The primary purpose of this project is to investigate risk factors for coronary heart disease (CHD) and stroke in the elderly. Risk factors for the development and progression of cardiovascular diseases will be examined in an elderly cohort. Risk factors for development of overt cardiovascular disease in an older population with prevalent atherosclerosis may differ from those related to the development of atherosclerosis in a younger population. In an elderly population with prevalent atherosclerosis it is important to assess the prediction of clinical disease from measures of preclinical disease such as cartoid atherosclerosis. The primary objective of the Ultrasound Reading Center is to develop and implement a system to assess atherosclerosis in the carotid arteries using ultrasound. This will involve 1) coordinating development of a protocol for ultrasound examinations at the field Centers and a method for evaluating extent of carotid atherosclerosis, 2) training ultrasound technicians of each Field Center, 3) interpreting all ultrasound examinations and 4) monitoring the ultrasound examinations at all field Centers. During the periods of data collection, the Ultrasound Reading Center shall have the responsibility of assessing within and between individual variation among technicians and coders. The contractor shall serve as the Ultrasound Reading Center for this study. Duties of the Ultrasound Reading Center include equipment selection, protocol development, technician training, central reading, and data transmittal and analysis for the ultrasonographic examinations within the study.