Effect of Balloon Angioplasty vs Stenting Following Residual Stenosis After Endovascular Treatment of Intracranial Atherosclerotic Acute Ischemic Stroke

Prior treatment

• Gastrointestinal or genitourinary bleeding within 30 days before stroke onset, or major surgery within 14 days before stroke onset.
• Use of any glycoprotein IIb/IIIa inhibitor other than tirofiban.

Other illness

• Any intracranial hemorrhage identified on imaging before randomization; or major intracranial hemorrhage, defined as parenchymal hematoma type 1 or type 2, identified on intraprocedural flat-panel CT. Parenchymal hematoma type 1 is defined as blood clots involving less than 30% of the infarcted area, with or without a slight space-occupying effect; parenchymal hematoma type 2 is defined as blood clots involving more than 30% of the infarcted area with a substantial space-occupying effect.
• Pre-existing neurological or psychiatric disease that may confound neurological or functional outcome assessment.
• Arterial tortuosity or another arterial condition that would prevent the study device from reaching the target vessel.

Lab values

• Bleeding diathesis, including platelet count below 100 × 10⁹/L, activated partial thromboplastin time greater than 50 seconds, or international normalized ratio greater than 2.0; treatment with a direct oral anticoagulant within the preceding 48 hours; or a history of heparin-induced thrombocytopenia.
• Severe renal impairment, defined as glomerular filtration rate below 30 mL/min or serum creatinine above 220 μmol/L (2.5 mg/dL).
• Any definite cardioembolic source, including chronic or paroxysmal atrial fibrillation, sick sinus syndrome, mitral stenosis, mechanical heart valve, endocarditis, history of atrial or ventricular thrombus, myocardial infarction within the preceding 3 months, dilated cardiomyopathy, spontaneous echo contrast in the left atrium, or left ventricular ejection fraction below 30%.

Other

• Pregnancy or breastfeeding at admission.
• Contraindication to iodinated contrast agents, nickel, titanium, or their alloys.
• Life expectancy of less than 6 months.
• Unlikely to complete the 90-day follow-up.

• Age 18 years or older.
• Pre-stroke modified Rankin Scale (mRS) score of 0-1.
• Symptoms of acute ischemic stroke presenting within 24 hours of the last known well time.
• Baseline National Institutes of Health Stroke Scale (NIHSS) score of at least 6.
• Baseline Alberta Stroke Program Early CT Score (ASPECTS) of at least 6 for anterior-circulation stroke, or posterior-circulation ASPECTS (pc-ASPECTS) of at least 6 for posterior-circulation stroke.
• Occlusion of the intracranial internal carotid artery, M1 segment of the middle cerebral artery, V4 segment of the vertebral artery, or basilar artery.
• The clinical care team plans to perform endovascular treatment.
• The participant or the participant's legally authorized representative is able to provide written informed consent.
• Baseline CT perfusion or MR perfusion imaging demonstrating an ischemic core volume of less than 70 mL, a mismatch ratio of at least 1.2, and a mismatch volume of at least 15 mL.
• Intracranial atherosclerosis is considered the underlying etiology, with residual stenosis of at least 50% after endovascular treatment, and rescue balloon angioplasty or stenting is planned