title: Validation of a Simple Score to Determine Risk of Early Rejection After Pediatric Heart Transplantation.
abstract: OBJECTIVE
  This study aimed to develop a reliable and feasible score to assess the risk of rejection in pediatric heart transplantation recipients during the first post-transplant year.
  
  
  BACKGROUND
  The first post-transplant year is the most likely time for rejection to occur in pediatric heart transplantation. Rejection during this period is associated with worse outcomes.
  
  
  METHODS
  The United Network for Organ Sharing database was queried for pediatric patients (age <18 years) who underwent isolated orthotopic heart transplantation from January 1, 2000 to December 31, 2012. Transplantations were divided into a derivation cohort (n = 2,686) and a validation (n = 509) cohort. The validation cohort was randomly selected from 20% of transplantations from 2005 to 2012. Covariates found to be associated with rejection (p < 0.2) were included in the initial multivariable logistic regression model. The final model was derived by including only variables independently associated with rejection. A risk score was then developed using relative magnitudes of the covariates' odds ratio. The score was then tested in the validation cohort.
  
  
  RESULTS
  A 9-point risk score using 3 variables (age, cardiac diagnosis, and panel reactive antibody) was developed. Mean score in the derivation and validation cohorts were 4.5 ± 2.6 and 4.8 ± 2.7, respectively. A higher score was associated with an increased rate of rejection (score = 0, 10.6% in the validation cohort vs. score = 9, 40%; p < 0.01). In weighted regression analysis, the model-predicted risk of rejection correlated closely with the actual rates of rejection in the validation cohort (R(2) = 0.86; p < 0.01).
  
  
  CONCLUSIONS
  The rejection score is accurate in determining the risk of early rejection in pediatric heart transplantation recipients. The score has the potential to be used in clinical practice to aid in determining the immunosuppressant regimen and the frequency of rejection surveillance in the first post-transplant year.
authors.affiliation: Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina. Electronic address: butts@musc.edu.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Butts
authors.affiliation: Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Savage
authors.affiliation: Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Atz
authors.affiliation: Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Heal
authors.affiliation: Department of Transplant Services, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Ali L
authors.initials: AL
authors.lastname: Burnette
authors.affiliation: Division of Pediatric Cardiothoracic Surgery, Department of Surgery, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Minoo M
authors.initials: MM
authors.lastname: Kavarana
authors.affiliation: Division of Pediatric Cardiothoracic Surgery, Department of Surgery, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Bradley
authors.affiliation: Division of Cardiology, Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Shahryar M
authors.initials: SM
authors.lastname: Chowdhury
mesh_terms: D000293:Adolescent; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000175:diagnosis* / Q000453:epidemiology; D016027:Heart Transplantation; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009206:Myocardium / Q000473:pathology*; D011184:Postoperative Period; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D014481:United States / Q000453:epidemiology
keywords: heart transplant; pediatrics; rejection