Prevalence of asymptomatic critical carotid artery stenosis in Korean patients with chronic atherosclerotic lower extremity ischemia: is a screening carotid duplex ultrasonography worthwhile?

This study aimed to investigate prevalence of asymptomatic carotid artery stenosis (ACAS) in Korean patients with peripheral arterial disease (PAD) and identify predictive factors of ACAS in patients with PAD. Between 1994 and 2008, 546 patients who underwent bypass surgery due to PAD were identified in a single tertiary teaching hospital. Of those, 409 patients underwent preoperative screening carotid duplex ultrasonography (CDUS). Patients who had an episode of cerebrovascular event or previous carotid artery intervention were excluded and then a retrospective analysis was made of 340 patients. The degree of internal carotid artery (ICA) stenosis was determined by the criteria of Society of Radiologists in Ultrasound Consensus Conference. To determine the risk factors of ACAS, demographic, coexisting medical condition and lesion characteristics were tested with binary logistic regression model. The prevalence of > or = 70% ICA stenosis was 14%. ICA occlusion was detected in 7.1%. Multivariate analysis revealed age > 65 yr (OR: 2.610, 95% CI: 1.197-5.691) and coronary artery disease (CAD, OR: 2.333, 95% CI: 1.169-4.657) are predictive factors of > or = 70% stenosis. A PAD patient who needs revascularization, particularly, > 65 yr or has a concomitant CAD, can be a good candidate of screening CDUS.