04 Sep 2006

Carotid intima-media thickening, Non-invasive imaging

Dr. Serge Kownator

Session number: 946000
Session title: Carotid intima-media thickening
Authors: Kownator, S. Thionville, France

Carotid intima-media thickness as measured with ultrasound is actually recognised as a strong marker of atherosclerotic disease and predictor of cardiovascular events. Nevertheless it is still questioning if intima media thickening (IMT) is only a pathological process or is influenced by ageing.

From several epidemiological studies it appears that IMT is age and gender dependant. The evolution of IMT in subjects without any modifiable risk factors is in the range of 0.052 mm/yr. The presence of risk factors induces a modification in the slope of progression, which becomes steeper.

In order to standardise the methodology of measurement, the Mannheim consensus has been published. This multidisciplinary document emphasises the definition of IMT and plaques and proposes standardised semi-automatic computerised methods of evaluation as the reference.

Regarding the site of measurement the far wall of the common carotid artery appears easier to perform and provides a better reproducibility. Nevertheless, measuring the bifurcation and the internal carotid can be of interest as far as it can assume the presence of plaques. Definition of normal values is critical and should be performed in the different populations. In a French study these values are age and gender dependent and are always lower in people without risk factors as compared with people with risk factors.

If IMT is a strongly associated with cardiovascular events the presence of plaques reinforces this predictive value. The sum of the thickness of plaques in the carotid and femoral arteries, “the total plaque thickness “ (TPT) allows predictive value to be increased. In a group of 767 pts a TPT <0.4 is related to a prevalence of 4.3 % of events. A TPT > 4 is related to 29 % of events.

With a threshold of .83 mm IMT associated to the presence of iliac or femoral plaques has a sensitivity and a specificity respectively of 97% and 77 % for the diagnosis of coronary artery disease. Conclusion At the end pharmacological and lifestyle intervention allows to stop the progression and some time to reduce IMT, assuming an objective effect on the atherosclerotic disease.

The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.