['Carotid stenosis and plaque stability are critical determinants of risk for ischemic stroke. The aim of this study is to elucidate the association of CAC with carotid stenosis and plaque characteristics.', 'We examined data from the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective cohort study of subclinical cardiovascular disease in multiethnic participants (N = 6814). The association between CAC measured by computed tomography and carotid ultrasonography of carotid plaque was examined using multiple logistic linear models adjusting for traditional vascular risk factors including ethnicity. We also developed ethnic specific models to compare the relationship between CAC and carotid disease across the four ethnicities.', 'Significant carotid stenosis was associated with the presence of CAC (OR 1.73; 95% CI, 1.20-2.49) and log-transformed Agatston score (OR per 1 point increase, 1.18; 95% CI 1.04-1.35). Overt carotid stenosis was also associated with the presence of CAC (OR, 2.34; 95% CI, 1.93-2.83) and log-transformed Agatston score (OR per 1 point increase, 1.53; 95% CI 1.38-1.69). Irregular plaque surface was associated with the presence of CAC (OR, 1.87; 95% CI 1.50-2.32) and the log-transformed Agatston score (OR per 1 point 1 increase, 1.31; 95% CI 1.16-1.48). Associations between CAC and stenosis/stability were not different across ethnicities.'] Is coronary artery calcium associated with degree of stenosis and surface irregularity of carotid artery?