Impact of the Revised Heart Allocation System at a Large Volume Center

Purpose In October of 2018, the United Network for Organ Sharing (UNOS) instituted a revised allocation system (RAS) for heart transplantation (HT). We sought to explore how these changes impacted our own center's listing and bridging strategies and rates of adult HT. Methods We performed a retrospective review comparing adult patients transplanted at our center between October 1, 2017 and October 17, 2018 (prior to RAS, Cohort A) with those transplanted between October 18, 2018 and August 1, 2019 (following RAS, Cohort B). Among the characteristics we explored were patient blood type, status at time of listing and HT, status justification, and for patients listed by exception, reason for exception request Results Between October 1, 2017 and August 1, 2019, a total of 178 adults underwent HT at our institution, including 98 patients in Cohort A and 80 patients in Cohort B. Relative to patients in Cohort A, patients in Cohort B were more likely to be bridged to HT with temporary mechanical circulatory support (MCS) (9 (11%) vs 2 (2%), less likely to be bridged with durable LVAD (21 (26%) vs 39 (40%)) and equally likely to be listed by status exception request (23 (29%) vs 28 (29%)). Among 21 patients in Cohort B bridged with durable LVAD, only 4 (19%) underwent HT at status 4 whereas 17 (81%) required upgrade to status 3 using their ‘30-day time’ (n=15) or due to complications (n=2), in order to achieve HT. By comparison, among 39 patients in Cohort A bridged with durable LVAD, 18 (46%) underwent HT at Status 1B (equivalent to status 4 in the RAS). Nineteen (49%) transplanted LVADs in Cohort A had ABO O blood type, compared to only 6 (29%) in Cohort B. Conclusion While implementation of the RAS did not significantly impact our center's rate of HT, it influenced decision-making at time of HT listing in favor of temporary MCS when justified, and against durable MCS, especially in patients with O blood type. Moreover, despite RAS changes aimed at reducing status exception requests, requests made by our center remain equally likely now as they were prior to RAS implementation.