Network For Organ Sharing Database Research Articles

Characterizing Adaptive Changes and Patient Survival After 2018 Donor Allocation Restructuring: A UNOS Database Analysis.

We sought to characterize adaptive changes to the revised United Network for Organ Sharing donor heart allocation policy and estimate long-term survival trends for heart transplant (HTx) recipients. Patients listed for HTx between October 17, 2013 and September 30, 2021 were identified from the United Network for Organ Sharing database, and stratified into pre- and postpolicy revision groups. Subanalyses were performed to examine trends in device utilization for extracorporeal membranous oxygenation (ECMO), durable left ventricular assist device (LVAD), intra-aortic balloon pump (IABP), microaxial support (Impella), and no mechanical circulatory support (non-MCS). Survival data post-HTx were fitted to parametric distributions and extrapolated to 5 years. We identified 27,523 HTx waitlist candidates during the study period, most of whom (n = 16,376) were waitlisted in the prepolicy change period. Overall, 19,554 patients underwent HTx during the study period (pre: 12,037 and post: 7517). Listings increased after the policy change for ECMO ( P < 0.01), Impella ( P < 0.01), and IABP ( P < 0.01) patients. Listings for LVAD ( P < 0.01) and non-MCS ( P < 0.01) patients decreased. HTx increased for ECMO ( P < 0.01), Impella ( P < 0.01), and IABP ( P < 0.01) patients after the policy change and decreased for LVAD ( P < 0.01) and non-MCS ( P < 0.01) patients. Waitlist survival increased for the overall ( P < 0.01), ECMO ( P < 0.01), IABP ( P < 0.01), and non-MCS ( P < 0.01) groups. Waitlist survival did not differ for the LVAD ( P = 0.8) and Impella ( P = 0.1) groups. Post-transplant survival decreased for the overall ( P < 0.01), LVAD ( P < 0.01), and non-MCS ( P < 0.01) populations. Allocation policy revisions have contributed to greater utilization of ECMO, Impella, and IABP, decreased utilization of LVADs and non-MCS, increased waitlist survival, and decreased post-HTx survival.

The impact of the OPTN policy change on patients with a durable left ventricular assist device and chronic kidney disease: Analysis of the UNOS database.

The Organ Procurement and Transplantation Network (OPTN) implemented modifications in 2018 to the adult heart transplant allocation system to better stratify the most medically urgent transplant candidates. We evaluated the impact of these changes on patients supported by a durable left ventricular assist device (LVAD) with chronic kidney disease (CKD). To evaluate the impact of the OPTN policy change on patients supported by durable left ventricular assist devices (LVAD) with chronic kidney disease (CKD). We performed an analysis of patients from the United Network of Organ Sharing Database supported by durable LVAD listed for a heart transplant (HT) between October 17, 2016 and September 30, 2021. Patients were divided into two groups: pre- and postpolicy, depending on whether they were listed on or prior to October 17, 2018. Patients who were on dialysis prior to surgery or discharge were excluded from the analysis. Patients with simultaneous heart and kidney transplants were excluded. Patients who were listed for transplant prepolicy change but transplanted postpolicy change were excluded. This cohort was then subdivided into degrees of CKD based on estimated glomerular filtration rate (eGFR), which resulted in 678 patients (23.7%) in Stage 1 (GFR ≥89.499) (Prepolicy: 345, Postpolicy: 333), 1233 (43.1%) in Stage 2 (89.499 > GFR ≥ 59.499) (Prepolicy: 618, Postpolicy: 615), 613 (21.4%) in Stage 3a (59.499 > GFR ≥ 44.499) (Prepolicy: 291, Postpolicy: 322), 294 (10.3%) in Stage 3b (44.499 > GFR ≥ 29.499) (Prepolicy: 143, Postpolicy: 151), 36 (1.3%) in Stage 4 (29.499 > GFR ≥ 15) (Prepolicy: 21, Postpolicy: 15), and 9 (0.3%) in Stage 5 (15 > GFR) (Prepolicy: 4, Postpolicy: 5). The primary outcome was 1-year and 2-year post-HT survival. There were 2863 patients who met the study criteria (1422 prepolicy, 1441 postpolicy). Overall survival, regardless of CKD stage, was lower following the policy change (p < 0.01). There was a similar risk of primary graft failure (PGF) in the pre- and postpolicy period (1.8% vs. 1.2%, p = 0.26). 1-year overall survival was 93% (91, 94) and 89% (87, 91) in the pre- and postpolicy periods, respectively. 2-year overall survival was 89% (88, 91) and 85% (82, 87) in the pre- and postpolicy periods, respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 1 -year survival was 93% (91, 95), 92% (90,93), 89% (86, 91), 89% (86, 93), 80% (68, 94), and 100% (100, 100), respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 2-year survival was 91% (88, 93), 88% (86, 90), 84% (81, 88), 84% (80, 89), 73% (59, 90), and 100% (100, 100), respectively. Patients with CKD 1 and 2 had better survival compared to those with CKD 3 (p < 0.01) and CKD 4 and 5 (p = 0.03) in the pre- and postpolicy periods. Patients with CKD 3 did not have a survival advantage over those with CKD 4 and 5 (p = 0.25). On cox regression analysis, advancing degrees of CKD were associated with an increased risk of mortality. Patients with LVAD support had decreased overall survival after the OPTN policy change. Patients with more advanced CKD had lower survival than patients without advanced CKD, though they were not impacted by the OPTN policy change.

