Outcomes of Orthotopic Heart Transplantation with Extended Allograft Ischemic Time

Abstract

Purpose Heart procurement for orthotopic heart transplant (OHT) is limited by the conventional four hours of cold ischemic time (IT). Based on a recent report from our center showing that extended IT from a young donor group does not compromise outcomes, we widened our geographical reach, resulting in almost 40% of our transplants having an IT >4 hours. Methods and Materials We retrospectively reviewed records of adult patients who underwent OHT from January 2006 to December 2011. The primary outcome was mortality, and the secondary outcomes included resource utilization, end organs dysfunction and one year incidence of acute cellular rejection. Overall survival was analyzed using Kaplan-Meier curves and log-rank tests. Resource utilization and postoperative complications were compared between groups with a combination of parametric and non-parametric statistics. Results From January 2006 to December 2011, 323 patients underwent OHT. There was a significant difference in overall mortality and survival time between the standard and extended IT groups (85.7% vs 76.4%, P=0.03; 51.8 vs 45.4 months, p=0.04). There were no significant differences between the groups for hospital or ICU length of stay, duration of inotropic and ventilator support, transfusion requirement or number/severity of cellular rejection episodes. There was a higher incidence of liver dysfunction in the extended IT group [84.9% vs. 73%), P=0.01]. Further examination of ischemic times revealed that the mortality rate remains comparable at 5 hours (85.7% vs. 87%, p=0.80), but begins to climb after roughly 300 minutes. Additional analyses support the conclusion that ischemic time up to 5 hours may be safe. Conclusions Limited donor availability for OHT dictates alternative strategies to enlarge the donor pool. Our results suggest that although there is an overall increasing risk with extended ischemic time beyond 4 hours, it may be possible to increase the threshold to at least 5 hours without compromising the outcomes.