United Network For Organ Sharing Research Articles

Improvement in patient selection, management, and outcomes in infant heart transplant from 2000 to 2020.

The study's primary outcome was to evaluate if post-transplant survival has improved over the last two decades. Secondary outcomes were the infant's waitlist mortality, waitlist time, and identifying factors that affected the infant's survival. United Network for Organ Sharing (UNOS) database was queried for infants (age ≤ 1) who were listed for heart transplantation between 2000-2020. The years were divided into three eras (Era 1 2000-2006, Era 2 2007-2013, and Era 3 2014-2020). Non-parametric tests, Chi-Squared, Log-Rank test, and Cox-Proportional hazard ratio were used for analysis (alpha = 0.05). 4234 infants were listed for heart transplants between 2000 and 2020. At the time of listing, Infants in era 3 were more likely to be heavier (in kg (p < 0.001) and had better renal function (p < 0.001). Additionally, they were less likely to be on dialysis (p < 0.001), on a ventilator (p < 0.001), and on ECMO (p < 0.001). There has been a significant increase in LVAD use (p < 0.001), though there was no difference in waitlist (0.154) or post-transplant survival (0.51). In all three eras, waitlist survival (p < 0.001) and post-transplant survival (p < 0.001) have improved significantly. CHD and ECMO were associated with worse waitlist survival in all three eras (p < 0.05). Infants are now waiting longer on the waitlist (in days) (33 Era 1 v. 46 Era 2 v. 67 Era 3, p < 0.001). Infant heart transplant outcomes have improved, but they are now waiting longer on the waitlist. Further improvement in increasing the donor pool, expert consensus on listing strategies, and donor utilization is needed to improve outcomes.

Does the introduction of acuity circle policy change split liver transplantation practice?

With the Acuity Circles (AC) policy aiming to reduce disparities in liver transplantation (LT) access, the allocation of high-quality grafts has shifted, potentially affecting the use and outcomes of split LT. Data from the United Network for Organ Sharing (UNOS) database (February 4, 2016, to February 3, 2024) were analyzed, including 1,470 candidates who underwent deceased donor split LT, with 681 adult and 789 pediatric cases. The study periods were divided into pre-AC (February 4, 2016, to February 3, 2020) and post-AC (February 4, 2020, to February 3, 2024). The study assessed changes in split LT volumes and examined the impact of center practices. Both adult and pediatric split LTs decreased in the initial three years post-policy change, followed by an increase in the final year, with an overall 11.9% and 13.9% decrease between the eras. Adult female split LT cases remained consistent, ensuring access for smaller recipients. High-quality "splittable" livers were increasingly allocated to high MELD patients (MELD-Na ≥30). Despite the overall decrease in case volume, adult split LT volume increased in newly active LDLT centers, with six centers increasing LDLT volume by over 50.0%. Pediatric split LT volumes decreased despite additional priorities for pediatric candidates. The number of split LTs decreased in the initial period after the AC policy introduction, but there was a consistent need for small female candidates. In the adult population, LDLT and split LT demonstrated a synergistic effect in boosting center transplant volumes, potentially improving access for female candidates who need small grafts.

Outcomes of Multiorgan Heart Transplant Between Donation After Circulatory Death and Brain Death.

There is insufficient data on the outcomes of donation after circulatory death (DCD) multiorgan transplant that includes heart. The primary objective of this study is to compare the overall survival outcomes of DCD and donation after brain death (DBD) multiorgan transplants. We identified all heart transplant patients from 2019 to June of 2023 using the United Network for Organ Sharing (UNOS) Database who also received an additional organ (kidney, liver, and lungs). A total of 1,844 DBD and 91 DCD multiorgan transplants occurred within the study period, the majority being combined heart-kidney transplantation. More patients were listed at a higher status in the DBD group (p < 0.05) and were in the intensive care unit (ICU) before transplant (p < 0.05). Despite the higher ischemia time in the DCD group (p < 0.05), the overall unmatched survival did not differ between the two groups (p < 0.05). Within the heart-kidney transplants, the overall survival between DBD and DCD heart-kidney transplants did not differ in either unmatched or matched groups (unmatched p = 0.5, matched p = 0.5). In conclusion, the data on the outcomes of DCD multiorgan transplants are limited. Still, our analysis of the currently available data suggests that the overall survival is comparable in the DCD multiorgan transplants.

