Network For Organ Sharing Database Research Articles

Race-Specific Interpretation of Spirometry: Impact on the Lung Allocation Score.

Rationale: Interpretation of spirometry using race-specific reference equations may contribute to health disparities via underestimation of the degree of lung function impairment in Black patients. The use of race-specific equations may differentially affect patients with severe respiratory disease via the use of percentage predicted forced vital capacity (FVCpp) when included in the lung allocation score (LAS), the primary determinant of priority for lung transplantation. Objectives: To determine the impact of a race-specific versus a race-neutral approach to spirometry interpretation on the LAS among adults listed for lung transplantation in the United States. Methods: We developed a cohort from the United Network for Organ Sharing database including all White and Black adults listed for lung transplantation between January 7, 2009, and February 18, 2015. The LAS at listing was calculated for each patient under race-specific and race-neutral approaches, using the FVCpp generated from the Global Lung Function Initiative equation corresponding to each patient's race (race-specific) or from the Global Lung Function Initiative "other" (race-neutral) equation. Differences in LAS between approaches were compared by race, with positive values indicating a higher LAS under the race-neutral approach. Results: In this cohort of 8,982 patients, 90.3% were White and 9.7% were Black. The mean FVCpp was 4.4% higher versus 3.8% lower among White versus Black patients (P < 0.001) under a race-neutral compared with a race-specific approach. Compared with White patients, Black patients had a higher mean LAS under both a race-specific (41.9 vs. 43.9; P < 0.001) and a race-neutral (41.3 vs. 44.3; P < 0.001) approach. However, the mean difference in LAS under a race-neutral approach was -0.6 versus +0.6 for White versus Black patients (P < 0.001). Differences in LAS under a race-neutral approach were most pronounced for those in group B (pulmonary vascular disease) (-0.71 vs. +0.70; P < 0.001) and group D (restrictive lung disease) (-0.78 vs. +0.68; P < 0.001). Conclusions: A race-specific approach to spirometry interpretation has potential to adversely affect the care of Black patients with advanced respiratory disease. Compared with a race-neutral approach, a race-specific approach resulted in lower LASs for Black patients and higher LASs for White patients, which may have contributed to racially biased allocation of lung transplantation. The future use of race-specific equations must be carefully considered.

Trends in pediatric donor heart discard rates and the potential use of unallocated hearts for allogeneic valve transplantation

ObjectivesAllogeneic valve transplantation is an emerging therapy that delivers a living valve from a donor heart. We reviewed the national discard rate of pediatric and young adult (aged 25 years or younger) donor grafts to estimate the number of hearts potentially available to source valve allotransplantation. MethodsWe queried the United Network for Organ Sharing database to identify pediatric and young adult heart donors from 1987 to 2022. Donor heart discard was defined as nontransplantation of the allograft. ResultsOf 72,460 pediatric/young adult heart donations, 41,065 (56.7%) were transplanted and 31,395 (43.3%) were unutilized. The average annual number of discarded hearts in era 1 (1987-2000), era 2 (2000-2010), and era 3 (2010-2022) was 791 (42.8%), 1035 (46.3%), and 843 (41.2%), respectively. From 2017 to 2021, the average annual number of discards by age was: 39 (31.8%) neonates/infants, 78 (38.0%) toddlers, 41 (49.4%) young children, 240 (38.0%) adolescents, and 498 (40.1%) young adults. High-volume procurement regions had the greatest proportion of nonutilization, with the national average discard rate ranging from 39% to 49%. The most frequently documented reasons for nonallocation were distribution to the heart valve industry (26.5%), presumably due to suboptimal graft function, poor organ function (22.7%), and logistical challenges (10.8%). ConclusionsWith ∼900 pediatric/young adult donor hearts discarded annually, unutilized grafts represent a potential source of valves for allogeneic valve transplant to supplement current conduit and valve replacement surgery. The limited availability of neonatal and infant hearts may limit this technique in the youngest patients, for whom cryopreserved homografts or xenografts will likely remain the primary valve substitute.

Outcomes of Lung Transplant Candidates Aged ≥70 Years During the Lung Allocation Score Era

BackgroundWith the increasing age of lung transplant candidates, we studied waitlist and posttransplantation outcomes of candidates ≥70 years during the Lung Allocation Score era. MethodsAdult lung transplant candidates from 2005 to 2020 in the United Network for Organ Sharing database were included and stratified on the basis of age at listing into 18 to 59 years old, 60 to 69 years old, and ≥70 years old. Baseline characteristics, waitlist outcomes, and posttransplantation outcomes were assessed. ResultsA total of 37,623 candidates were included (52.3% aged 18-59 years, 40.6% aged 60-69 years, 7.1% aged ≥70 years). Candidates ≥70 years were more likely than younger candidates to receive a transplant (81.9% vs 72.7% [aged 60-69 years] vs 61.6% [aged 18-59 years]) and less likely to die or to deteriorate on the waitlist within 1 year (9.1% vs 10.1% [aged 60-69 years] vs 12.2% [aged 18-59 years]; P < .001). Donors for older recipients were more likely to be extended criteria (75.7% vs 70.1% [aged 60-69 years] vs 65.7% [aged 18-59 years]; P < .001). Recipients ≥70 years were found to have lower rates of acute rejection (6.7% vs 7.4% [aged 60-69 years] vs 9.2% [aged 18-59 years]; P < .001) and prolonged intubation (21.7% vs 27.4% [aged 60-69 years] vs 34.5% [aged 18-59 years]; P < .001). Recipients aged ≥70 years had increased 1-year (adjusted hazard ratio [aHR], 1.19 [95% CI, 1.06-1.33]; P < .001), 3-year (aHR, 1.28 [95% CI, 1.18-1.39]; P < .001), and 5-year mortality (aHR, 1.29 [95% CI, 1.21-1.38]; P < .001) compared with recipients aged 60 to 69 years. ConclusionsCandidates ≥70 years had favorable waitlist and perioperative outcomes despite increased use of extended criteria donors. Careful selection of candidates and postoperative surveillance may improve posttransplantation survival in this population.

Up to an Hour of Donor Resuscitation Does Not Affect Pediatric Heart Transplantation Survival

BackgroundIn pediatric heart transplantation, surgeons historically avoided donors requiring cardiopulmonary resuscitation (CPR), despite evidence that donor CPR does not change posttransplant survival (PTS). This study sought to determine whether CPR duration affects PTS. MethodsAll potential brain-dead donors aged <40 years from 2001 to 2021 consented for heart procurement were identified in the United Network for Organ Sharing database (n = 54,671). Organ acceptance was compared by CPR administration and duration. All recipients aged <18 years with donor CPR data were then identified (n = 5680). Survival analyses were conducted using increasing CPR duration as a cut point to identify the shortest duration beyond which PTS worsened. Additional analyses were performed with multivariable and cubic spline regression. ResultsFifty-one percent of donors (28,012 of 54,671) received CPR. Donor acceptance was lower after CPR (54% vs 66%; P < .001) and across successive quartiles of CPR duration (P < .001). Of the transplant recipients, 48% (2753 of 5680) belonged to the no-CPR group, and 52% (2927 of 5680) belonged to the CPR group. Kaplan-Meier analyses of CPR duration attained significance at 55 minutes, after which PTS worsened (11.1 years vs 9.2 years; P = .025). There was no survival difference between the CPR ≤55 minutes group and the no-CPR group (11.1 years vs 11.2 years; P = .571). A cubic spline regression model confirmed that PTS worsened at more than 55 minutes of CPR. A Cox regression demonstrated that CPR >55 minutes predicted worsened PTS relative to no CPR (HR, 1.51; P = .007) but CPR ≤55 minutes did not (HR, 1.01; P = .864). ConclusionsDonor CPR decreases organ acceptance for transplantation; however, shorter durations (≤55 minutes) had equivalent PTS when controlling for other risk factors.

Heart Transplant Waitlist Outcomes and Wait Time by Center Volume in the Pre-2018 Allocation Change Era.

Although the transplant outcomes of centers are heavily monitored and compared, with a particular link between posttransplant outcomes and center volume demonstrated, little data exist comparing waitlist outcomes. Here, we explored waitlist outcomes by transplant center volume. We performed a retrospective analysis of adults listed for primary heart transplantation (HTx) from 2008 to 2018 using the United Network for Organ Sharing database. Transplant centers were split into low (<10 HTx/year), medium (10-30 HTx/year), and high (>30 HTx/year) volume, and waitlist outcomes were compared. Of the 35,190 patients included in our study, 23,726 (67.4%) underwent HTx, 4,915 (14.0%) died or deteriorated before receiving HTx, 1,356 (3.9%) were delisted due to recovery, and 1,336 (3.8%) underwent left ventricular assist device (LVAD) implantation. High-volume centers had higher rates of survival to transplant (71.3% vs. 60.6% for low-volume centers and 64.9% for medium-volume centers), and low rates of death or deterioration (12.6% vs. 14.6% for low-volume centers and 15.1% for medium-volume centers). Listing at a low-volume center was independently associated with death or delisting before HTx (HR 1.18, p = 0.007), whereas listing at a high-volume center (HR 0.86; p < 0.001) and prelisting LVAD (HR 0.67, p < 0.001) were protective. Death or delisting before HTx was lowest for patients listed in higher volume centers.

