Coronary artery calcium: utilization for primary prevention of CHD.

The rapidly accumulating data supporting coronary artery calcium (CAC) has necessitated multiple paradigm shifts in primary prevention: 1) CAC is the most powerful predictor of cardiac risk in the asymptomatic primary prevention population. 2) The most important role of risk factors may be to identify the modifiable targets of risk reduction in patients with risk already established by CAC. 3) "Normal cholesterol" values derived from population-based studies are not relevant for individual patients. 4) Measures of subclinical atherosclerosis (ie, serial CAC), rather than lipid values, define residual risk just as they define pretreatment risk. 5) Randomized controlled trials are not a prerequisite for implementation of CAC screening. 6) Trials evaluating lipid-treating drugs should exclude patients with 0 CAC. 7) CAC is the most cost-effective primary prevention approach.