The Paradoxical Relationship Between Donor Distance and Survival After Heart Transplantation

Abstract

Concerns over prolonged allograft ischemia have limited the widespread adoption of long-distance organ procurement in heart transplantation (HT). We sought to assess whether donor distance from the center of transplantation independently affects mortality. We queried the United Network for Organ Sharing (UNOS) database for adults undergoing isolated HT from 2005 to 2012. Risk-adjusted Cox proportional hazards models were constructed for the primary outcomes of 30-day and 1-year mortality, and the independent impact of donor distance from transplantation center at the time of procurement was assessed. We included 14,588 heart transplant recipients. The mean distance from location of the donor heart to transplantation center was 184.4 ± 214.6 miles; 1,214 HTs (8.3%) occurred at the same location as the donor heart. Ischemic times were inversely related to the distance from the site of donor procurement to recipient transplantation. After risk adjustment, longer donor distances (in miles) were associated with a significantly lower risk of mortality at both 30 days (hazard ratio [HR] 0.9993, 95% confidence interval [CI]: 0.9988 to 0.9998, p<0.01) and 1 year (HR 0.9994, 95% CI: 0.9989 to 0.9999, p= 0.015). Risk-adjusted hazards for mortality were significantly reduced in recipients receiving hearts from more than 25 miles away. The hazard reduction was greatest in recipients receiving donor hearts from more than 500 miles away (1-year HR0.64, p < 0.01; 30-day HR 0.47, p < 0.01). Longer distances between donor location and center of heart transplantation are associated with a reduced hazard for survival at 30 days and 1 year, despite greater ischemic times. Future studies are necessary to elucidate the protective factors surrounding long-distance heart donation.