title: The effect of ischemic time on survival after heart transplantation varies by donor age: an analysis of the United Network for Organ Sharing database.
abstract: OBJECTIVE
  (1) To examine the interaction of donor age with ischemic time and their effect on survival and (2) to define ranges of ischemic time associated with differences in survival.
  
  
  METHODS
  The United Network for Organ Sharing provided de-identified patient-level data. The study population included 33,640 recipients undergoing heart transplantation between October 1, 1987, and December 31, 2004. Recipients were divided by donor age into terciles: 0 to 19 years (n = 10,814; 32.1%), 20 to 33 years (11,410, 33.9%), and 34 years or more (11,416, 33.9%). Kaplan-Meier survival functions and Cox regression were used for time-to-event analysis. Receiver operating characteristic curves and stratum-specific likelihood ratios were generated to compare 5-year survival at various thresholds for ischemic time.
  
  
  RESULTS
  In univariate Cox proportional hazards regression, the effect of ischemic time on survival varied by donor age tercile: 0 to 19 years (P = .141), 20 to 33 years (P < .001), and 34 years or more (P < .001). These relationships persisted in multivariable regression. Threshold analysis generated a single stratum (0.37-12.00 hours) in the 0- to 19-year-old group with a median survival of 11.4 years. However, in the 20- to 33-year-old-group, 3 strata were generated: 0.00 to 3.49 hours (limited), 3.50 to 6.24 hours (prolonged), and 6.25 hours or more (extended), with median survivals of 10.6, 9.9, and 7.3 years, respectively. Likewise, 3 strata were generated in the group aged 34 years or more: 0.00 to 3.49 (limited), 3.50 to 5.49 (prolonged), and 5.50 or more (extended), with median survivals of 9.1, 8.5, and 6.3 years, respectively.
  
  
  CONCLUSIONS
  The effect of ischemic time on survival after heart transplantation is dependent on donor age, with greater tolerance for prolonged ischemic times among grafts from younger donors. Both donor age and anticipated ischemic time must be considered when assessing a potential donor.
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, College of Physicians and Surgeons, Columbia University, New York, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Russo
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Chen
authors.forename: Robert A
authors.initials: RA
authors.lastname: Sorabella
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Martens
authors.forename: Mauricio
authors.initials: M
authors.lastname: Garrido
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Davies
authors.forename: Isaac
authors.initials: I
authors.lastname: George
authors.forename: Faisal H
authors.initials: FH
authors.lastname: Cheema
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Mosca
authors.forename: Seema
authors.initials: S
authors.lastname: Mital
authors.forename: Deborah D
authors.initials: DD
authors.lastname: Ascheim
authors.forename: Michael
authors.initials: M
authors.lastname: Argenziano
authors.forename: Allan S
authors.initials: AS
authors.lastname: Stewart
authors.forename: Mehmet C
authors.initials: MC
authors.lastname: Oz
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Naka
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D016027:Heart Transplantation / Q000379:methods* / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology*; D009926:Organ Preservation; D011183:Postoperative Complications / Q000401:mortality; D011336:Probability; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D014481:United States