A 67-year-old man with diabetes, arterial hypertension, and coronary artery disease was found to have a left carotid bruit. He had no retinal or hemispheric ischemic events.

Our patient had an asymptomatic carotid artery bruit. Noninvasive studies (carotid ultrasound and magnetic resonance angiography [MRA]) showed bilateral 50% to 79% internal carotid artery stenosis.

Approximately 4% of adults have asymptomatic neck bruits. However, a carotid bruit is a poor predictor of carotid artery disease or high-grade carotid artery stenosis. Although screening for carotid artery stenosis is advocated by some, the U.S. Preventive Service Task Force does not recommend routine screen for stroke prevention because more patients with asymptomatic carotid artery stenosis will experience cardiovascular events than stroke. Moreover, the sensitivity of carotid bruits in detecting carotid artery stenosis greater than 70% is low.

The estimated annual stroke risk among individuals with asymptomatic carotid bruits is 1.5% at 1 year and 7.5% at 5 years. The incidence of ischemic events correlates with
the progression of carotid artery stenosis. Asymptomatic carotid artery stenosis less than equal to 75% carries a stroke risk of 1% to 2% annually. When the carotid artery stenosis is greater than equal to 75%, the annual stroke rate is about 5% to 6%.