Background:
Tolerance of donor hearts of different ABO blood types to allograft ischemic time has not been previously examined.
Objectives:
We determined the impact of allograft ischemic time on heart transplant outcomes with differing ABO donor organ types.
Methods:
We identified 32,454 heart transplants (2000-2016) from the United Network for Organ Sharing database. Continuous variables were analyzed with t-test and categorical variables were compared with Chi-squared test. Survival was determined using log-rank or Cox regression tests. Propensity matching adjusted for preoperative variables.
Results:
Comparing allograft ischemic times <4 hours (hr, n=6579) versus ≥4hr (n=25,875), the odds ratio (OR) for death at 15 years following prolonged allograft ischemic time (≥4hrs) for blood type O, A, B, and AB were 1.106 (P<0.001), 1.062 (P<0.001), 1.059 (P=0.062), 1.114 (P=0.221), respectively. Unadjusted data demonstrated higher mortality for transplantation of O versus non-O donor hearts for allograft ischemic times ≥4 hours (OR=1.164, P<0.001). Following propensity matching, O donor hearts continued to have worse survival if preserved for ≥4hrs (OR=1.137, P=0.008), but not if allograft ischemic time was <4hrs (OR=1.042, P=0.113). In a matched group with ≥4hrs of allograft ischemic time, patients receiving O donor organs were more likely to experience death from primary allograft dysfunction (2.5% vs 1.7%, P=0.052) and chronic allograft rejection (1.9% versus 1.1%, P=0.021). No difference in death from primary allograft graft dysfunction or chronic allograft rejection was seen with <4hr of allograft ischemic time (P>0.150).
Conclusions:
Compared with non-O hearts, transplantation with O donor hearts stored for ≥4hrs leads to worse survival, with higher rates of primary graft dysfunction and chronic rejection. Caution should be practiced when considering donor hearts with the O blood type when extended cold preservation times are anticipated.
A Novel Pathway of Chronic Allograft Rejection Mediated by NK Cells and Alloantibody