Impact of Left Ventricular Unloading on Outcome of Heart Transplant Bridging With Extracorporeal Membrane Oxygenation Support in New Allocation Policy.

The new heart allocation policy places veno-arterial extracorporeal membrane oxygenation (VA-ECMO)-supported heart transplant (HT) candidates at the highest priority status. Despite increasing evidence supporting left ventricular (LV) unloading during VA-ECMO, the effect of LV unloading on transplant outcomes following bridging to HT with VA-ECMO remains unknown. From October 18, 2018 to March 21, 2023, 624 patients on VA-ECMO at the time of HT were identified in the United Network for Organ Sharing database and were divided into 2 groups: VA-ECMO alone (N=384) versus VA-ECMO with LV unloading (N=240). Subanalysis was performed in the LV unloading group: Impella (N=106) versus intra-aortic balloon pump (N=134). Recipient age was younger in the VA-ECMO alone group (48 versus 53 years, P=0.018), as was donor age (VA-ECMO alone, 29 years versus LV unloading, 32 years, P=0.041). One-year survival was comparable between groups (VA-ECMO alone, 88.0±1.8% versus LV unloading, 90.4±2.1%; P=0.92). Multivariable Cox hazard model showed LV unloading was not associated with posttransplant mortality after HT (hazard ratio, 0.92; P=0.70). Different LV unloading methods had similar 1-year survival (intra-aortic balloon pump, 89.2±3.0% versus Impella, 92.4±2.8%; P=0.65). Posttransplant survival was comparable between different Impella versions (Impella 2.5, versus Impella CP, versus Impella 5.0, versus Impella 5.5). Under the current allocation policy, LV unloading did not impact waitlist outcome and posttransplant survival in patients bridged to HT with VA-ECMO, nor did mode of LV unloading. This highlights the importance of a tailored approach in HT candidates on VA-ECMO, where routine LV unloading may not be universally necessary.

Changes in Donor Utilization and Outcomes for Patients Bridged With Durable Left Ventricular Assist Device.

We studied the impact of the 2018 heart allocation policy change on donor characteristics and posttransplant outcomes of left ventricular assist device (LVAD)-bridged heart transplant (HT) recipients. Left ventricular assist device-bridged adult HT recipients from October 2014 to October 2022 in the United Network for Organ Sharing database were categorized into old allocation policy (OAP) and new allocation policy (NAP) cohorts. Baseline characteristics, posttransplant outcomes, and subgroup analyses of unstable and stable LVAD-bridged recipients were assessed. The study included 7,384 HT recipients; 4,345 (58.8%) were transplanted in the OAP era and 3,039 (41.2%) in the NAP era. Old allocation policy recipients were most frequently status 1A at transplantation (71.1%), whereas NAP recipients were most frequently status 3 (40.0%), and status 4 (31.9%). Median donor sequence number (DSN) was higher in the NAP versus OAP era (9 vs. 3, p < 0.001). On multivariable analysis, NAP recipients had 20% higher 1 year mortality compared to OAP (adjusted hazard ratio [aHR] = 1.20 [95% confidence interval {CI}: 1.04-1.40], p = 0.01). Status 1 or 2 recipients had 28% higher 1 year mortality compared to status 1A (aHR = 1.28 [95% CI: 1.01-1.63], p = 0.04). Status 1 and 2 LVAD-supported recipients had higher mortality following the 2018 allocation change, indicating the need for closer surveillance of LVAD-bridged patients who may decompensate on the waitlist.

A Decade of Liver Transplantation in the United States: Drivers of Discard and Underutilization.

Organ shortage remains a major challenge for the field of transplantation. Maximizing utilization and minimizing discard of available organs is crucial to reduce waitlist times. Our aim was to investigate the landscape of liver recovery, discard over the past decade in the United States, and identify areas to reduce organ discard. This study used the Scientific Registry of Transplant Recipients United Network for Organ Sharing database to analyze the rates and associated reasons of discarded organs from 2010 to 2021. All deceased donors were evaluated, and data were analyzed by organ type, year, and region. Organ disposition was analyzed by year and region. Donor demographics and liver biopsy data were also analyzed. The volume of liver transplantation increased steadily, with a 44% increase from 2010 to 2021. Donation after circulatory death transplantation increased by 239%, comprising 10.6% of transplants in 2021, yet discard rates remained high at 30% for this donor subset. For all donor types, the liver discard rate has remained stable around 10% despite a 74% increase in available donors. Seventy percent of liver discards were attributed to organ factors, with biopsy findings accounting for 40% of all discards. Of livers that were biopsied, 70% had macrosteatosis of <30%. Analysis of trends in transplantation and discard allow for identifying areas of underutilization. Donation after circulatory death livers have expanded the pool of transplanted livers but remain discarded at high rates. Significant differences remain in discard rates between geographic regions. We identify several areas to lower the discard rates. The expanding role of machine perfusion may allow for utilization of previously discarded organs.

Live-donor kidney transplant outcome prediction (L-TOP) using artificial intelligence.

Outcome prediction for live-donor kidney transplantation improves clinical and patient decisions and donor selection. However, the concurrently used models are of limited discriminative or calibration power and there is a critical need to improve the selection process. We aimed to assess the value of various artificial intelligence (AI) algorithms to improve the risk stratification index. We evaluated pre-transplant variables among 66914 live-donor kidney transplants (performed between 01/12/2007-01/06/2021) from the United Network of Organ Sharing database, randomized into training (80%) and test (20%) sets. The primary outcome measure was death-censored graft survival. We tested four machine learning models for discrimination (time-dependent concordance index, CTD, and area under the ROC curve) and calibration (integrated Brier score, IBS). We used decision curve analysis to assess the potential clinical utility. Among the models, the deep Cox mixture model showed the best discriminative performance (AUC=0.70, 0.68, and 0.68 at 5, 10, and 13 years post-transplant, respectively). CTD reached 0.70, 0.67, and 0.66 at 5, 10, and 13 years post-transplant. The IBS score was 0.09, indicating good calibration. In comparison, applying the Living Kidney Donor Profile Index (LKDPI) on the same cohort produced a CTD of 0.56 and an AUC of 0.55-0.58 only. Decision curve analysis showed an additional net benefit compared to the LKDPI, 'Treat all' and 'Treat None' approaches. Our AI-based deep Cox mixture model, termed Live-Donor Kidney Transplant Outcome Prediction outperforms existing prediction models, including the LKDPI, with the potential to improve decisions for optimum live donor selection by ranking potential transplant pairs based on graft survival. This model could be adopted to improve the outcomes of paired exchange programs.

Enhancing the usability of older DCD donors through strategic approaches in liver transplantation in the United States.

The use of older donors after circulatory death (DCD) for liver transplantation (LT) has increased over the past decade. This study examined whether outcomes of LT using older DCD (≥50y) have improved with advancements in surgical/perioperative care and normothermic machine perfusion (NMP) technology. A total of 7602 DCD LT cases from the United Network for Organ Sharing database (2003-2022) were reviewed. The impact of older DCD donors on graft survival was assessed using the Kaplan-Meier and HR analyses. In all, 1447 LT cases (19.0%) involved older DCD donors. Although there was a decrease in their use from 2003 to 2014, a resurgence was noted after 2015 and reached 21.9% of all LTs in the last 4 years (2019-2022). Initially, 90-day and 1-year graft survivals for older DCDs were worse than younger DCDs, but this difference decreased over time and there was no statistical difference after 2015. Similarly, HRs for graft loss in older DCD have recently become insignificant. In older DCD LT, NMP usage has increased recently, especially in cases with extended donor-recipient distances, while the median time from asystole to aortic cross-clamp has decreased. Multivariable Cox regression analyses revealed that in the early phase, asystole to cross-clamp time had the highest HR for graft loss in older DCD LT without NMP, while in the later phases, the cold ischemic time (>5.5h) was a significant predictor. LT outcomes using older DCD donors have become comparable to those from young DCD donors, with recent HRs for graft loss becoming insignificant. The strategic approach in the recent period could mitigate risks, including managing cold ischemic time (≤5.5h), reducing asystole to cross-clamp time, and adopting NMP for longer distances. Optimal use of older DCD donors may alleviate the donor shortage.

National Trends in Utilization of Normothermic Machine Perfusion in DCD Liver Transplantation.

In liver transplantation, advances in ex situ normothermic machine perfusion (NMP) have improved outcomes compared with traditional static cold storage (SCS) in donation after circulatory death (DCD) organs. We aimed to characterize trends in the utilization of NMP versus SCS in DCD liver transplantation in the United States. This retrospective cohort study used data from the United Network for Organ Sharing database to identify recipient-donor adult liver transplant pairs from DCD donors from January 2016 to June 2022. Utilization of NMP and changes in donor risk index (DRI) and components between NMP and SCS were assessed across transplant year eras (2016-2018, 2019-2020, and 2021-2022). Statistical comparisons were made using the Kruskal-Wallis test or the chi-square test. A total of 3937 SCS and 127 NMP DCD donor transplants were included. Utilization of NMP ranged from ~0.4% to 3.5% from 2016 to 2021 and rose significantly to 11.2% in early 2022. Across transplant eras, median DRI increased significantly for SCS and NMP, but the magnitude of the increase was larger for NMP. With NMP DCDs, there were significant increases in median donor age, national share proportion, and "cold ischemic time" over time. Finally, there was a shift toward including higher DRI donors and higher model for end-stage liver disease score transplant recipients with NMP in later transplant eras. In recent years, NMP utilization has increased and expanded to donors with higher DRI and recipients with higher model for end-stage liver disease score at transplant, suggesting increasing familiarity and risk tolerance with NMP technology. As NMP remains a relatively new technique, ongoing study of patient outcomes, organ allocation practices, and utilization patterns is critical.

Indications and outcomes of liver transplantation for liver tumors in the United States

BackgroundWhile hepatocellular carcinoma (HCC) remains the leading cause of liver transplant (LT) for liver tumors, indications have broadened over the years. Data regarding patient characteristics and outcomes of LT for liver tumors are limited. MethodsFrom Jan-2002 to March-2022, 14,406 LT recipients for various liver tumors were identified in United Network for Organ Sharing database. Overall post-transplant survival analysis was performed with Kaplan-Meier method and multivariable Cox proportional-hazards model. ResultsDuring the study period, indications for LT for various hepatic tumors were HCC (88.5 %), benign tumors (5.1 %), cholangiocarcinoma (3.9 %), angiosarcoma (0.7 %), bile duct cancer (0.7 %), secondary tumors (0.5 %) and others (0.7 %). Compared to non-HCC, LT recipients for HCC were older (median age 61 vs 54 years, P < 0.001), more often male (77% vs 48 %, P < 0.001), more often Hispanic (16% vs 8.0 %), had higher BMI (28.2 vs 25.3, P < 0.001) and higher prevalence of Hepatitis C (53% vs 3.9 %, P < 0.001). Donor characteristics across various groups were similar. One-year survival in LT recipients of HCC was higher (HCC: 91.7% vs. non-HCC: 90.3 %) with adjusted Hazard Ratio (aHR) of 0.87; 95 % CI 0.77–0.99, P = 0.033 in a multivariable Cox regression analysis. Compared to HCC, survival outcomes were worse in cholangiocarcinoma (aHR 1.70; 95 %CI 1.43–2.01, P < 0.001), bile duct cancer (aHR 3.03; 95 %CI 2.12–4.33, P < 0.001), secondary tumors including colon cancer and neuroendocrine tumors (aHR 1.88; 95 % CI 1.24–2.85, P = 0.003), with best survival in patients with benign tumors (aHR 0.57; 95 %CI 0.46–0.70, P < 0.001). ConclusionsLT is performed for various liver tumors with variable outcomes among these primary indications.

(913) - Does Ex Vivo Lung Perfusion Mitigate the Detrimental Effects of Primary Graft Dysfunction? A Propensity Matched Analysis of the United Network for Organ Sharing Database

(913) - Does Ex Vivo Lung Perfusion Mitigate the Detrimental Effects of Primary Graft Dysfunction? A Propensity Matched Analysis of the United Network for Organ Sharing Database

(893) - Have Policy Changes Improved Geographical Disparities in Lung Transplantations? An Analysis of the United Network of Organ Sharing Database

(893) - Have Policy Changes Improved Geographical Disparities in Lung Transplantations? An Analysis of the United Network of Organ Sharing Database

Long-Term Survival Following Primary Graft Dysfunction Development in Lung Transplantation

IntroductionPrimary graft dysfunction (PGD) is a known risk factor for early mortality following lung transplant (LT). However, the outcomes of patients who achieve long-term survival following index hospitalization are unknown. We aimed to determine the long-term association of PGD grade 3 (PGD3) in patients without in-hospital mortality. MethodsLT recipients were identified from the United Network for Organ Sharing Database. Patients were stratified based on the grade of PGD at 72 h (No PGD, Grade 1/2 or Grade 3). Groups were assessed with comparative statistics. Long-term survival was evaluated using Kaplan–Meier methods and a multivariable shared frailty model including recipient, donor, and transplant characteristics. ResultsThe PGD3 group had significantly increased length of stay, dialysis, and treated rejection post-transplant (P < 0.001). Unadjusted survival analysis revealed a significant difference in long-term survival (P < 0.001) between groups; however, following adjustment, PGD3 was not independently associated with long-term survival (hazard ratio: 0.972; 95% confidence interval: 0.862-1.096). Increased mortality was significantly associated with increased recipient age and treated rejection. Decreased mortality was significantly associated with no donor diabetes, bilateral LT as compared to single LT, transplant in 2015-2016 and 2017-2018, and no post-transplant dialysis. ConclusionsWhile PGD3 remains a challenge post LT, PGD3 at 72 h is not independently associated with decreased long-term survival, while complications such as dialysis and rejection are, in patients who survive index hospitalization. Transplant providers should be aggressive in preventing further complications in recipients with severe PGD to minimize the negative association on long-term survival.

Predictors of early mortality after lung transplantation for idiopathic pulmonary arterial hypertension.

