Probucol for Symptomatic Intracranial and Extracranial Artery Stenosis

Prior treatment

• Usage of probucol within 30 days before randomization;
• With Q-Tc interval prolongation, or currently using drugs that may cause Q-Tc interval prolongation (male Q-Tc\>450ms, female Q-Tc\>470ms);
• Planned surgery or interventional treatment requiring cessation of the study drug during the study;
• Participating in another clinical trial with an investigational drug or device concurrently or during the last 30 days;
• Serious drug or alcohol abuse in the past 1 year；

Other illness

• Presumed cardiac source of embolus, such as atrial fibrillation, prosthetic cardiac valve, endocarditis or patent foramen ovale;
• Stroke/TIA due to arterial dissection, angioplasty, or vascular surgery;
• Known allergy or sensitivity or intolerance to probucol;
• Myocardial disease within the past 30 days, including myocardial infarction, myocarditis;
• Cardiac syncope or unexplained syncope;
• Inability to understand and/or follow research procedures due to mental, cognitive, or emotional disorders, or to be an unsuitable candidate for the study for any other considered by the investigator.

Lab values

• Impaired hepatic (ALT or AST \> twice the upper limit of normal range) or kidney (creatinine exceeding 1.5 times of the upper limit of normal range or eGFR less than 50 ml/min) function at randomization;
• Anemia (haemoglobin \<10g/dL), thrombocytopenia (platelet count \<100×109/L) or leucopenia (white blood cell \<3×109/L) at randomization;

Other

• With ventricular tachycardia, bradycardia, tip-twist ventricular tachycardia；
• Pregnant or lactating women; Pregnant, currently trying to become pregnant, or of child-bearing potential and not using birth control;
• Severe non-cardiovascular comorbidity with a life expectancy of less than 1 years;

• 1.40 years or older than 40 years; 2.Ischemic stroke or transient ischemic attack (TIA); 3.Within 7 days from onset to randomization; 4.Main intracranial or extracranial arteries supplying the ischemic event region are narrowed by more than 50%; 5.Informed consent signed.