Carotid Stenosis

A 53-year-old woman who smoked and had hypertension had brief numbness of the right side of her body. Six months later, aphasia and right hemiparesis suddenly developed, and they resolved after 48 hours. Computed tomographic angiography (CTA) showed left internal-carotid-artery stenosis of 70% just distal to the bifurcation. Magnetic resonance imaging (MRI) confirmed a left frontotemporal infarct without hemorrhagic transformation or cerebral edema. Cardiac evaluation was normal. What is the appropriate management of this patient's carotid stenosis?