Transplant Allocation System Research Articles

France's New Lung Transplant Allocation System: Combining Equity With Proximity by Optimizing Geographic Boundaries Through the Supply/Demand Ratio.

A new lung allocation system was introduced in France in September 2020. It aimed to reduce geographic disparities in lung allocation while maintaining proximity. In the previous two-tiered priority-based system, grafts not allocated through national high-urgency status were offered to transplant centres according to geographic criteria. Between 2013 and 2018, significant geographic disparities in transplant allocation were observed across transplant centres with a mean number of grafts offered per candidate ranging from 1.4 to 5.2. The new system redistricted the local allocation units according to supply/demand ratio, removed regional sharing and increased national sharing. The supply/demand ratio was defined as the ratio of lungs recovered within the local allocation unit to transplants performed in the centre. A driving time between the procurement and transplant centres of less than 2 h was retained for proximity. Using a brute-force algorithm, we designed new local allocation units that gave a supply/demand ratio of 0.5 for all the transplant centres. Under the new system, standard-deviation of graft offers per candidate decreased from 0.9 to 0.5 (p = 0.08) whereas the mean distance from procurement to transplant centre did not change. These preliminary results show that a supply/demand ratio-based allocation system can achieve equity while maintaining proximity.

Consequences of Changes in the Liver Allocation System for Transplantation in the Silesian Voivodeship and in the Transplantation Center in Katowice

For a number of years, the system of procured livers for transplantation by transplant centers in a fixed order, regardless of the location of the procurement site, was in force in Poland. In mid-2018, priority was introduced in the collection of livers by a team from a given province. The aim of the study was to evaluate the impact of changing the liver transplantation allocation system at the Katowice Transplant Center (KTW) on the number of transplanted livers and on the selected parameters of donors from which the liver was procured. The rates and cold ischemia time (CIT) of procured livers were analyzed. The rate of livers procured by the KTW transplant team increased from 36.6% to 53.3%, and at the same time the rate of livers procured by this team and sent for transplantation in other transplant centers increased. The rate of livers transplanted in the KTW, which were procured in the Silesian Voivodeship, increased from 37.4% to 61.0%, and the rate of livers procured outside the Silesian Voivodeship decreased from 54.8% to 36.4%. The CIT of livers transplanted in the KTW was reduced from 407.5 to 360.0 minutes. The comparative analysis of donor parameters of livers procured by the KTW transplant team and transplanted in Katowice revealed no differences regarding analyzed clinical and biochemical parameters. The change in the allocation system increased the number of livers procured by the local team and shortened CIT of livers transplanted at the KTW.

The effect of recipient BMI on waitlist and post-transplant outcomes after the 2018 heart transplant allocation policy change.

ObjectiveThe effects of recipient body mass index (BMI) on waitlist strategies, waitlist outcomes, and post‐transplant outcomes among adult patients listed for heart transplantation under the updated 2018 allocation system have not been well characterized.MethodsThe United Network of Organ Sharing data set between October 2015 and March 2021 was analyzed, and patients were grouped based on recipient BMI and whether listing occurred in the old (pre‐October 2018) or new allocation system.ResultsListing strategies differed by BMI group, but trends of increased use of temporary mechanical support and decreased use of durable support remained among all BMI groups, except those with BMI > 35 kg/m2. Waitlist outcomes improved among all BMI cohorts in the new allocation system, including among patients with BMI 30–34.9 and >35 kg/m2, although patients with higher BMIs continued to have longer waitlist times. Post‐transplant outcomes in the new allocation system are worse for patients with BMI > 30 kg/m2 (hazard ratio: 1.47; confidence interval: 1.19–1.82; p < .001).ConclusionsThe 2018 change to the heart transplant allocation system was associated with similar changes in the use of mechanical support for listing strategy across BMI ranges, except in the most obese, and improved waitlist outcomes across all BMI ranges. Post‐transplant outcomes in the new allocation system are worse for patients with BMI > 30 kg/m2 compared to patients with BMI < 30 kg/m2. These findings have important clinical implications for our understanding of the ongoing influence of BMI on waitlist courses and post‐transplant outcomes among patients listed for heart transplantation

