Detection of early atherosclerosis with B mode carotid ultrasonography: assessment of a new quantitative approach.
OBJECTIVE
To examine the relation between carotid artery (CA) intima-media thickness (IMT) assessed by B mode ultrasonography (US), presence of plaques and major risk factors in a population without known vascular disease. Alternative methods of quantifying US results and implications for starting lipid-lowering therapy were also explored.


METHODS
Prospective study.


METHODS
Specialized lipid clinic.


METHODS
One hundred and sixty patients with hyperlipidemia but without symptomatic coronary or peripheral vascular disease were examined by US, of whom 92 patients with normal blood pressure who were not receiving lipid-lowering treatment were included in the analysis.


METHODS
B mode US of the CA was performed. Measurements were made of the IMT of the right and left common CA, and the average IMT (AIMT) was calculated. The number of plaques (PN) in the CA and its bifurcations was counted, and the average total thickness (ATT), the total area (TA), and average plaque thickness (APT) were calculated.


RESULTS
Stepwise regression analysis showed that age, the ratio of total cholesterol to high-density-lipoprotein cholesterol, weight and smoking significantly predicted ATT, APT and PN. By contrast, age, weight and apo B levels predicted AIMT. Detection of patients with CA abnormalities was improved by incorporating plaque dimensions: AIMT had a 63% sensitivity in detecting CA abnormalities, whereas TA had a sensitivity of 72%.


CONCLUSIONS
Indices of CA atherosclerosis that integrate the contribution of plaque to overall atheroma burden are related to known risk factors and are more sensitive than AIMT for detection of abnormalities.
Aminbakhsh
A
A
Department of Medicine, University of British Columbia, St Paul's Hospital.
Frohlich
J
J
Mancini
G B
GB
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D017536:Carotid Artery, Common / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012044:Regression Analysis; D015203:Reproducibility of Results; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography