Coronary computed tomography angiography as a screening tool for the detection of occult coronary artery disease in asymptomatic individuals

Objectives The purpose of this study was to evaluate the prevalence of occult coronary artery disease ( CAD) with coronary computed tomography angiography (CTA) to characterize plaque composition and to evaluate the potential of this new technology to impact risk stratification in asymptomatic middle-aged subjects. Background There is a paucity of information regarding the role of CTA for the detection of occult CAD in asymptomatic individuals. Methods We consecutively enrolled 1,000 middle-aged asymptomatic subjects ( age 50 +/- 9 years, 63% men) who underwent CTA ( 64-slice multidetector row computed tomography) as part of a general health evaluation. Results Atherosclerotic plaques were identified in 215 ( 22%, 2 +/- 1 segments/subject) individuals; 40 individuals (4%) had only noncalcified plaques. Fifty-two (5%) subjects had significant ( >= 50%) diameter stenosis and 21 (2%) had severe (>= 75%) stenosis. Thirteen (25%) and 30 (58%) subjects with significant stenosis were classified into National Cholesterol Education Program low-risk and mild coronary calcification ( coronary artery calcium scores <100), respectively. Midterm follow-up ( 17 +/- 2 months) revealed 15 cardiac events only in those with CAD on CTA: 1 unstable angina requiring hospital stay and 14 revascularization procedures. Most (87%) events occurred within 90 days of index CTA. Conclusions The prevalence of occult CAD in apparently healthy individuals was not negligible, although their midterm prognosis was good. CTA has a potential to provide a better insight about the occult CAD in this population. However, on the basis of our results and considering present radiation exposure data, we cannot recommend that CTA be used as a screening tool for this population at this point.