This is a prospective cohort study to investigate the early impact of evolocumab on patients with acute ischemic stroke (AIS) in China. Evolocumab, a proprotein convertase subtilisin/kexin taye 9 inhibitor, can significantly reduce low density lipoprotein cholesterol (LDL-C) levels and has a positive effect on improving cardiovascular events. However, existing studies have focused almost exclusively on the long-term effects of Evolocumab, and the early effects of Evolocumab on AIS patients remains unclear.

Patients aged 18-80 years old admitted to the Department of Neurology, Xuanwu Hospital, Capital Medical University, with a definite diagnosis of acute ischemic stroke and receiving lipid-lowering therapy with statins with or without evolocumab will be included in this study. Participants will be divided into two groups according to the lipid-lowering therapy they used: 1) statin-alone group: the participants receive statins alone (atorvastatin 20mg qn or rosuvastatin 10mg qn or pivastatin 2mg qn) for lipid reduction, and 2) PCSK9-i group: the participants receive statins (atorvastatin 20mg qn or rosuvastatin 10mg qn or pivastatin 2mg qn) and evolocumab (140mg twice a month) for lipid reduction. Most importantly, the lipid-lowering therapy of participants will be decided only by clinicians not involved in the study, not by the investigators. The levels of blood lipid (TC, TG, HDL-C, LDL-C, Apo AI and Apo B) and inflammatory biomarkers (hsCRP and IL-6) of these participants at different time points (day 1, day 3, day 5, and month 3) will be recorded. The target level of LDL-C is the LDL-C reduction ≥50% from the baseline and LDL-C<1.4mmol/L (55mg/dL). In addition, the cardiovascular events and adverse drug reactions of these participants during follow-up will also be recorded. During the follow-up period (3 months), participants who changed their lipid-lowering regimen, including the type, dosage and frequency of statins and evolocumab, will be excluded from the study.

Inclusion Criteria:

• Diagnosed with acute ischemic stroke;
• Aged 18-80 years, gender unlimited;
• The fasting LDL-C≥1.8mmol/L (70mg/dL);
• Received lipid-lowering therapy with statins with or without evolocumab;
• Premorbid mRS ≤ 2;
• NIHSS ≤ 15;
• Subjects participated in the study voluntarily and signed informed consent.

Exclusion Criteria:

• Participants who changed their lipid-lowering regimen;
• Participants allergic to PCSK9 inhibitors;
• Participants treated with cholesterol ester transfer protein inhibitor within 12 months prior to enrollment;
• LDL or plasma apheresis within 12 months prior to enrollment；
• Last known left ventricular ejection fraction < 30%
• Known hemorrhagic stroke at any time；
• Severe renal dysfunction, defined as an estimated glomerular filtration rate (eGFR) < 20 mL/min/1.73m2 at final screening；
• Active liver disease or hepatic dysfunction, defined as aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 3 times；
• Pregnant or lactating women；
• Severe, concomitant non-cardiovascular disease that is expected to reduce life expectancy to less than 3 years.

Acute ischemic stroke patients aged 18 to 80 years