Computed Tomography for Coronary Artery Calcification Scoring: Mammogram for the Heart

Coronary artery calcium (CAC), identified via low-radiation, non-contrast computed tomography of the heart, quantifies the burden of calcified coronary atherosclerosis. This modality is highly useful for cardiovascular (CV) risk stratification among individuals without known coronary heart disease (CHD), especially for those at intermediate risk. The presence of CAC is associated with up to a 10-fold higher risk of adverse CV events, even after fully adjusting for the standard CV risk factors. In fact, the CAC score is among the strongest clinically available predictors of future risk of adverse CV events among primary prevention patients. Additionally, the absence of CAC in asymptomatic individuals confers a very low risk of CV events. Even in the presence of a benign CV risk factor profile and normal cardiac stress test, a very high CAC score portends a high risk of adverse CV events. On the other hand, a CAC score of zero is associated with a low CHD risk despite significant CV risk factor profiles. CAC scoring is a quick, low-cost screening tool to help risk-stratify patients and identify those likely to benefit from aggressive preventive treatments (such as high-intensity statin therapy, ezetimibe, PCSK9 inhibitors, and aspirin) and to identify those likely who warrant close monitoring. Moreover, individuals with a zero CAC score may be at low enough risk to avoid or defer daily aspirin therapy and pharmacological therapy for cholesterol management, and instead work on therapeutic lifestyle changes. An abnormal CAC score may also lead to better adherence to pharmacological regimens and suggested lifestyle changes.