Interactions among donor characteristics influence post-transplant survival: a multi-institutional analysis.

BACKGROUND Quantification of donor-associated risk in a specific heart transplant recipient is often difficult. Our aim was to identify donor characteristics that affect survival in the contemporary era. METHODS Between 1990 and 2006, 7,322 patients from 32 centers in the Cardiac Transplant Research Database underwent heart transplantation. Multivariable logistic regression analysis was used to identify donor-associated risk predictors and important interactions between these donor characteristics. Recipient survival was examined using parametric regression analysis in the hazard function domain. RESULTS Donor characteristics associated with post-transplant death included donor age, donor requirement for vasoactive therapy, positive donor cytomegalovirus serology, longer graft ischemic time, and lower donor body weight. Several interactions between individual donor characteristics affected survival. In male donors, history of hypertension and diabetes mellitus were risk factors for death (p = 0.006, p = 0.04, respectively), but not in female donors (p = 0.5, p = 0.8, respectively). There was a significant interaction between donor age and recipient-donor weight difference. If the donor was of younger age, increasing recipient-donor weight difference did not result in increased death. With increasing donor age, weight difference did result in compromised survival (p < 0.0003). Donor and recipient gender further modified the degree of risk: risk was higher in female donors and when recipients were male (p < 0.0003). CONCLUSIONS This multi-institutional analysis identified important interactions between donor characteristics that affect post-transplant survival that explain some of the discrepancies in the results of previous studies. The results are likely to aid in efficient organ allocation.