title: Endothelial function assessment: flow-mediated dilation and constriction provide different and complementary information on the presence of coronary artery disease.
abstract: OBJECTIVE
  A number of risk factors for atherosclerosis have been identified, but it remains difficult, on an individual patient basis, to predict how these factors interact in determining the development of coronary artery disease (CAD). It also remains unclear whether the study of endothelial function provides information that is additive to that of traditional risk factors.
  
  
  RESULTS
  Flow-mediated dilation (FMD) and low-flow-mediated constriction (L-FMC) were measured in 451 consecutive patients before coronary angiography. Low-flow-mediated constriction (P< 0.0001) and FMD (P=0.0005) progressively decreased with the number of diseased vessels, and L-FMC showed a significant linear correlation with the SYNTAX score (R=0.38; P< 0.0001). Logistic regression analysis confirmed the association between endothelial function parameters and CAD (P=0.001 for L-FMC, P=0.02 for FMD). Receiver operating characteristic analysis demonstrated that the addition of L-FMC alone and of the combination of FMD and L-FMC improved the predictive power of a model based on traditional risk factors for CAD (area under the curve of the risk factor model=0.716; risk factor model + FMD=0.734, P=0.1 compared with risk factor model; risk factor model + L-FMC=0.771, P=0.004; risk factor model + L-FMC + FMD=0.779, P=0.002). Reclassification statistics showed that the introduction of FMD to the model based on the traditional risk factors correctly reclassified an additional 5% of patients, and that the introduction of L-FMC net correctly reclassified 19% of the patients. There was no correlation between different parameters of endothelial function.
  
  
  CONCLUSIONS
  Endothelial function assessment provides modest but statistically significant additional information in predicting the presence of CAD.
authors.affiliation: Department of Cardiology and Angiology,  University Medical Center Mainz,  Germany.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Gori
authors.forename: Selina
authors.initials: S
authors.lastname: Muxel
authors.forename: Ana
authors.initials: A
authors.lastname: Damaske
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Radmacher
authors.forename: Federica
authors.initials: F
authors.lastname: Fasola
authors.forename: Sarina
authors.initials: S
authors.lastname: Schaefer
authors.forename: Andreas
authors.initials: A
authors.lastname: Schulz
authors.forename: Alexander
authors.initials: A
authors.lastname: Jabs
authors.forename: John D
authors.initials: JD
authors.lastname: Parker
authors.forename: Thomas
authors.initials: T
authors.lastname: Münzel
mesh_terms: D000368:Aged; D003250:Constriction; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012307:Risk Factors; D014661:Vasoconstriction / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology*