title: Relationship of aortic knob width with cardio-ankle vascular stiffness index and its value in diagnosis of subclinical atherosclerosis in hypertensive patients: a study on diagnostic accuracy.
abstract: OBJECTIVE
  The aim of our study was to determine the usefulness of the aortic knob width (AKW) in the assessment of subclinical atherosclerosis in hypertensive patients.
  
  
  METHODS
  In this study on diagnostic accuracy, 374 consecutive hypertensive patients with at least one cardiovascular risk factor were enrolled. AKW was measured on chest X-ray. Cardio-ankle vascular index (CAVI) was measured by VaSera-1000 CAVI instrument. The diagnostic value of AKW was assessed using ROC analysis.
  
  
  RESULTS
  There was a significant correlation between aortic knob width and CAVI (r=0.45, p<0.001), age (0.39, p<0.001), systolic (r=0.17, p<0.001), diastolic (r=0.23, p<0.001) and mean (r=0.2, p<0.001) blood pressures. In linear regression analysis CAVI (β=0.3, 95% CI 0.33-0.98, p<0.001), age (β=0.3, 95% CI 0.09 - 0.21, p<0.001) and diastolic blood pressure β=0.2, 95% CI 0.08-1.9, p<0.001) were independently associated with AKW. It was significantly higher in patients with subclinical atherosclerosis (CAVI ≥9) than borderline (8 ≤CAVI <9) (41.4±5.5 versus 36.7±5.3 mm, p<0.001) and healthy (CAVI <8) subjects (41.4±5.5 versus 35.5±4.3 mm, p<0.001). Analysis using the ROC curve has demonstrated that aortic knob of 41 mm constitutes the cut-off value for the presence of subclinical atherosclerosis with 71% sensitivity and 77% specificity (AUC-0.67, 95% CI 0.51-0.82).
  
  
  CONCLUSIONS
  Observation of aortic knob on chest X-ray in hypertensive patients may provide important predictive information of subclinical atherosclerosis.
authors.affiliation: Clinic of Cardiology, Ahievren Thoracic and Cardiovascular Surgery Training and Research Hospital, Trabzon-Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Korkmaz
authors.forename: Hakan
authors.initials: H
authors.lastname: Erkan
authors.forename: Ayça Ata
authors.initials: AA
authors.lastname: Korkmaz
authors.forename: Zeydin
authors.initials: Z
authors.lastname: Acar
authors.forename: M Tarık
authors.initials: MT
authors.lastname: Ağaç
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Bektaş
authors.forename: Ali Rıza
authors.initials: AR
authors.lastname: Akyüz
authors.forename: Adem
authors.initials: A
authors.lastname: Adar
authors.forename: Sükrü
authors.initials: S
authors.lastname: Çelik
mesh_terms: D000842:Ankle / Q000098:blood supply*; D001011:Aorta / Q000503:physiopathology*; D001795:Blood Pressure Determination; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006973:Hypertension; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity