Assessment of the efficacy of noninvasive screening for patients with asymptomatic neck bruits.

Abstract

Several recent clinical trials have shown that endarterectomy is efficacious in patients with asymptomatic carotid artery stenosis. The purpose of this study was to evaluate the effectiveness of various test strategies for screening and diagnosing carotid artery disease. We constructed a model of the natural history of carotid artery disease using literature-based estimates of the prevalence and incidence of carotid artery stenosis and associated morbidity and mortality. Markov cohort simulation was used to estimate the mean quality-adjusted life years and monetary costs associated with various management strategies. Screening is cost-effective in the baseline model. Key parameters affecting the efficacy of screening are prevalence of operable lesions, benefit of surgery, surgical complication rates, quality of life with stroke, rate of stenosis progression, and excess morbidity and mortality. Asymptomatic patients with carotid bruits may benefit from screening if the prevalence rate is > or = 20%, the benefits and risks associated with surgery are similar to those observed in the Asymptomatic Carotid Atherosclerosis Study, and the quality of life with stroke is considerably lower than the quality of life without stroke. Ultrasound followed by three-dimensional time-of-flight MR angiography, if indicated, is a promising test strategy.