We desire to serve as the Ultrasound Reading Center (USRC) for the CARDIA (Coronary Artery Risk Development in Young Adults) study, an NHLBI-sponsored prospective observational study of the distribution and evolution of risk factors for cardiovascular disease (CVD) during young adulthood in black and white men and women. CARDIA will perform ultrasound examination of the carotid arteries during the Year 20 examination beginning June I, 2005, on 3,490 participants. The objectives of the five-year renewal are to: identify predictors of earlier development and more rapid progression of subclinical atherosclerosis; assess racial differences in severity and progression of early subclinical disease to elucidate possible differences in CVD pathogenesis; test whether inflammation precedes subclinical disease; and assess the roles of genetic variation and gene by environment interactions in early development and progression of subclinical disease. As USRC, we will develop a protocol for ultrasound scanning. The protocol will specify the techniques to measure carotid artery wall thickness and atherosclerotic lesion characteristics as well as other potential characteristics of interest in the carotid arteries in an examination not to exceed 30 minutes of participants' time (examination time). We believe there is a strong likelihood that IMT will be repeated at a later time in CARDIA and suggest that the protocol be designed to maximize CARDIA's ability to measure IMT progression. We recommend acquiring images of the right CCA in a manner that permits controlling for cardiac cycle and the use of an automated edge detection algorithm. We will propose appropriate methods pertaining to training of sonographers and ongoing quality control procedures.
