Increased Frequency Of Transplantation In Stable Low-priority Listed Patients With The New Allocation System: A Unos Database Analysis

Purpose To compare the clinical, epidemiological characteristics, waitlist and post-transplant outcomes in patients that were listed at the lowest priority status, before (status 2) and after (status 6) the new UNOS heart transplant (HT) allocation system. Methods Adult patients listed for HT as status 2 in the old allocation system from October 18, 2016 to October 17, 2018 and as status 6 in the new allocation system from October 18, 2018 to October 17, 2019 were included in the study. Clinical characteristics at listing and at the time of transplant were compared between both groups. Competing outcomes in the waitlist (death/removal from the waitlist, transplantation, or alive) and post-transplant survival were compared between old and new systems. Results A total of 2825 patients were listed for HT. Of these, 1956 were listed as status 2 in the old system, and 869 were listed as status 6 in the new system. Patients listed in the new system were older and had a higher frequency of inotropic support at the time of listing. The cumulative incidence of transplantation was higher in patients listed in the new system (51% vs. 44%, p<0.001). Being listed in the new system was an independent factor associated with transplantation (HR: 1.33 (1.17-1.52). A total of 679 and 424 patients received HT in the old and new systems, respectively. The waitlist time was shorter, and the ischemic time was longer in the new allocation system. The 180 days post-transplant survival was similar between old and new systems (93.1% vs. 94.5%, p=0.369). Conclusion With the implementation of the new HT allocation system, patients listed at the lowest priority status have a shorter waitlist time and increased incidence of HT without differences in the post-transplant survival. To compare the clinical, epidemiological characteristics, waitlist and post-transplant outcomes in patients that were listed at the lowest priority status, before (status 2) and after (status 6) the new UNOS heart transplant (HT) allocation system. Adult patients listed for HT as status 2 in the old allocation system from October 18, 2016 to October 17, 2018 and as status 6 in the new allocation system from October 18, 2018 to October 17, 2019 were included in the study. Clinical characteristics at listing and at the time of transplant were compared between both groups. Competing outcomes in the waitlist (death/removal from the waitlist, transplantation, or alive) and post-transplant survival were compared between old and new systems. A total of 2825 patients were listed for HT. Of these, 1956 were listed as status 2 in the old system, and 869 were listed as status 6 in the new system. Patients listed in the new system were older and had a higher frequency of inotropic support at the time of listing. The cumulative incidence of transplantation was higher in patients listed in the new system (51% vs. 44%, p<0.001). Being listed in the new system was an independent factor associated with transplantation (HR: 1.33 (1.17-1.52). A total of 679 and 424 patients received HT in the old and new systems, respectively. The waitlist time was shorter, and the ischemic time was longer in the new allocation system. The 180 days post-transplant survival was similar between old and new systems (93.1% vs. 94.5%, p=0.369). With the implementation of the new HT allocation system, patients listed at the lowest priority status have a shorter waitlist time and increased incidence of HT without differences in the post-transplant survival.