A Comparison of the LVAD Population 1-Year Clinical Outcomes Before and After the Transplant Allocation System Change

<h3>Purpose</h3> In October 2018, the transplant allocation system deprioritized left ventricular assist devices (LVAD) as an indication for heart transplant. After the allocation system change, the majority of LVADs are implanted as destination therapy. As a greater proportion of LVAD patients are implanted as destination therapy, we hypothesized that the overall population of patients implanted after the allocation system change will experience less favorable 12-month outcomes and decreased rates of progression to transplant as compared to those implanted prior. <h3>Methods</h3> The data cohort includes patients implanted with LVADs at an academic high volume transplant center since 2005. The overall cohort was divided into two groups- those implanted prior to the allocation system change and those implanted after. Baseline characteristics and one-year outcomes were compared; survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. <h3>Results</h3> 50 patients were implanted with a LVAD between November 1^st, 2018 and July 1^st, 2020, and 181 patients received an implant between 2005 and before November 1^st, 2018. After the allocation system change, 86% of patients received a LVAD as destination therapy, compared to 45.4% implanted prior to allocation system change (p<0.0001). Patients who were implanted prior to the allocation system change had a lower pre-implant INTERMACS status than those implanted after the change (p=0.0001), and had a higher rate of device malfunction and pump thrombosis (p=0.02). The log-rank test comparing the survival curves for the combined outcome of death and rehospitalization did not demonstrate a significant difference (p=0.63). We did not find a significant difference in time from implant to transplantation nor in the rate of transplantation. <h3>Conclusion</h3> While there were important differences in baseline characteristics and outcomes, patients implanted with a LVAD after the allocation system change did not clearly have poorer pre-implant health, 1 year outcomes, or lower rates of transplantation at 1 year than patients implanted after. Furthermore, the practice patterns of transplanting patients with a LVAD did not change significantly at this academic high volume transplant center.

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

<h3>Purpose</h3> 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. <h3>Methods</h3> 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. <h3>Results</h3> 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). <h3>Conclusion</h3> 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.

Clinical Impact of the Lung Allocation Policy: A Nationwide Study

<h3>Purpose</h3> In the Italian lung transplant (LTX) allocation system, patients receive national priority (NP) only if on ECMO or mechanical ventilation (MV). We hypothesized that LAS could contribute to identify patients with increased waitlist mortality and who could benefit from NP. <h3>Methods</h3> We retrospectively reviewed the outcome and calculated the entry list LAS of patients who were listed for LTX in Italy between 2015 and 2021 either with or without NP. Probability of LTX was estimated using a competitive risk survival analysis. Postoperative 1-yr and 3-yr outcome was calculated with the Kaplan-Meier model. <h3>Results</h3> 1031 patients listed for LTX in the study period (85.3%) had complete data for analysis. 119 (11.5%) were listed with NP and 912 without. Mean LAS was 38.6 in the standard listing group and 50.1 in the NP group (p=0.0001). After stratifying for the value of LAS at the time of listing, more patients (43%) were listed with NP in the 4^thquartile (LAS>50) group. The probability of LTX was lower in patients in the LAS>50 quartile who were not placed on NP. The same group had the highest risk of death on the list (20.73%, p<0.001 compared to all other groups). Post-transplant outcomes were available for 481 patients out of 548 who received LTX in the study period (92.5%). 66 patients (13.7%) were transplanted after being on NP. 1-yr KM survival was less favorable in NP patients compared to non-NP patients, although not reaching statistical significance (p=0.08). In the >50 LAS quartile, 36.7% of patients were transplanted on the NP list, and had a worse KM survival compared to other quartiles (p=0.02). <h3>Conclusion</h3> In a non-LAS allocation context, retrospective analysis shows that high-LAS patients (>50) who do not receive NP allocation display high mortality on the waiting list. NP patients (ECMO/MV) have the worse postoperative outcomes. High LAS (>50) may earlier identify patients who are at higher risk of pre-transplant mortality and need NP, preventing the high postoperative mortality of LTX after ECMO/MV.

Isolated Durable LVAD Bridge to Transplant: Institutional Review Following 2018 Allocation Changes

<h3>Purpose</h3> The purpose of this study was to compare our institutional experience using durable left ventricular assist devices (dLVADs) as a bridge to transplant before and after the 2018 heart allocation policy change. <h3>Methods</h3> Since the allocation change, 29 patients have been bridged to heart transplantation with an isolated dLVAD at our institution. We matched these patients with the most recent 29 consecutive patients bridged to heart transplantation with isolated dLVAD. Baseline pretransplant characteristics and comorbidities were compared between cohorts. Incidence of posttransplant complications, intensive care unit and hospital lengths of stay were compared, as well as 90-day mortality. <h3>Results</h3> Annual number of recipients bridged to transplant using a dLVAD declined after the first year following the allocation policy change (Figure A). Median age, body mass index, and distributions of primary heart failure etiology and dLVAD usage were similar between cohorts. The new policy cohort had a higher incidence of female recipients (21% vs 3%; P=0.044), but a lower incidence of patients maintained on intravenous inotropic therapy at time of transplant (3% vs 21%; P=0.044). Rates of prolonged mechanical ventilation, re-intubation, stroke and renal failure were comparable between cohorts. Intensive care unit length of stay and hospital length of stay were also similar. At 90 days, the new policy cohort experienced higher mortality (21% vs 3%; P=0.044) (Figure B). <h3>Conclusion</h3> From our institutional experience, there appears to be continual decline in patients bridged with dLVAD following the allocation policy change. While rates of many postoperative complications appear comparable to the prior era, short-term mortality appears to be higher. Changes in the heart transplant allocation system have resulted in changes in donor availability and selection for recipients with durable LVADs. These changes, along with the impact of the COVID-19 pandemic, may be responsible for these observations.

Outcomes Of IABP Vs Impella As A Bridge To Cardiac Transplantation - Analysis Of National United Network For Organ Sharing Database

<h3>Introduction</h3> Temporary mechanical circulatory support technology has advanced vastly in the last decade. United Network for Organ Sharing (UNOS) heart transplant allocation system was updated in 2018 to accommodate the new Era. Among patients requiring temporary mechanical circulatory support as a bridge to transplantation, device choice relies on patient, practitioner, and institutional factors. To date, there is limited outcome data to contrast the different mechanical circulatory support platforms. <h3>Objective</h3> We aim to compare heart transplant survival in those bridged with intra-aortic balloon pump (IABP) vs Impella mechanical support. <h3>Methods</h3> Using the national UNOS database, we studied heart transplantation recipients listed on the new UNOS allocation system (oct 18^th 2018) and then compared survival of those bridged with IABP vs Impella to transplantation as status 2. The last date of follow up was Sep 4^th 2020. Cohort demographics, serum biochemistry, hemodynamic measurements, and organ support interventions were collected. Wilcoxon-Mann-Whitney test was used for continuous variables, Chi-square test for categorical variables, and Log-rank test for survival analysis. <h3>Results</h3> A total of 1721 patients (1524 IABP, 197 Impella) met our criteria, in whom, there was no difference between IABP vs Impella groups in age, BMI, or waiting list time (Table 1). We found that Impella was used more often in males (74% vs 88%, p <0.01) and Hispanics (9% vs 15% p <0.01). Clinical data are summarized in Table 1. Impella was associated with more mechanical ventilation (4 vs 16%, p <0.01), dialysis (3 vs 10%, p <0.01), and vasoactive medication support (79 vs 89%). Plasma free hemoglobin > 50 mg/dL was noted in 13.3% of the Impella group. Median survival (figure 1) was similar between IABP vs Impella (181 vs 183 days, p=0.92). <h3>Conclusion</h3> There was no observed difference in waiting time nor post-transplant survival between IABP vs Impella groups, however, the latter group was in more critical condition, and from that perspective, Impella seems to be an effective platform to bridge higher acuity status 2 patients.

The heart transplant allocation change attenuates but does not eliminate blood group O waitlist outcome disadvantage.

BackgroundPatients with blood group O have historically been disadvantaged in the United Network for Organ Sharing (UNOS) heart transplant allocation system. We sought to determine whether the new UNOS allocation system implemented in 2018 had an impact on waitlist and post‐transplant outcomes among blood groups.MethodsUsing the UNOS database we included all adult patients listed and transplanted with first‐time single‐organ heart transplant between 10/17/15 and 10/1/21. For post‐transplant outcomes, we separately evaluated all adult patients transplanted with the same time‐frame. We used exclusion criteria and censoring to limit biases from changing clinical practices around the allocation change (10/18/2018), and from unequal or inadequate follow‐up. We compared clinical characteristics and outcomes before and after the allocation change among each blood group. Fine‐Gray and Cox regression models were used to estimate the effect of the new allocation system on competing waitlist outcomes‐ transplantation, death‐or‐removal from waitlist‐ and post‐transplant survival, respectively.ResultsOf the 21,565 patients listed for transplantation 14,000 met criteria for waitlist analysis (7,035 in the old system vs. 6,965 in the new), and 7,657 met criteria for post‐transplant analysis (3,519 in the old system vs. 4,138 in the new). Among each blood group, new allocation change was associated with higher transplantation rates lower waitlist days and lower waitlist mortality (except Group AB). However, despite improvements, Group O was still associated with worse waitlist outcomes for each metric compared to non‐O Groups. The new allocation system did not have a significant impact on post‐transplant survival among any blood groups.ConclusionChanges in heart transplant allocation have attenuated but not eliminated blood group O disadvantage in access to donor hearts.

Interaction between ischemic time and donor age under the new donor heart allocation system: Effect on post-transplant survival.

Ischemic time (IT) under the new heart transplant (HTx) allocation system has increased compared to the old system. We investigated the effect of IT and donor age on post-HTx survival. The United Network for Organ Sharing (UNOS) database was analyzed to identify adult HTx between October 2015 and August 2020. Recipients were stratified by donor age, transplantation era, and IT. Kaplan-Meier and log-rank tests were used to compare 180-day post-HTx mortality. Cox proportional hazards modeling and propensity score matching were performed to adjust for confounders. Under the new system (N=3654), IT≥4h led to decreased survival compared to IT<4h (91.4%vs. 93.7%; P=.02), although this decrease was undetectable among those with donors ≥39years old (90.4%vs. 91.1%; P=.73). IT≥4h led to decreased survival with donors<39years old (91.7%vs. 94.6%; P<.01). Under the old system (N=5987), IT≥4h resulted in decreased survival (89.8%vs. 93.9%; P<.01), including with donors ≥39years old (86.9%vs. 92.4%; P<.01). IT≥4h remains a risk for post-HTx mortality under the new system. However, the magnitude of this effect is blunted when donor age is ≥39years, likely secondary to increased allocation of these organs to lower status, more stable recipients.

Exploring Physician Perceptions of the 2018 United States Heart Transplant Allocation System

BackgroundAfter the implementation of the 2018 US heart transplant allocation system, the experience and perceptions of heart transplant clinicians have not been well-cataloged. Methods and ResultsThis web-based survey of both heart failure cardiologists and surgeons examined physician perspectives about the policy changes and whether the system is meeting its intended goals. The majority of participants (94%, n = 113) responded that the 2018 heart allocation system requires modification. Eighty-four percent reported using more temporary mechanical circulatory support to achieve higher status and 86% were concerned about the change in physician behavior and practices under the new system. ConclusionsSuggestions for possible improvement included higher status for patients on durable left ventricular assist device support, changes to criteria for status 2, modification of status exceptions, and advocacy for a heart allocation score.

Decreased frequency of transplantation and lower post-transplant survival free of re-transplantation in LVAD patients with the new heart transplant allocation system.

To evaluate the effect of the new heart transplant (HT) allocation system in left ventricular assist device (LVAD) supported patients listed as bridge to transplantation (BTT). Adult patients who were listed for HT between October 18, 2016 and October 17, 2019, and were supported with an LVAD, enrolled in the UNOS database were included in this study. Patients were classified in the old or new system if they were listed or transplanted before or after October 18, 2018, respectively. A total of 3261 LVAD patients were listed for transplant. Of these, 2257 were classified in the old and 1004 in the new system. The cumulative incidence of death or removal from the transplant list due to worsening clinical status at 360-days after listing was lower in the new system (4%vs. 7%, P=.011). LVAD Patients listed in the new system had a lower frequency of transplantation within 360-days of listing (52%vs. 61%, P<.001). A total of 1843 LVAD patients were transplanted, 1004 patients in the old system and 839 patients in the new system. The post-transplant survival at 360 days was similar between old and new systems (92.3%vs. 90%, P=.08). However, LVAD patients transplanted in the new system had lower frequency of the combined endpoint, freedom of death or re-transplantation at 360 days (92.2%vs. 89.6%, P=.046). The new HT allocation system has affected the LVAD-BTT population significantly. On the waitlist, LVAD patients have a decreased cumulative frequency of transplantation and a concomitant decrease in death or delisting due to worsening status. In the new system, LVAD patients have a decreased survival free of re-transplantation at 360 days post-transplant.

Changes in waitlist and posttransplant outcomes in patients with adult congenital heart disease after the new heart transplant allocation system.

In 2018, the United Network for Organ Sharing (UNOS) introduced new criteria for heart allocation. This study sought to assess the impact of this change on waitlist and posttransplant outcomes in adult congenital heart disease (ACHD) recipients. Between January 2010 and March 2020, we extracted first heart transplant ACHD patients listed from the UNOS database. We compared waitlist and post-transplant outcomes before and after the policy change. A total of 1206 patients were listed, 951 under the old policy and 255 under the new policy. Prior to transplant, recipients under the new policy era were more likely to be treated with extracorporeal membrane oxygenation (P=.018), and have intra-aortic balloon pumps (P<.001), and less likely to have left ventricular assist devices (P=.027).Compared to patients waitlisted in the pre-policy change era, those waitlisted in the post policy change era were more likely to receive transplants (P=.001) with no significant difference in waiting list mortality (P=.267) or delisting (P=.915). There was no difference in 1-year survival post-transplant between the groups (P=.791). The new policy altered the heart transplant cohort in the ACHD group, allowing them to receive transplants earlier with no changes in early outcomes after heart transplantation.

O-13 Hepatocellular carcinoma patients are advantage in the Brazilian current liver transplant allocation system. A competing risk analysis. A RETROSPECTIVE STUDY

In Brazil, the Model for End-Stage Liver Disease (MELD) score is used to prioritize patients for deceased donor liver transplantation (DDLT). Patients with hepatocellular carcinoma (HCC) receive standardized MELD exception points to account for their cancer risk of mortality, which is not reflected by their MELD score. To compare DDLT rates between patients with and without HCC in Rio Grande do Sul, the Southernmost state of Brazil. We retrospectively studied 825 patients on the liver-transplant waiting list from January 1, 2007, to December 31, 2016, in a transplant center located in Porto Alegre, the capital of Rio Grande do Sul, to compare DDLT rates between those with and without HCC. The time-varying hazard of waiting list/DDLT was estimated, reporting the subhazard ratio (SHR) of waiting list/DDLT/dropout with 95% confidence intervals (CI). The final competing risk model was adjusted for age, MELD score, exception points, and ABO group. Patients with HCC underwent a transplant almost three times faster than patients with a calculated MELD score (SHR 2.64; 95% CI 2.10-3.31; P<0.001). The DDLT rate per 100 person-months was 11.86 for HCC patient's vs 3.38 for non-HCC patients. The median time on the waiting list was 5.6 months for patients with HCC and 25 months for patients without HCC. Our results demonstrated that, in our center, patients on the waiting list with HCC have a clear advantage over candidates listed with a calculated MELD score.

Mechanical ventilation at the time of heart transplantation and associations with clinical outcomes.

The impact of mechanical ventilation (MV) at the time of heart transplantation is not well understood. In addition, MV was recently removed as a criterion from the new US heart transplantation allocation system. We sought to assess for the association between MV at transplantation and 1-year mortality. We utilized the United Network for Organ Sharing database and included all adult, single organ heart transplantations from 1990 to 2019. We utilized multivariable logistic regression adjusting for demographics, comorbidities, and markers of clinical acuity. We identified 60 980 patients who underwent heart transplantation, 2.4% (n = 1431) of which required MV at transplantation. Ventilated patients were more likely to require temporary mechanical support, previous dialysis, and had a shorter median waitlist time (21 vs. 95 days, P < 0.001). At 1 year, the mortality was 33.7% (n = 484) for ventilated patients and 11.7% (n = 6967) for those not ventilated at the time of transplantation (log-rank P < 0.001). After multivariable adjustment, patients requiring MV continued to have a substantially higher 90-day [odds ratio (OR) 3.20, 95% confidence interval (CI): 2.79-3.66, P < 0.001] and 1-year mortality (OR 2.67, 95% CI: 2.36-3.03, P < 0.001). For those that survived to 90 days, the adjusted mortality at 1 year continued to be higher (OR 1.48, 95% CI: 1.16-1.89, P = 0.002). We found a strong association between the presence of MV at heart transplantation and 90-day and 1-year mortality. Future studies are needed to identify which patients requiring MV have reasonable outcomes, and which are associated with substantially poorer outcomes.

Racial Differences in In-Hospital Outcomes after the Use of Temporary Mechanical Circulatory Support as a Bridge to Heart Transplant

Purpose The use of temporary mechanical circulatory support (tMCS) as a bridge to heart transplant (HTx) (BTT) has increased over time, especially after implementation of the new adult heart allocation system. We sought to assess if racial differences existed in in-hospital outcomes among patients BTT with a tMCS. Methods The National Inpatient Sample was queried for all patients who were BTT with a tMCS [intra-aortic balloon pumps (IABP), percutaneous left-ventricular assist device (PVAD), or extracorporeal membrane oxygenation (ECMO)] between 2008 and 2017. Patients were stratified by race and evaluated for in-hospital, death, MACE, discharge disposition, and costs. Multivariable logistic regression was used to identify predictors of in-hospital mortality for each of the tMCS devices. Results Out of 5,063 HTx, 17.8% (901) who were bridged with a tMCS (IABP 577, ECMO 366, PVAD 80). The incidence of MACE (9.7% White vs. 8.6% Black vs. 9.0% Hispanic vs. 7.6% Others; p value 0.520), non-home discharge (17.5% White vs. 17.1% Black vs. 12.6% Hispanic vs. 15.5% Others; p value 0.056) and procedural costs [White $354,406.72 vs. Black $329,752.47 vs. Hispanic $482,146.45 vs. Others $384,841.00; p value p Conclusion Among patients BTT with a tMCS, there was no racial difference in in-hospital complications or death, irrespective of the type of tMCS used. With the recent change in the transplant allocation system, the use of tMCS as a BTT has increased, and the results herein highlight that in-patient outcomes prior to the allocation system change are similar among racial groups and may ensure equitable access to transplantation in the new system.

Changes in Wait List Mortality, Transplantation Rates and Early Post-Transplant Outcomes in LVAD BTT with New Heart Transplant Allocation Score. A UNOS Database Analysis

PurposeTo evaluate the effect of the new heart transplant allocation system on LVAD supported patients listed as bridge to transplantation (BTT).MethodsAdult patients, who were listed for heart transplant between October 1,2016 and September 30, 2019, and were supported with an LVAD, enrolled in the UNOS database were enrolled in this study. Patients were classified according in the old or new system if they were listed or transplanted before or after October 18, 2018.ResultsA total of 2184 LVAD patients were listed for transplant. Of these, 1229 were classified in the old and 955 in the new system. The cumulative incidence of death or removal from the transplant list due to worsening clinical status, 1 year after listing, was lower in the new system (5% vs. 9%, p<0.001). Patients listed in the new system had a lower frequency of transplantation within 1 year of listing (52% vs. 60%, p=0.004) (Figure 1). A total of 1086 and 853 patients were transplanted in the old and new systems, respectively. Patients who were transplanted in the new system were more likely to receive a Hep C (+) donor heart and had a longer ischemic time. The 6 months post-transplant survival was 93.2% and 91.5% for the old and new systems, respectively (p=0.18).ConclusionWith the implementation of the new HT allocation system, LVAD-BTT patients have a lower frequency of transplantation and similar short-term post-transplant survival. LVAD-BTT patients are more likely to receive Hep C (+) donor hearts. To evaluate the effect of the new heart transplant allocation system on LVAD supported patients listed as bridge to transplantation (BTT). Adult patients, who were listed for heart transplant between October 1,2016 and September 30, 2019, and were supported with an LVAD, enrolled in the UNOS database were enrolled in this study. Patients were classified according in the old or new system if they were listed or transplanted before or after October 18, 2018. A total of 2184 LVAD patients were listed for transplant. Of these, 1229 were classified in the old and 955 in the new system. The cumulative incidence of death or removal from the transplant list due to worsening clinical status, 1 year after listing, was lower in the new system (5% vs. 9%, p<0.001). Patients listed in the new system had a lower frequency of transplantation within 1 year of listing (52% vs. 60%, p=0.004) (Figure 1). A total of 1086 and 853 patients were transplanted in the old and new systems, respectively. Patients who were transplanted in the new system were more likely to receive a Hep C (+) donor heart and had a longer ischemic time. The 6 months post-transplant survival was 93.2% and 91.5% for the old and new systems, respectively (p=0.18). With the implementation of the new HT allocation system, LVAD-BTT patients have a lower frequency of transplantation and similar short-term post-transplant survival. LVAD-BTT patients are more likely to receive Hep C (+) donor hearts.

Contemporary Outcomes for Cardiogenic Shock Patients Bridged to Advanced Heart Therapies with Temporary Mechanical Circulatory Support

<h3>Purpose</h3> The use of temporary mechanical circulatory support (tMCS) as a bridge to advanced heart replacement therapies (HRT) has increased in the context of the new heart transplant allocation system. As such, it is important to assess contemporary outcomes for this patient population. The purpose of this study was to assess outcomes of cardiogenic shock patients that were bridged with tMCS to HRT since the allocation system changes. <h3>Methods</h3> All adult cardiogenic shock patients that were bridged with tMCS to either heart transplantation (OHT) or durable left ventricular assist device (LVAD) at our center between October 2018 and September 2020 were identified. The tMCS devices included extracorporeal membrane oxygenation (ECMO), Impella, or temporary surgical VAD. Early and late clinical outcomes were assessed. <h3>Results</h3> A total of 33 cardiogenic shock patients were bridged to HRT using tMCS devices (OHT = 12, LVAD = 21). Most patients were male (84.9%) and the median age for all patients was 53 years. In terms of initial tMCS therapy, ECMO was used most commonly (64%) followed by Impella (24%) and temporary surgical VAD (12%). Ten patients (30%) required a second bridge-to-bridge device prior to HRT. Median duration of tMCS support for OHT and LVAD patients were 15.5 days (IQR 6.25-25) and 8 days (IQR 5-18.5), respectively. There were no in-hospital or 30-day mortality events. There was one late death in the VAD group at 16 months. Kaplan-meier curve (Figure 1) shows overall survival with median follow up of 8 months. <h3>Conclusion</h3> Cardiogenic shock patients can be bridged to HRT using contemporary tMCS technology and management with excellent early- and mid-term outcomes.

Improved Access to Heart Re-Transplantation with the New Heart Transplant Allocation System

<h3>Purpose</h3> To evaluate the effect of the new heart transplant allocation system on patients listed for re-transplantation. <h3>Methods</h3> Adult patients, who were listed for heart re-transplant between Jan 1, 2017 and September 30, 2019, enrolled in the UNOS database were included in this study. Patients were classified in the old or new system if they were listed or re-transplanted before or after October 18, 2018, respectively. <h3>Results</h3> A total of 214 patients were listed for re-transplant in the study period. Of these, 127 and 87 patients were classified in the <i>old</i> and <i>new</i> systems, respectively. Patients listed in the new system had a higher frequency of transplantation within 1 year of listing (HR: 1.63 (1.23-2.17), p=0.001) (Figure 1A). Patient listed for re-transplant in the new system had a higher frequency of ECMO (16.1% vs. 6.8%, p=0.037) and IABP (20.7% vs. 4.7%, p=0.001) support. A total of 72 and 93 patients were re-transplanted in the old and new systems, respectively. Clinical characteristics did not differ between re-transplanted patients in old vs. new systems. The 1-year post-transplant survival was 91.5% and 86.4% for the old and new systems, respectively (Figure 1B, p=0.35). <h3>Conclusion</h3> With the implementation of the new HT allocation system, Patients listed for re-transplantation have an increased access to a second heart transplant with similar 1-year post-re-transplant survival.

Impact of the New UNOS Heart Transplant Allocation System on Waitlist and Early Post-Transplant Mortality among Adults with Congenital Heart Disease

<h3>Purpose</h3> Adults with congenital heart disease (ACHD) are more likely to die or be delisted while awaiting heart transplant, less likely to receive a heart transplant and more likely to die in the early (30-day) post-transplant period compared to non-ACHD patients. On October 18, 2018; the UNOS heart allocation system was redesigned providing unique listing status for ACHD patients. The impact of this change on outcomes is unstudied. <h3>Methods</h3> Using the Scientific Registry of Transplant Recipients we compared ACHD patients listed for the first-time for heart transplant from 2 eras of equal duration (new era: October 18, 2018 to June 2, 2020 and prior era: March 3, 2017 to October 17, 2020). Patients with transplants occurring in the new era who were initially listed in the prior era were excluded. We compared baseline characteristics, Kaplan Meier curves and log-rank tests to assess differences in early post-transplant mortality and the composite of waitlist mortality or delisting due to clinical worsening among those with CHD between both eras. <h3>Results</h3> Out of 535 ACHD patients listed, 293 were in the new era (4.7% of total listings) and 242 were in the prior era (3.7%). Age, sex, racial distribution, renal function, hemodynamics and need for ECMO were identical between the two groups. 163 (56%) ACHD patients in the new era versus 150 (62%) in the prior era were transplanted; 11 (3.8%) versus 15 (6.2%) died on the waitlist; 32 (11%) versus 35 (14%) were delisted and 15 (9.2%) versus 19 (12.7%) died within 30 days of transplant respectively. In the new era, ACHD patients were significantly less likely to experience waitlist mortality or delisting due to clinical worsening but had similar early post-transplant mortality compared to the prior era. <h3>Conclusion</h3> The new UNOS heart transplant allocation system improved waitlist outcomes among ACHD patients listed for heart transplant.