title: Quantitative myocardial blush grade for the detection of cardiac allograft vasculopathy.
abstract: BACKGROUND
  Cardiac allograft vasculopathy (CAV) progressively compromises microvascular perfusion and function in heart transplantation (HTx)-recipients. The aim of our study was to investigate the ability of quantitative myocardial blush grade (MBG) to detect CAV.
  
  
  METHODS
  In consecutive HTx-recipients (n = 72) who underwent surveillance cardiac catheterization, MBG was assessed visually and quantitatively, by analyzing the time course of contrast agent intensity rise. Hereby, the parameter G(max)/T(max) was calculated as the plateau of grey-level intensity (G(max)) divided by the time-to-peak intensity (T(max)). HTx-recipients and 18 healthy volunteers underwent cardiac magnetic resonance, to assess diastolic strain rates and myocardial perfusion reserve during pharmacologic hyperemia.
  
  
  RESULTS
  Significant correlations were observed between G(max)/T(max) with perfusion reserve and with mean diastolic strain rates (r(2) = 0.68 and r(2) = 0.58, P < .001 for both). Visual and quantitative MBG using a cutoff value of G(max)/T(max) = 2.7/s yielded significantly higher accuracy than stenosis severity on coronary angiograms for the detection of impaired microvascular integrity as a surrogate marker for CAV (AUC = 0.78, SE = 0.06, 95% CI = 0.66-0.87 for lumen narrowing versus AUC = 0.91, SE = 0.03, 95%CI = 0.84-0.97 for G(max)/T(max); P < .01). Furthermore, quantitative MBG provided more robust prediction of survival (chi(2)= 14.0, P < .001), compared to visually estimated blush (chi(2)= 5.4, P = .02) and to coronary lumen narrowing assessment, (chi(2)= 4.8, P = .04).
  
  
  CONCLUSIONS
  Quantification of MBG can be performed on coronary angiograms of HTx-recipients, and may help with the identification of early CAV in patients with impaired perfusion reserve but without angiographically evident atherosclerosis.
authors.affiliation: University of Heidelberg, Department of Cardiology, Heidelberg, Germany. gkorosoglou@hotmail.com
authors.forename: Grigorios
authors.initials: G
authors.lastname: Korosoglou
authors.forename: Nina
authors.initials: N
authors.lastname: Riedle
authors.forename: Markus
authors.initials: M
authors.lastname: Erbacher
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Dengler
authors.forename: Christian
authors.initials: C
authors.lastname: Zugck
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rottbauer
authors.forename: Stefan
authors.initials: S
authors.lastname: Hardt
authors.forename: Raffi
authors.initials: R
authors.lastname: Bekeredjian
authors.forename: Arnt
authors.initials: A
authors.lastname: Kristen
authors.forename: Evangelos
authors.initials: E
authors.lastname: Giannitsis
authors.forename: Neal F
authors.initials: NF
authors.lastname: Osman
authors.forename: Hartmut
authors.initials: H
authors.lastname: Dickhaus
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D003326:Coronary Circulation; D005260:Female; D006085:Graft Survival; D016027:Heart Transplantation; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014184:Transplantation, Homologous