Relation of Circulating Endothelium-derived Microparticle to Carotid Atherosclerosis

The investigators hypothesized that circulating endothelium-derived microparticle (EMP) may be a useful surrogate marker of atherosclerosis and future episode of cerebrovascular events. Peripheral blood is drawn at the time of carotid ultrasound examination. Circulating EMPs are counted using flow-cytometry. The correlation among circulating EMP, ultrasound findings, and atherosclerotic risk factors are determined by multiple stepwise regression analysis. The prevalence of cerebrovascular events is also determined during 3-year follow-up period.