In recent years, the positive results of trials for mechanical thrombectomy (MT) have brought a new era for large artery occlusion patients, especially those beyond the time window of intravenous thrombolysis. However, interventional procedures can cause endothelial injuries leading to local activation of platelet aggregation and subsequent thromboembolic complications or early re-occlusion.Tirofiban is a specific antagonist of the platelet glycoprotein (GP) IIb/IIIa receptor, which is considered highly effective against the final common pathway of platelet aggregation and preventing vascular reocclusion. However, there is no consensus on if AIS patients treated with MT also benefit from intravenous tirofiban. This study aims to evaluate the effectiveness and safety of profiles of tirofiban during MT and provide reliable clinical evidence for the treatment of tirofiban in AIS patients.

This study is a multicenter, prospective, open-label, randomized controlled, blinded-endpoint trial with two parallel groups and a 3-month follow-up. A total of 200 eligible participants recruited from 4-6 stroke centers will be randomly allocated to either an experimental group (intravenous tirofiban + MT therapy) or a control group (MT alone) in a 1:1 ratio. The primary outcome is a composite endpoint, including the rate of recanalisation after the first embolectomy and the risk of symptomatic intracerebral haemorrhage. The secondary outcomes include clinical and neuroimaging outcomes, procedure-related complications, and adverse events to evaluate the effects of MT in combination with tirofiban treatment compared to MT alone in AIS patients. Intention-to-treat (ITT) analysis will be undertaken in this study, and the full analysis set (FAS) population serves as the primary population for the analysis of efficacy data.

Inclusion Criteria:

1. Age 18-85 years (including 18 and 85);
2. Acute ischemic stroke within 24 hours of onset, and NIHSS >5 points;
3. Acute large vessel occlusion, including internal carotid artery, M1 segment of middle cerebral artery, M2 segment of middle cerebral artery;
4. Multimodal CT/MRI imaging was completed before thrombectomy, and the following criteria were met: penumbra>10ml, infarct core volume <70ml, and mismatch rate >1.2;
5. Planned to receive endovascular treatment;
6. Informed consent was obtained.

Exclusion Criteria:

1. History of atrial fibrillation or atrial flutter, or 12-lead ECG before randomization and after admission showing atrial flutter or atrial fibrillation;
2. Treated with intravenous thrombolysis for this stroke or currently taking new oral anticoagulant drugs, warfarin, ticagrelor and other drugs that may increase the risk of bleeding;
3. Pre-stroke disability (pre-stroke mRS score > 2);
4. Severe comorbidity (such as severe cardiopulmonary dysfunction, or the terminal stage of malignant tumors with expected survival less than 90 days);
5. CT shows hypodensity lesions in more than 1/3 of the territory of the middle cerebral artery;
6. Allergy to tirofiban or having any contraindications to the use of tirofiban (patients with active internal bleeding, history of intracranial hemorrhage, intracranial tumors, arteriovenous malformations, and intracranial aneurysms, or patients resulting in thrombocytopenia from the use of tirofiban previously);
7. Contraindications to the contrast agents used in multimodal CT/MRI examination (such as allergy to the contrast agents, etc.);
8. Pregnant or breastfeeding women;
9. Patients currently participating in other clinical study trials;
10. Other conditions determined by the investigator are not suitable for inclusion in this study.

Images from each study site will be uploaded to the central server and all analyses will be performed by a trained physician at the study coordinating center who is unaware of group assignments. Similarly, follow-up assessments at 90 days after stroke will be conducted by a trained accessor in a blinded manner.