UTILITY OF ROUTINE CAROTID DUPLEX SCREENING IN PATIENTS WHO HAVE CLAUDICATION

Purpose: The recently published Asymptomatic Carotid Atherosclerosis S tudy (ACAS) demonstrated the benefit of performing carotid endarterect omy in selected asymptomatic patients who have >60% carotid stenoses. It therefore becomes clinically important to identify the subgroups of patients who have a sufficiently high incidence of high-grade carotid stenosis to warrant routine carotid duplex screening. Methods: To det ermine the incidence of asymptomatic carotid disease in patients who h ad a chief complaint of claudication, we evaluated 188 patients who ha d claudication and no history of cerebrovascular symptoms. After a com plete history was taken and a physical examination performed, patients underwent standard lower-extremity noninvasive vascular laboratory st udies and carotid duplex scanning. Carotid duplex findings were interp reted by the Strandness criteria. Associated atherosclerotic risk fact ors were assessed (patient age, male sex, diabetes, hypertension, smok ing history, lipid levels, history of coronary artery disease, coronar y or vascular surgery, and family history of cerebrovascular disease). Presence of a carotid bruit was also noted. Univariate analysis, logi stic regression, and odds ratios were performed to identify subgroups of patients that had an increased incidence of significant carotid dis ease. Results: Of the 188 patients with claudication who were screened , 8% had an internal carotid artery stenosis of 16% to 49%, 21.8% had a stenosis that exceeded 50%, and 2.7% had an occluded internal caroti d artery. The presence of a carotid bruit on physical examination was predictive of a greater than or equal to 50% internal carotid artery s tenosis (p = 0.027). The ankle-brachial index was highly predictive of the presence of carotid stenoses in an inverse relationship (p = 0.00 1). Patient age approached significance (p = 0.143). Patients older th an 65 years of age who had claudication, an ankle-brachial index less than 0.7, and a carotid bruit had a 45%, incidence of significant caro tid disease. The atherosclerotic risk factors of male sex, diabetes, h ypertension, hyperlipidemia, smoking history, coronary history, previo us coronary or vascular surgical history, and family history were nor predictive of the presence of a >50% carotid stenosis. Conclusions: In patients who seek medical attention with the chief complaint of claud ication and p;ho have no cerebrovascular symptoms, there is a 24.5% in cidence of a >50% internal. carotid artery stenosis or occlusion on du plex examination. Select subsets of these patients have upwards of a 4 5% incidence of significant asymptomatic carotid disease. All patients who seek medical attention with claudication should therefore undergo routine carotid duplex screening to detect asymptomatic high-grade st enosis.