Atherosclerotic Disease of the Carotid Artery Atherosclerosis is a degenerative disease of the arteries resulting in plaques consisting of necrotic cells, lipids, and cholesterol crystals. Atherosclerosis is a degenerative disease of the arteries resulting in plaques consisting of necrotic cells, lipids, and cholesterol crystals. These plaques can result in symptoms by causing a stenosis, embolizing, and thrombosing. These plaques can result in symptoms by causing a stenosis, embolizing, and thrombosing.

Atherosclerotic Disease of the Carotid Artery Stroke from any cause represents the third leading cause of death in the United States. Stroke from any cause represents the third leading cause of death in the United States. Half a million new strokes occur each year in the United States, resulting in approximately 150,000 deaths. Half a million new strokes occur each year in the United States, resulting in approximately 150,000 deaths. Stroke is the leading cause of serious long-term disability in the United States. Direct and indirect cost of stroke in the United States in 1997 was estimated at $40 billion. Stroke is the leading cause of serious long-term disability in the United States. Direct and indirect cost of stroke in the United States in 1997 was estimated at $40 billion.

Atherosclerotic Disease of the Carotid Artery Etiology: Ninety percent of all extracranial carotid lesions are due to atherosclerosis. Etiology: Ninety percent of all extracranial carotid lesions are due to atherosclerosis. Pathophysiology: Currently, embolization is considered the most common mechanism causing ischemic strokes from atherosclerotic lesions in the carotid bulb. Thrombosis and low flow are other possible mechanisms. Pathophysiology: Currently, embolization is considered the most common mechanism causing ischemic strokes from atherosclerotic lesions in the carotid bulb. Thrombosis and low flow are other possible mechanisms.

Atherosclerotic Disease of the Carotid Artery Clinical: Clinical: Amaurosis fugax (transient visual loss) Amaurosis fugax (transient visual loss) Transient ischemic attacks (TIAs) Transient ischemic attacks (TIAs) Crescendo TIAs Crescendo TIAs Stroke-in-evolution Stroke-in-evolution Cerebral infarction Cerebral infarction

Management of Carotid Artery Disease Risk Factor Modification and Medical Therapy Risk Factor Modification and Medical Therapy Carotid Endarterectomy Carotid Endarterectomy Carotid Artery Stenting Carotid Artery Stenting

Management of Risk Factors Hypertension Hypertension is the most powerful, prevalent, and treatable risk factor for stroke. Hypertension is the most powerful, prevalent, and treatable risk factor for stroke. Both systolic and diastolic blood pressure are independently related to stroke incidence. Both systolic and diastolic blood pressure are independently related to stroke incidence. Reduction of elevated blood pressure significantly lowers risk of stroke. Reduction of elevated blood pressure significantly lowers risk of stroke. Meta-analyses of randomized trials found that an average reduction in diastolic blood pressure of 6 mm Hg produces a 42% reduction in stroke incidence. Meta-analyses of randomized trials found that an average reduction in diastolic blood pressure of 6 mm Hg produces a 42% reduction in stroke incidence.

Management of Risk Factors Cigarette Smoking Cigarette smoking substantially increases risk of stroke with relative risk values of 1.5 to 2.2. Cigarette smoking substantially increases risk of stroke with relative risk values of 1.5 to 2.2. Smoking cessation promptly reduces risk of stroke. Smoking cessation promptly reduces risk of stroke.

Management of Risk Factors Blood Lipids Recently the Scandinavian Simvastatin Survival Study (4S) reported a 30% reduction in fatal and nonfatal strokes in patients taking simvastatin. Recently the Scandinavian Simvastatin Survival Study (4S) reported a 30% reduction in fatal and nonfatal strokes in patients taking simvastatin. Other lipid-lowering trials using statin drugs found a slowing of the progression of carotid atherosclerosis by ultrasound. Other lipid-lowering trials using statin drugs found a slowing of the progression of carotid atherosclerosis by ultrasound. Lipid lowering may be effective in reducing risk of some kinds of cerebrovascular disease. Lipid lowering may be effective in reducing risk of some kinds of cerebrovascular disease.

Antiplatelet Therapy Antiplatelet therapy has been shown in individual trials and meta-analysis to reduce risk of stroke and other vascular events in patients at high risk. Antiplatelet therapy has been shown in individual trials and meta-analysis to reduce risk of stroke and other vascular events in patients at high risk. The Antiplatelet Trialists Collaboration overview found a 23% reduction in risk for nonfatal stroke with antiplatelet therapy compared with placebo among persons with a history of transient ischemic attack (TIA) or stroke. The Antiplatelet Trialists Collaboration overview found a 23% reduction in risk for nonfatal stroke with antiplatelet therapy compared with placebo among persons with a history of transient ischemic attack (TIA) or stroke.

