concomitant medication as following: Azole antifungals, macrolides antibiotics, cardiac calcium channel blockers, Rifampicin, sildenafil, simvastatin, immunosuppressants, antidepressants, valproic acid, cimetidine, aliskiren, NSAIDs, protease inhibitors (ritonavir) and drugs that affect potassium in the blood * with hepatic insufficiency, renal insufficiency, kidney transplantation, diabetic nephropathy, biliary obstructive disease, or the presence of end-stage disease affecting clinical prognosis assessment (such as end-stage cancer, end-stage heart disease, liver failure, renal failure, pulmonary failure) * with depression, schizophrenia, bipolar disorder, epilepsy, tuberculosis, AIDS, primary hyperaldosteronism, hyperkalemia, hypercalcemia, hyperuricemia, gout * participating other trails which would affect the evaluation of outcomes * with reserpine and clonidine intake within 1 week