Electron Beam Computed Tomography and Coronary Artery Disease: Scanning for Coronary Artery Calcification

Abstract

To review the association of coronary artery calcification with coronary atherosclerosis and its potential clinical application as detected on electron beam computed tomography (EBCT). A literature review of coronary artery calcification, coronary artery disease, and EBCT is presented, and clinical applications of EBCT are discussed. Recent studies have confirmed that arterial calcification is an active process intimately associated with atherosclerotic plaque evolution. Clinical investigations with use of EBCT have shown that a scan "negative" for coronary calcification is common in patients with normal or near-normal findings on coronary angiography, whereas patients with severe obstructive disease most commonly have "positive" scans--greater amounts of coronary artery calcium are associated with more severe luminal disease. Coronary artery calcium as evaluated on EBCT follows patterns that reflect the development of coronary atheromatous disease as a function of age and gender. Although histologic studies have confirmed that not all atherosclerotic segments have detectable calcification, the area of coronary artery calcification quantified on EBCT has a direct, positive relationship with the histopathologic coronary plaque area. The long-held notion of "degenerative" calcification of the coronary arteries with aging is incorrect. Although the incidence of coronary artery calcification increases with patient age, this relationship simply parallels the increased incidence of coronary atherosclerosis with advancing age. Data suggest that EBCT is a highly sensitive and specific test for coronary atherosclerosis and provide a basis for clinical applications when EBCT is viewed as a noninvasive method to estimate human coronary atherosclerotic involvement and "plaque burden."