Letter to the Editor: Can ex-situ normothermic perfusion improve graft survival among donation after circulatory death liver allografts?

To the editor, We read with great interest the manuscript by Ibeabuchi et al recently published in Liver Transplantation.1 The authors found that ex-situ normothermic liver perfusion (ENLP) improved graft survival compared to static cold storage among donation after circulatory death (DCD) liver allografts by identifying the United Network of Organ Sharing database. This was consistent with the results of a randomized trial, which confirmed that ENLP was associated with a 50% lower level of graft injury, with these benefits being greatest in the DCD subgroup.2 Besides, considering that ENLP DCDs were performed at 20 (19.8%) of the 101 centers, the authors conducted a subanalysis restricted to the 20 centers to eliminate potential baseline differences in graft outcomes related to center experience, and the results were largely unchanged. Despite this, the results should still be interpreted with caution. The number of ENLP DCDs performed among these 20 centers ranged from 1 to 10 (median: 2; interquartile range: 1–4.5). In only a few cases in each center, it was not clear in what circumstances ENLP was selected, which inevitably led to significant limitations. All the time, the time window for evaluating the feasibility of donor livers is relatively short, and the time for surgery is severely limited. These all lead to the urgency of liver transplantation and sometimes to the fact that part of the liver available for transplantation has to be wasted. The advantages of ENLP are to create a more physiological environment in vitro and maintain the normal physiological function of donor livers, which can provide opportunities for precise evaluation and intervention treatment of donor livers. ENLP intervention allows longer total preservation times, achieves higher organ use rates, and may indeed be a promising option for organ preservation in vitro.3 However, the ENLP process is relatively complex and requires advanced equipment and technological capabilities. Once problems occur in the operation process, it is likely to cause further damage to the liver. Meanwhile, ENLP does not appear to be suitable for split liver transplantation because it may increase the warm ischemia time through additional rewarming steps. Last, whether ENLP is required for the full duration of livers’ preservation or can equally well be applied after a short period of static cold storage when the livers reach the transplant center.

Limited cumulative experience with ex vivo lung perfusion is associated with inferior outcomes after lung transplantation

ObjectiveEx vivo lung perfusion (EVLP) allows for prolonged preservation and evaluation/resuscitation of donor lungs. We evaluated the influence of center experience with EVLP on lung transplant outcomes. MethodsWe identified 9708 isolated, first-time adult lung transplants from the United Network for Organ Sharing database (March 1, 2018-March 1, 2022), 553 (5.7%) involved using donor lungs after EVLP. Using the total volume of EVLP lung transplants per center during the study period, centers were dichotomized into low- (1-15 cases) and high-volume (>15 cases) EVLP centers. ResultsForty-one centers performed EVLP lung transplants, including 26 low-volume and 15 high-volume centers (median volume, 3 vs 23 cases; P < .001). Recipients at low-volume centers (n = 109) had similar baseline comorbidities compared with high-volume centers (n = 444). Low-volume centers used numerically more donation after circulatory death donors (37.6 vs 28.4%; P = .06) and more donors with Pao2/Fio2 ratio <300 (24.8 vs 9.7%; P < .001). After EVLP lung transplants, low-volume centers had worse 1-year survival (77.8% vs 87.5%; P = .007), with an adjusted hazard ratio of 1.63 (95% CI, 1.06-2.50, adjusting for recipient age, sex, diagnosis, lung allocation score, donation after circulatory death donor, donor Pao2/Fio2 ratio, and total annual lung transplant volume per center). When compared to non-EVLP lung transplants, 1-year survival of EVLP lung transplants was significantly worse at low-volume centers (adjusted hazard ratio, 2.09; 95% CI, 1.47-2.97) but similar at high-volume centers (adjusted hazard ratio, 1.14; 95% CI, 0.82-1.58). ConclusionsThe use of EVLP in lung transplantation remains limited. Increasing cumulative EVLP experience is associated with improved outcomes of lung transplantation using EVLP-perfused allografts.

Does Failure to Rescue Drive Race/Ethnicity-based Disparities in Survival After Heart Transplantation?

The objective was to assess whether race/ethnicity is an independent predictor of failure to rescue (FTR) after orthotopic heart transplantation (OHT). Outcomes following OHT vary by patient level factors; for example, non-White patients have worse outcomes than White patients after OHT. Failure to rescue is an important factor associated with cardiac surgery outcomes, but its relationship to demographic factors is unknown. Using the United Network for Organ Sharing database, we included all adult patients who underwent primary isolated OHT between 1/1/2006 snd 6/30/2021. FTR was defined as the inability to prevent mortality after at least one of the UNOS-designated postoperative complications. Donor, recipient, and transplant characteristics, including complications and FTR, were compared across race/ethnicity. Logistic regression models were created to identify factors associated with complications and FTR. Kaplan Meier and adjusted Cox proportional hazards models evaluated the association between race/ethnicity and posttransplant survival. There were 33,244 adult, isolated heart transplant recipients included: the distribution of race/ethnicity was 66% (n=21,937) White, 21.2% (7,062) Black, 8.3% (2,768) Hispanic, and 3.3% (1,096) Asian. The frequency of complications and FTR differed significantly by race/ethnicity. After adjustment, Hispanic recipients were more likely to experience FTR than White recipients (OR 1.327, 95% CI[1.075-1.639], P =0.02). Black recipients had lower 5-year survival compared with other races/ethnicities (HR 1.276, 95% CI[1.207-1.348], P <0.0001). In the US, Black recipients have an increased risk of mortality after OHT compared with White recipients, without associated differences in FTR. In contrast, Hispanic recipients have an increased likelihood of FTR, but no significant mortality difference compared with White recipients. These findings highlight the need for tailored approaches to addressing race/ethnicity-based health inequities in the practice of heart transplantation.

Use of Donor Hearts ≥50 Years Old for Septuagenarians in Heart Transplantation

BackgroundThe impact of using donors ≥50 years old on heart transplantation outcomes of septuagenarians is unknown, which may have a potential to expand the donor pool. MethodsFrom January 2011 to December 2021, 817 septuagenarians received donor hearts <50 years old (DON<50) and 172 septuagenarians received donor hearts ≥50 years old (DON≥50) in the United Network for Organ Sharing database. Propensity score matching was performed using recipient characteristics (167 pairs). The Kaplan-Meier method and Cox proportional hazards model were used to analyze death and graft failure. ResultsThe number of heart transplants in septuagenarians has been increasing (54 per year in 2011 to 137 per year in 2021). In a matched cohort, the donor age was 30 years in DON<50 and 54 years in DON≥50. In DON≥50, cerebrovascular disease was the main cause of death (43%), whereas head trauma (38%) and anoxia (37%) were the causes in DON<50 (P < .001). The median heart ischemia time was comparable (DON<50, 3.3 hours; DON≥50, 3.2 hours; P = .54). In matched patients, 1- and 5-year survival rates were 88.0% (DON<50) vs 87.2% (DON≥50) and 79.2% (DON<50) vs 72.3% (DON≥50), respectively (log-rank, P = .41). In the multivariable Cox proportional hazards models, donors ≥50 years old were not associated with death in matched (hazard ratio, 1.05; 95% CI, 0.67-1.65; P = .83) and nonmatched groups (hazard ratio, 1.11; 95% CI, 0.82-1.50; P = .49). ConclusionsThe use of donor hearts older than 50 years can be an effective option for septuagenarians, thereby potentially increasing organ availability without compromising outcomes.

Indexed donor cardiac output for improved size matching in heart transplantation: A United Network for Organ Sharing database analysis

ObjectiveImplantation of an appropriately sized donor heart is critical for optimal outcomes after heart transplantation. Although predicted heart mass has recently gained consideration, there remains a need for improved granularity in size matching, particularly among small donor hearts. We sought to determine if indexed donor cardiac output is a sensitive metric to assess the adequacy of a donor heart for a given recipient. MethodsA retrospective analysis was performed (2003-2021) in isolated orthotopic heart transplant recipients from the United Network for Organ Sharing database. Donor cardiac output was divided by recipient body surface area to compute cardiac index (donor cardiac index). Predicted heart mass ratio was computed as donor/recipient predicted heart mass. The primary outcome was mortality 1 year after transplant. ResultsAmong transplant recipients, median donor cardiac output was 7.3 (5.8-9.0) liters per minute and donor cardiac index was 3.7 (3.0-4.6) liters per minute/m2. Predicted heart mass ratio was 1.01 (0.91-1.13). After multivariable adjustment, higher donor cardiac index was associated with lower 1-year mortality risk (odds ratio, 0.92, P = .042). Recipients with predicted heart mass ratio less than 0.80 (n = 255) had a lower median donor cardiac index than those with a predicted heart mass ratio of 0.80 or greater (3.2 vs 3.7, P < .001). As predicted, heart mass ratio became smaller and the association between donor cardiac index and 1-year mortality became progressively stronger. ConclusionsHigher donor cardiac index was associated with a lower probability of 1-year mortality among patients undergoing heart transplantation and served to further quantify mortality risk among those with a small predicted heart mass ratio. Donor cardiac index appears to be an effective tool for size matching and may serve as an adjunctive strategy among small donor hearts with a low predicted heart mass ratio.

The impact of thoracoabdominal normothermic regional perfusion on early outcomes in donation after circulatory death lung transplantation

Thoracoabdominal normothermic regional perfusion has emerged as an alternative method to procure donation after circulatory death (DCD) hearts, but its impact on concomitantly procured lung allografts remains unclear. The United Network for Organ Sharing database identified 627 DCD donors whose hearts were procured (211 in situ perfused, 416 directly procured) between December 2019 to December 2022. Lung utilization rates were 14.9% (63/422) for in situ perfused donors and 13.8% (115/832) for directly procured donors (p=0.80). Following transplantation, lung recipients from in situ perfused donors required numerically lower rates of extracorporeal membrane oxygenation (7.7% vs 17.0%, p=0.26) and mechanical ventilation (34.6% vs 47.2%, p=0.29) at 72 hours. Six-month post-transplant survival was similar between groups (85.7% vs 89.1%, p=0.67). These results suggest that the use of thoracoabdominal normothermic regional perfusion in DCD heart procurement may not adversely impact recipients of concomitantly procured lung allografts.

Heart retransplant recipients with renal dysfunction benefit from simultaneous heart-kidney transplantation

Given ongoing donor shortages, appropriate patient selection for dual-organ transplantation is critical. We evaluated outcomes of heart retransplant with simultaneous kidney transplant (HRT-KT) vs isolated heart retransplant (HRT) across varying levels of renal dysfunction. The United Network for Organ Sharing database identified 1189 adult patients undergoing heart retransplantation between 2005 and 2020. Recipients undergoing HRT-KT (n=251) were compared to those undergoing HRT (n=938). The primary outcome was 5-year survival; subgroup analyses and multivariable adjustment were performed utilizing the following 3 estimated glomerular filtration (eGFR) groups: <30 ml/min/1.73m2, 30-45 ml/min/1.73m2, and >45 ml/min/1.73m2. HRT-KT recipients were older and had longer waitlist times, longer inter-transplant periods, and lower eGFR levels. HRT-KT recipients were less likely to require pretransplant ventilator (1.2% vs 9.0%, p < 0.001) or ECMO (2.0% vs 8.3%, p < 0.001) support but were more likely to have severe functional limitation (63.4% vs 52.6%, p=0.001). After retransplantation, HRT-KT recipients had less treated acute rejection (5.2% vs 9.3%, p=0.02) and more dialysis requirement (29.1% vs 20.2%, p < 0.001) before discharge. Survival at 5-years was 69.1% after HRT and 80.5% after HRT-KT (p < 0.001). After adjustment, HRT-KT was associated with improved 5-year survival among recipients with eGFR <30 ml/min/1.73m2 (HR:0.42, 95% CI: 0.26-0.67) and 30 to 45 ml/min/1.73m2 (HR:0.29, 95% CI 0.13-0.65), but not among those with eGFR>45 ml/min/1.73sm2 (HR 0.68, 95% CI 0.30-1.54). Simultaneous kidney transplantation is associated with improved survival following heart retransplantation in patients with eGFR <45 ml/min/1.73m2 and should be strongly considered to optimize organ allocation stewardship.

Lung transplantation for COVID-2019 respiratory failure in the United States: Outcomes 1-year posttransplant and the impact of preoperative extracorporeal membrane oxygenation support

ObjectivePatients with end-stage respiratory failure after severe coronavirus disease 2019 (COVID-19) infection may benefit from lung transplant; however, data on transplant outcomes and the impact of prolonged circulatory support before transplant in these patients are limited. MethodsWe assessed survival, postoperative complications, and the impact of pretransplant extracorporeal membrane oxygenation (ECMO) in patients undergoing lung transplant in the United States from August 2020 through March 2022 using records validated by United Network for Organ Sharing experts and extracted from the United Network for Organ Sharing database. ResultsIn 305 patients with COVID-19–related respiratory failure and validated data, survival for up to 1-year posttransplant did not differ between 188 patients with COVID-19–related acute respiratory distress syndrome and 117 patients with post-COVID-19 pulmonary fibrosis (P = .8). Pretransplant ECMO support (median 66 days) was required in 191 patients (63%), and venovenous ECMO was used in 91.2% of patients. One-, 6-, and 12-month survival was not significantly different between patients requiring ECMO and patients without ECMO (95.8% vs 99.1%, 93.1% vs 96.4%, 84.8% vs 90.9%, P = .2) In addition, 1-year survival was similar in recipients requiring ECMO for COVID-19 lung failure and recipients requiring ECMO for non-COVID-19 restrictive lung failure (84.8% vs 78.0%, P = .1). ConclusionsThese findings suggest that lung transplant in patients with COVID-19 respiratory failure yields acceptable 1-year outcomes. Despite an often more complex postoperative course, prolonged ECMO pretransplant in well-selected patients was associated with adequate clinical and functional status.

Improved 3 Year Heart Transplant Survival in Black recipients Following the Affordable Care Act.

To improve healthcare access, the US government implemented the Affordable Care Act (ACA) in 2014. Previous studies investigating its impact on healthcare inequities showed significant improvement in Black transplant recipient outcomes. Our objective is to determine the ACA's impact on Black heart transplant (HTx) recipients. Using the United Network for Organ Sharing database, we analyzed 3,462 Black HTx recipients pre- and post-ACA (January 2009 to December 2012, and January 2014 to December 2017). Black recipient numbers and rates of overall HTx, insurance effects on survival, geographic changes in HTx, and post-HTx survival were compared pre- and post-ACA. Black recipients increased from 1,046 (15.3%) to 2,056 (22.2%) post-ACA (p < 0.001). Three year survival increased among Black recipients (85.8-91.9%, p = 0.01; 79.4-87.7%, p < 0.01; 78.3-84.6%, p < 0.01). Affordable Care Act implementation was protective for survival (hazard ratio [HR] = 0.64 [95% confidence interval [CI], 0.51-0.81], p < 0.01). Publicly insured patient survival increased post-ACA to match that of privately insured (87.3-91.8%, p = 0.001). United Network for Organ Sharing (UNOS) Regions 2, 8, and 11 experienced improved survival post-ACA (p = 0.047, p = 0.02, and p < 0.01, respectively). The post-ACA era showed improved HTx access and survival in Black recipients, indicating that national medical policy may play a strong role in eliminating racial disparities. Further attention is required to improve inequities in medical care.

Living-Donor Liver Transplant and Improved Post-Transplant Survival in Patients with Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is the leading indication of liver transplantation (LT) among autoimmune liver disease patients. There is a scarcity of studies comparing survival outcomes between living-donor liver transplants (LDLT)s and deceased-donor liver transplants (DDLTs) in this population. Using the United Network for Organ Sharing database, we compared 4679 DDLTs and 805 LDLTs. Our outcome of interest was post-LT patient survival and post-LT graft survival. A stepwise multivariate analysis was performed, adjusting for recipient age, gender, diabetes mellitus, ascites, hepatic encephalopathy, cholangiocarcinoma, hepatocellular carcinoma, race, and the model for end-stage liver disease (MELD) score; donor' age and sex were also included to the analysis. According to univariate and multivariate analysis, LDLT had a patient and graft survival benefit compared to DDLT (HR, 0.77, 95% CI 0.65-0.92; p < 0.002). LDLT patient survival (95.2%, 92.6%, 90.1%, and 81.9%) and graft survival (94.1%, 91.1%, 88.5%, and 80.5%) at 1, 3, 5, and 10 years were significantly better than DDLT patient survival (93.2%, 87.6%, 83.3%, and 72.7%) and graft survival (92.1%, 86.5%, 82.1%, and 70.9%) (p < 0.001) in the same interval. Variables including donor and recipient age, male recipient gender, MELD score, diabetes mellitus, hepatocellular carcinoma, and cholangiocarcinoma were associated with mortality and graft failure in PSC patients. Interestingly, Asians were more protected than Whites (HR, 0.61; 95% CI, 0.35-0.99; p < 0.047), and cholangiocarcinoma was associated with the highest hazard of mortality (HR, 2.07; 95% CI, 1.71-2.50; p < 0.001) in multivariate analysis. LDLT in PSC patients were associated with greater post-transplant patient and graft survival compared to DDLT patients.

National Trends, Risk Factors, and Outcomes of Acute In-Hospital Stroke Following Lung Transplantation in the United States: Analysis of the United Network for Organ Sharing Registry

Lung transplantation (LTx) is the definitive treatment for end-stage lung failure. However, there have been no large, long-term studies on the impact of acute in-hospital stroke in this population. What are the trends, risk factors, and outcomes of acute stroke in patients undergoing LTx in the United States? We identified adult first-time isolated LTx recipients from the United Network for Organ Sharing database, which comprehensively captures every transplant in the United States, between May 2005 and December 2020. Stroke was defined as occurring at any time after LTx but prior to discharge. Multivariable logistic regression with stepwise feature elimination was used to identify risk factors for stroke. Freedom from death in patients with a stroke vsthose without a stroke was evaluated with Kaplan-Meier analysis. Cox proportional hazards analysis was used to identify predictors of death at 24months. Of 28,564 patients (median age, 60 years; 60%male), 653 (2.3%) experienced an acute in-hospital stroke after LTx. Median follow-up was 1.2 (stroke) and 3.0 (non-stroke) years. Annual incidence of stroke increased (1.5%in 2005 to 2.4%in 2020; P for trend= .007), as did lung allocation score and utilization of post-LTx extracorporeal membrane oxygenation (P= .01 and P< .001, respectively). Compared with those without stroke, patients with stroke had lower survival at 1month (84%vs98%), 12months (61%vs88%), and 24months (52%vs80%) (log-rank test, P< .001 for all). In Cox analysis, acute stroke conferred a high hazard of mortality (hazard ratio, 3.01; 95%CI, 2.67-3.41). Post-LTx extracorporeal membrane oxygenation was the strongest risk factor for stroke (adjusted OR, 2.98; 95%CI, 2.19-4.06). Acute in-hospital stroke post-LTx has been increasing over time and is associated with markedly worse short- and long-term survival. As increasingly sicker patients undergo LTx as well as experience stroke, further research on stroke characteristics, prevention, and management strategies is warranted.

Demographic inequities exist and influence transplant outcomes in liver transplantation for acute alcohol-associated hepatitis

BackgroundLiver transplantation has inherent disparities but data is scarce in liver transplant (LT) candidates with acute alcohol-associated hepatitis (AAH). We aimed to investigate demographic inequities and its impact on survival outcomes among AAH LT candidates. MethodsA retrospective analysis using the United Network of Organ Sharing database was conducted between 2000 and 2021. 25 981 LT recipients with alcohol-associated liver cirrhosis and 662 recipients with AAH were included. Waitlisted candidates were also evaluated. ResultsIn comparison with alcohol-associated liver cirrhosis, AAH LT recipients were more likely Asian or “other” race and younger. Hispanics demonstrated better graft and patient survival (p < 0.05) but were less likely to be waitlisted and transplanted for AAH than for liver cirrhosis. Women with AAH were more likely to be waitlisted and transplanted. Pre-existing diabetes and male sex were associated with higher graft failure (25% and 8% respectively). Increasing recipient age were 2% more likely to experience negative outcomes. Chronicity of liver disease did not impact graft (p = 0.137) or patient survival (p = 0.145). ConclusionOur results revealed demographic factors have a significant impact on transplant listing, organ allocation and survival outcomes. Further investigations are imperative to minimize disparities in LT evaluation and provide equity in healthcare.

Simultaneous heart-kidney transplant in patients with borderline estimated glomerular filtration rate without dialysis dependency.

