Donors' characteristics and impact on outcomes in pediatric heart transplant recipients

Organ availability and acceptability limit pediatric HTx. What characteristics define an unacceptable or high-risk pediatric donor remains unclear. The purpose of this study was to characterize a large cohort of pediatric donors and determine the donor risk factors, including cumulative risk, that affect recipient survival. Data from the PHTS, a prospective multicenter study, were used to examine the impact of donor factors on the outcomes of patients listed <18yr of age who received a HTx between 1993 and 2009. Donor data were available for 3149 of 3156 HTx (99.8%). Donor cause of death, need for inotropes, or CPR did not affect survival outcomes (p=0.05). Ischemic time also did not have an impact on overall recipient survival; however, longer ischemic times negatively impacted one-yr post-transplant survival (p<0.0001). There was no impact of cumulative risk factors on survival (p=0.8). Although used in a minority of cases, hormonal therapy in the donor positively impacted survival (p=0.03). In multivariate analysis, the only donor factor associated with decreased survival was smaller donor BSA, the other factors being related to the recipient characteristics. When analyzed by recipient age, there were no donor-related factors that affected survival for those who received a transplant at <6months of age. Longer ischemic time (p<0.0001) and greater age difference between the recipient and donor (p=0.0098) were donor-related factors impacting early-phase survival for recipients who received a graft at 10yr of age. Factors perceived to define a marginal or high-risk pediatric heart donor including inotrope use, CPR and donor cause of death may have less impact on outcomes than previously thought. Longer ischemic times did impact oneyr, but not overall survival, and this impact was much greater with older donors. Parameters for accepting a donor heart can potentially be expanded, especially in the infant age group, but strong consideration should always be given to the interaction between ischemic time and donor age.