To observe the safety and efficacy of intensive drug therapy for ischemic stroke caused by severe intracranial arterial stenosis.Patients with acute stroke caused by intracranial arterial stenosis (stenosis rate ≥70%) were enrolled and accept dual antiplatelet therapy (DAPT) (aspirin 100 mg/d and clopidogrel 75 mg/d for 90 days, followed by aspirin 100 mg/d for long term) under the guidance of platelet function analysis (Verifynow) combined with the intensive statin therapy (40 mg/d for 14 days, followed by 20 mg/d for long term).

Patients (35 to 80 years ) with acute ischemic stroke, who can be treated within 72 hours of symptom onset will be enrolled. Patients fulfilling all of the inclusion criteria and none of the exclusion criteria will be randomly selected.Patients were treated with dual antiplatelet therapy (DAPT) (aspirin 100 mg per day and clopidogrel 75 mg per day were administered for 90 days, followed by aspirin 100 mg per day for long term) and atorvastatin (40 mg per day for 14 days, followed by 20 mg per day long term) after enrollment. Patients with aspirin resistance (aspirin reaction units [ARU] ≥550) or clopidogrel resistance (P2Y12 reaction units [PRU] ≥208) were excluded on the 7th day of therapy.The primary objective is to observe the safety and efficacy of intensive drug therapy for ischemic stroke patients. A Data and Safety Monitoring Board (DSMB) will regularly monitor safety during the study. The trial has been approved by Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine affiliated to Shanghai University of Traditional Chinese Medicine.

Inclusion Criteria:

• Age between 35 and 80 years;
• Onset <72 hours;
• New-onset ischemic stroke confirmed by skull magnetic resonance diffusion weighted imaging (MR-DWI);
• Severe ICAS (stenosis ≥70%) indicated by time-of-flight magnetic resonance angiography (TOF-MRA).

Exclusion Criteria:

• Ischemic stroke caused by other etiological factors (e.g., cardio-embolism, arterial dissection, vasculitis, etc.);
• Post-infarction hemorrhagic transformation and intraplaque hemorrhage as indicated by imaging examination;
• Contraindications to aspirin, clopidogrel, or atorvastatin;
• Intracranial hemorrhage within 3 months and a recent history of surgery or trauma;
• Severe organ impairment, liver insufficiency, and renal insufficiency;
• Complicated with tumors or hemorrhagic diseases;
• Use of drugs forbidden to use in combination after onset, including other antiplatelet drugs, anticoagulants, thrombolytic drugs, and drugs affecting antiplatelet agents and statin metabolism.

Patients with acute stroke caused by intracranial arterial stenosis (stenosis rate ≥70%)