Comparative performance of subclinical atherosclerosis tests in predicting coronary heart disease in asymptomatic individuals.

The prognostic performance of subclinical atherosclerosis in predicting coronary heart disease (CHD) needs to be clarified because of the existence of many non-invasive tests available for its detection in the clinical setting: ultrasound measurement of carotid intima-media thickness (IMT) and plaque, cardiac computed tomography assessment of coronary artery calcium, Doppler stethoscope measurement of ankle-arm index pressure (AAI), and mechanographic or Doppler determination of aortic pulse wave velocity (PWV). Data analysis of the main prospective studies in asymptomatic populations allows the establishment of a dose-response relationship between subclinical atherosclerosis burden and cumulative incidence of future CHD event (absolute risk). Negative subclinical atherosclerosis testing conveys a low 10-year CHD risk inferior to 10% whatever the test considered, i.e. IMT less than the 1st tertile or 1st quintile, AAI > or = 0.90, PWV less than the first tertile, no discernible carotid plaque, or zero coronary calcium score. Positive testing for IMT (>95th percentile or 5th quintile), AAI (<0.90), or PWV (>3rd tertile) conveys a moderately high 10-year CHD risk between 10 and 20%. Positive testing for carotid plaque (focal protrusion >1.5 mm or mineralization) or coronary calcium (total score >300 or 400 units) conveys a high 10-year CHD risk superior to 20%. Therefore, positive subclinical atherosclerosis measurement seems to have its place in the context of existing prediction models, namely for intermediate risk classification. It also remains to be established whether individuals with negative subclinical atherosclerosis may be considered at low CHD risk and receive conservative management.