title: Coronary distensibility index measured by computed tomography is associated with the severity of coronary artery disease.
abstract: BACKGROUND
  Atherosclerotic changes within the coronary artery wall can affect vessel distensibility.
  
  
  OBJECTIVE
  This study evaluated the relationship between the coronary distensibility index (CDI) and the severity of coronary artery disease (CAD) measured by computed tomographic angiography (CTA).
  
  
  METHODS
  One hundred thirteen subjects, age 63 +/- 10 years, 32% women, who underwent coronary artery calcium (CAC) scanning and CTA, were studied. Early diastolic and mid diastolic (MD) cross-section area (CSA) of the left anterior descending (LAD) artery were measured 5 mm distal to the left main bifurcation. CDI was defined as Deltalumen CSA/[lumen CSA in MD x estimated central pulse pressure (eCPP)] x 10(3) {eCPP = 0.77 x peripheral pulse pressure}. LAD diameter measured by CTA and quantitative coronary angiography (QCA) was compared in 19 subjects without CAD. CAD was defined as normal (no stenosis and CAC 0), mild (stenosis <or= 30%), moderate (stenosis 31%-69%), and severe (stenosis >or= 70%) on CTA.
  
  
  RESULTS
  Excellent correlation was observed between CTA and QCA measured by CDI (r(2) = 0.96, P = 0.0001). CDI decreased from normal coronaries (6.75 +/- 1.43) to arteries with mild (5.78 +/- 1.45), moderate (3.96 +/- 1.06), and severe (3.31 +/- 1.06) disease (P = 0.004). The risk factor adjusted odds ratio of lowest versus 2 upper tertiles of CDI was 1.28 for mild, 8.47 for moderate, and 10.59 for severe CAD compared with the normal cohort. The area under the ROC curve to predict obstructive CAD (stenosis >or= 50%) increased significantly from 0.71 to 0.84 by addition of CDI to CAC (P < 0.05).
  
  
  CONCLUSIONS
  CTA-measured CDI is inversely related to the severity of CAD independent of age, sex, cardiovascular risk factors, and CAC.
authors.affiliation: Los Angeles Biomedical Research Institute at Harbor University of California Los Angeles (UCLA) Medical Center, Torrance, CA 90502, USA. nahmadi@labiomed.org
authors.forename: Naser
authors.initials: N
authors.lastname: Ahmadi
authors.forename: David
authors.initials: D
authors.lastname: Shavelle
authors.forename: Vahid
authors.initials: V
authors.lastname: Nabavi
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Hajsadeghi
authors.forename: Shahin
authors.initials: S
authors.lastname: Moshrefi
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Flores
authors.forename: Shahdad
authors.initials: S
authors.lastname: Azmoon
authors.forename: Song S
authors.initials: SS
authors.lastname: Mao
authors.forename: Ramin
authors.initials: R
authors.lastname: Ebrahimi
authors.forename: Matthew
authors.initials: M
authors.lastname: Budoff
mesh_terms: D000368:Aged; D001794:Blood Pressure; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D017023:Coronary Angiography / Q000379:methods* / Q000592:standards; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology; D003971:Diastole; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards