1. Hypothesis Evaluated in these Papers
CIMT is Used a Tool for Atherosclerosis-Related Event Prediction and for the Evaluating Atherosclerosis Progression/Regression
400 scientific articles published in peer-reviewed journals during 2003 that included CIMT
Hypothesis Evaluated in these Papers
Prediction of CVD events
Association with prevalent disease
Efficacy of pharmaceutical interventions
impact of diet and exercise modification
Association with traditional and non-
traditional risk factors
Evidence of genetic determinants of
atherosclerosis

2. Advantages of Carotid IMT (cIMT) Testing
Noninvasive, safe, inexpensive, accepted by patients, ethically sound
Identifies minor (early) and major (late) ASO
Nomograms (age, sex, and race-based) for normal values exist
Predicts risk of future MI and STROKE
Incremental predictive power
Recommended by AHA for patients > 45 for “further clarification of CHD risk”
In one population-based study cIMT was the single risk factor
best able to predict cardiovascular events, with a level of event
prediction nearly as great as all of the other risk factors combined !!!
del Sol AL, et al. Stroke 2001, 32:1532

3. cIMT shown in clinical trials to
Identify prevalence of cardiovascular disease (total CVD, angina, MI, Stroke, TIA, and PAD)
Predict future risk of coronary heart disease and stroke (i.e., predicts incidence!)
In these (and other prospective studies), CIMT remains a statistically significant predictor even after adjustment for know cardiovascular risk factors
ARIC Study, Burke GL, et al. Stroke 1995;26:286
Chambless EL, et al. Am J Epidemiol 2000;151:487
ARIC, Chambless LE, et al. Am J Epidemiol 1997;146:1483

4. The FDA-Accepted Means to evaluate Progression of ASO
Quantitative angiograms
cIMT

5. How Can CIMT be Used in Clinical Trials
As means of predicting the rate of progression/regression of atherosclerosis
in response to using/withholding an intervention
Regression
Progression
CIMT

6. Principles of Image Acquisition
3 segments can be evaluated:
- CCA
Bulb
ICA
Focus on the WALL
- not the lumen -
Gated measurement (3 ECG
leads in place throughout
the study)
Properly insonate the artery
May need to use several angles

7. Technical Considerations
High frequency transducer
VCR or Digital storage
High frame rate
High dynamic range
One focal zone at the level of interest
ECG on
TGC slope numbers if possible displayed

8. Segment: R CCA
Angle of insonation: 135

9. Image Acquisition Doppler of the CCA, ECA, and ICA
Transverse scan to look at intima
135 degree approach for the right
225 degree approach for the left
AP diameter of the distal CCA
Find the Y bifurcation Best practice for identifying the flow divider

10. Identify CCA

11. Identify ECA

12. Identify ICA

13. Flow Divider
CCA
ICA
Bulb