What is the role of calcium scoring in the age of coronary computed tomographic angiography?

Non-contrast-enhanced CT for coronary artery calcification (CAC) as a marker of coronary atherosclerosis has been studied extensively in the primary prevention setting. With rapidly evolving multidetector CT technology, contrast-enhanced coronary CT angiography (CCTA) has emerged as the non-invasive method of choice for detailed imaging of the coronary tree. In this review, we systematically evaluate the role of CAC testing in the age of CCTA in both asymptomatic and symptomatic patients, across varying levels of risk. Although the role of CAC testing is well established in asymptomatic subjects, its use in evaluating those with stable symptoms that represent possible obstructive coronary artery disease is controversial. Nevertheless, available data suggest that in low-to-intermediate risk symptomatic patients, CAC scanning may serve as an appropriate gatekeeper to further testing with either CCTA (if no or only mild CAC present) versus functional imaging or invasive coronary angiography (when moderate or severe CAC present). Given the strong short-term prognostic value of CAC = 0, studies are needed to further evaluate the role of CAC scanning in low-risk patients with acute chest pain presenting to the emergency room.