Coronary artery calcium scoring using electron-beam computed tomography: where does this test fit into a clinical practice?

Studies have indicated that the very early detection of a coronary artery burden is possible with electron-beam computed tomography (EBCT). However, both the Prevention Conference V and the ACC/AHA Expert Consensus Document on EBCT have recommended against the routine use of EBCT for screening for coronary artery disease in asymptomatic individuals. Moreover, there is no evidence so far to support using the results of EBCT in an asymptomatic patient to select a therapy or to guide referral to invasive investigations. The clinical role of EBCT is yet to be established in terms of screening for disease or risk assessment. EBCT is highly sensitive, but its specificity is low. In fact, when referral to angiography is based on the results of EBCT, referrals will be made for very few patients with normal results while many referrals will be made for those with abnormal results. The outcome will be that, in clinical practice, the observed sensitivity of EBCT will be increased, and the observed specificity will be reduced. To date, there are no well-conducted studies that clearly demonstrate the incremental value of calcium scoring over traditional assessments of risk factors, and the clinical role of EBCT is yet to be established in terms of screening for disease or risk assessment.