title: Non-invasive endothelial function assessment using digital reactive hyperaemia correlates with three-dimensional intravascular ultrasound and virtual histology-derived plaque volume and plaque phenotype.
abstract: OBJECTIVE
  To study relationships between endothelial dysfunction (ED) and coronary atherosclerosis derived from intravascular ultrasound (IVUS) and virtual histology (VH).
  
  
  METHODS
  Endothelial dysfunction was examined by EndoPAT system (Itamar Medical) in 56 patients who underwent IVUS and VH (Volcano corp.). Reactive hyperaemia index (RHI) < 2 was used for definition of ED. IVUS sequences were divided into 5 mm-long non-overlapping and adjacent vessel segments. Plaque phenotype was determined for each frame and 5 mm vessel segment was labeled according to highest frame score (from 0 for "no lesion" to 5 for "thin cap fibroatheroma; TCFA").
  
  
  RESULTS
  IVUS-VH data were collected from 41 patients suitable for three-dimensional analysis. Patients with ED exhibited larger plaque burden than those without ED (0.46 ± 0.08 vs. 0.39 ± 0.07, p = 0.014), smaller lumen area (8.59 ± 2.19 vs. 11.90 ± 3.50, p = 0.016), higher plaque risk score (2.82 ± 1.18 vs. 1.84 ± 0.90, p = 0.012), and higher number of TCFA frames (0.36 ± 0.22 vs. 0.22 ± 0.16, p = 0.038). Relative amounts of fibrous tissue correlated positively with RHI (p = 0.034, r = 0.33). The numbers of fibroatheromas and calcified plaques correlated with RHI inversely (r = -0.34, p = 0.031 and r = -0.32, p = 0.044, respectively).
  
  
  CONCLUSIONS
  Endothelial dysfunction correlates with severity and phenotype of coronary lesions and can contribute to non-invasive detection of individuals with higher risk of cardiovascular events.
authors.affiliation: 2nd Department of Medicine, Department of Cardiovascular Medicine, 1st Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic. tomas.kovarnik@vfn.cz.
authors.forename: Tomas
authors.initials: T
authors.lastname: Kovarnik
authors.forename: Stepan
authors.initials: S
authors.lastname: Jerabek
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.forename: Andreas
authors.initials: A
authors.lastname: Wahle
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Gabriela
authors.initials: G
authors.lastname: Dostalova
authors.forename: Hana
authors.initials: H
authors.lastname: Skalicka
authors.forename: Ales
authors.initials: A
authors.lastname: Kral
authors.forename: Jan
authors.initials: J
authors.lastname: Horak
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
authors.forename: Ales
authors.initials: A
authors.lastname: Linhart
mesh_terms: D000368:Aged; D002986:Clinical Trials as Topic; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D004727:Endothelium / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D006940:Hyperemia; D008875:Middle Aged; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional
keywords: endothelial dysfunction; intravascular ultrasound; prediction; thin cap fibroatheroma