Coronary artery calcium screening: implications for clinical practice

Cardiovascular disease is the most common cause of death in the Western hemisphere, and in the majority of cases the event announcing the presence of atherosclerosis is either sudden death or a disabling myocardial infarction or stroke. Although traditional risk factors are present in most individuals suffering a cardiovascular event, the prognostic ability of risk factors to predict events in the short term is limited. The focus of research has therefore turned to the application of noninvasive modalities to image the atherosclerotic plaque in its preclinical stages. Measurements of coronary artery calcium serve as a quantitative reflection of the severity of coronary artery disease, and greater calcium burdens correlate with more advanced disease. Coronary artery calcium has been shown in several studies to add prognostic value to traditional risk factors in patients at intermediate risk, and in this group of patients it may be cost effective. There is, however, an inherent danger in raising the cost of care by increasing downstream unnecessary testing if such screening were to be applied to low-risk individuals. This article is a systematic review of the most relevant literature regarding the utilization of coronary artery calcium screening as a tool to refine risk assessment and to evaluate the efficacy of therapy for atherosclerosis.