Carotid intima-media thickening indicates a higher vascular risk across a wide age range: prospective data from the Carotid Atherosclerosis Progression Study (CAPS).
OBJECTIVE
Carotid intima-media thickness (IMT) is an independent predictor of vascular events in age groups >45 years. However, there is little information about the predictive value of IMT in younger individuals.


METHODS
In the Carotid Atherosclerosis Progression Study (CAPS; n=5056; age range 19 to 90 years; mean age 50.1 years), common carotid artery (CCA) IMT, bifurcation IMT, internal carotid artery IMT and vascular risk factors were evaluated at baseline. The incidence of stroke, myocardial infarction (MI), and death was determined prospectively. Data for younger (<50 years; n=2436) and older subjects (> or =50 years; n=2620) were analyzed separately using Cox proportional hazard regression models.


RESULTS
During a mean follow-up period of 4.2 years, there were 228 cases of MI, 107 strokes, and 50 deaths. IMT at all carotid segments was highly predictive of all end points (eg, hazard rate ratios [HRRs] per 1 SD CCA-IMT increase were 1.43 [95% CI: 1.35 to 1.51] for MI, 1.47 [1.35 to 1.60] for stroke, and 1.45 [1.38 to 1.52] for MI, stroke or death; all P<0.0001). Even after adjustment for age, sex, and vascular risk factors, the predictive value of CCA-IMT and bifurcation IMT remained significant for MI and the combined end point. For the latter, the HRRs were considerably higher in the younger than in the older age group (eg, HRR per 0.1 mm CCA-IMT was 1.34 [1.16 to 1.55] vis-à-vis 1.10 [1.05 to 1.15]; P=0.011 for age-IMT interaction).


CONCLUSIONS
Carotid IMT independently predicts future vascular events. Its predictive value is at least as high in younger subjects as in older subjects.
Lorenz
Matthias W
MW
Department of Neurology, Johann Wofgang Goethe-University, Frankfurt am Main, Germany. matthias.lorenz@em.uni-frankfurt.de
von Kegler
Stefan
S
Steinmetz
Helmuth
H
Markus
Hugh S
HS
Sitzer
Matthias
M
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels / Q000473:pathology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000473:pathology; D013997:Time Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography