OBJECTIVE To clarify the definition of carotid artery diseases, the appropriateness of screening for disease, investigation and management of patients presenting with transient ischemic attacks, and management of asymptomatic carotid bruits.
Once an acute TIA is clinically diagnosed, carotid imaging should be performed immediately, and if indicated, patients should be referred for urgent carotid endarterectomy (CEA). Two major randomized trials have confirmed that symptomatic patients benefit from CEA
The proposed new definition of TIA is a brief episode of neurologic dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than 1 hour and no evidence of acute infarction. The corollary is that persistent clinical signs or characteristic imaging abnormalities of infarction detected by computerized tomography (CT) or magnetic resonance imaging (MRI) constitute a stroke
Classic symptoms of TIA are contrasted with vertebrobasilar symptoms in Table 2 . Although not always possible, it is important to distinguish between these two types of symptoms because patients with transient ischemia of the vertebrobasilar system do not benefit from CEA.
Asymptomatic carotid bruit . Asymptomatic carotid artery stenosis is usually detected by a physician auscultating a patient’s carotid arteries and hearing a bruit or coincidentally during ultrasound examination of the neck. Among patients with carotid bruit, only 35% have hemodynamically significant lesions (70% to 90% stenosis). Among patients with significant hemodynamic carotid stenosis, only 50% have a bruit noted during physical examination. The annual incidence of stroke among those with asymptomatic bruits but no prior TIA is 1% to 3% (level II).21-23
MAIN MESSAGE Patients with symptoms of hemispheric transient ischemic attacks associated with >70% stenosis of the internal carotid artery are at highest risk of major stroke or death. Risk is greatest within 48 hours of symptom onset; patients should have urgent evaluation by a vascular surgeon for consideration of carotid endarterectomy (CEA). Patients with 50% to 69% stenosis might benefit from urgent surgical intervention depending on clinical features and associated comorbidity. Patients with <50% stenosis do not benefit from surgery. Asymptomatic patients with >60% stenosis should be considered for elective CEA.
Current data also confirm that asymptomatic patients aged 75 years or younger with >60% carotid stenosis are likely to benefit from CEA
CONCLUSION Symptomatic carotid artery syndromes need urgent carotid duplex evaluation to determine the need for urgent surgery. Those with the greatest degree of stenosis derive the greatest benefit from timely CEA.
