Contemporary Pediatric Heart Transplant Waitlist Mortality.

BACKGROUND: In 2016, the United Network for Organ Sharing revised its pediatric heart transplant (HT) allocation policy. OBJECTIVES: This study sought to determine whether the 2016 revisions are associated with reduced waitlist mortality and capture patient-specific risks. METHODS: Children listed for HT from 1999 to 2023 were identified using Organ Procurement and Transplantation Network data and grouped into 3 eras (era 1: 1999-2006; era 2: 2006-2016; era 3: 2016-2023) based on when the United Network for Organ Sharing implemented allocation changes. Fine-Gray competing risks modeling was used to identify factors associated with death or delisting for deterioration. Fixed-effects analysis was used to determine whether allocation changes were associated with mortality. RESULTS: Waitlist mortality declined 8 percentage points (PP) across eras (21%, 17%, and 13%, respectively; P < 0.01). At listing, era 3 children were less sick than era 1 children, with 6 PP less ECMO use (P < 0.01), 11 PP less ventilator use (P < 0.01), and 1 PP less dialysis use (P < 0.01). Ventricular assist device (VAD) use was 13 PP higher, and VAD mortality decreased 9 PP (P < 0.01). Non-White mortality declined 10 PP (P < 0.01). ABO-incompatible listings increased 27 PP, and blood group O infant mortality decreased 13 PP (P < 0.01). In multivariable analyses, the 2016 revisions were not associated with lower waitlist mortality, whereas VAD use (in era 3), ABO-incompatible transplant, improved patient selection, and narrowing racial disparities were. Match-run analyses demonstrated poor correlation between individual waitlist mortality risk and the match-run order. CONCLUSIONS: The 2016 allocation revisions were not independently associated with the decline in pediatric HT waitlist mortality. The 3-tier classification system fails to adequately capture patient-specific risks. A more flexible allocation system that accurately reflects patient-specific risks and considers transplant benefit is urgently needed.

Burden of Portal Hypertension Complications Is Greater in Liver Transplant Wait-Listed Registrants with End-Stage Liver Disease and Type 2 Diabetes.

BACKGROUND AND AIMS: Impact of type 2 diabetes mellitus (T2DM) in patients with end-stage liver disease (ESLD) awaiting liver transplantation (LT) remains poorly defined. The objective of the present study is to evaluate the relationship between T2DM and clinical outcomes among patients with LT waitlist registrants. We hypothesize that the presence of T2DM will be associated with worse clinical outcomes. METHODS: 593 patients adult (age 18 years or older) who were registered for LT between 1/2010 and 1/2017 were included in this retrospective analysis. The impact of T2DM on liver-associated clinical events (LACE), survival, hospitalizations, need for renal replacement therapy, and likelihood of receiving LT were evaluated over a 12-month period. LACE was defined as variceal hemorrhage, hepatic encephalopathy, and ascites. Kaplan-Meier and Cox regression analysis were used to determine the association between T2DM and clinical outcomes. RESULTS: The baseline prevalence of T2DM was 32% (n = 191) and patients with T2DM were more likely to have esophageal varices (61% vs. 47%, p = 0.002) and history of variceal hemorrhage (23% vs. 16%, p = 0.03). The presence of T2DM was associated with increased risk of incident ascites (HR 1.91, 95% CI 1.11, 3.28, p = 0.019). Patients with T2DM were more likely to require hospitalizations (56% vs. 49%, p = 0.06), hospitalized with portal hypertension-related complications (22% vs. 14%; p = 0.026), and require renal replacement therapy during their hospitalization. Patients with T2DM were less likely to receive a LT (37% vs. 45%; p = 0.03). Regarding MELD labs, patients with T2DM had significantly lower bilirubin at each follow-up; however, no differences in INR and creatinine were noted. CONCLUSION: Patients with T2DM are at increased risk of clinical outcomes. This risk is not captured in MELD score, which may potentially negatively affect their likelihood of receiving LT.

Optimizing pediatric liver transplantation: Evaluating the impact of donor age and graft type on patient survival outcome.

