Ultrasound Imaging of Subclinical Atherosclerosis: Clinical Importance of Carotid Intima-Media Thickness as a Risk Marker - Abstract
Carotid intima media thickness (IMT) has been widely utilized as an indicator of
atherosclerosis in epidemiological, observational, and interventional clinical studies.
It has been applied as an outcome variable in clinical investigation, and it has been
employed as an exposure variable in studies on the prognostic value to predict
coronary artery disease and stroke. There are different markers that can be used
to determine atherosclerosis risks in the clinical trials. Although several biomarkers
have been widely utilized to assess the risk of developing atherosclerosis, carotid IMT
can directly visualize atherosclerosis in the vessel wall. Indeed, carotid IMT can be
considered as a biomarker halfway between risk factors and organ damage that can
help prevent clinical events. This approach avoids the substantial costs and lengthy
follow-up required of traditional clinical randomized trials that are focused on hard
clinical end points. Ultrasound measurement is a well-validated technique that has
undergone in recent years substantial technical improvements in both the manner of
imaging and the IMT quantification. However, it is still a limited imaging modality for
assessing carotid atherosclerosis. Newer non-invasive techniques such as magnetic
resonance imaging have attractive properties that may improve the assessment of
atherosclerosis. Carotid magnetic resonance imaging modalities are being utilized
to investigate the artery wall changes associated with pharmacological treatment.
Anyway, regardless of the technique utilized to perform the assessments, carotid IMT
measurements have increasingly been used in clinical studies. Indeed, the change in
carotid IMT over time as an indicator for atherosclerosis progression, has predominantly
served in interventional studies as a primary outcome variable aimed at assessing the
effects of risk factor interventions.