Efficacy and Safety of PCSK9 Inhibitors in Patients With Large-Artery Atherosclerosis (LAA) Ischemic Stroke

Prior treatment

• Prior intracranial or extracranial endovascular therapy before enrollment, planned acute endovascular therapy within 90 days, or planned surgery that may affect outcome assessment.
• Participation in another interventional clinical study within 30 days before enrollment, or concurrent participation in another interventional study that may affect outcome assessment.

Other illness

• Hemorrhagic transformation or other intracranial hemorrhage (including hemorrhagic infarction, subarachnoid hemorrhage, subdural hematoma, or epidural hematoma), except cerebral microbleeds detected only by SWI.
• Severe cardiac insufficiency：NYHA class III or IV.
• Pre-existing neurologic or psychiatric disease likely to affect neurologic or functional outcome assessment; severe neurologic deficit causing loss of independent living; dementia or psychiatric disease preventing completion of follow-up.
• Autoimmune disease (for example systemic sclerosis, systemic lupus erythematosus, Sjogren syndrome, Behcet disease, mixed connective tissue disease, or IgG4-related disease).
• Active seizures, hypotension, hyperthyroidism, asthma, and other allergic respiratory diseases, as well as individuals with a tendency toward allergies.
• Any other condition judged by the investigator to make participation inappropriate or to pose substantial risk.

Lab values

• Severe hepatic dysfunction (ALT or AST \>3 x upper limit of normal) or severe renal dysfunction (serum creatinine \>2 mg/dL, eGFR \<30 mL/min/1.73 m2, or requiring dialysis).
• Platelet count \<100 x 10\^9/L.
• Active gastrointestinal ulcer, active bleeding tendency: corrected international normalized ratio (INR) \> 1.5, bleeding time exceeding the upper limit by more than 1 minute, or increased bleeding risk due to heparin-induced thrombocytopenia; major systemic bleeding occurring within 30 days prior to enrollment.

Other

• Pregnancy or breastfeeding.
• Giant intracranial tumor, giant cerebral aneurysm, or arteriovenous malformation.

• Age 18-80 years.
• Acute ischemic stroke diagnosed according to the Chinese Guidelines for Diagnosis and Treatment of Acute Ischemic Stroke (2023), based on clinical and imaging criteria.
• Large-artery atherosclerotic subtype (TOAST classification) confirmed within 72 hours after stroke onset.
• NIHSS score 4-20 before treatment.
• Pre-stroke modified Rankin Scale (mRS) score ≤1.
• LDL-C ≥1.8 mmol/L before enrollment.
• Able to use evolocumab and statin medications in accordance with the physician's instructions and the prescribing information.
• No prior use of a PCSK9 inhibitor before enrollment.
• Written informed consent provided by the participant or legally authorized representative.