Patient description: A 46-year-old man presents with dizziness and frequent headaches. He has a family history of CAD, but no other cardiovascular risk factors such as smoking, high blood pressure, and diabetes mellitus and is physically active. The patient's LDL-C and HDL-C levels were 545 and 53 mg/dL, respectively. His fasting glucose and triglyceride levels (85 and 158 mg/dL, resp.) were within normal limits. The patient reported no use of lipid-lowering medications. Neck auscultation revealed a systolic murmur 3+/6+ in the neck, radiating to the skull. Ultrasonography of the carotid arteries, revealed severe stenosis in the left internal carotid artery (LICA), as well as moderate stenosis in the right internal carotid artery (RICA) estimated between 40% and 50%. For the LICA, the peak-systolic (PSV) and end-diastolic velocity (EDV) cutoff values were 208.5 cm/s and 54.5 cm/s, respectively; RICA PSV was 91.72 cm/s and RICA EDV was 37.37 cm/s. Plaque was observed in the anterior and posterior walls of the internal carotid artery and common carotid artery, which were characterized as bulky plates extending to the middle third of the internal coronary arteries (ICAs) and as predominantly echogenic and hyperechoic, with less than 50% of the area being echolucent with uneven surfaces.

Clinical trial eligibility criteria: eligible ages (years): 40.0-999.0,  Carotid Artery Stenosis Asymptomatic Carotid Artery Stenosis Age ≥ 40 years old 2. Significant (70-99%) carotid artery stenosis on one side, as measured by duplex ultrasound or angiogram 3. Asymptomatic carotid stenosis (no history of ipsilateral stroke or TIA within 180 days) 4. Deemed to be fit for carotid endarterectomy 5. At least one of the following high risk features: (a) prior stroke >6months prior to randomization; (b) peripheral artery disease; (c) current smoker; and/or (d) type II diabetes 6. On a moderate to high intensity statin therapy (defined as atorvastatin 40-80mg daily, rosuvastatin 20-40mg or simvastatin 40mg daily) unless a lower dose, or another statin or non-statin therapy is clinically justified  Contraindications for MRI (pacemaker; neurostimulator; non-removable metal fragments in the eye; etc.) 2. Patients in whom additional lowering of LDL-C with evolocumab is deemed to be clinically inappropriate 3. Currently taking simvastatin >40mg/day 4. High risk comorbidities such as severe heart failure, severe COPD, severe renal disease, known severe hepatic impairment, unstable coronary syndrome, and/or advanced dementia 5. eGFR <30 mL/min/1.73m2 6. Anatomic contraindications for CEA such as previous neck radiation or radical neck surgery; inaccessible lesion above C2 level; tracheostomy; contralateral laryngeal nerve paralysis 7. Current, prior within past year, or known planned use of PCSK9 inhibition treatment 8. Known intolerance or allergy to evolocumab or other PCSK9 inhibitors 9. Known latex allergy 10. Women who are pregnant or breastfeeding 11. Women of child bearing potential who are unwilling to use proper family planning or birth control methods to avoid pregnancy. Women are considered post-menopausal and not of childbearing potential after 12 months of natural (spontaneous) amenorrhea or have had a surgical procedure such as hysterectomy which makes pregnancy impossible 12. Inability to comply with protocol-required study visits or procedures, including administration of study drug 13. Severe concomitant disease that is expected to reduce life expectancy to less than 5 years 14. Participation in another investigational device or drug study which is likely to affect the primary outcome, within 30 days of planned initiation of study drug If all listed above are met, the participant will undergo a time-of-flight MR angiogram, where one additional will be assessed to confirm 1. Evidence of IPH on MRI