title: Edge-detected common carotid artery intima-media thickness and incident coronary heart disease in the multi-ethnic study of atherosclerosis.
abstract: BACKGROUND
  Common carotid artery intima-media thickness (IMT) can be measured either by hand or with an automated edge detector. We performed a direct comparison of these 2 approaches and studied their respective associations with coronary heart disease outcomes.
  
  
  RESULTS
  We studied 5468 participants of the Multi-Ethnic Study of Atherosclerosis, composed of white, Chinese, Hispanic, and black participants with an average age of 61.9 years (47.8% men) and who were free of coronary heart disease at baseline. Manual-traced and edge-detected IMT measurements were made in the same location on ultrasound images of the right common carotid artery far wall in an area free of plaque. Manual-traced and edge-detected common carotid artery IMT measurements were added separately to multivariable Cox proportional hazards models with time to incident coronary heart disease as the outcome and adjusted for traditional coronary heart disease Framingham risk factors, lipid-lowering therapy, blood pressure-lowering therapy, and race or ethnicity. Additional models were generated after adding clinic site and reader. There were 349 events during a median follow-up of 10.2 years. In adjusted models, the hazard ratio was not significant (1.31; 95% CI 0.84 to 2.06) for each millimeter increase in manual-traced IMT but was significant for edge-detected IMT (hazard ratio 1.63; 95% CI 1.12 to 2.37). Edge-detected IMT remained statistically associated with outcomes after additional adjustment for clinic site and reader performing the IMT measurement (hazard ratio 1.59; 95% CI 1.07 to 2.35).
  
  
  CONCLUSIONS
  Edge-detected common carotid artery far wall IMT has similar if not stronger associations with coronary heart disease outcomes when compared with manual-traced IMT.
  
  
  BACKGROUND
  URL: https://www.clinicaltrials.gov/. Unique identifier: NCT00063440.
authors.affiliation: Department of Radiology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA (J.F.P.).
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Polak
authors.affiliation: Saint Elizabeth's Medical Center, Boston, MA (D.H.L.).
authors.forename: Daniel H
authors.initials: DH
authors.lastname: O'Leary
mesh_terms: D001741:Black or African American; D044466:Asian People; D050197:Atherosclerosis / Q000453:epidemiology / Q000208:ethnology / Q000473:pathology*; D017536:Carotid Artery, Common / Q000473:pathology*; D059168:Carotid Intima-Media Thickness; D003327:Coronary Disease / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology / Q000473:pathology*; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012307:Risk Factors
keywords: atherosclerosis; carotid arteries; epidemiology; risk factors; ultrasonics