title: Asymmetrical distribution of atherosclerosis in the carotid artery: identical patterns across age, race, and gender.
abstract: BACKGROUND
  Small autopsy studies and clinical practice indicated that carotid atherosclerosis develops in an asymmetrical helical pattern coinciding with regions of low shear stress. We investigated the distribution of carotid atherosclerosis as determined by maximum carotid intima-media thickness (CIMT), to assess if we could confirm this atherosclerotic configuration across various populations with different cardiovascular risk.
  
  
  RESULTS
  We used the individual baseline CIMT data from 3364 subjects from four recent international multicentre randomized controlled trials in which the carotid artery was systematically examined using the same ultrasound protocol and method to quantify CIMT. For each subject, circumferential information on the maximum CIMT of the left and right carotid arteries was obtained for the common carotid, bifurcation, and internal carotid artery segments. In each segment (common, bifurcation, internal), mixed modelling was used to study the differences in CIMT between angles, sides, gender, age, race, and studies. Each segment showed a different circumferential CIMT pattern. In all segments there were statistically significant differences between maximum CIMT across circumferential angles (p < 0.001); on average CIMT was highest in the posteromedial wall of the bifurcation and internal carotid segments and in the anterolateral wall of the common carotid segment. This asymmetric circumferential pattern was found to be identical in men and women, in young and old age, in different race groups, and across the studies.
  
  
  CONCLUSIONS
  We confirmed the asymmetrical helix-like distribution of atherosclerosis in the carotid arteries and expand the evidence by showing that the atherosclerotic configuration is similar across populations with different vascular risks and across gender, age, and race. This has implications for future design of carotid ultrasound studies, as the angle of insonation is an important predictor of maximum CIMT.
authors: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Parvin
authors: P
authors: Tajik
authors: Rudy
authors: R
authors: Meijer
authors: Raphaël
authors: R
authors: Duivenvoorden
authors: Sanne A E
authors: SA
authors: Peters
authors: John J
authors: JJ
authors: Kastelein
authors: Frank J
authors: FJ
authors: Visseren
authors: John R
authors: JR
authors: Crouse
authors: Mike K
authors: MK
authors: Palmer
authors: Joel S
authors: JS
authors: Raichlen
authors: Diederick E
authors: DE
authors: Grobbee
authors: Michiel L
authors: ML
authors: Bots