BACKGROUND: We examined the combined effects of donor age and graft type on pediatric liver transplantation outcomes with an aim to offer insights into the strategic utilization of these donor and graft options. METHODS: A retrospective analysis was conducted using a national database on 0-2-year-old (N = 2714) and 3-17-year-old (N = 2263) pediatric recipients. These recipients were categorized based on donor age (≥40 vs <40 years) and graft type. Survival outcomes were analyzed using the Kaplan-Meier and Cox proportional hazards models, followed by an intention-to-treat (ITT) analysis to examine overall patient survival. RESULTS: Living and younger donors generally resulted in better outcomes compared to deceased and older donors, respectively. This difference was more significant among younger recipients (0-2 years compared to 3-17 years). Despite this finding, ITT survival analysis showed that donor age and graft type did not impact survival with the exception of 0-2-year-old recipients who had an improved survival with a younger living donor graft. CONCLUSIONS: Timely transplantation has the largest impact on survival in pediatric recipients. Improving waitlist mortality requires uniform surgical expertise at many transplant centers to provide technical variant graft (TVG) options and shed the conservative mindset of seeking only the "best" graft for pediatric recipients.

The Impact of Local Programmatic Decisions on Outcomes in Transplant-Listed Adults With Congenital Heart Disease.

BACKGROUND: We investigated variables impacting waitlist times and negative waitlist outcomes in adults with congenital heart disease (ACHD) who were waiting for orthotopic heart transplant (OHT) after the 2018 allocation change. METHODS: Adult candidates for OHT who were listed between 10/18/2018 and 12/31/2022 in the United Network for Organ Sharing database were categorized as ACHD vs non-ACHD. Waitlist time and time to upgrade for those upgraded into status 1-3 were compared by using rank-sum tests. Death/delisting for deterioration was assessed by using Fine-Gray subdistribution hazard ratios (SHRs). RESULTS: Of 15,424 OHT candidates, 589 (3.8%) were ACHD. ACHD vs non-ACHD candidates had less urgent status at initial listing (4.2% vs 4.7% listed at status 1; 17.2% vs 23.7% listed at status 2; P < 0.001), but not final listing (5.9% vs 7.6% final status 1; 35.6% vs 36.8% final status 2; P < 0.001). ACHD vs non-ACHD candidates upgraded into status 1 (65.0 vs 30.0 days; P = 0.09) and status 2 (113.0 vs 64.0 days; P = 0.003) spent longer times on the waitlist. ACHD vs non-ACHD candidates spent longer times waiting for an upgrade into status 1 (51.4 vs 17.6 days; P = 0.027) and status 2 (76.7 vs 34.7 days; P = 0.003). Once upgraded, there was no difference between groups in waitlist time to status 1 (9.7 vs 5.5 days = 0.66). ACHD vs non-ACHD candidates with a final status of 1 (20.0% vs 8.6%; SHR 2.47 [95%CI = 1.19-5.16]; P = 0.02) and 2 (8.9% vs 2.3%; SHR 3.59 [95%CI = 2.18-5.91]; P < 0.001) experienced higher rates of death and deterioration. CONCLUSIONS: ACHD candidates have longer waitlist times, have lower priority status at initial listing, wait longer for upgrades, and have higher mortality rates at the same final status as non-ACHD candidates, suggesting that they are being upgraded too late.

OPTN/SRTR 2022 Annual Data Report: COVID-19.

This chapter updates the COVID-19 chapter from the 2021 Annual Data Report with trends through November 12, 2022, and introduces trends in recovery and use of organs from donors with a positive COVID-19 test. Posttransplant mortality and graft failure, which remained a concern in all organs at the last report due to the Omicron variant wave, have returned to lower levels in the most recent available data through November 2022. Use of organs from donors with a positive COVID-19 test has grown, particularly after the first year of the pandemic. Mortality due to COVID-19 should continue to be monitored, but most other measures have sustained their recovery and may now be responding more to changes in policy than to ongoing concerns with COVID-19.

Excess waitlist mortality among candidates for multivisceral liver-intestine transplant in acuity circle allocation.

