Pre-operative Antihypertension Strategies-Carotid Artery Stenting (PASS-CAS)

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