This is a prospective, multicenter, randomized controlled clinical study to evaluate the efficacy of PCSK9 inhibitor in addition to standard therapy in patients with acute ischemic stroke undergoing endovascular therapy.

Inclusion Criteria:

• Age ≥ 18 years.
• Meets the diagnostic criteria for acute ischemic stroke according to the Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2023.
• Severe stenosis or occlusion of large anterior circulation vessels confirmed by DSA, MRA, or CTA.
• Preoperative NIHSS score ≥ 4 and < 25.
• Meets the indications for endovascular therapy per the Chinese Guidelines for Endovascular Therapy of Acute Ischemic Stroke 2023, and successful reperfusion of the target vessel (mTICI ≥ 2b) achieved via emergency endovascular intervention.
• LDL-C > 1.8 mmol/L or non-HDL cholesterol > 2.6 mmol/L.
• Signed informed consent provided by the patient or their legally authorized representative.

Exclusion Criteria:

• Confirmed non-atherosclerotic causes of vascular stenosis/occlusion (e.g., cardioembolism, vasculitis, vascular malformation, moyamoya disease, iatrogenic causes).
• History of intracranial hemorrhage or systemic bleeding within the past 3 months.
• Presence of hemorrhagic transformation (PH1/PH2) immediately after the procedure.
• Severe hepatic impairment: ALT > 3 times the upper limit of normal, INR > 1.2, hepatic encephalopathy, or history of drug-induced liver injury.
• Use of PCSK9 inhibitors within 6 months prior to enrollment.
• Pre-stroke mRS ≥ 2.
• Terminal illness (e.g., malignancy, end-stage renal disease) with an expected survival of < 3 months.
• Pregnancy or lactation.
• Other neurological diseases that may interfere with neurological function assessment during follow-up.
• Allergy or intolerance to PCSK9 inhibitors or statins.
• Participation in another interventional clinical trial.