The Introduction of a Super-urgent Heart Allocation Scheme in the UK: A 2-year Review

Background: In response to a growing number of patients on the UK urgent heart transplant waiting list, the UK donor heart allocation scheme was revised in October 2016 with the introduction of a new super-urgent category. Patients with temporary mechanical circulatory support (tMCS) became eligible for super-urgent registration. The aim of this study was to compare activity, indications, and outcomes before and after the change.

Methods: Data on adult (aged ≥16 years) heart transplant registrations and recipients in the 2 years before (Era 1: July 1, 2014-June 30, 2016) and after (Era 2: January 2017-December 2018) the introduction of the new scheme were extracted from the UK Transplant Registry and analyzed using competing risks analysis, Kaplan-Meier analysis, and Cox proportional-hazards regression.

Results: There were 525 waiting-list registrations in Era 1 and 594 in Era 2, including 14% super-urgent registrations, with 90% having some form of tMCS. Median waiting time to transplant was 41 days for all urgent registrations in Era 1 compared with 17 days for super-urgent registrations and 71 days for urgent registrations in Era 2. Numbers of non-urgent transplants were not affected. Deaths on the waiting list significantly decreased from 5% to 2% at 6 months between Era 1 and Era 2 (adjusted hazard ratio = 0.29, 95% CI = 0.13-0.62). In addition, total number of patients with tMCS were not different between both eras, suggesting no significant change in this area of clinical decision making. Post-transplant survival at 1 year for super-urgent recipients was not significantly different from post-transplant survival at 1 year for other categories.

Conclusions: The Introduction of a super-urgent heart allocation scheme in the UK reduces waiting time to transplant for the sickest patients, with comparable post-transplant survival while reducing deaths on the waiting list.