Candidates for multivisceral transplant (MVT) have experienced decreased access to transplant in recent years. Using Organ Procurement and Transplantation Network data, transplant and waiting list outcomes for MVT (ie, liver-intestine, liver-intestine-pancreas, and liver-intestine-kidney-pancreas) candidates listed between February 4, 2018, and February 3, 2022, were analyzed, including model for end-stage liver disease/pediatric end-stage liver disease and exception scores by era (before and after acuity circle [AC] implementation on February 4, 2020) and age group (pediatric and adult). Of 284 MVT waitlist registrations (45.6% pediatric), fewer had exception points at listing post-AC compared to pre-AC (10.0% vs 19.1%), and they were less likely to receive transplant (19.1% vs 35.9% at 90 days; 35.7% vs 57.2% at 1 year). Of 177 MVT recipients, exception points at transplant were more common post-AC compared to pre-AC (30.8% vs 20.2%). Postpolicy, adult MVT candidates were more likely to be removed due to death/too sick compared with liver-alone candidates (13.5% vs 5.6% at 90 days; 24.2% vs 9.8% at 1 year), whereas no excess waitlist mortality was observed among pediatric MVT candidates. Under current allocation policy, multivisceral candidates experience inferior waitlist outcomes compared with liver-alone candidates. Clarification of guidance around submission and approval of multivisceral exception requests may help improve their access to transplantation and achieve equity between multivisceral and liver-alone candidates on the liver transplant waiting list.

COVID-19 and Access to Kidney Transplantation for Older Candidates in the United States: A National Registry Study.

Rationale & Objective: Coronavirus disease (COVID)-19 has likely impacted accessibility to transplantation services among older adults (age ≥65 years). We quantified the impact of COVID-19 on kidney transplantation access for older kidney-only candidates registered on the United States (US) kidney waitlist. Study Design: Retrospective analysis of registry data. Setting & Participants: 57,222 older adults who were part of or added to the US kidney waitlist between January 1, 2016 and February 28, 2022, identified using the Scientific Registry of Transplant Recipients (SRTR). Exposures: Four COVID-19 waves and one nonwave period based on the national incidence of COVID-19 in the US (initial: March 15-May 30, 2020; winter 2020-2021: December 1, 2020-January 31, 2021; delta: August 1, 2021-September 30, 2021; omicron: December 1, 2021-February 28, 2022; nonwave: inter-wave periods). Outcomes: Waitlist registrations, deceased-donor kidney transplants, living-donor kidney transplants, waitlist mortality, and waitlist removals due to deteriorating condition (hereafter referred to as removals). Analytical Approach: Poisson regression for the adjusted incidence rate ratio (aIRR) of each outcome during the COVID-19 waves and the nonwave period relative to reference (January 1, 2016-December 31, 2019), adjusted for seasonality and secular trends. Results: Waitlist registrations initially declined and increased henceforth. Deceased-donor kidney transplants and living-donor kidney transplants remained below-expected levels during all waves. Waitlist mortality peaked during the winter 2020-2021 wave (aIRR: 1.701.982.30) and has declined since; mortality rates were 139%, 107%, and 251% above expected for Black candidates, men, and candidates aged ≥75 years, respectively, during the winter 2020-2021 wave. Removals increased from 22% below expected levels (initial wave) to 26% above expected levels (omicron wave); removals were nonsignificantly higher than expected during the omicron wave for older Black and Hispanic candidates. Limitations: The findings are not generalizable to those listed at earlier ages with prolonged waitlist times. Additionally, using national COVID-19 incidence does not consider local policy and health care variations. Lastly, aIRRs must be interpreted cautiously due to smaller daily event counts. Conclusions: COVID-19 was associated with fewer transplants and increased mortality and removals in older kidney transplant candidates. Transplant providers should consider this impact and implement policies and practices to ensure the continuity of care. Plain-Language Summary: The proportion of older adults on the kidney transplant waitlist is increasing, but the impact of COVID-19 on this population is not well characterized. In this study, we looked at incident waitlist registrations, deceased- and living-donor kidney transplants, and waitlist mortality and removals due to deteriorating condition over 4 waves of COVID-19. We found that transplantation services did not fully recover to prepandemic levels as of March 2022. Notably, racial/ethnic minorities and older men experienced lower rates of kidney transplants and higher rates of waitlist mortality, respectively, relative to White candidates and older women. Identifying vulnerable subpopulations affected by COVID-19 and its long-term impact is crucial for creating strategies to ensure the continuity of care in this population during public health emergencies.

Abdominal computed tomography measurements of body composition and waitlist mortality in kidney transplant candidates.

Body mass index is often used to determine kidney transplant (KT) candidacy. However, this measure of body composition (BC) has several limitations, including the inability to accurately capture dry weight. Objective computed tomography (CT)-based measures may improve pre-KT risk stratification and capture physiological aging more accurately. We quantified the association between CT-based BC measurements and waitlist mortality in a retrospective study of 828 KT candidates (2010-2022) with clinically obtained CT scans using adjusted competing risk regression. In total, 42.5% of candidates had myopenia, 11.4% had myopenic obesity (MO), 68.8% had myosteatosis, 24.8% had sarcopenia (probable = 11.2%, confirmed = 10.5%, and severe = 3.1%), and 8.6% had sarcopenic obesity. Myopenia, MO, and sarcopenic obesity were not associated with mortality. Patients with myosteatosis (adjusted subhazard ratio [aSHR] = 1.62, 95% confidence interval [CI]: 1.07-2.45; after confounder adjustment) or sarcopenia (probable: aSHR = 1.78, 95% CI: 1.10-2.88; confirmed: aSHR = 1.68, 95% CI: 1.01-2.82; and severe: aSHR = 2.51, 95% CI: 1.12-5.66; after full adjustment) were at increased risk of mortality. When stratified by age, MO (aSHR = 2.21, 95% CI: 1.28-3.83; P interaction = .005) and myosteatosis (aSHR = 1.95, 95% CI: 1.18-3.21; P interaction = .038) were associated with elevated risk only among candidates <65 years. MO was only associated with waitlist mortality among frail candidates (adjusted hazard ratio = 2.54, 95% CI: 1.28-5.05; P interaction = .021). Transplant centers should consider using BC metrics in addition to body mass index when a CT scan is available to improve pre-KT risk stratification at KT evaluation.

Severe hepatic encephalopathy with mechanical ventilation may inform waitlist priority in acute liver failure: A UNOS database analysis.

BACKGROUND & AIMS: Patients with acute liver failure (ALF) awaiting liver transplantation (LT) may develop multiorgan failure, but organ failure does not impact waitlist prioritization. The aim of this study was to examine the impact of organ failure on waitlist mortality risk and post LT outcomes in patients with ALF. METHODS: We studied adults waitlisted for ALF in the United Network for Organ Sharing (UNOS) database (2002-2019). Organ failures were defined using a previously described Chronic Liver Failure modified sequential organ failure score assessment adapted to UNOS data. Regression analyses of the primary endpoints, 30-day waitlist mortality (Competing risk), and post-LT mortality (Cox-proportional hazards), were performed. Latent class analysis (LCA) was used to determine the organ failures most closely associated with 30-day waitlist mortality. RESULTS: About 3212 adults with ALF were waitlisted, for hepatotoxicity (41%), viral (12%) and unspecified (36%) etiologies. The median number of organ failures was three (interquartile range 1-3). Having ≥3 organ failures (vs. ≤2) was associated with a sub hazard ratio (HR) of 2.7 (95%CI 2.2-3.4)) and a HR of 1.5 (95%CI 1.1-2.5)) for waitlist and post-LT mortality, respectively. LCA identified neurologic and respiratory failure as most impactful on 30-day waitlist mortality. The odds ratios for both organ failures (vs. neither) were higher for mortality 4.5 (95% CI 3.4-5.9) and lower for delisting for spontaneous survival .5 (95%CI .4-.7) and LT .6 (95%CI .5-.7). CONCLUSION: Cumulative organ failure, especially neurologic and respiratory failure, significantly impacts waitlist and post-LT mortality in patients with ALF and may inform risk-prioritized allocation of organs.

Pediatric heart transplantation: Looking forward after five decades of learning.

Heart transplantation has become the standard of care for pediatric patients with end-stage heart disease throughout the world. Since the first transplant was performed in 1967, the number of transplants has grown dramatically with 13 449 pediatric heart transplants being reported to The International Society of Heart and Lung Transplant (ISHLT) between January 1992 and June 30, 2018. Outcomes have consistently improved over the last few decades, specifically short-term outcomes. Most recent survival data demonstrate that recipients who survive to 1-year post-transplant have excellent long-term survival with more than 60% of those who were transplanted as infants being alive 25 years later. Nonetheless, the rates of graft loss beyond the first year have remained relatively constant over time; driven primarily by our poor understanding and lack of treatments for chronic allograft vasculopathy (CAV). Acute rejection, CAV, graft failure, and infection continue to be the major causes of death within the first 5 years post-transplant. In addition, renal dysfunction, malignancy, and the need for re-transplantation remain as significant issues that require close follow-up. Looking forward, key challenges include improving donor utilization rates (including donation after cardiac death (DCD) and the use of ex vivo perfusion devices), the development of non-invasive biomarkers for rejection, efforts to mitigate the long-term effects of immunosuppression, and prevention of CAV. It is not possible to cover the entire evolution of pediatric heart transplantation over the last five decades, but in this review, we hope to touch on key observations, lessons learned, and practice changes that have advanced the field, as well as glance ahead to the next decade.

