Asymptomatic carotid artery stenosis screening in patients with lower extremity atherosclerosis: a prospective study

Eighty-nine male veterans presenting to a vascular surgery clinic with symptomatic lower extremity atherosclerosis were prospectively screened by duplex scan for asymptomatic carotid artery stenosis (CAS). Their chief complaint was: claudication (90%), rest pain (6%), and ischemic ulcer or gangrene (4%). The mean ankle-brachial index (ABI) was 0.77. Twenty-five CAS > 50% were detected in 18 (20%) patients. Twelve CAS > 75% were detected in 11 (12%) patients. There was no difference between patients with and without CAS > 50% with regards to mean ABI, history of angina, diabetes, hypertension, prior coronary artery bypass, or history of smoking. Carotid bruit was associated with ipsilateral CAS > 50% [p < 0.0001, sensitivity (52%), specificity (88%), positive predictive value (41%), negative predictive value (92%)]. As a result of the screening, eight elective carotid endarterectomies have been performed to date in six (7%) patients with one transient twelfth cranial nerve paresis as the only postoperative complication. We conclude that: (1) male patients presenting with symptomatic lower extremity atherosclerosis have a 20% prevalence of asymptomatic CAS > 50%, (2) there is no correlation between the degree of lower extremity ischemia and CAS > 50%, (3) carotid bruit is significantly associated with CAS > 50%, but has a low sensitivity, and (4) routine CAS screening should be considered for all male patients with symptomatic lower extremity atherosclerosis regardless of whether a bruit is present.