Common carotid intima-media thickness predicts occurrence of carotid atherosclerotic plaques - Longitudinal results from the aging vascular study (EVA) study

The role of the increase in the common carotid artery (CCA) intima-media wa ll thickness (IMT) in the atherosclerotic process is questionable. This lon gitudinal study examined the predictive value of CCA-IMT measured at baseli ne examination (at sites free of plaques) on the occurrence of atherosclero tic plaques in the extracranial carotid arteries during 4 years of follow-u p study in a sample of 1010 subjects aged 59 to 71 years. Ultrasound examin ations were performed at baseline and 2 years and 4 years later. The occurr ence of carotid plaques during follow-up was defined as the appearance of g reater than or equal to 1 plaque in previously normal carotid segments and/ or the appearance of new plaques in the carotid segments that previously ha d plaques. Carotid plaque occurrence was observed in 185 subjects (18.3%). Age- and sex- adjusted odds ratios of carotid plaque occurrence were 2.66 ( 95% CI 1.58 to 4.46, P<0.001) in subjects having intermediate baseline CCA- IMT values (quartiles 2 and 3) and 3.67 (CI 2.09 to 6.44, P<0.001) in those having the highest baseline CCA-IMT values (quartile 4) compared with thos e having the lowest baseline CCA-IMT values (quartile 1), Multivariate adju stment for major cardiovascular risk factors did not alter the results. The se findings were observed for men and women as well as for subjects with an d without carotid plaques at baseline, This 4-year longitudinal study shows that CCA-IMT predicts carotid plaque occurrence in a large sample of relat ively old subjects. it extends the findings obtained from cross-sectional s tudies and suggests that increased intima-media thickness might occur in an earlier phase of the atherosclerotic process.