To evaluate the prognostic value of coronary CT angiography (CCTA) for risk stratification in asymptomatic adults in comparison with conventional risk stratification (CRS) and coronary artery calcium scoring (CACS).

The risk stratification of cardiovascular disease (CVD) in asymptomatic individuals represents a major challenge. For this purpose, a lot of risk prediction models that take demographic and clinical characteristics into account have been developed. Although Framingham risk score (FRS) is most widely used among multiplr risk prediction models, it has some limitation for prediction of CVD especially in young adult and women. Recently, coronary artery calcium score (CACS) has known to be powerful screening method for CVD, however, it cannot detect the noncalcified coronary plaques (NCP), so it does not represent the entire spectrum of atherosclerotic plaques and it also cannot evaluate the degree of stenosis. On the contrary, Coronary CT angiography (CCTA)can provide detailed coronary artery anatomy and plaque imaging about the location, burden and characteristics of atherosclerotic plaque per se, which might give additional insight to stratify the risk of future cardiac events and therapy.

In this study, we will evaluate the prevalence and characteristics of subclinical coronary atherosclerosis on CCTA in asymptomatic population. And we will investiage the follow up data for major cardiac adverse event such as cardiac death, nonfatal myocardial infarction, unstable angina and revascularization. Therefore, we will finally evaluate the prognostic value of CCTA for risk stratification in asymptomatic adults in comparsion with conventional risk stratification such as FRS and CACS.

Inclusion Criteria:

• asymptomatic subjects
• adults > 20 years
• subjects who underwent both calcium score and coronary CT angiography

Exclusion Criteria:

• typical or atypical chest pain
• subjects who underwent previous percutaneous coronary intervention
• serious comorbid conditions(i.e. malignancy)
• insufficient medical record
• poor image quality

Asymptomatic adults without previous coronary artery disease