Discordance between Risk Factors and Coronary Artery Calcium: Implications for Guiding Treatment Strategies in Primary Prevention Settings

Preventive efforts including smoking cessation campaigns, increased awareness of healthy lifestyle habits, risk factor modification, and the appropriate use of statins have been successful in reducing cardiovascular mortality over the last decade. The coronary artery calcium (CAC) scan has reliably been an additive predictor to traditional risk estimation methods, partly because of the heterogeneity between risk factor burden and atherosclerotic burden. The focus of this review is to highlight this heterogeneity by focusing on groups in which risk factor burden and subclinical atherosclerosis burden, as measured by CAC, are discordant. In high-risk groups with 0 CAC, the event rates are consistently low; in low-risk groups with elevated CAC (CAC > 100), the event rates are consistently high. We conclude with our clinical perspective of the considerable heterogeneity between risk factors and atherosclerotic burden in the context of the 2013 ACC/AHA cholesterol treatment and risk assessment guidelines.