Coronary calcium: The good, the bad, and the uncertain

Background Coronary calcium deposits have been widely regarded to result Fr om a passive process of encrustation or adsorption of mineral onto advanced , complex atherosclerotic lesions. Increasing interest has Focused on nonin vasive radiologic detection of these calcium deposits as a diagnostic and p rognostic adjunct to clinical evaluation of coronary artery disease, partic ularly with the use of newer, high-resolution imaging techniques such as el ectron beam computed tomography. Methods and Results We reviewed the literature on coronary calcium and its relation to pathologic atherosclerosis, angiographic stenoses, and clinical events. Clinical calcium detection studies have demonstrated an associatio n between coronary calcium and both extent of coronary artery disease and r isk of adverse events. These studies have in the past tended to reinforce t he perception that calcific deposits result from a passive mineralization p rocess, signify advanced coronary artery disease, and foreshadow future cor onary events. Conclusions Recent pathologic, genetic, clinical, and biochemical evidence reviewed in this article suggests that coronary calcium deposits are a mani festation of a complex, organized, and regulated process similar in many re spects to new bone formation and may not be a reliable indicator of either the extent of coronary disease or the risk of a future event. These studies also suggest that atherosclerosis and calcific deposits may be distinct pa thologic entities that frequently occur together and are related-to each ot her in ways that are poorly understood.