Despite extensive research over many years, noninvasive methods for detection of the presence and severity of coronary artery disease remain imperfect, in part due to the fact that different, partially interrelated, facets of coronary atherosclerosis may predispose to different manifestations (e.g., luminal diameter narrowing to myocardial ischemia and wall plaque burden to a higher risk or acute thrombosis). One noninvasive index of the degree of coronary atherosclerosis, the extent of coronary artery calcification, has become more accessible to non-invasive evaluation due to the development of fast electron-beam computed tomography (EBCT). Initial studies have shown that EBCT coronary calcification is related to a variety of coronary risk factors and is also predictive to a variable extent in different populations of incident coronary heart disease events, but few data are available concerning the evolution of EBCT-detected coronary calcification and its relation to coronary risk factors or to prevalent or incident coronary heart disease.