Aspirin (30-1350 mg/day) irreversibly acetylates the cyclooxygenase of platelets, thus inhibiting platelet synthesis of thromboxane A2. Prostacyclin production in the endothelium is reduced, but this effect is reversible and short-lived. A reduction in transient ischemic attacks (TIAs), stroke, and death in men was shown in the Canadian Cooperative Study Group. [14]
Statins, which include atorvastatin, rosuvastatin, simvastatin, pravastatin, and lovastatin, are 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors that lower LDL cholesterol levels. Statin therapy, with a target low-density lipoprotein (LDL) level below 100 mg/dL, is recommended for all patients with extracranial carotid atherosclerotic disease. A lower target LDL level, 70mg/dL, is recommended in high-risk patients. [15]
Ticlopidine (250 mg q12hr) is a thienopyridine that irreversibly alters the platelet membrane and inhibits platelet aggregation. It is approximately 10% more effective than aspirin. Toxicity includes neutropenia and diarrhea. Clopidogrel (75 mg/day) is similar to ticlopidine; the risk of neutropenia is low.
Warfarin (titrated international normalized ratio [INR] 2-3) use in patients with noncardiac emboli is controversial.
Antiplatelet therapy (cilostazol) may reduce the progression of carotid artery stenosis after stent implantation. [16]
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Arteriogram of aortic arch and its branches.
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Arteriogram of carotid stenosis.
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Atherosclerotic plaque removed at time of carotid endarterectomy (areas of ulceration with thrombus and intraplaque hemorrhage are present).
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Carotid artery exposed prior to carotid endarterectomy (coil present in internal carotid artery).
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Carotid artery following endarterectomy and prior to closure (tapered endpoint and smooth appearance of lumen).
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Carotid artery following Dacron patch angioplasty.
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Selective left carotid angiogram.
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Oblique view of left carotid artery demonstrating lesion within internal carotid artery.
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Placement of stent into internal carotid artery. Note filter wire in upper photos (dots at top of internal carotid artery).
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Angioplasty after stent placement; again, note filter wire protecting distal carotid artery.
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Completion arteriogram displaying improvement in diameter of internal carotid artery.
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Normal carotid arteries on color flow duplex ultrasonography.
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Color flow duplex ultrasonogram reveals 80-99% left carotid stenosis and normal right carotid.
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Carotid plaque.
