The Regional Impact of the 2018 United States Heart Allocation System Change

Abstract

Purpose In October 2018, the US Organ Procurement and Transplantation Network (OPTN) implemented a change in the donor heart allocation policy, with priority given to those with temporary mechanical circulatory support and expanded regional sharing. The purpose of the current study was to examine changes in waitlist/transplant outcomes across the US with the policy change, stratified by geographic region. Methods Retrospective analysis was performed of adult patients listed for heart transplant between January 2016-July 2021 as identified in the OPTN database. Patients were grouped by era according to initial listing date before or after October 18, 2018 as well as OPTN region. Competing outcomes regression was performed for waitlist death, transplant, or delisting utilizing the method of Fine and Gray, along with cause-specific hazard modeling. Models were censored at 3y. Results During the study period, 23,146 patients were listed, with 11,494 prior to (Era 1, 49.7%) and 11,652 after system change (Era 2, 50.3%). IABP and ECMO usage amongst waitlist patients increased in Era 2 across all regions (all p<0.05). Waitlist mortality improved in all regions except the South (Region 3 and 4) and Northwest (Regions 6-8, p>0.10). Odds of transplantation increased in all regions to varying degrees. However, amongst patients with LVAD support, waitlist mortality was only improved in Region 2 (Mid-Atlantic, p=0.016) and Region 5 (Southwest, p=0.041), with a commensurate increase in transplantation in Region 5 (SHR 1.48 [1.22-1.80], p<0.001). Among those transplanted, organ distance increased by >80 mi in all regions except Region 1 (Northeast), with increases in ischemic time in all regions except Region 1 (p=0.358). Conclusion The implementation of the new allocation system broadly decreased waitlist mortality and improved rates of transplantation, though effects were dependent on geographic region. Continued examination of listing practices and organ allocation with respect towards geographic variation is warranted. In October 2018, the US Organ Procurement and Transplantation Network (OPTN) implemented a change in the donor heart allocation policy, with priority given to those with temporary mechanical circulatory support and expanded regional sharing. The purpose of the current study was to examine changes in waitlist/transplant outcomes across the US with the policy change, stratified by geographic region. Retrospective analysis was performed of adult patients listed for heart transplant between January 2016-July 2021 as identified in the OPTN database. Patients were grouped by era according to initial listing date before or after October 18, 2018 as well as OPTN region. Competing outcomes regression was performed for waitlist death, transplant, or delisting utilizing the method of Fine and Gray, along with cause-specific hazard modeling. Models were censored at 3y. During the study period, 23,146 patients were listed, with 11,494 prior to (Era 1, 49.7%) and 11,652 after system change (Era 2, 50.3%). IABP and ECMO usage amongst waitlist patients increased in Era 2 across all regions (all p<0.05). Waitlist mortality improved in all regions except the South (Region 3 and 4) and Northwest (Regions 6-8, p>0.10). Odds of transplantation increased in all regions to varying degrees. However, amongst patients with LVAD support, waitlist mortality was only improved in Region 2 (Mid-Atlantic, p=0.016) and Region 5 (Southwest, p=0.041), with a commensurate increase in transplantation in Region 5 (SHR 1.48 [1.22-1.80], p<0.001). Among those transplanted, organ distance increased by >80 mi in all regions except Region 1 (Northeast), with increases in ischemic time in all regions except Region 1 (p=0.358). The implementation of the new allocation system broadly decreased waitlist mortality and improved rates of transplantation, though effects were dependent on geographic region. Continued examination of listing practices and organ allocation with respect towards geographic variation is warranted.