Appropriate patient selection for simultaneous heart-kidney transplantation (sHK) in patients with moderate renal dysfunction remains challenging. From the United Network for Organ Sharing database (2003-2020), we identified 5678 adults with an estimated pre-transplant glomerular filtration rate (eGFR) between 30 and 45mL/min/1.73m2 and no pre-transplant dialysis. Patients undergoing sHK (n=293) were compared with those undergoing heart transplantation alone (n=5385) using 1:3 propensity score matching. The sHK utilization rate increased from 1.8% in 2003 to 12.2% in 2020 (p<.001). After matching, 1 and 5-year survival was 87.7% (95% confidence interval [CI] 83.3-91.0) and 80.0% (95% CI 74.2-84.6) after sHK, and 87.3% (95% CI 85.2-89.1) and 71.8% (95% CI 68.4-74.9) after heart transplant alone (p=.04). In the subgroup analysis, sHK was associated with a 5-year survival benefit only in patients with 30<eGFR≤35mL/min/1.73m2 (p=.05) but not in those with 35<eGFR<45mL/min/1.73m2 (p=.45). Patients who underwent heart transplants alone also had a higher incidence of becoming chronic dialysis-dependent after transplant within 5-year follow-up (10.2%, 95% CI 8.0-12.6 vs. 3.8%, 95% CI 1.7-7.1, p=.004). The 5-year incidence of subsequent kidney waitlisting and transplants after heart transplants alone was 5.6% and 1.9%, respectively. Among propensity-matched patients without pre-transplant dialysis, compared to heart transplants alone, sHK had improved 5-year survival in those with 30<eGFR≤35 but not in those with 35<eGFR<45mL/min/1.73m2 . One-year survival was similar irrespective of eGFR. Receiving a kidney after a heart transplant alone is rare under the current allocation system.

Prevalence of pulmonary hypertension in patients with COVID-19 related lung disease listed for lung transplantation: A UNOS registry analysis.

COVID-19 related lung disease (CRLD) has emerged as an indication for lung transplantation (LT) in highly select patients. The prevalence and prognostic implication of coexisting pulmonary hypertension (PH) in patients with CRLD listed for LT is not known. Adult patients in the United Network for Organ Sharing database listed for LT for COVID-19 related acute respiratory distress syndrome or fibrosis through March 2022 were identified. The prevalence and impact of precapillary PH on pre- and posttransplantation survival was determined. Time-to-event analysis was used to compare outcomes between those with and without precapillary PH. We identified 245 patients listed for LT for CRLD who had right heart catheterization data available at the time of registry listing. Median age of the cohort was 54 years (interquartile range [IQR]: 46, 60), 56 (22.9%) were female, and the median lung allocation score was 81.3 (IQR: 53.3, 89.4). The prevalence of precapillary PH at the time of transplant listing was 27.9%. There was no significant difference in pretransplant mortality in patients with and without precapillary PH (sHR: 0.5; 95% confidence interval [CI]: 0.1-1.7, p = 0.261). A total of 187 patients ultimately underwent LT; of those, 60 (31.0%) were identified as having precapillary PH during the waitlist period. Posttransplantation survival was similar between patients with and without pretransplant precapillary PH (hazard ratio: 0.96; 95% CI: 0.2-3.7, p = 0.953). We observed a high rate of concomitant precapillary PH in patients listed for LT for CRLD. Though common, coexisting precapillary PH was not associated with a significant difference in either pre- or post-transplantation outcomes.

Waitlist Mortality and Extracorporeal Membrane Oxygenation Bridge to Lung Transplant

BackgroundUse of extracorporeal membrane oxygenation (ECMO) as bridge to lung transplant has increased. However, little is known about patients placed on ECMO who die while on the waiting list. Using a national lung transplant data set, we investigated variables associated with waitlist mortality of patients bridged to lung transplant. MethodsAll patients supported on ECMO at time of listing were identified using the United Network for Organ Sharing database. Univariable analyses were performed using bias-reduced logistic regression. Cause-specific hazard models were used to determine the effect of variables of interest on hazard of outcomes. ResultsFrom April 2016 to December 2021, 634 patients met inclusion criteria. Of these, 445 (70%) were successfully bridged to transplant, 148 (23%) died on the waitlist, and 41 (6.5%) were removed for other reasons. Univariable analysis found associations between waitlist mortality and blood group, age, body mass index, serum creatinine, lung allocation score, days on waitlist, United Network for Organ Sharing region, and being listed at a lower-volume center. Cause-specific hazard models demonstrated that patients at high-volume centers were 24% more likely to survive to transplant and 44% less likely to die on the waitlist. Among patients who were successfully bridged to transplant, there was no difference in survival between low- and high-volume centers. ConclusionsECMO is an appropriate strategy to bridge selected high-risk patients to lung transplant. Of those placed on ECMO with intent to transplant, about one quarter may not survive to transplantation. High-risk patients requiring advanced support strategies may be more likely to survive to transplant when bridged at a high-volume center.