The investigators propose to assess the efficacy and safety of intravenous tirofiban after bridging therapy (endovascular therapy [EVT] following intravenous Tenecteplase) for acute ischemic stroke due to intracranial atherosclerotic disease related large vessel occlusion (ICAD related LVO). This study will recruit 564 patients from about 50 hospitals in China. Inclusion criteria for the trial are: (1)age ≥18 years old, (2)Pre-mRS 0-2, (3)Baseline NIHSS 6-30 points, (4) Baseline ASPECTS ≥6 points, (5) Baseline CTA/MRA diagnosed: the ICA or MCA-M1/M2 occlusion, (6) Receiving bridging therapy (EVT following IV Tenecteplase) within 24 hours from stroke onset (7) Baseline DSA diagnosed: ICAD related LVO(if any one the following criteria is fulfilled: 1) absence of atrial fibrillation; 2) truncal-type occlusion; 3) residual stenosis ≥30% on DSA after the first retriever; 4) researchers determined it to be ICAD-related LVO based on the TOAST classification, (8) Have achieved successful reperfusion after EVT (mTICI ≥2b). Patients with previously known permanent, persistent, or paroxysmal atrial fibrillation, permanent stenting during EVT, severe bleeding or had a higher bleeding risk in the last 6 months, imaging examination before randomization showed the Heidelberg hemorrhage type 1c, 2, or 3 ICH with or without clinical exacerbation, infarct area greater than 50% of the middle cerebral artery blood supply area or infarct volume ≥70ml, cerebral hernia signs, and some other severe organic diseases and an expected survival time of less than 90 days, severe liver insufficiency or renal insufficiency will be excluded. Patients will be randomly assigned to the experimental group or control group at a 1:1 ratio. Experimental group will receive intravenous tirofiban of a dose of 0.4 μg/kilo/min for 30 minutes after the completion of bridging therapy, followed by a continuous infusion of 0.1 μg/kilo/min for up to 24 hours. Then the patient will transition to standard medical therapy, with no restrictions on the antiplatelet regimen but is advised to receive loading dose dual antiplatelet therapy (oral aspirin 100 mg and clopidogrel 300 mg four hours before the end of intravenous tirofiban and daily oral aspirin 100 mg and clopidogrel 75 mg for 30 days). Control group will receive standard medical therapy after bridging treatment. The primary endpoint is the proportion of modified Rankin Scale (mRS) score 0 to 2 at 90±7 days after onset. The primary safety outcome is the symptomatic intracerebral hemorrhage (sICH) within 48 hours after randomization according to ECASS III criteria. This trial will provide important information for the standardization of antiplatelet medication regimens after bridging therapy for improving functional outcomes in patients with acute large vessel atherosclerotic occlusive ischemic stroke.

Inclusion Criteria:

1. Age ≥18 years old.

2. Pre-mRS 0-2.

3. Baseline NIHSS 6-30 points.

4. Baseline ASPECTS ≥6 points.

5. Baseline CTA/MRA diagnosed: the ICA or MCA-M1/M2 occlusion.

6. Receiving bridging therapy (EVT following IV Tenecteplase) within 24 hours from stroke onset.

7. Baseline DSA diagnosed: ICAD related LVO.

   * ICAD-related LVO is assumed if any one the following criteria is fulfilled: (1) absence of atrial fibrillation; (2) truncal-type occlusion; (3) residual stenosis ≥30% on DSA after the first retriever; (4) researchers determined it to be ICAD-related LVO based on the TOAST classification.

8. Patients have achieved successful reperfusion after EVT (mTICI ≥2b).

9. Patients or their eligible surrogates provided informed consent.

Exclusion Criteria:

1. Previously known permanent, persistent, or paroxysmal atrial fibrillation.
2. Permanent stenting during EVT;
3. Patient had severe bleeding or the following conditions, such as active gastrointestinal ulcer, aortic dissection, platelet count <100 ×109/L, hemoglobin <100 g/L, INR≥1.7 in the last 6 months.
4. Contraindication to glycoprotein IIb/IIIa inhibitors.
5. Imaging examination (Flat-panel NCCT/DCT) before randomization showed the following: Heidelberg hemorrhage type 1c, 2, or 3 ICH with or without clinical exacerbation (an increase of ≥4 points in the NIHSS score from baseline or an increase of ≥2 points in any of the NIHSS scores or resulting in intubation, decompression of bone valves, ventricular drainage, or other significant medical/surgical intervention), infarct area greater than 50% of the middle cerebral artery blood supply area or infarct volume ≥70ml, cerebral hernia signs.
6. Vascular malformations, arterial dissection, intracranial aneurysms, tumors (except for small meningiomas), cerebrovascular inflammation, cerebral amyloid angiopathy, or other major non-ischemic craniocerebral diseases (e.g. multiple sclerosis) as diagnosed by head imaging.
7. Acute renal failure, dialysis, or estimated glomerular filtration rate (eGFR) < 30ml/min/1.72m2, or serum creatinine > 220mmol/L (2.5mg/dl).
8. History of severe liver disease, or aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) and/or glutamyltransferase (GGT) ≥3×ULN and/or total bilirubin (TBIL) ≥2×ULN.
9. Acute ST elevation myocardial infarction (MI), acute decompensated heart failure, QTc>500 ms, hospitalization or involuntary coronary intervention due to acute coronary syndrome, MI, cardiac arrest within the past 3 months.
10. Severe non-cardiovascular comorbidity with life expectancy < 3 months (e.g., malignant tumors).
11. Any clinical conditions determined by the study team that may limit adherence to the study process.
12. Currently receiving an investigational drug or device.
13. Women of childbearing age not practicing reliable contraception who do not have a documented negative pregnancy test.
14. The subject's informed consent was not obtained.

There is not a plan to make IPD available. Sharing IPD will require IRB approval from Tiantan Hospital and other participating institutes in China.