What is the incidence of cerebral and cardiac ischemic events in asymptomatic patients with cervical bruits?
Patients with asymptomatic cervical bruits have a higher risk of cardiac ischemic events than strokes, although severe carotid stenosis strongly predicts cerebral ischemic events.
Five hundred asymptomatic patients with cervical bruits were followed prospectively by clinical and Doppler examination for up to four years (mean, 23.2 months) to identify the variables predicting outcome. Thirty-six patients had strokes or transient ischemic attacks, 51 had cardiac ischemic events, and 45 died. At one year the incidence of cerebral ischemic events (transient ischemic attacks and strokes) was 6 percent, that of cardiac ischemic events was 7 percent, and that of death was 4 percent. The overall incidence of stroke at one year was 1.7 percent (1 percent in patients without previous transient ischemic attacks), but the incidence was 5.5 percent in patients with severe carotid-artery stenosis (greater than 75 percent). Cerebral ischemic events were most frequent in patients with severe carotid-artery stenosis (P less than 0.0001), progressing carotid-artery stenosis (P less than 0.0005), or heart disease (P less than 0.0005) and in men (P less than 0.025). The degree of carotid-artery stenosis on initial presentation was a powerful predictor of neurologic sequelae. Patients with asymptomatic cervical bruits have a higher risk of a cardiac ischemic event than of a stroke. Although the risk of cerebral ischemic events is highest in patients with severe carotid-artery stenosis, in most instances even these patients do not have strokes without some warning.
Chambers et al. (1986) studied this question.