Improving Neuroprotective Strategy for Ischemic Stroke Before Endovascular Thrombectomy by Intravenous Tirofiban

• Intravenous tirofiban before endovascular thrombectomy (Drug): The tirofiban was administrated as a bolus dose of 10 μg/kg, followed by continuous infusion of 0.15 μg/kg/min for up to 24 hours.
• Intravenous placebo before endovascular thrombectomy (Drug): The placebo was administrated as a bolus dose of 10 μg/kg, followed by continuous infusion of 0.15 μg/kg/min for up to 24 hours.

Primary outcomes

• The proportion of patients with functional independence (modified Rankin Scale [mRS] score of 0 to 2) [Day 90]: mRS ranges from 0-6, with high score meaning poor outcome

Secondary outcomes

• The proportion of patients without disability (modified Rankin Scale [mRS] score of 0 to 1) or who returned to their premorbid mRS score at 90 days (for patients with prestroke mRS score >1) [Day 90]: mRS ranges from 0-6, with high score meaning poor outcome
• ordinal distribution of modified Rankin Scale (mRS) [Day 90]: mRS ranges from 0-6, with high score meaning poor outcome
• The proportions of patients with substantial reperfusion at initial preprocedure catheter angiogram (defined as mTICI score ≥2b) [immediately after first catheter angiogram]: Substantial reperfusion was defined as an expanded Thrombolysis In Cerebral Infarction grade of 2b50 (substantial reperfusion), 2c (nearcomplete reperfusion), or 3 (complete reperfusion).
• The proportions of patients with substantial reperfusion at final angiogram [immediately after final angiogram]
• The proportions of patients with complete recanalization as assessed by CTA or MRA 48 hours after endovascular treatment [24 (-6/+24) hours]
• Change in National Institute of Health stroke scale (NIHSS) [24 (-6/+24) hours]: NIHSS ranges from 0-42, with high score meaning poor outcome
• change in National Institute of Health stroke scale (NIHSS) [7 (-2/+2) days]: NIHSS ranges from 0-42, with high score meaning poor outcome
• The incidence of symptomatic intracranial hemorrhage assessed according to Heidelberg bleeding classification [24 (-6/+24) hours]
• The incidence of intraparenchymal hemorrhage (PH1 and PH2) [24 (-6/+24) hours]
• The incidence of non-intracranial hemorrhage complications [24 (-6/+24) hours]
• Serious adverse events [7 (-2/+2) days]: eg, acute respiratory failure, large or malignant middle cerebral artery infarction, acute heart failure, hemicraniectomy
• Procedure-associated complications [Periprocedural]
• The proportion of patients with thrombocytopenia [24 (-6/+24) hours]
• The incidence of mortality [Day 90]

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Age ≥ 18 years;
* Anterior circulation large vessel occlusion (the internal carotid artery or the first or second segment of the middle cerebral artery) confirmed by computed tomography angiography (CTA) or magnetic resonance angiography (MRA);
* Eligible for endovascular treatment within 12 hours of symptom onset;
* Based on the patient's medical history, clinical presentation, and imaging findings, large artery atherosclerosis is highly suspected as the underlying etiology;
* Baseline National Institute of Health Stroke Scale (NIHSS) ≥ 6;
* Baseline ASPECTS ≥ 6 on CT;
* A pre-stroke modified Rankin Scale (mRS) score of ≤2;
* Signed informed consent by patient or their legally authorized representative.

Exclusion Criteria:

* History of atrial fibrillation or atrial flutter, or 12-lead Electrocardiogram before randomization and after admission showing atrial flutter or atrial fibrillation;
* Hemorrhagic stroke: cerebral hemorrhage, subarachnoid hemorrhage, or a history of bleeding within one month;
* Intracranial aneurysms or malformations, tortuous arteries that hinder thrombectomy, and space-occupying effect brain tumors;
* The following drugs are taken within one week: dual antiplatelet drugs, direct oral anticoagulants (DOACs), warfarin and other drugs that increase the risk of bleeding;
* Severe uncontrolled hypertension (systolic blood pressure over 200mmHg or diastolic blood pressure over 110 mmHg);
* Deficiency of anticoagulant factors or international normalized ratio (INR) > 1.7, platelet count < 90×10⁹/L;;
* Severe renal insufficiency and advanced disease with an expected life expectancy of less than 6 months;
* Pregnancy or lactation;
* Allergy to drugs or contrast agents;
* Participating in other clinical trials;
* Other conditions that the researcher deems unsuitable for participation in this study.