title: Common carotid artery intima-media thickness is as good as carotid intima-media thickness of all carotid artery segments in improving prediction of coronary heart disease risk in the Atherosclerosis Risk in Communities (ARIC) study.
abstract: OBJECTIVE
  Carotid intima-media thickness (CIMT) and plaque information can improve coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF). However, obtaining adequate images of all carotid artery segments (A-CIMT) may be difficult. Of A-CIMT, the common carotid artery intima-media thickness (CCA-IMT) is relatively more reliable and easier to measure. We evaluated whether CCA-IMT is comparable to A-CIMT when added to TRF and plaque information in improving CHD risk prediction in the Atherosclerosis Risk in Communities (ARIC) study.
  
  
  RESULTS
  Ten-year CHD risk prediction models using TRF alone, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque were developed for the overall cohort, men, and women. The area under the receiver operator characteristic curve (AUC), per cent individuals reclassified, net reclassification index (NRI), and model calibration by the Grønnesby-Borgan test were estimated. There were 1722 incident CHD events in 12 576 individuals over a mean follow-up of 15.2 years. The AUC for TRF only, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque models were 0.741, 0.754, and 0.753, respectively. Although there was some discordance when the CCA-IMT + plaque- and A-CIMT + plaque-based risk estimation was compared, the NRI and clinical NRI (NRI in the intermediate-risk group) when comparing the CIMT models with TRF-only model, per cent reclassified, and test for model calibration were not significantly different.
  
  
  CONCLUSIONS
  Coronary heart disease risk prediction can be improved by adding A-CIMT + plaque or CCA-IMT + plaque information to TRF. Therefore, evaluating the carotid artery for plaque presence and measuring CCA-IMT, which is easier and more reliable than measuring A-CIMT, provide a good alternative to measuring A-CIMT for CHD risk prediction.
authors.affiliation: Section of Atherosclerosis and Vascular Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, USA. vnambi@bcm.tmc.edu
authors.forename: Vijay
authors.initials: V
authors.lastname: Nambi
authors.forename: Lloyd
authors.initials: L
authors.lastname: Chambless
authors.forename: Max
authors.initials: M
authors.lastname: He
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Folsom
authors.forename: Tom
authors.initials: T
authors.lastname: Mosley
authors.forename: Eric
authors.initials: E
authors.lastname: Boerwinkle
authors.forename: Christie M
authors.initials: CM
authors.lastname: Ballantyne
mesh_terms: D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology*; D059168:Carotid Intima-Media Thickness / Q000592:standards*; D003327:Coronary Disease / Q000401:mortality / Q000473:pathology*; D042241:Early Diagnosis; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology*