Coronary heart disease risk assessment and characterization of coronary artery disease using coronary CT angiography: comparison of asymptomatic and symptomatic groups
Received 2 November 2009; received in revised form 1 April 2010; accepted 7 April 2010. published online 11 June 2010.
Aim
To evaluate the prevalence of coronary artery disease (CAD) in relation to risk of coronary heart disease (CHD) and assess plaque characteristics from coronary computed tomography (CT) angiography in asymptomatic and symptomatic patients.
Materials and methods
Three hundred and ninety consecutive patients [asymptomatic group, n=138; symptomatic group (atypical or non-anginal chest pain), n=252] were retrospectively enrolled. They were subsequently classified into three CHD risk categories, based on the National Cholesterol Education Program guidelines, and 10 year risks of coronary events were calculated using Framingham risk score. CT was evaluated for stenosis, plaque composition, and coronary calcium scores.
Results
CAD was observed in 42% of the asymptomatic group and 62% of the symptomatic group. In the former, the prevalence of CAD in low-, moderate- and high-risk subgroups was 21.4, 47.4 and 65%, respectively, and was 33.3, 74.4, and 72.4% in the symptomatic group. Framingham 10-year risks of coronary events were significantly higher in patients with CAD than in normal participants, and receiver operating characteristics curves showed that discriminatory power was poor in the asymptomatic group and symptomatic men, and good in symptomatic women. Of the participants in the asymptomatic group, 12% exhibited only non-calcified plaques and of the symptomatic group, 7% exhibited only non-calcified plaques. The coronary calcium score was significantly higher for significant stenosis than for non-significant stenosis in both groups.
Conclusions
The prevalence of CAD was not negligible even in subgroups with low-to-moderate CHD risk. Additionally, the Framingham risk score was effective for predicting CAD only in symptomatic women. Coronary calcium scores correlated with significant stenosis; however, a sizeable percentage of both groups had only non-calcified plaques.
aDepartment of Radiology, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
bDivision of Cardiology in Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
cDepartment of Preventive Medicine, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
Guarantor and correspondent: Y. Kim, Department of Radiology, Ewha Womans University Mokdong Hospital, 911-1, Mokdong, Yancheon-gu, Seoul 158-710, Republic of Korea. Tel.: +82 2 2650 5380; fax: +82 2 2650 5302.
ABSTRACT