Ischemic time and patient outcomes after the 2018 UNOS donor heart allocation system change

Area of Science:

• Cardiology
• Transplantation Medicine
• Public Health Policy

Background:

• The US heart donor allocation system was revised on October 18, 2018, leading to increased donor-recipient travel distances and ischemic times.
• This study investigates the impact of the new allocation system on patient outcomes and the role of ischemic time.

Purpose of the Study:

• To evaluate patient survival outcomes following the 2018 heart allocation system change in the United States.
• To analyze the differential effects of organ ischemic time on survival under both the old and new allocation systems.

Main Methods:

• Utilized data from the United Network for Organ Sharing Registry (UNOS) for 62,301 adult heart transplants from October 1, 1987, to March 1, 2021.
• Compared 30-day and 1-year survival outcomes and ischemic times using adjusted logistic and Cox regression models.

Main Results:

• Mean ischemic time increased slightly under the new system (3.43 hours vs. 3.03 hours).
• No significant differences in overall survival were observed between the old and new systems in adjusted models.
• Longer ischemic times showed a trend towards being more detrimental to long-term survival under the new system compared to the old, but this did not reach statistical significance.

Conclusions:

• Despite increased travel distances, heart transplant survival outcomes have not significantly changed under the new allocation system.
• Organ ischemic time remains a critical factor influencing recipient survival and should be minimized.
• Further research is warranted to fully understand the long-term impacts of travel distances and ischemic time within the current allocation framework.