Carotid Endarterectomy Carotid endarterectomy is an excellent example of evidence-based medicine in practice. Carotid endarterectomy is an excellent example of evidence-based medicine in practice. The beneficial effects of Carotid Endarterectomy depend on the clinical presentation of the patient. The beneficial effects of Carotid Endarterectomy depend on the clinical presentation of the patient. Symptomatic vs. Asymptomatic Symptomatic vs. Asymptomatic Degree of stenosis Degree of stenosis

Carotid Endarterectomy for Symptomatic Severe Stenosis Randomized clinical trials have clearly established the benefit of carotid endarterectomy for patients with symptomatic high-grade stenosis. Randomized clinical trials have clearly established the benefit of carotid endarterectomy for patients with symptomatic high-grade stenosis. In NASCET, symptomatic patients with ipsilateral carotid stenosis of 70% to 99% who were randomized to carotid endarterectomy and medical management had significantly better outcomes than those randomized to medical management alone. In NASCET, symptomatic patients with ipsilateral carotid stenosis of 70% to 99% who were randomized to carotid endarterectomy and medical management had significantly better outcomes than those randomized to medical management alone.

Moderate stenosis In both NASCET and ECST, enrollment of symptomatic patients with moderate carotid artery stenosis was continued after enrollment of patients with severe stenosis was halted. In both NASCET and ECST, enrollment of symptomatic patients with moderate carotid artery stenosis was continued after enrollment of patients with severe stenosis was halted. Carotid endarterectomy in symptomatic patients with carotid artery stenosis of 50% to 69% yielded only a moderate reduction in the risk of stroke. Carotid endarterectomy in symptomatic patients with carotid artery stenosis of 50% to 69% yielded only a moderate reduction in the risk of stroke. Results of these two studies have shown that carotid endarterectomy should not be performed in symptomatic patients with carotid artery stenosis of less than 50%. Results of these two studies have shown that carotid endarterectomy should not be performed in symptomatic patients with carotid artery stenosis of less than 50%.

Asymptomatic carotid artery stenosis It is often detected incidentally or in a patient with a neck bruit; the prevalence is age- dependent and ranges from 0.5% in persons under 60 years to 10% in those over 80 years. It is often detected incidentally or in a patient with a neck bruit; the prevalence is age- dependent and ranges from 0.5% in persons under 60 years to 10% in those over 80 years. A number of observational studies suggest that the rate of unheralded stroke ipsilateral to a hemodynamically significant asymptomatic carotid artery stenosis is about 1% to 2% annually A number of observational studies suggest that the rate of unheralded stroke ipsilateral to a hemodynamically significant asymptomatic carotid artery stenosis is about 1% to 2% annually

Asymptomatic carotid artery stenosis Starting in the late 1980s, a number of clinical trials were conducted to assess the benefit, if any, of carotid endarterectomy in reducing the risk of ischemic stroke in asymptomatic patients with carotid artery stenosis. Starting in the late 1980s, a number of clinical trials were conducted to assess the benefit, if any, of carotid endarterectomy in reducing the risk of ischemic stroke in asymptomatic patients with carotid artery stenosis. Four major randomized clinical trials have been performed. Four major randomized clinical trials have been performed.

Asymptomatic carotid artery stenosis Asymptomatic Carotid Atherosclerosis Study (ACAS) is the largest and considered to be the most definitive study on this issue to date. Asymptomatic Carotid Atherosclerosis Study (ACAS) is the largest and considered to be the most definitive study on this issue to date. The study was terminated with a median follow-up of 2.7 years because surgery was found to have a significant benefit. The 5-year projected aggregate risk of ipsilateral stroke was estimated to be 11% for the medically treated group and 5.1% for the surgically treated group. These risk rates translated into a 53% reduction in relative risk for ipsilateral stroke in the carotid endarterectomy treatment group The study was terminated with a median follow-up of 2.7 years because surgery was found to have a significant benefit. The 5-year projected aggregate risk of ipsilateral stroke was estimated to be 11% for the medically treated group and 5.1% for the surgically treated group. These risk rates translated into a 53% reduction in relative risk for ipsilateral stroke in the carotid endarterectomy treatment group

Indications for Revascularization

Medical Management of Peripheral Vascular Disease Most people with PAD can be treated with lifestyle changes, medications or both. Lifestyle changes to lower risk include: Most people with PAD can be treated with lifestyle changes, medications or both. Lifestyle changes to lower risk include: Stop smoking (smokers are 2 to 25 times more likely to get PAD). Stop smoking (smokers are 2 to 25 times more likely to get PAD). Control diabetes. Control diabetes. Control blood pressure. Control blood pressure. Be physically active (including a supervised exercise program). Be physically active (including a supervised exercise program). Eat a low-saturated-fat, low-cholesterol diet. Eat a low-saturated-fat, low-cholesterol diet.

Medical Management of Peripheral Vascular Disease PAD may require drug treatment, too. Drugs include: PAD may require drug treatment, too. Drugs include: medicines to help improve walking distance (cilostazol and pentoxifylline). medicines to help improve walking distance (cilostazol and pentoxifylline). antiplatelet agents antiplatelet agents cholesterol-lowering agents (statins) cholesterol-lowering agents (statins)