Outcomes of Donation After Circulatory Death (DCD) and Ex-Vivo Lung Perfusion (EVLP) Lung Transplantation

BackgroundDonation after circulatory death (DCD) and ex-vivo lung perfusion (EVLP) have been adopted to expand the donor pool in lung transplantation, but outcomes data have been conflicting. This study explores mid-term outcomes of DCD lung transplantation in the modern era, with a focus on EVLP and risk factors for graft failure. MethodsThe United Network for Organ Sharing (UNOS) database was queried for adult lung transplants from 1/1/2015 to 3/1/2023. Loss to follow-up, multiorgan and prior lung transplants were excluded. DCD vs DBD (donation after brain death) lung transplants were compared, with subgroup analysis +/- EVLP. Outcomes were survival and postoperative complications. Overall survival was analyzed separately for an early era (2015-2018) and modern era (2019-2023). ResultsThe study included 1103 DCD (221 with EVLP, and 882 without) and 17973 donation after brain death (DBD) lung transplants (524 with EVLP, and 17449 without). Median follow-up was 3 years. DCD donors were less likely to be CDC high risk (19.3% vs 24.1%, p<0.001), have purulence on bronchoscopy (13.3% vs 18.3%, p<0.001) or infiltrates on chest x-ray (66.7% vs 67.8%, p=0.013). EVLP was more likely to be used for DCD transplants (20.0% vs 2.9%, p<0.001).After transplant, DCD recipients were more likely to be reintubated (24.3% vs 18.5%, p<0.001) and require ECMO within 72 hours (14.9% vs 7.8%, p<0.001), and DCD donation was an independent risk factor for these complications on multivariable logistic regression. Overall survival did not differ significantly between DCD and DBD transplants on adjusted survival analysis in the early or modern era (p=0.774 and p=0.468 respectively). On multivariable Cox regression, DCD and EVLP were not independent risk factors for mortality.On subgroup analysis, the DCD+EVLP cohort had significantly worse survival in the modern era, which remained significant after adjusting for donor and recipient factors (p=0.005). EVLP was an independent risk factor for graft failure in the DCD cohort (HR 1.33, 95% CI 1.00-1.77, p=0.047), but did not significantly affect DBD graft survival (p=0.870). Risk factors for graft failure and mortality in the DCD+EVLP cohort included pulmonary hypertension (HR 77.5, 95% CI 6.15-979, p<0.001), transfusion prior to transplant (HR 2.60, 95% CI 1.07-6.31, p=0.035), elevated creatinine (HR 2.82, 95% CI 1.34-5.90, p=0.006), and higher allocation score (HR 1.02, 95% CI 1.00-1.04, p=0.017) ConclusionStudy findings suggest increased risks of mortality and perioperative complications following transplantation with DCD lungs that have undergone EVLP. DCD lung transplantation without EVLP confers equivalent survival but with some increase in perioperative complications. Further investigation and careful recipient selection is warranted to optimize the use of these extended criteria donors in the modern era.

Gender Dynamics In Organ Donation And Transplantation: An Analysis Of Donor And Recipient Trends

Organ donation and transplantation represent critical components of modern medicine, offering life-saving solutions for individuals with organ failure. Despite advancements in medical practices, significant gender disparities exist within these processes, where women disproportionately contribute as donors while men are predominantly recipients. This study integrates an in-depth statistical analysis of data from major registries like the United Network for Organ Sharing (UNOS) and the Organ Procurement and Transplantation Network (OPTN), utilizing chi-square tests, logistic regression, multivariate analysis, and stratified sampling to elucidate these trends. By combining quantitative data with socio-cultural theories, this research aims to uncover the multifaceted causes behind these gender-based discrepancies, revealing that social conditioning, altruistic behaviour, and systemic biases in medical practices play crucial roles. The results indicate statistically significant correlations between gender and donor/recipient status, suggesting that both traditional gender roles and healthcare biases need to be addressed to create a more equitable organ donation system. The study concludes by proposing policy reforms and advocacy strategies to foster gender neutrality in organ transplantation, ultimately promoting a fairer healthcare paradigm.

The association between pretransplant malignancy and post-transplant survival and cancer recurrence in bilateral lung transplantation: An analysis of 23,291 recipients

BackgroundGiven the increasing need for lung transplants among older patients with a history of cancer, this study analyzed database registry to assess outcomes for BLT recipients with Pre-TM. MethodsThis study evaluated the United Network for Organ Sharing (UNOS) registry for adult BLT performed between 2005 and 2023. Patients with a history of previous or multi-organ transplants, and those with donors who had cancer history, were excluded. Propensity-score matching was used to compare patients with or without Pre-TM. Overall and Post-TM-free survival were analyzed. ResultsAmong the 23,291 recipients of BLT, 8.0%(1,870) had Pre-TM. Compared to those without Pre-TM, patients with Pre-TM had worse overall (hazard ratio[HR] 1.20, 95% confidence interval[CI] 1.12-1.29, p<0.001) and Post-TM-free survival (HR 1.32, 95% CI 1.24-1.41, p<0.001). However, after adjusting for age, sex, and race through propensity-score matching, the survival difference between the groups became non-significant (HR 1.05, 95% CI 0.97-1.13, p=0.229). While the Pre-TM group still had worse Post-TM-free survival, this difference diminished after excluding cutaneous Post-TM (HR 1.06, 95% CI 0.99-1.15, p=0.116). Additionally, the recurrence rate of Pre-TM after transplant wasn't higher than de novo cancers in patients without Pre-TM. ConclusionPatients with Pre-TM had similar overall survival rates after BLT as those without Pre-TM. Importantly, there was no increased risk of the primary Pre-TM type recurring post-transplant compared to patients without Pre-TM. If patients with PreTM are free from recurrence or metastasis for a significant amount of time, there could be some who can benefit from BLT. Further data regarding timeline between PreTM and BLT would be necessary to draw conclusion in this issue.

Ambient Air Pollution Exposure and Outcomes in Patients Receiving Lung Transplant

Elevated ambient fine particulate matter (PM2.5) air pollution exposure has been associated with poor health outcomes across several domains, but its associated outcomes among lung transplant recipients are poorly understood. To investigate whether greater PM2.5 exposure at the zip code of residence is associated with a higher hazard for mortality and graft failure in patients with lung transplants. This retrospective cohort study used panel data provided by the United Network for Organ Sharing, which includes patients receiving transplants across all active US lung transplant programs. Adult patients who received lung transplants between May 2005 and December 2016 were included, with a last follow-up of September 10, 2020. Data were analyzed from September 2022 to May 2023. Zip code-level annual PM2.5 exposure was constructed using previously published North American estimates. The primary outcome was time to death or lung allograft failure after lung transplant. A gamma shared frailty Cox proportional hazards model was used to produce unadjusted and adjusted hazard ratios (HRs) to estimate the association of zip code PM2.5 exposure at the time of transplant with graft failure or mortality. Among 18 265 lung transplant recipients (mean [SD] age, 55.3 [13.2] years; 7328 female [40.2%]), the resident zip code's annual PM2.5 exposure level was greater than or equal to the Environmental Protection Agency (EPA) standard of 12μg/m3 for 1790 patients (9.8%) and less than the standard for 16 475 patients (90.2%). In unadjusted analysis, median graft survival was 4.87 years (95% CI, 4.57-5.23 years) for recipients living in high PM2.5 areas and 5.84 years (95% CI, 5.71-5.96 years) for recipients in the low PM2.5 group. Having an annual PM2.5 exposure level greater than or equal to the EPA standard 12 μg/m3 was associated with an increase in the hazard of death or graft failure (HR, 1.11; 95% CI, 1.05-1.18; P < .001) in the unadjusted analysis and after adjusting for covariates (HR, 1.08; 95% CI, 1.01-1.15; P = .02). Each 1 μg/m3 increase in exposure was associated with an increase in the hazard of death or graft failure (adjusted HR, 1.01; 95% CI, 1.00-1.02; P = .004) when treating PM2.5 exposure as a continuous variable. In this study, elevated zip code-level ambient PM2.5 exposure was associated with an increased hazard of death or graft failure in lung transplant recipients. Further study is needed to better understand this association, which may help guide risk modification strategies at individual and population levels.

Current Burden of and Geographic Disparities in Liver Mortality and Access to Liver Transplant

Liver disease is a leading cause of mortality in the US. Liver transplant can be a lifesaving procedure for patients with severe liver disease. To assess temporal trends and geographic variance in liver-related mortality (LRM) and liver transplant in the US. In this cohort study, the frequencies and geographic variance of LRM in 2018 and 2021 were obtained in a cross-sectional analysis of the Underlying Cause of Death data available on the Centers for Disease Control and Prevention's Epidemiologic Research database. The number of livers donated and transplanted according to the state of residence of each donor and recipient were obtained from the United Network for Organ Sharing. Liver-related mortality in 2018 and 2021, overall and by state, as well as the liver transplant rate according to state of residence of recipient and donor. Overall LRM in the US was 93 418 in 2021, with a crude rate of 28.1 per 100 000 individuals, an increase of 19.1% compared with rates seen immediately prior to the COVID-19 pandemic in 2018 (77 282 [23.6 per 100 000 individuals]). Liver-related mortality in 2021 varied several-fold between states, from 18.4 per 100 000 individuals per year in Utah to 65.9 per 100 000 individuals per year in New Mexico. The mean number of liver-related deaths per transplant from all donor sources (in state and out of state) was 7.2 in the lowest LRM quintile compared with 21.5 in the highest (95% CI, 12.1-16.6; SE, 1.1; P < .001). Ten states had no liver transplant center. Paradoxically, residents of states with the highest LRM had a much lower rate of liver transplant (at any location) from organs procured from in-state residents than states with the lowest LRM quintile (13.0% vs 35.2% in-state donors; 95% CI, 14.1%-30.3%; SE, 3.9%; P < .001). This study suggests that rates of LRM have increased dramatically since the COVID-19 pandemic and vary several-fold between states. Rates of liver transplant are paradoxically lowest among residents living in states with the highest LRM. These findings highlight apparent geographic disparities in access to liver transplant that allocation policy cannot address.

Multidisciplinary approaches to downstaging hepatocellular carcinoma: present and future.

Downstaging of hepatocellular carcinoma (HCC) is typically defined as the reduction in size or number of viable tumors through locoregional therapy (LRT), aiming to meet the established criteria for liver transplantation (LT). According to the Barcelona Clinic Liver Cancer (BCLC) staging system, a subgroup of patients with BCLC-B may benefit most from downstaging therapies. The United Network Organ Sharing downstaging protocol identifies potential candidates for downstaging by setting out 'inclusion criteria' and defining 'successful downstaging.' Additionally, the protocol considers factors related to tumor biology, such as an alphafetoprotein level <500 ng/mL after LRT. Reports indicate that successful downstaging rates following LRT are about 50%, with post- LT recurrence rates comparable to those of patients within the Milan criteria. A comprehensive multicenter US study on 10-year outcomes post-LT after downstaging showed 10-year post-LT survival and recurrence rates of 52.1% and 20.6%, respectively, for patients whose disease was downstaged; this compares to 61.5% and 13.3% for those consistently within the Milan criteria. Recently, the development of effective systemic treatments for HCC, such as immuno-oncologic agents, has provided additional opportunities for downstaging. Numerous clinical trials are exploring a multidisciplinary approach (MDA) combining LRT and systemic therapy. Although concrete evidence of the superiority of MDA for HCC downstaging is lacking, some retrospective studies and phase I and II trials have shown promising results regarding the efficacy and safety of MDA for this purpose. In this review, we will also discuss the future of MDA protocols in downstaging for improved clinical outcomes.

Regional disparities in heart transplant mortality in the United States.

Mortality after heart transplantation can be influenced by multiple factors. This study analyzed its variation across 4 regions of the United States. Analyze the differences in mortality among patients receiving a heart transplant across 4 regions of the United States. Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) registry was analyzed for adult heart transplant recipients from 1987-2023. They were divided into 4 regions according to heart transplant recipients' residence: the Northeast, Midwest, South, and West. The endpoint was all-cause mortality. A total of 33,482 heart transplant recipients were included in the analysis. Baseline characteristics differed by region. The median survival (years) was lower in the South [Northeast 12.9 (6.1-17.9), Midwest 13.1 (6.5-18.1), South 11.6 (5.3-16.8), West 13.6 (7.0-18.6); p<0.0001]. Mortality incidence rate was greater in the South. When compared to the Northeast, in the unadjusted analysis, mortality was higher in the South [HR 1.13 (95%CI 1.07-1.19), p<0.001] and lower in the West [HR 0.89 (95%CI 0.83-0.94), p<0.001]. After adjusting for demographic and clinical variables, only the South retained significant differences [HR 1.17 (95%CI 1.10-1.24), p<0.001]. Mortality significantly increased in all regions after 2018. Mortality of heart transplant recipients varies across region of residence in the United States. A significant increase in adjusted mortality was observed in the South. These findings suggest that there are regional disparities in the mortality rates of heart transplant recipients.

Impact of Functional Status at the Time of Transplant on Short-Term Pediatric Lung Transplant Outcomes in the USA.

Poor functional status is associated with pediatric lung transplant (LTx) waitlist mortality. We investigate how pre-transplant functional status affects post-LTx survival. A retrospective analysis was performed using The United Network for Organ Sharing (UNOS) Registry data. Pediatric first-time lung transplant candidates between ages 1 and 18years with reported Lansky Play-Performance Scores (LPPS) at the time of waitlist and/or transplant were included from 2005 and 2021. Functional status by the LPPS scores is defined as severe limitation for LPPS score 10-40, mild limitation for LPPS score 50-70, and normal activity for LPPS score 80-100. Univariate analyses, multivariable Cox regression, and Kaplan-Meier plots were used to assess the impact of functional status on 1-year post-LTx survival. There were 913 and 610 patients at the time of LTx listing and transplant with LPPS scores, respectively. Poor functional status as determined by the LPPS score at the time of LTx, but not at the time of waitlist, was associated with worse 1-year post-LTx outcome (p value 0.0025 vs. 0.071). Multivariable survival analysis using Cox proportional hazards regression identified that a severely limited functional status at the time of LTx was the most profound risk factor for worse 1-year post-LTx survival outcomes when compared to a normal functional status (HR 2.16; 95% CI 1.15-4.07, p value 0.017). Children with severely limited functional status at the time of LTx have worse 1-year post-LTx outcome. It is important to develop strategies to optimize the functional status of children for improved post-LTx outcomes.

The Association Between Pulmonary Vascular Resistance and Posttransplant Outcomes Differs by Left Ventricular Assist Device Status.

Elevated pulmonary vascular resistance (PVR) is a risk factor for mortality after heart transplantation (HT), but whether this association differs for patients with and without left ventricular assist device (LVAD) support before HT is unknown. We analyzed adult first-time HT recipients from the United Network for Organ Sharing (UNOS) registry transplanted between 2010 and 2021. We quantified the association between PVR and the outcomes of 30 day graft failure and 1 year mortality using multivariable logistic regression, stratified by LVAD support status at the time of HT. Pulmonary vascular resistance was modeled using restricted cubic splines to identify clinically relevant risk thresholds. We also examined the association with 10 year survival using multivariable Cox proportional hazards regression. For PVR values less than approximately 2 WU, higher PVR was independently associated with a higher risk of early graft failure (odds ratio [OR] = 1.58, 95% CI: 1.06-2.36) and a higher risk of 1 year mortality (OR = 1.32, 95% CI: 1.10-1.59) among LVAD patients only (interaction p = 0.023 and 0.03, respectively). However, for patients surviving at least 1 year, PVR was not associated with long-term mortality among either subgroup. Whether more aggressive reduction of PVR among HT candidates supported with LVADs can mitigate these risks requires further study.

Transplantation Outcomes in Hepatitis C Virus-Positive Donor Hearts After Circulatory Death

Although the use of hepatitis C virus (HCV)-positive hearts has been shown to be safe and effective among donors with donation after brain death (DBD), it remains unknown whether such organs recovered after circulatory death (DCD) have similar outcomes. In contradistinction to recovery from DBD using cold static organ storage, DCD procurement processes typically use normothermic-perfusion transport strategies that necessitate the use of a large volume of donor blood and involve exposure to temperatures oscillating between cold to dominantly normothermic conditions. We performed a retrospective analysis of United Network for Organ Sharing (UNOS) registry data in the United States and found that clinical outcomes do not differ with respect to rates of treated allograft rejection, early and 1-year survival. Ideally, the organ-recovery source should not result in a bias in organ-offer acceptance from HCV-positive donors, although long-term outcome data are yet unavailable.

Sex-mismatching in isolated heart transplantation confers no postoperative risk

BackgroundFor heart transplantation, optimal donor-recipient matching is an important factor in the ongoing development of the United Network for Organ Sharing (UNOS) continuous distribution framework. Donor-recipient sex-mismatch has decreased since the 1990s, but this may be related to the risk posed by size mismatching, particularly when donor hearts are undersized. Thus, the impact of sex-mismatching, controlling for other factors including size mismatch, is uncertain. MethodsAdult first-time, isolated heart transplant patients from the UNOS database between October 1, 1987 and December 31, 2022 were analyzed. Cohorts were separated into male and female recipients. Propensity score matching on known preoperative risk factors was performed. Equivalence testing via Two One-Sided Testing (TOST) was performed to assess between-arm equivalence in postoperative outcomes. Survival differences were measured by the between-arm ratio of Restricted Mean Survival Time and binary outcome differences by the Odds Ratio (OR). ResultsIn the propensity matched cohort, we found significant equivalence between arms in both male (TOST P<0.001) and female (TOST P<0.001) recipients for overall survival at all temporal endpoints, postoperative treatment for rejection within one year, and pre-discharge dialysis. ConclusionsSex-mismatch in isolated heart transplantation confers no additional risk to postoperative outcomes when controlling for other factors, including size mismatch. Consequently, sex-mismatch should not factor into individual assessments of organ acceptance or be incorporated into any national organ allocation policy. Increasing the acceptance of sex-mismatched donors has the potential to expand the donor pool and increase female donor utilization.

Highly Sensitized Kidney Transplant Outcomes After the 2014 Kidney Allocation System Change.

Introduction: Kidney Allocation System (KAS) was implemented by United Network for Organ Sharing in 2014 to reduce allocation disparities. Research Questions: Outcomes of highly sensitized patients (calculated panel reactive antibody (cPRA) ≥ 97%) before and after KAS were compared to low-risk recipients (cPRA <10%) in the post-KAS era were examined. The impact on racial disparities was determined. Design: This was a retrospective study of national registry data. Two cohorts of adult candidates waitlisted for deceased donor transplantation during 3-year periods before and after KAS were identified. Results: Highly sensitized patients (N = 1238 and 4687) received a deceased donor kidney transplant between January 1, 2011 and December 31, 2013 and between January 1, 2015 and December, 31, 2017. Racial disparity for highly sensitized patients improved, yet remained significant (P < 0.001), with Black patients comprising 40% and 41% of the highly sensitized candidates and 28% and 34% of the recipients pre- and post-KAS. While posttransplant death-censored graft failure for highly sensitized recipients was similar overall, post-KAS was associated with improved graft survival in the first year after transplant (HR 0.56, 95% CI 0.40-0.78). When compared to contemporaneous lowrisk recipients, both death-censored and all-cause graft failure were similar for highly sensitized recipients and was associated with increased risk for death-censored graft failure beyond the first year (HR 1.39, 95% CI 1.11-1.73). Conclusion: The allocation system led to an increase in transplantation in highly sensitized candidates without compromising outcomes. Although KAS has led to more balanced transplant rates between highly sensitized Black and White patients, racial inequalities persist.

Risk factors and prognostic modeling in bridging extracorporeal membrane oxygenation patients before lung transplantation.

The increased use of preoperative extracorporeal membrane oxygenation (ECMO) as a life support system before lung transplantation demands a better understanding of the associated prognostic factors. This study aims to discern the critical factors influencing the survival outcomes of ECMO patients and design a prognostic model tailored to this patient group. We retrospectively gathered and analyzed baseline and clinical data of patients who underwent preoperative bridging ECMO before lung transplantation from the United Network for Organ Sharing (UNOS) database. Univariate and multivariate Cox regression analyses were conducted and a prognostic model was generated to identify the independent factors influencing survival outcomes in these patients. The predictive model was cross-validated using the k-fold method where k=5. Our study included 1,202 patients. Both single and multiple analyses showed that age over 51 years, high body mass index (BMI), a history of dialysis before transplantation, donor hypertension, prolonged cold ischemia time, and high serum total bilirubin are adverse prognostic factors for the survival of ECMO-bridged lung transplant patients. Using the multivariate analysis, we created a prognosis model and a nomogram to predict 1-year post-transplant survival, with a receiver operating characteristic (ROC) curve area of 0.760 in internal validation. The 1-year survival rate calibration curve supported the nomogram's accuracy. This study involved the development of a survival prognosis model for patients undergoing lung transplantation with preoperative ECMO bridging, which was validated through extensive data analysis. The prognosis model exhibited high accuracy and predictive capability, effectively predicting the survival outcomes of patients both pre- and post-surgery.

Racial and ethnic disparities in post-liver transplant outcomes for patients with acute-on-chronic liver failure: An analysis of the UNOS database.

The incidence of hospitalisations related to acute-on-chronic liver failure (ACLF) is increasing. Liver transplantation (LT) remains the definitive treatment for the condition. To evaluate the influence of race and ethnicity on LT outcomes in ACLF. We conducted a retrospective analysis utilising LT data from the United Network for Organ Sharing (UNOS) database. White patients served as the control group and patients of other races were compared at each ACLF grade. The primary outcomes assessed were graft failure and all-cause mortality. Blacks exhibited a higher all-cause mortality (Grade 1: aHR 1.36, 95% CI 1.18-1.57, p < 0.001; Grade 2: aHR 1.27, 95% CI 1.08-1.48, p = 0.003; Grade 3: aHR 1.19, 95% CI 1.04-1.37, p = 0.01) and graft failure (Grade 1: aHR 2.05, 95% CI 1.58-2.67, p < 0.001; Grade 2: aHR 1.91, 95% CI 1.43-2.54, p < 0.001; Grade 3: aHR 1.50, 95% CI 1.15-1.96, p = 0.002). Hispanics experienced a lower all-cause mortality at grades 1 and 3 (Grade 1: aHR 0.83, 95% CI 0.72-0.96, p = 0.01; Grade 3: aHR 0.80, 95% CI 0.70-0.91, p < 0.001) and Asians with severe ACLF demonstrated decreased all-cause mortality (Grade 3: aHR 0.55, 95% CI 0.42-0.73, p < 0.001). Black patients experienced the poorest outcomes and Hispanic and Asian patients demonstrated more favourable outcomes compared to Whites.

Application of donor predicted heart mass in heart transplant recipients with left ventricular assist device

IntroductionAn association between predicted heart mass (PHM) and post heart transplantation outcomes has been well established; however, there is limited data on the effect of donor PHM on recipients bridged with a durable left ventricular assist device (LVAD). This retrospective observational study seeks to challenge the theoretical benefit of oversizing donor hearts for recipients bridged with LVADs. MethodsAnalysis of the United Network for Organ Sharing (UNOS) database revealed 10,806 adult patients with one of three durable LVADs (HeartMate 2, HeartMate 3 [HM3], HeartWare [HVAD]) between January 1, 2015 and December 31, 2021. Baseline characteristics were compared between seven equally sized groups based on donor-to-recipient PHM. Univariable and multivariable Cox regression analyses were constructed to evaluate the effect of PHM size-matching on the primary outcome of 1-year post-transplant survival. Further analyses were performed specifically on HM3 patients and with PHM as a continuous variable. ResultsMultivariable analysis revealed that severely undersized donor hearts (PHM ratio < 0.86) resulted in worse outcomes with respect to 1-year mortality (HR 1.30; CI 1.03-1.64, p=0.03). There was no significant benefit to oversizing donor hearts. Similar results were found in patients bridged to transplant with HM3. ConclusionSimilar to prior studies on heart transplant recipients, recipients bridged with durable LVAD had worse outcomes when using severely undersized donor hearts. Oversized donor hearts did not significantly improve 1-year mortality, compared to size-matched references. These results were consistent in a subgroup analysis of patients bridged only with HM3 LVADs.

Extended ischemic times during exvivo lung perfusion is not associated with increased mortality.

