title: Which parameter is better to define endothelial dysfunction in a test of postocclusive hyperemia measured by laser-Doppler flowmetry?
abstract: OBJECTIVE
  Endothelial function can be measured by the level of reactive vasodilation due to a transient ischemia caused by a blood pressure cuff on the arm, measured using Laser-Doppler flowmetry. This device has software that provides various parameters that can measure the magnitude of this response, but there are no general agreements with regard to which of them is the best to use. In this study, we analyze which of the parameters obtained using this technique is better to discriminate between patients with coronary artery disease (CAD) and healthy controls.
  
  
  METHODS
  We analyzed 40 patients with proven CAD and 60 healthy controls. We studied the hyperemic response to the ischemia in the forearm using a Laser-Doppler flowmeter.
  
  
  RESULTS
  The most important differences between patients and controls were determined considering the area of hyperemia, which was 2.6 times higher in healthy controls than that in patients (754.9±566.4 vs 1981.3±1156.3 perfusion units per second, P<0.001). To diagnose the disease, a cutoff point of 860 perfusion units per second had a sensitivity of 0.82 and a specificity of 0.97. This is probably because the area of hyperemia measures at the same time speed, intensity, and duration of the hyperemic response.
  
  
  CONCLUSIONS
  The area of hyperemia was the parameter with a higher sensitivity and specificity for identification of patients with CAD. Nevertheless, further studies are needed to confirm the usefulness of this parameter, obtained using a noninvasive test, to assess the presence of subclinical coronary heart disease.
authors: Unidad Clínico-Experimental de Riesgo Vascular-UCAMI, Servicio de Medicina Interna, IBIS, Hospitales Universitarios Virgen del Rocío, Sevilla, Spain. stiefel@cica.es
authors: Pablo
authors: P
authors: Stiefel
authors: Rafael
authors: R
authors: Moreno-Luna
authors: Antonio J
authors: AJ
authors: Vallejo-Vaz
authors: Luis M
authors: LM
authors: Beltrán
authors: Alzenira
authors: A
authors: Costa
authors: Luis
authors: L
authors: Gómez
authors: Antonio
authors: A
authors: Ordóñez
authors: José
authors: J
authors: Villar
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000175:diagnosis* / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D013030:Spain; D034941:Upper Extremity / Q000098:blood supply*