title: Interaction of older donor age and survival after weight-matched pediatric heart transplantation.
abstract: BACKGROUND
  Donors are matched for weight in pediatric heart transplantation (PHT), yet age differences are not considered in this decision. In this study we attempt to identify the effect of age differences in weight-matched patients and the effect these differences have on post-transplant survival.
  
  
  METHODS
  The United Network of Organ Sharing (UNOS) database was queried for the period from October 1987 to March 2014 for all pediatric heart transplant patients. Transplants with donor-to-recipient (D-R) weight ratios of 0.8 to 1.5 were identified (weight-matched). D-R age differences were categorized as: donors 5 years younger than recipients (D<R-5); donors within 5 years of recipients (D=R±5); and donors 5 years older than recipients (D>R+5).
  
  
  RESULTS
  A total of 4,408 patients were identified as weight-matched transplants. Of these transplants, 681 were D>R+5, 3,596 were D=R±5 and 131 were D<R-5. D>R+5 transplants were found to be associated with decreased post-transplant survival compared with D=R±5 (p = 0.002). Rates of acute rejection were similar among all groups but post-transplant coronary allograft vasculopathy (CAV) was more prevalent in D>R+5 than D=R±5 patients (28% and 18%, respectively; p < 0.001). Increasing age difference by each year was associated with decreasing median post-transplant survival time (p < 0.001; hazard ratio 1.018, range 1.011 to 1.025). The overall negative association with mortality was due to the adolescent cohort (11 to 17 years), specifically D>R+5 transplants, utilizing organs from donors >25 of age.
  
  
  CONCLUSIONS
  In PHT, increasing D-R age difference decreases survival; however, this effect is driven by recipients 11 to 17 years old and donors >25 years old. Allocation of younger donor organs to adolescent recipients should be a priority.
authors.affiliation: Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Westbrook
authors.affiliation: Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: David L S
authors.initials: DLS
authors.lastname: Morales
authors.affiliation: Department of Family Medicine, University of Oklahoma, Tulsa, Oklahoma, USA.
authors.forename: Muhammad S
authors.initials: MS
authors.lastname: Khan
authors.affiliation: Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Roosevelt
authors.initials: R
authors.lastname: Bryant
authors.affiliation: Division of Cardiology, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Chesney
authors.initials: C
authors.lastname: Castleberry
authors.affiliation: Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Clifford
authors.initials: C
authors.lastname: Chin
authors.affiliation: Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA. Electronic address: farhan.zafar@cchmc.org.
authors.forename: Farhan
authors.initials: F
authors.lastname: Zafar
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D006084:Graft Rejection / Q000401:mortality*; D006085:Graft Survival; D016027:Heart Transplantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D053208:Kaplan-Meier Estimate; D019520:Living Donors; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009929:Organ Size; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D066027:Transplant Recipients; D016896:Treatment Outcome; D014481:United States
keywords: adolescent age donors; age mismatch; donor age; pediatric heart transplant; weight-match heart transplants