The purpose of this study was to identify the association of increasing ischemic times in recipients who receive lungs evaluated by exvivo lung perfusion (EVLP) and their association with outcomes following lung transplantation. Lung transplant recipients who received an allograft evaluated by EVLP were identified from the United Network for Organ Sharing (UNOS) Database from 2016-2023. Recipients were stratified into three groups based on total ischemic time (TOT): short TOT (STOT, 0 to <7 h), medium TOT (MTOT, 7> to <14 h), and long TOT (LTOT, +14 h). The groups were assessed with comparative statistics and Kaplan-Meier methods. A Cox regression was created to determine the association of ischemic time in EVLP donors and long-term mortality. Recipients in the LTOT group had significantly longer length of stay and post-operative extracorporeal membrane use at 72 h (p < 0.05 for both). Additionally, they had nonsignificant increases in rate of stroke (4.7%, p = 0.05) and primary graft dysfunction grade 3 (PGD3, 27.5%, p = 0.082). However, there was no significant difference in hospital mortality or mid-term survival (p > 0.05 for both). On multivariable analysis, ischemic time was not associated with increased mortality whereas increasing recipient age, preoperative ECMO use and donation after circulatory death donors were (p < 0.05 for all). If EVLP technology is available, under certain circumstances, surgeons should not be dissuaded from using an allograft with extended ischemic time.

Three-year outcomes after bridge to transplantation ECMO—pre- and post-2018 UNOS revised heart allocation system

BackgroundUtilization of temporary mechanical circulatory support including veno-arterial extra-corporeal membrane oxygenation (VA-ECMO) as a bridge to heart transplantation (HT) has increased significantly under the revised United Network for Organ Sharing (UNOS) donor heart allocation system since October 2018. The revised heart allocation system aimed to lower waitlist times and mortality for the most critically ill patients requiring bi-ventricular, non-dischargeable, mechanical circulatory support. While previous reports have shown improved 1-year post-HT survival in the current Era, 3-year survival and factors associated with mortality among bridge to transplant (BTT) ECMO patients are not well described. MethodsWe queried the UNOS database for all adult (age ≥ 18 years) heart-only transplants performed between 2010 and 2019. Patients were stratified as either pre- (January 2010 to September 2018; Era 1) or post-allocation change (November 2018 to December 2019; Era 2) cohort based on their HT date. Baseline recipient characteristics and post-transplant outcomes were compared. A Cox regression analysis was performed to explore risk factors for 3-year mortality among BTT-ECMO patients in Era 2. For each Era, 3-year mortality was also compared between BTT ECMO patients and those transplanted without ECMO support. ResultsDuring the study period, 116 patients were BTT ECMO during Era 1 and 154 patients during Era 2. Baseline recipient characteristics were similar in both groups. Median age was 48 (36-58 IQR) years in Era 2 while it was 51 (27-58 IQR) years in Era 1. Majority of BTT-ECMO patients were males in both Era 2 and Era 1 (77.7% vs 71.5%, p = 0.28). Median ECMO run times while listed for HT were significantly shorter (4 days vs 7 days, p < 0.001) in Era 2. Waitlist mortality among BTT ECMO patients was also significantly lower in Era 2 (6.3% vs 19.3%, p < 0.001). Post-HT survival at 6 months (94.2% vs 75.9%, p < 0.001), 1 year (90.3% vs 74.2%, p < 0.001), and 3 years (87% vs 66.4%, p < 0.001) was significantly improved in Era 2 as compared to Era 1. Graft failure at 1 year (10.3% vs 25.8%, p = 0.0006) and 3 years (13.6% vs 33.6%, p=0.0001) was also significantly lower in Era 2 compared to Era 1. Three-year survival among BTT ECMO patients in Era 2 was similar to that of patients transplanted in Era 2 without ECMO support (87% vs 85.7%, p=0.75). In multi-variable analysis of BTT-ECMO patients in Era 2, every 1 kg/m2 increase in body mass index (BMI) was associated with higher mortality at 3 years (HR 1.09, 95% CI 1.02-1.15, p = 0.006). Similarly, both post-HT stroke (HR 5.58, 95% CI 2.57-12.14, p < 0.001) and post-HT renal failure requiring hemodialysis (HR 4.36, 95% CI 2.43-7.82, p < 0.001) were also associated with 3-year mortality. ConclusionThree years post-HT survival in patients bridged with ECMO has significantly improved under the revised donor heart allocation system compared to prior system. BTT ECMO recipients under the revised system have significantly shorter ECMO waitlist run times, lower waitlist mortality and 3-year survival similar to those not bridged with ECMO. Overall, the revised allocation system has allowed more rapid transplantation of the sickest patients without a higher post-HT mortality.