Interaction of Donor and Recipient Age: Do Older Heart Transplant Recipients Require Younger Hearts?

Abstract

Older patients (aged 60 years or more) awaiting heart transplant often have comorbidities that may limit overall survival independent of cardiac status. We hypothesized that these comorbidities have a more-limiting impact on survival than age of donor heart and that older allografts might be utilized in these patients without compromising outcomes. We identified all transplant recipients aged more than 60 years in the United Network for Organ Sharing database. Local regression analysis detected the point above which increasing donor age incurred increasing risk of mortality, above and below which two cohorts were defined. Kaplan-Meier analysis compared cumulative 5-year survival between groups. Cox proportional hazard modeling was then used to determine the hazards of death in the two groups. An inflection point in posttransplant survival was detected near donor age 50 years. Of 14,113 older recipients studied, 86% received younger donor hearts (less than 50 years of age), and 14% received advanced age allografts (50 years of age or more). Baseline characteristics were comparable between groups except more recipients had left ventricular assist devices at time of transplant in the younger donor group (15% versus 9%, p < 0.001). Five-year survival was significantly lower among recipients receiving advanced age hearts compared with those receiving younger hearts (67% versus 73%, log rank p < 0.001). Adjusting for relevant recipient baseline characteristics, patients receiving advanced age hearts were 30% more likely to die by 5 years compared with patients receiving younger hearts. Transplant recipients aged 60 years and more who receive advanced age donor hearts (50 years or more) have a significantly increased risk of mortality. With careful allograft selection, use of donor hearts to age 50 may be acceptable among older transplant recipients.