title: Myocardial strain and strain rate from speckle-tracking echocardiography are unable to differentiate asymptomatic biopsy-proven cellular rejection in the first year after cardiac transplantation.
abstract: BACKGROUND
  Cellular rejection after cardiac transplantation is treatable with timely diagnosis. Because noninvasive methods for diagnosis are limited, surveillance endomyocardial biopsies are routinely performed in the first year after transplantation. The aim of this study was to test whether myocardial strain and strain rate as assessed by speckle-tracking echocardiography would be a sensitive noninvasive method for the detection of asymptomatic rejection.
  
  
  METHODS
  Surveillance biopsies and echocardiograms obtained in the first year after transplantation were retrospectively reviewed, and patients with asymptomatic biopsy-proven cellular rejection were identified, as well as control transplantation patients without rejection or cardiac complications. Circumferential and longitudinal strain and strain rate were measured using Velocity Vector Imaging software from echocardiograms performed at three time points for patients with rejection-baseline (no rejection), rejection, and resolution (of rejection)-and three time points for control patients-baseline (within the first month after transplantation), 6 months, and 12 months after transplantation.
  
  
  RESULTS
  Speckle-tracking strain and strain rate measurements were obtained from 30 patients with asymptomatic biopsy-proven rejection and 14 control transplantation patients. There were no significant differences in circumferential and longitudinal strain or strain rate between the baseline, rejection, and resolution studies. Furthermore, there were no significant differences in strain and strain rate in control transplantation patients during the first year after transplantation or compared with patients with rejection.
  
  
  CONCLUSIONS
  Speckle-tracking analysis was unable to detect changes on serial studies from patients with asymptomatic rejection and thus cannot replace biopsy. Other noninvasive methods for the diagnosis of cellular-mediated rejection are needed.
authors.affiliation: Division of Cardiology, University of Colorado, Aurora, Colorado. Electronic address: amrut.ambardekar@ucdenver.edu.
authors.forename: Amrut V
authors.initials: AV
authors.lastname: Ambardekar
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, Oregon.
authors.forename: Nitya
authors.initials: N
authors.lastname: Alluri
authors.affiliation: Division of Cardiology, University of Colorado, Aurora, Colorado.
authors.forename: Amit C
authors.initials: AC
authors.lastname: Patel
authors.affiliation: Vanderbilt Heart and Vascular Center, Nashville, Tennessee.
authors.forename: JoAnn
authors.initials: J
authors.lastname: Lindenfeld
authors.affiliation: Cardiology Department, Colorado Kaiser Permanente Medical Group, Denver, Colorado.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Dorosz
mesh_terms: D000328:Adult; D001706:Biopsy; D003937:Diagnosis, Differential; D004452:Echocardiography / Q000379:methods*; D055119:Elastic Modulus; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D016027:Heart Transplantation / Q000009:adverse effects*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014783:Viscosity
keywords: Cellular rejection; Endomyocardial biopsy; Myocardial mechanics; Orthotopic heart transplantation; Speckle-tracking echocardiography