Efficacy and Safety of Tirofiban for Patients With BAD (BRANT) (BRANT)

Inclusion Criteria: Age: 18-75 years old Acute ischemic stroke Time from onset to randomization ≤48h; if onset time is unknown, time from last known well to randomization ≤48h Meet the following BAD Diagnostic Imaging Criteria 4.1. DWI infarcts: single (isolated) deep (subcortical) infarcts; 4.2. The culprit arteries are either Lenticulostriate artery (LSA) or Paramedian pontine artery (PPA), and the infarct lesion on DWI conforms to one of the following characteristics (A/B): A. LSA: 1) "Comma-like" infarct lesions with "Fan-shaped" extension from bottom to top in the coronary position; or 2) ≥ 3 layers (layer thickness 5-7 mm) on axial DWI brain images; B. PPA: The infarct lesion extends from the deep pons to the ventral pons on the axial DWI brain images; 4.3. No more than 50% stenosis on the parent artery of the criminal artery (i.e. corresponding basilar or middle cerebral artery) (Confirmed by magnetic resonance angiography [MRA] or computed tomography angiography [CTA] or digital substraction angiography [DSA]). Singed informed consent by the patient or legally authorized representatives. Exclusion Criteria: Transient ischemic attack (TIA) Intracranial hemorrhagic diseases, vascular malformations, aneurysms, brain abscesses, malignant space-occupying lesions, or other non-ischemic intracranial lesions detected by baseline CT/MRI, or MRA/CTA/DSA; Presence of ≥50% stenosis in extracranial artery in tandem relationship ipsilateral to the lesion; Cardiogenic embolism: atrial fibrillation, myocardial infarction, heart valve disease, dilated cardiomyopathy, infective endocarditis, atrioventricular block disease, heart rate less than 50 beats per minute Have received or plan to receive endovascular therapy or thrombolysis after onset; Stroke of other clear causes, e.g., moyamoya disease, arterial entrapment, vasculitis, etc. modified Rankin Scale ≥2 before onset Use of tirofiban within 1 week before or after onset Low platelets (<100×10^9 /L), or Prothrombin time >1.3 times of the upper normal limit, or INR >1.5, or other systemic hemorrhagic tendencies such as hematologic disorders Elevation of ALT or AST more than 1.5 times the upper normal limit; Glomerular filtration rate <60 ml/min/1.73m^2 Known malignant tumors History of trauma or major surgical intervention within 6 weeks prior to onset History of intracranial hemorrhage Active or recent history(within 30 days prior to onset) of clinical bleeding (e.g., gastrointestinal bleeding) Malignant hypertension (systolic blood pressure >200 mmHg, or diastolic blood pressure >120 mmHg) Life expectancy ≤ 6 months Contraindications of 3 T MRI examination Pregnant or lactating women Have participated in another clinical trial within 3 months prior to the date of informed consent, or are participating in another clinical trial.