title: Reproducibility of serial intravascular ultrasound measurements in patients with angiographically silent coronary artery disease after heart transplantation.
abstract: BACKGROUND
  Intracoronary ultrasound (ICUS) imaging is the most sensitive method for the early detection and serial evaluation of vasculopathy of transplants. Both lack of agreement between observers and lack of agreement between serial, independent pullback procedures (repeatability), which can result in a variable intraluminal catheter position may limit the reproducibility of ICUS measurements.
  
  
  OBJECTIVE
  To evaluate the reproducibility of serial measurements of standard linear and area cross-sectional coronary dimensions in patients with non-obstructive transplant vasculopathy.
  
  
  METHODS
  We performed ICUS imaging of patients without angiographic evidence of obstructive epicardial coronary artery disease after heart transplantation. A 30 MHz phased-array transducer was used. Two independent pullbacks of the left anterior descending coronary artery were performed and recorded on CD-ROM for off-line quantitative analysis of the most severely diseased site. Agreement of observers and repeatability of serial measurements were calculated by the use of linear regression analysis and Bland-Altman plots.
  
  
  RESULTS
  Regarding agreement of observers, correlation coefficients for intra-observer agreement ranged from r = 0.98 to r = 0.99; those for interobserver agreement ranged from r = 0.87 to r = 0.98. Serial measurements of the identical coronary artery cross-section within independent catheter pullback procedures were possible for 104 of 112 target lesions (92.90/%). Correlation coefficients ranged from r = 0.91 to r = 0.97 (for lumen diameter r = 0.91, for lumen area r = 0.93, for vessel diameter r = 0.91, for vessel area r = 0.97, for thickness of plaque r = 0.96 and for area of plaque 0.94). The mean difference of measurements was around zero for all parameters with SD from 0.13 to 0.4 mm for linear parameters and from 1.53 to 1.82 mm2 for area parameters.
  
  
  CONCLUSIONS
  Serial intravascular ultrasound measurements are highly reproducible without any evidence of systematic error and a SD of differences of measurements beyond the maximal spatial resolution of currently available intravascular ultrasound catheters.
authors.affiliation: Department of Internal Medicine/Cardiology, German Heart Institute Berlin, Humboldt Universität zu Berlin. wolfgang.bocksch@charite.de
authors.forename: W
authors.initials: W
authors.lastname: Bocksch
authors.forename: E
authors.initials: E
authors.lastname: Wellnhofer
authors.forename: M
authors.initials: M
authors.lastname: Schartl
authors.forename: S
authors.initials: S
authors.lastname: Dreysse
authors.forename: W
authors.initials: W
authors.lastname: Klimek
authors.forename: R
authors.initials: R
authors.lastname: Franke
authors.forename: M
authors.initials: M
authors.lastname: Musci
authors.forename: R
authors.initials: R
authors.lastname: Hetzer
authors.forename: E
authors.initials: E
authors.lastname: Fleck
mesh_terms: D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012044:Regression Analysis; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods