Waiting List Deaths Research Articles

Targeted Broader Sharing for Liver Continuous Distribution.

In recent years, changes to US organ allocation have aimed to improve equity and accessibility across regions. The Organ Procurement and Transplantation Network plans to adopt continuous liver distribution, prioritizing candidates based on a weighted composite allocation score (CAS) incorporating proximity, ABO types, medical urgency, and pediatric priority. The Liver Committee has requested research on CAS variations that account for geographical heterogenicity. We describe a method for designing a geographically heterogeneous CAS with targeted broader sharing (CAS-TBS) to balance the highly variable geographic distributions of liver transplant listings and liver donations. CAS-TBS assigns each donor hospital to either broader sharing or nearby sharing, adjusting donor-candidate distance allocation points accordingly. We found that to reduce geographic disparity in the median Model for End-stage Liver Disease at transplant (MMaT), >75% of livers recovered in regions 2 and 10 should be distributed with broader sharing, whereas 95% of livers recovered in regions 5 and 1 should be distributed with nearby sharing. In a 3-y simulation of liver allocation, CAS-TBS decreased MMaT by 2.1 points in high-MMaT areas such as region 5 while increasing MMaT only by 0.65 points in low-MMaT areas such as region 3. CAS-TBS significantly decreased median transport distance from 202 to 167 nautical miles under acuity circles and decreased waitlist deaths. Our CAS-TBS design methodology could be applied to design geographically heterogeneous allocation scores that reflect transplant community values and priorities within the continuous distribution project of the Organ Procurement and Transplantation Network. In our simulations, the incremental benefit of CAS-TBS over CAS was modest.

Majority Rules? Assessing Access to Kidney Transplantation in a Predominantly Hispanic Population.

Despite being the national's largest ethnic minority, Hispanic Americans have inferior kidney transplant opportunities. San Antonio, Texas is the largest US city with a majority Hispanic population. We assessed the impact of this unique ethnic milieu on waitlisting and transplant practices among Hispanic patients. We studied patients >18 years old listed at our center for a kidney-only transplant between 2003-2022. Timing of waitlisting, transplant rates and waitlist outcomes were compared between Hispanic and non-Hispanic White patients. We evaluated 11,895 patients, of whom 67% (n = 8,008) were Hispanic, and 20% (n = 2,341) were White. Preemptive listing was less frequent in Hispanic patients (18% vs 37%). One-third of listed Hispanic patients (37%) and half of White patients (50%) were transplanted, with living-donor kidney transplant performed in 59% (n = 1,755) and 77% (n = 898), respectively. Adjusting for age, sex, blood type, preemptive listing, immunologic sensitization, education, employment, and listing era, Hispanic patients remained less likely to receive a deceased-donor transplant (HR 0.82, 95% CI 0.71 - 0.95). On covariate adjustment, White patients were more likely to experience waitlist death or deterioration (HR 1.23, 95% CI 1.12 - 1.36). Although waitlist attrition was more favorable among Hispanic patients, waitlist registration was delayed and kidney transplants less frequent compared to White patients. These data demonstrate that majority status alone does not mitigate ethnic disparities in kidney transplantation, while underlining the critical need for ongoing efforts to address physician and patient attitudes relating to suitability of Hispanic patients for transplantation.

The impact of surging transplantation of alcohol-associated liver disease on transplantation for HCC and other indications.

Liver transplantation (LT) for alcohol-associated liver disease (ALD) is increasing and may impact LT outcomes for patients listed for HCC and other indications. Using US adults listed for primary LT (grouped as ALD, HCC, and other) from October 8, 2015, to December 31, 2021, we examined the impact of center-level ALD LT volume (ATxV) on waitlist outcomes in 2 eras: Era 1 (6-month wait for HCC) and Era 2 (MMaT-3). The tertile distribution of ATxV (low to high) was derived from the listed candidates as Tertile 1 (T1): <28.4%, Tertile 2 (T2): 28.4%-37.6%, and Tertile 3 (T3): >37.6% ALD LTs per year. Cumulative incidence of waitlist death and LT within 18 months from listing by LT indication were compared using the Gray test, stratified on eras and ATxV tertiles. Multivariable competing risk regression estimated the adjusted subhazard ratios (sHRs) for the risk of waitlist mortality and LT with interaction effects of ATxV by LT indication (interaction p). Of 56,596 candidates listed, the cumulative waitlist mortality for those with HCC and other was higher and their LT probability was lower in high (T3) ATxV centers, compared to low (T1) ATxV centers in Era 2. However, compared to ALD (sHR: 0.92 [0.66-1.26]), the adjusted waitlist mortality for HCC (sHR: 1.15 [0.96-1.38], interaction p = 0.22) and other (sHR: 1.13 [0.87-1.46], interaction p = 0.16) were no different suggesting no differential impact of ATxV on the waitlist mortality. The adjusted LT probability for HCC (sHR: 0.89 [0.72-1.11], interaction p = 0.08) did not differ by AtxV while it was lower for other (sHR: 0.82 [0.67-1.01], interaction p = 0.02) compared to ALD (sHR: 1.04 [0.80-1.34]) suggesting a differential impact of ATxV on LT probability. The high volume of LT for ALD does not impact waitlist mortality for HCC and others but affects LT probability for other in the MMAT-3 era warranting continued monitoring.

Neighborhood-level Social Determinants of Health and Waitlist Mortality for Liver Transplantation: The Liver Outcomes and Equity Index.

To examine neighborhood-level disparities in waitlist mortality for adult liver transplantation (LT), we developed novel area-based social determinants of health (SDOH) index using a national transplant database. ZIP Codes of individuals listed for or received LT in the Scientific Registry of Transplant Recipients database between June 18, 2013, and May 18, 2019, were linked to 36 American Community Survey (ACS) variables across 5 SDOH domains for index development. A step-wise principal component analysis was used to construct the Liver Outcomes and Equity (LOEq) index. We then examined the association between LOEq quintiles (Q1 = worst and Q5 = best neighborhood SDOH) and waitlist mortality with competing risk regression among listed adults in the study period and acuity circle (AC) era. The final LOEq index consisted of 13 ACS variables. Of 59 298 adults waitlisted for LT, 30% resided in LOEq Q5 compared with only 14% in Q1. Q1 neighborhoods with worse SDOH were disproportionately concentrated in transplant regions with low median Model for End-Stage Liver Disease at transplant (MMAT) and shorter wait times. Five years cumulative incidence of waitlist mortality was 33% in Q1 in high MMAT regions versus 16% in Q5 in low MMAT regions. Despite this allocation advantage, LOEq Q1-Q4 were independently associated with elevated risk of waitlist mortality compared with Q5, with highest increased hazard of waitlist deaths of 19% (95% CI, 11%-26%) in Q1. This disparity persisted in the AC era, with 24% (95% CI, 10%-40%) increased hazard of waitlist deaths for Q1 versus Q5. Neighborhood SDOH independently predicts waitlist mortality in adult LT.

A modular simulation framework for organ allocation

BackgroundWe describe and validate a new simulation framework addressing important limitations of the Simulated Allocation Models (SAMs) long used to project population effects of transplant policy changes. MethodsWe developed the Computational Open-source Model for Evaluating Transplantation (COMET), an agent-based model simulating interactions of individual donors and candidates over time to project population outcomes. COMET functionality is organized into interacting modules. Donors and candidates are synthetically generated using data-driven probability models which are adaptable to account for ongoing or hypothetical donor/candidate population trends and evolving disease management. To validate the first implementation of COMET, COMET-Lung, we attempted to reproduce lung transplant outcomes for U.S. adults from 2018-2019 and in the six months following adoption of the Composite Allocation Score (CAS) for lung transplant. ResultsSimulated (median [Interquartile Range, IQR]) versus observed outcomes for 2018-2019 were: 0.162 [0.157, 0.167] versus 0.170 waitlist deaths per waitlist year; 1.25 [1.23, 1.28] versus 1.26 transplants per waitlist year; 0.115 [0.112, 0.118] versus 0.113 post-transplant deaths per patient year; 202 [102, 377] versus 165 nautical miles travel distance. The model accurately predicted the observed precipitous decrease in transplants received by type O lung candidates in the six months following CAS implementation. ConclusionsCOMET-Lung closely reproduced most observed outcomes. The use of synthetic populations in the COMET framework paves the way for examining possible transplant policy and clinical practice changes in populations reflecting realistic future states. Its flexible, modular nature can accelerate development of features to address specific research or policy questions across multiple organs.

Assessing LSAM's ability to account for changes in organ donation and transplant center behavior.

The Liver Simulated Allocation Model (LSAM) is used to evaluate proposed organ allocation policies. Although LSAM has been shown to predict the directionality of changes in transplants and nonused organs, the magnitude is often overestimated. One reason is that policymakers and researchers using LSAM assume static levels of organ donation and center behavior because of challenges with predicting future behavior. We sought to assess the ability of LSAM to account for changes in organ donation and organ acceptance behavior using LSAM 2019. We ran 1-year simulations with the default model and then ran simulations changing donor arrival rates (ie, organ donation) and center acceptance behavior. Changing the donor arrival rate was associated with a progressive simulated increase in transplants, with corresponding simulated decreases in waitlist deaths. Changing parameters related to organ acceptance was associated with important changes in transplants, nonused organs, and waitlist deaths in the expected direction in data simulations, although to a much lesser degree than changing the donor arrival rate. Increasing the donor arrival rate was associated with a marked decrease in the travel distance of donor livers in simulations. In conclusion, we demonstrate that LSAM can account for changes in organ donation and organ acceptance in a manner aligned with historical precedent that can inform future policy analyses. As Scientific Registry of Transplant Recipients develops new simulation programs, the importance of considering changes in donation and center practice is critical to accurately estimate the impact of new allocation policies.

Outcomes of listing for lung and heart-lung transplantation in pulmonary hypertension: comparative experience in France and the UK.

Lung or heart-lung transplantation (LT/HLT) for severe pulmonary hypertension (PH) as the primary disease indication carries a high risk of waiting list mortality and post-transplant complications. France and the UK both have coordinated PH patient services but with different referral pathways for accessing LT services. We conducted a comparative analysis of adult PH patients listed for LT/HLT in the UK and France. We included 211 PH patients in France (2006-2018) and 170 in the UK (2010-2019). Cumulative incidence of transplant, delisting and waiting list death within 3 years were 81%, 4% and 11% in France versus 58%, 10% and 15% in the UK (p<0.001 for transplant and delisting; p=0.1 for death). Median non-priority waiting time was 45 days in France versus 165 days in the UK (p<0.001). High-priority listing occurred in 54% and 51% of transplanted patients respectively in France and the UK (p=0.8). Factors associated with achieving transplantation related to recipients' height, male sex, clinical severity and priority listing status. 1-year post-transplant survival was 78% in France and 72% in the UK (p= 0.04). Access to transplantation for PH patients is better in France than in the UK where more patients were delisted due to clinical deterioration because of longer waiting time. High rates of priority listing occurred in both countries. Survival for those achieving transplantation was slightly better in France. Ensuring optimal outcomes after transplant listing for PH patients is challenging and may involve early listing of higher risk patients, increasing donor lung utilisation and improving allocation rules for these specific patients.

Diuretic dose is a strong prognostic factor in ambulatory patients awaiting heart transplantation.

The prognostic value of 'high dose' loop diuretics in advanced heart failure outpatients is unclear. We aimed to assess the prognosis associated with loop diuretic dose in ambulatory patients awaiting heart transplantation (HT). All ambulatory patients (n=700, median age 55years and 70% men) registered on the French national HT waiting list between 1 January 2013 and 31 December 2019 were included. Patients were divided into 'low dose', 'intermediate dose', and 'high dose' loop diuretics corresponding to furosemide equivalent doses of ≤40, 40-250, and >250mg, respectively. The primary outcome was a combined criterion of waitlist death and urgent HT. N-terminal pro-B-type natriuretic peptide, creatinine levels, pulmonary capillary wedge pressure, and pulmonary pressures gradually increased with higher diuretic dose. At 12months, the risk of waitlist death/urgent HT was 7.4%, 19.2%, and 25.6% (P=0.001) for 'low dose', 'intermediate dose', and 'high dose' patients, respectively. When adjusting for confounders, including natriuretic peptides, hepatic, and renal function, the 'high dose' group was associated with increased waitlist mortality or urgent HT [adjusted hazard ratio (HR) 2.23, 1.33 to 3.73; P=0.002] and a six-fold higher risk of waitlist death (adjusted HR 6.18, 2.16 to 17.72; P<0.001) when compared with the 'low dose' group. 'Intermediate doses' were not significantly associated with these two outcomes in adjusted models (P>0.05). A 'high dose' of loop diuretics is strongly associated with residual congestion and is a predictor of outcome in patients awaiting HT despite adjustment for classical cardiorenal risk factors. This routine variable may be helpful for risk stratification of pre-HT patients.

Impella 5.5 as a bridge to heart transplantation: Waitlist outcomes in the United States.

The 2018 United Network for Organ Sharing allocation policy change has led to a significant increase in the use of mechanical circulatory support devices in patients listed for orthotopic heart transplantation. However, there has been a paucity of data regarding the newest generation Impella 5.5, which received FDA approval in 2019. The United Network for Organ Sharing registry was queried for all adults awaiting orthotopic heart transplantation who received Impella 5.5 support during their listing period. Waitlist, device, and early post-transplant outcomes were assessed. A total of 464 patients received Impella 5.5 support during their listing period with a median waitlist time of 19 days. Among them, 402 (87%) patients were ultimately transplanted, with 378 (81%) being directly bridged to transplant with the device. Waitlist death (7%) and clinical deterioration (5%) were the most common reasons for waitlist removal. Device complications and failure were uncommon (<5%). The most common post-transplant complication was acute kidney injury requiring dialysis (16%). Survival at 1-year post-transplant survival was 89.5%. Since its approval, the Impella 5.5 has been increasingly used as a bridge to transplant. This analysis demonstrates robust waitlist and post-transplant outcomes with minimal device-related and postoperative complications.

Racial and Ethnic Disparities in Liver Transplantation for Alcohol-associated Liver Diseases in the United States.

Emerging data suggest disparities exist in liver transplantation (LT) for alcohol-associated liver disease (ALD). As the incidence of ALD increases, we aimed to characterize recent trends in ALD LT frequency and outcomes, including racial and ethnic disparities. Using United Network for Organ Sharing/Organ Procurement and Transplantation Network data (2015 through 2021), we evaluated LT frequency, waitlist mortality, and graft survival among US adults with ALD (alcohol-associated hepatitis [AH] and alcohol-associated cirrhosis [AAC]) stratified by race and ethnicity. We used adjusted competing-risk regression analysis to evaluate waitlist outcomes, Kaplan-Meier analysis to illustrate graft survival, and Cox proportional hazards modeling to identify factors associated with graft survival. There were 1211 AH and 26 526 AAC new LT waitlist additions, with 970 AH and 15 522 AAC LTs performed. Compared with non-Hispanic White patients (NHWs) with AAC, higher hazards of waitlist death were observed for Hispanic (subdistribution hazard ratio [SHR] = 1.23, 95% confidence interval [CI]: 1.16-1.32), Asian (SHR = 1.22, 95% CI:1. 01-1.47), and American Indian/Alaskan Native (SHR = 1.42, 95% CI: 1.15-1.76) candidates. Similarly, significantly higher graft failures were observed in non-Hispanic Black (HR = 1.32, 95% CI: 1.09-1.61) and American Indian/Alaskan Native (HR = 1.65, 95% CI: 1.15-2.38) patients with AAC than NHWs. We did not observe differences in waitlist or post-LT outcomes by race or ethnicity in AH, although analyses were limited by small subgroups. Significant racial and ethnic disparities exist for ALD LT frequency and outcomes in the United States. Compared with NHWs, racial and ethnic minorities with AAC experience increased risk of waitlist mortality and graft failure. Efforts are needed to identify determinants for LT disparities in ALD that can inform intervention strategies.

Impact of the COVID-19 pandemic on liver transplant waitlist outcome in France

The objective of this study was to investigate the impact of the COVID-19 pandemic on the outcome of patients on the liver transplantation (LT) waitlist in 2020 in France, in particular, the incidence of deaths and delisting for worsening condition, depending on the allocation score component. The 2020 cohort of patients on the waiting list was compared with the 2018/2019 cohorts. 2020 saw fewer LTs than in either 2019 or 2018 (1128, 1356, and 1325, respectively), together with fewer actual brain dead donors (1355, 1729, and 1743). In 2020, deaths or delisting for worsening condition increased significantly versus 2018/2019 (subdistribution hazard ratio 1.4, 95% confidence interval [CI] 1.2–1.7), after adjustment for age, place of care, diabetes, blood type, and score component, although COVID-19-related mortality was low. This increased risk mainly concerned patients with hepatocellular carcinoma (1.52, 95% CI 1.22–1.90), with 650 MELD exception points (2.19, 95% CI 1.08–4.43), and especially those without HCC and MELD scores from 25 to 30 (3.36 [95% CI 1.82–6.18]). In conclusion, by significantly decreasing LT activity in 2020, the COVID-19 pandemic increased the number of waitlist deaths and delisting for worsening condition, and significantly more for particular components of the score, including intermediate severity cirrhosis.

Advancing the Field of Pediatric Liver Transplantation: Urgent Action Items Identified During the 2022 Society of Pediatric Liver Transplantation Meeting.

Advancing the Field of Pediatric Liver Transplantation: Urgent Action Items Identified During the 2022 Society of Pediatric Liver Transplantation Meeting.

Removing geographic boundaries from liver allocation: A method for designing continuous distribution scores.

The Organ Procurement and Transplantation Network (OPTN) is eliminating geographic boundaries in liver allocation, in favor of continuous distribution. Continuous distribution allocates organs via a composite allocation score (CAS): a weighted sum of attributes like medical urgency, candidate biology, and placement efficiency. The opportunity this change represents, to include new variables and features for prioritizing candidates, will require lengthy and contentious discussions to establish community consensus. Continuous distribution could instead be implemented rapidly by computationally translating the allocation priorities for pediatric, status 1, and O/B blood type liver candidates that are presently implemented via geographic boundaries into points and weights in a CAS. Using simulation with optimization, we designed a CAS that is minimally disruptive to existing prioritizations, and that eliminates geographic boundaries and minimizes waitlist deaths without harming vulnerable populations. Compared with Acuity Circles (AC) in a 3-year simulation, our optimized CAS decreased deaths from 7771.2 to 7678.8 while decreasing average (272.66 NM vs. 264.30 NM) and median (201.14 NM vs. 186.49 NM) travel distances. Our CAS increased travel only for high MELD and status 1 candidates (423.24 NM vs. 298.74 NM), and reduced travel for other candidates (198.98 NM vs. 250.09 NM); overall travel burden decreased. Our CAS reduced waitlist deaths by sending livers for high-MELD and status 1 candidates farther, while keeping livers for lower MELD candidates nearby. This advanced computational method can be applied again after wider discussions of adding new priorities conclude; our method designs score weightings to achieve any specified feasible allocation outcomes.

Waitlist mortality in pediatric liver transplantation: The goal is zero.

Waitlist mortality in pediatric liver transplantation: The goal is zero.

Associated Factors and Impact of Persistent Renal Dysfunction in Pediatric Heart Transplantation

BackgroundWe evaluated the impact of significant renal dysfunction (SRD) on listing and pediatric heart transplantation (PHT) outcomes. MethodsThe United Network of Organ Sharing registry was queried. Our cohort included 11,625 children listed for PHT (2000-2020). At listing, 1494 (13%) had SRD, defined as an estimated glomerular filtration rate of <45 mL/min/1.73 m2 and/or dialysis requirement. Characteristics of children with and without SRD were compared. SRD impact on outcomes was examined. Factors associated with waiting list mortality, persistent SRD at PHT, and post-PHT survival with and without simultaneous heart-kidney transplantation were assessed. ResultsCompared with children with an estimated glomerular filtration rate >45 mL/min/1.73 m2, those with SRD had higher waiting list death (37% vs 14%, P < .01) and lower transplantation rate (51% vs 71%, P < .01). On multivariable analysis, SRD was associated with waiting list death (hazard ratio, 3.016; P < .0001). Among 767 children with SRD who received PHT, 361 (47%) had persistent SRD at the time of PHT. On multivariable analysis, factors associated with persistent SRD were older age (odds ratio [OR], 1.147 per year; 95% CI, 1.046-1.258 per year; P = .0035), bilirubin (OR, 1.127 per 1-mg/dL; 95% CI, 1.061-1.197 per 1-mg/dL; P < .0001), dialysis (OR, 1.839; 95% CI, 1.017-3.326; P = .0115), mechanical ventilation (OR, 1.972; 95% CI, 1.336-2.911; P = .0006), extracorporeal membrane oxygenation (OR, 1.747; 95% CI, 1.074-2.842; P = .0247), and not using a ventricular assist device (VAD) (OR, 0.498 [VAD use]; 95% CI, 0.277-0.895 VAD use; P = .0198). Post-PHT survival was 72%, 70%, and 56% (P < .01) at 8 years for PHT alone with improved renal function, simultaneous heart-kidney transplantation (n = 69), and PHT alone with persistent SRD, respectively. ConclusionsSRD is associated with high waiting list death and decreased transplantation rate. Timely proper pre-PHT support with VAD could enhance kidney recovery. Simultaneous heart-kidney transplantation neutralized persistent SRD effect on survival and might be considered in high-risk patients such as those on dialysis, mechanical ventilation, or extracorporeal membrane oxygenation support.

Transplantation Amid a Pandemic: The Fall and Rise of Kidney Transplantation in the United States.

Using SRTR data, we compared observed waitlist registrations, waitlist mortality, waitlist removal due to deteriorating condition, LDKT, and DDKT over 5 distinct pandemic periods to expected events based on calculations from preepidemic data while accounting for seasonality and secular trends. Although the number of daily waitlist additions has been increasing since May 2020, the size of the active waitlist has consistently declined, reaching a minimum of 52 556 on February 27, 2022. The recent Omicron surge knocked LDKT from 25% below baseline (incidence rate ratio [IRR] = 0.690.750.81) during the Delta wave to 38% below baseline (IRR = 0.580.620.67). DDKT, however, was less affected by the Omicron wave (IRR = 0.850.890.93 and 0.880.920.96 during the Delta and Omicron waves, respectively). Waitlist death decreased from 56% above baseline (IRR = 1.431.561.70) during Delta to 41% above baseline during Omicron, whereas waitlist removal due to deteriorating condition remained at baseline/expected levels during the Delta wave (IRR = 0.931.021.12) and the Omicron wave (IRR = 0.991.071.16). Despite exceptionally high COVID-19 incidence during the Omicron wave, the transplant system responded similarly to prior waves that imposed a lesser disease burden, demonstrating the transplant system's growing adaptations and resilience to this now endemic disease.

Expected effect of the lung Composite Allocation Score system on US lung transplantation

Efforts are underway to transition the current lung allocation system to a continuous distribution framework whereby multiple factors are simultaneously combined into a Composite Allocation Score (CAS) to prioritize candidates for lung transplant. The purpose of this study was to compare discrete CAS scenarios with the current concentric circle-based allocation system to assess their potential effects on the US lung transplantation system using the Scientific Registry of Transplant Recipients' thoracic simulated allocation model. Six alternative CAS scenarios were compared over 10 simulation runs using data from individuals on the lung transplant waiting list from January 1, 2018, through December 31, 2019. Outcome measures were transplant rate, count, waitlist deaths, posttransplant deaths within 2 years, donor-to-recipient distance, and percentage of organs predicted to have flown. Across scenarios, waitlist deaths decreased by 36% to 47%, with larger decreases in deaths at lower placement efficiency weight and higher weighting of the waitlist outcomes. When waitlist outcomes were equally weighted to posttransplant outcomes, more transplants occurred in individuals with the highest expected posttransplant survival. All CAS scenarios led to improved overall measures of equity compared with the current Lung Allocation Score system, including reduced waitlist deaths, and resulted in similar posttransplant survival.

Abstract 14072: Heart Retransplantation Under the 2018 Adult Heart Allocation Policy

Introduction: The new adult heart allocation policy was implemented on October 18, 2018. The purpose of the present study was to characterize the impact of this policy change on waitlist and post-transplant outcomes of heart retransplantation in the United States. Methods: All adults listed for heart retransplantation from May 2015 to March 2022 were identified using the United Network for Organ Sharing database. Patients were stratified into equal time eras (pre- and post-policy) based on the heart allocation change on October 18, 2018. Competing risks regressions were used to determine differences in waitlist outcomes, including waitlist death or deterioration and retransplantation rates following listing. Kaplan-Meier survival estimates were used to assess differences in 1-year post-transplant survival between eras. Results: Overall, 672 heart transplant candidates were included in analysis, with 49% listed during post-policy. Retransplantation candidates listed during post-policy were of similar age (45 vs 47 years, P=0.11) and female gender (33% vs 34%, P =0.70) compared to pre-policy candidates. Post-policy candidates had a shorter median waitlist duration (51 days vs 80 days, P&lt;0.01), along with a lower likelihood of death or deterioration on the waitlist (subdistribution hazard ratio, SHR 0.45, 95% CI 0.27-0.74) and higher likelihood of retransplantation within 30 days of listing (SHR 2.65, 95% CI 1.86-3.80) compared to pre-policy (Figure). Among those retransplanted, pre-policy recipients experienced similar rates of 30-day post-transplant mortality (6.9% vs 6.7%, P=1.00) and 1-year post-transplant survival (82% vs 87%, P=0.24). Conclusions: Heart retransplantation candidates have experienced improved waitlist outcomes following the 2018 adult heart allocation policy without significant changes to post-transplant survival. Continued monitoring for long-term outcomes is warranted in this patient population.

Clinical impact of a modified lung allocation score that mitigates selection bias.

The Lung Allocation Score (LAS) is used in the U.S. to prioritize lung transplant candidates. Selection bias, induced by dependent censoring of waitlisted candidates and prediction of posttransplant survival among surviving, transplanted patients only, is only partially addressed by the LAS. Recently, a modified LAS (mLAS) was designed to mitigate such bias. Here, we estimate the clinical impact of replacing the LAS with the mLAS. We considered lung transplant candidates waitlisted during 2016 and 2017. LAS and mLAS scores were computed for each registrant at each observed organ offer date; individuals were ranked accordingly. Patient characteristics associated with better priority under the mLAS were investigated via logistic regression and generalized linear mixed models. We also determined whether differences in rank were explained more by changes in predicted pre- or posttransplant survival. Simulations examined how 1-year waitlist, posttransplant, and overall survival might change under the mLAS. Diagnosis group, 6-minute walk distance, continuous mechanical ventilation, functional status, and age demonstrated the highest impact on differential allocation. Differences in rank were explained more by changes in predicted pretransplant survival than changes in predicted posttransplant survival, suggesting that selection bias has more impact on estimates of waitlist urgency. Simulations suggest that for every 1000 waitlisted individuals, 12.8 (interquartile range: 5.2-24.3) fewer waitlist deaths per year would occur under the mLAS, without compromising posttransplant and overall survival. Implementing a mLAS that mitigates selection bias into clinical practice can lead to important differences in allocation and possibly modest improvement in waitlist survival.

NINTEDANIB CESSATION IN WAITLISTED LUNG TRANSPLANT CANDIDATES IS NOT ASSOCIATED WITH INCREASED WAITLIST MORTALITY OR PERIOPERATIVE COMPLICATIONS

NINTEDANIB CESSATION IN WAITLISTED LUNG TRANSPLANT CANDIDATES IS NOT ASSOCIATED WITH INCREASED WAITLIST MORTALITY OR PERIOPERATIVE COMPLICATIONS