Screening for asymptomatic carotid stenosis in patients with peripheral vascular disease: a prospective study and risk factor analysis

Screening for asymptomatic carotid artery stenosis using color flow duplex scan was performed on 186 Chinese patients with peripheral vascular disease. They consist of 121 male and 65 females, with a mean age of 70.6 years. A carotid bruit was present in 43 (23.1%) of the patients. Internal carotid artery stenosis of 70% or greater was detected in 46 patients (24.7%) including six total occlusions. Another 79 patients (42.5%) had internal carotid artery stenosis in the 30-69% range. Significant internal carotid artery stenosis was associated with age, male sex, the quantity and duration of smoking and a carotid bruit, and inversely with cholesterol, triglyceride and VLDL. Age, the number of cigarettes consumed per day, and carotid bruit were independent significant predictors of > or =70% internal carotid artery stenosis on logistic regression analysis. The degree of internal carotid artery stenosis is more severe in patients with a carotid bruit, and correlated positively with age (P<0.01), the number of cigarettes smoked (P = 0.04), and the duration of smoking (P = 0.03). Multiple linear regression analysis showed that only the age of the patient bears a significant relationship with the degree of internal carotid artery stenosis (P<0.01). There was no relationship between the degree of lower limb ischemia with carotid stenosis. The prevalence of > or =70% internal carotid artery stenosis in a high risk population with peripheral vascular disease was 24.7%. Routine duplex screening is worthwhile in this group of patients, particularly in male, elderly smokers.