Measurement of subclinical atherosclerosis: beyond risk factor assessment.
OBJECTIVE
Assessment of subclinical atherosclerosis using the current available noninvasive imaging modalities holds promise for individual cardiovascular risk management and monitoring efficacy of therapeutic interventions (i.e. surrogate end-points). The present review addresses benefits and limitations of flow-mediated dilatation, intima-media thickness, electron-beam computed tomography and magnetic resonance coronary angiography.


RESULTS
Both carotid intima-media thickness and peripheral flow-mediated dilatation correlate inversely with cardiovascular risk factors and coronary artery disease. They have been shown to carry predictive value for future cardiovascular events, but clinical application of both intima-media thickness and flow-mediated dilatation demands further methodological maturation of these techniques. Intima thickening has been successfully targeted in numerous intervention trials, but determination of an explicit threshold value beyond which cardiovascular risk significantly increases will facilitate its utility as a routine clinical tool. Electron-beam computed tomography can accurately detect and quantify coronary artery calcification (an established marker of the total coronary plaque burden). However, lack of evidence of its additional predictive power for future coronary events warrants for further research. Finally, magnetic resonance coronary angiography appears to be a promising technique, integrating both functional and anatomical aspects of coronary artery disease. Properly designed studies are needed to determine its value in clinical practice.


CONCLUSIONS
Various noninvasive imaging techniques have recently emerged that may find applications in clinical research. However, before widespread clinical utilization, further technical refinement of all of the cited imaging modalities is mandatory. It will be a challenge over the coming few years to clarify whether improvements in surrogate end-points can directly be translated into improved outcomes.
Bisoendial
Radjesh J
RJ
Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Hovingh
G Kees
GK
de Groot
Eric
E
Kastelein
John J P
JJ
Lansberg
Peter J
PJ
Stroes
Erik S G
ES
D001783:Blood Flow Velocity; D002986:Clinical Trials as Topic; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology; D003326:Coronary Circulation; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D017539:Tunica Intima / Q000033:anatomy & histology