Revised Heart Allocation Policy Improved Waitlist Mortality and Waiting Time With Maintained Outcomes in En-Bloc Heart-Lung Transplant Candidates and Recipients.

The revised United Network for Organ Sharing heart allocation policy was implemented in October 2018. Using a national transplant database, this study evaluated the transplant rate, waitlist mortality, waiting time, and other outcomes of en-bloc heart-lung transplantation recipients. Adult patients registered on the national database for heart-lung transplants before and after the policy update were selected as cohorts. Baseline characteristics, transplant rates, waitlist mortality, waiting times, and other outcomes were compared between the two periods. In total, 370 patients were registered for heart-lung transplants during the pre- and post-periods. There were significantly higher transplant rates, shorter waitlist times, and substantially reduced waitlist mortality in the post-period. Registered patients waitlisted in the post-period had significantly higher utilization of intra-aortic balloon pumps, extracorporeal membrane oxygenation, and overall life support, including ventricular assist devices. Transplant recipients had significantly longer ischemic times, increased transport distances, and shorter waiting times before transplantation in the post-policy period. Transplant recipients held similar short-term survival before and after the policy change (log-rank test, p = 0.4357). Therefore, the revised policy significantly improved access to en-bloc heart-lung allografts compared with the prior policy, with better waitlist outcomes and similar post-transplant outcomes.

Association of the psoas muscle index with the survival of patients on a waiting list for lung transplantation: a Japanese single-institution study.

PURPOSES: Some predictive markers of death have been reported for patients on the waiting list for lung transplantation (LTx). We assessed whether or not the preoperative psoas muscle index (PMI) correlates with waitlist mortality. METHODS: In 81 patients with end-stage lung disease on the waiting list for LTx between 2011 and 2020 at Osaka University Hospital, we examined the association between baseline characteristics, including the diagnosis, respiratory function test results, blood collection items, steroid use, and psoas muscle mass on computed tomography, and survival during the waiting period using Kaplan-Meier curves and Cox proportional hazard regression models. RESULTS: Thirty-three patients (41%) died during follow-up. Univariate and multivariate analyses showed that patients with a low PMI had a higher rate of death during follow-up than those with a high PMI (p < 0.0001 and 0.0002, respectively). In addition, a diagnosis of interstitial pneumonia (hazard ratio 3.30, 95% confidence interval 1.52-7.17, p = 0.0025) and low albumin level (hazard ratio 2.21, 95% confidence interval 1.02-4.80, p = 0.0449) were also significant predictors of survival. CONCLUSION: A low PMI at registration is associated with a decreased survival time among LTx candidates and it may be a predictive factor of mortality in patients waiting for LTx.

Predicted Impact of the Model for End-Stage Liver Disease 3.0 in a Region Suffering Severe Organ Shortage.

BACKGROUND: The model for end-stage liver disease 3.0 (MELD3.0) is expected to address the flaws of the current allocation system for deceased donor liver transplantation (DDLT). We aimed to validate MELD3.0 in the Korean population where living donor liver transplantation is predominant due to organ shortages. METHODS: Korean large-volume single-centric waitlist data were merged with the Korean Network for Organ Sharing (KONOS) data. The 90-day mortality was compared between MELD and MELD3.0 using the C-index in 2,353 eligible patients registered for liver transplantation. Patient numbers and outcomes were compared based on changes in KONOS-MELD categorization using MELD3.0. Possible gains in MELD points and reduced waitlist mortality were analyzed. RESULTS: MELD3.0 performed better than MELD (C-index 0.893 for MELD3.0 vs. 0.889 for MELD). When stratified according to the KONOS-MELD categories, 15.9% of the total patients and 35.2% of the deceased patients were up-categorized using MELD3.0 versus MELD categories. The mean gain of MELD points was higher in women (2.6 ± 2.1) than men (2.1 ± 1.9, P < 0.001), and higher in patients with severe ascites (3.3 ± 1.8) than in controls (1.9 ± 1.8, P < 0.001); however, this trend was not significant when the MELD score was higher than 30. When the possible increase in DDLT chance was calculated via up-categorizing using MELD3.0, reducible waitlist mortality was 2.7%. CONCLUSION: MELD3.0 could predict better waitlist mortality than MELD; however, the merit for women and patients with severe ascites is uncertain, and reduced waitlist mortality from implementing MELD3.0 is limited in regions suffering from organ shortage, as in Korea.

New system, old problem: Increased wait time for high-priority transplant candidates.

The 2018 heart allocation policy sought to improve risk stratification and reduce waitlist mortality for the sickest patients. This study sought to evaluate changes in wait times for the highest priority patients since policy implementation. All adult single-organ transplant recipients were identified in the United Network for Organ Sharing registry from October 18, 2018, to July 8, 2022, and separated into 4 periods. Outcomes were compared by blood type and UNOS region. Over the study period, 897 of 9,143 patients were listed as status 1 with no significant change in median wait time by blood type or region. More patients were listed as status 2 (4,523/9,143), and each subsequent period postpolicy change was associated with a 4.2-day increase in mean status 2 waitlist time (95% confidence interval 3.0-5.5, p < 0.0001). Wait times were longest for candidates with blood type O and shortest for AB & A. Regional variations continued, however, wait time increased in every region over time.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development.

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Natural history of NASH cirrhosis in liver transplant waitlist registrants.

BACKGROUND AND AIMS: Non-alcoholic steatohepatitis (NASH) cirrhosis is rapidly growing as an indication for liver transplant(ation) (LT). However, the natural history of NASH cirrhosis among LT waitlist registrants has not been established. The present study aimed to define the natural history of NASH cirrhosis using the Scientific Registry of Transplant Recipients database. METHODS: The study cohort comprised patients registered on the LT waitlist between 1/1/2016 to 12/31/2021. The primary outcomes included probability of LT and waitlist mortality, comparing NASH (n = 8,120) vs. non-NASH (n = 21,409) cirrhosis. RESULTS: Patients with NASH cirrhosis were listed with lower model for end-stage liver disease (MELD) scores despite bearing a greater burden of portal hypertension, especially at lower MELD scores. The overall transplant probability in LT waitlist registrants with NASH [vs. non-NASH] cirrhosis was significantly lower at 90 days (HR 0.873, p <0.001) and 1 year (HR 0.867, p <0.001); this was even more pronounced in patients with MELD scores >30 (HR 0.705 at 90 days and HR 0.672 at 1 year, p <0.001 for both). Serum creatinine was the key contributor to MELD score increases leading to LT among LT waitlist registrants with NASH cirrhosis, while bilirubin was in patients with non-NASH cirrhosis. Finally, waitlist mortality at 90 days (HR 1.15, p <0.001) and 1 year (1.25, p <0.001) was significantly higher in patients with NASH cirrhosis compared to those with non-NASH cirrhosis. These differences were more pronounced in patients with lower MELD scores at the time of LT waitlist registration. CONCLUSIONS: LT waitlist registrants with NASH cirrhosis are less likely to receive a transplant compared to patients with non-NASH cirrhosis. Serum creatinine was the major contributor to MELD score increases leading to LT in patients with NASH cirrhosis. IMPACT AND IMPLICATIONS: This study provides important insights into the distinct natural history of non-alcoholic steatohepatitis (NASH) cirrhosis among liver transplant (LT) waitlist registrants, revealing that patients with NASH cirrhosis face lower odds of transplantation and higher waitlist mortality than those with non-NASH cirrhosis. Our study underscores the significance of serum creatinine as a crucial contributor to model for end-stage liver disease (MELD) score in patients with NASH cirrhosis. These findings have substantial implications, emphasizing the need for ongoing evaluation and refinement of the MELD score to more accurately capture mortality risk in patients with NASH cirrhosis on the LT waitlist. Moreover, the study highlights the importance of further research investigating the impact of the implementation of MELD 3.0 across the US on the natural history of NASH cirrhosis.

Association of high-priority exceptions with waitlist mortality among heart transplant candidates.

BACKGROUND: The US heart allocation system ranks candidates using six categorical status levels. Transplant programs can request exceptions to increase a candidate's status level if they believe their candidate has the same medical urgency as candidates who meet the standard criteria for that level. We aimed to determine if exception candidates have the same medical urgency as standard candidates. METHODS: Using the Scientific Registry of Transplant Recipients, we constructed a longitudinal waitlist history dataset of adult heart-only transplant candidates listed between October 18, 2018 and December 1, 2021. We estimated the association between exceptions and waitlist mortality with a mixed-effects Cox proportional hazards model that treated status and exceptions as time-dependent covariates. RESULTS: Out of 12,458 candidates listed during the study period, 2273 (18.2%) received an exception at listing and 1957 (15.7%) received an exception after listing. After controlling for status, exception candidates had approximately half the risk of waitlist mortality as standard candidates (hazard ratio [HR] 0.55, 95% confidence interval [CI] [0.41, 0.73], p < .001). Exceptions were associated with a 51% lower risk of waitlist mortality among Status 1 candidates (HR 0.49, 95% CI [0.27, 0.91], p = .023) and a 61% lower risk among Status 2 candidates (HR 0.39, 95% CI [0.24, 0.62], p < .001). CONCLUSIONS: Under the new heart allocation policy, exception candidates had significantly lower waitlist mortality than standard candidates, including exceptions for the highest priority statuses. These results suggest that candidates with exceptions, on average, have a lower level of medical urgency than candidates who meet standard criteria.

Artificial intelligence, machine learning, and deep learning in liver transplantation.

Liver transplantation (LT) is a life-saving treatment for individuals with end-stage liver disease. The management of LT recipients is complex, predominantly because of the need to consider demographic, clinical, laboratory, pathology, imaging, and omics data in the development of an appropriate treatment plan. Current methods to collate clinical information are susceptible to some degree of subjectivity; thus, clinical decision-making in LT could benefit from the data-driven approach offered by artificial intelligence (AI). Machine learning and deep learning could be applied in both the pre- and post-LT settings. Some examples of AI applications pre-transplant include optimising transplant candidacy decision-making and donor-recipient matching to reduce waitlist mortality and improve post-transplant outcomes. In the post-LT setting, AI could help guide the management of LT recipients, particularly by predicting patient and graft survival, along with identifying risk factors for disease recurrence and other associated complications. Although AI shows promise in medicine, there are limitations to its clinical deployment which include dataset imbalances for model training, data privacy issues, and a lack of available research practices to benchmark model performance in the real world. Overall, AI tools have the potential to enhance personalised clinical decision-making, especially in the context of liver transplant medicine.

One-year change in the health status predicts the subsequent hospitalization and mortality in patients waitlisted for lung transplantation in Japan.

BACKGROUND: Poor health-related quality of life (HRQL) at the registration for lung transplantation is related to waitlist mortality. We investigated the relationship between 1-year change in HRQL and subsequent outcomes in patients waitlisted for lung transplantation. METHODS: In a 5-year longitudinal study, we analyzed the factors related to waitlist mortality in 197 lung transplant patients registered on the Japan Organ Transplant Network. HRQL was assessed using St. George's Respiratory Questionnaire (SGRQ), and factors related to changes in SGRQ scores were evaluated after 1 year. We assessed the relationship between the 1-year change in SGRQ score and subsequent mortality or hospitalization. RESULTS: Among 197 patients, 108 remained waitlisted during the first-year assessment. During the median follow-up period of 469 d, 28 patients died, and 54 underwent lung transplantation. Univariate Cox proportional hazards analysis revealed that the changes in all components and total score of the SGRQ after 1 year were associated with waitlist mortality (p < 0.05). Stepwise multivariate analysis revealed that the 1-year changes in SGRQ scores were significantly related to waitlist mortality. Forty-three patients with worsened HRQL after 1 year had higher likelihoods of hospitalization (p = 0.038) and mortality (p = 0.026) after 1 and 4 years of follow-up, respectively, than 61 patients without worsened HRQL. CONCLUSIONS: Patients with worsened health status during the first year after registration had higher likelihoods of hospitalization and mortality after 1 and 4 years of follow-up, respectively, than those without worsened HRQL. Strategies to improve health status while waiting are needed to reduce waitlist hospitalization or mortality.