Lung transplantation remains an important therapeutic option for idiopathic pulmonary arterial hypertension (IPAH),yet short-term survival is the poorest among the major diagnostic categories. We sought to develop a prediction model for 90-day mortality using the United Network for Organ Sharing database for adults with IPAH transplanted between 2005 and 2021. Variables with a pvalue ≤ 0.1 on univariate testing were included in multivariable analysis to derive the best subset model. The cohort comprised 693 subjects, of whom 71 died (10.2%) within 90 days of transplant. Significant independent predictors of early mortality were: extracorporeal circulatory support and/or mechanical ventilation at transplant (OR:3; CI: 1.4-5), pulmonary artery diastolic pressure (OR:1.3 per 10 mmHg; CI: 1.07-1.56), forced expiratory volume in the first second percent predicted (OR:0.8 per 10%; CI: 0.7-0.94), recipient total bilirubin >2 mg/dL (OR:3; CI: 1.4-7.2) and ischemic time >6 h (OR: 1.7, CI: 1.01-2.86). The predictive model was able to distinguish 25% of the cohort with a mortality of ≥20% from 49% with a mortality of ≤5%. We conclude that recipient variables associated with increasing severity of pulmonary vascular disease, including pretransplant advanced life support, and prolonged ischemic time are important risk factors for 90-day mortality after lung transplant for IPAH.

(1346) - Panel Reactive Antibody, Crossmatch Status, and Outcomes in Pediatric Heart Transplant Recipients with Congenital Heart Disease: An Analysis of the United Network for Organ Sharing Database

(1346) - Panel Reactive Antibody, Crossmatch Status, and Outcomes in Pediatric Heart Transplant Recipients with Congenital Heart Disease: An Analysis of the United Network for Organ Sharing Database

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

We investigated variables impacting waitlist time and negative waitlist outcomes in adult congenital heart disease (ACHD) orthotopic heart transplant (OHT) candidates following the 2018 allocation change. Adult OHT candidates listed between 10/18/2018-12/31/2022 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 using rank-sum tests. Death/delisting for deterioration was assessed using Fine-Gray sub-distribution hazard ratios (SHRs). 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 on the waitlist. ACHD vs. non-ACHD candidates spent longer 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 as status 1 (9.7 vs. 5.5 days, p=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 death/deterioration. ACHD candidates have longer waitlist times, lower priority status at initial listing, wait longer for upgrade, and have higher mortality at the same final status as non-ACHD candidates, suggesting that they are being upgraded too late.

Is Time Scheduling Important? An Analysis of Donor Heart Cross-clamp Times During Heart Transplantation.

Outcomes in heart transplantation are affected by a variety of variables and patient factors. However, the impact of circadian rhythms, gene expression, and transcription remain underexplored. We thus evaluated the potential role of donor heart cross-clamp times on short-term and long-term outcomes after heart transplantation. A total of 31 713 heart transplants were identified from the United Network for Organ Sharing Database. Patients were first stratified on the basis of time of donor procurement: 12 am to 12 pm or 12 pm to 12 am. To evaluate a possible effect of circadian rhythms, donor time was further divided into 5 groups based on preclinical data: 4 am to 8 am; 8 am to 11 am; 11 am to 5 pm; 5 pm to 10 pm; 10 pm to 4 am. Groups were assessed with comparative statistics. Long-term survival was evaluated using Kaplan-Meier methods and a multivariate Cox proportional hazard model. Patients who received hearts recovered between 12 am and 12 pm had significantly higher survival than those who received hearts recovered between 12 pm and 12 am. This survival difference was observed in both unadjusted (P = 0.002) and adjusted analyses (hazard ratio [HR]: 0.93; 95% confidence interval [CI], 0.89-0.97; P < 0.001). On unadjusted analysis, the survival difference among the 5 groups was insignificant (P = 0.07). Following adjustment, the periods of 11 am to 5 pm (HR: 1.09, 95% CI, 1.02-1.17; P = 0.012), 5 pm to 10 pm (HR: 1.11; 95% CI, 1.04-1.19; P = 0.002), and 10 pm to 4 am (HR: 1.07; 95% CI, 1.01-1.15; P = 0.034), were all independently associated with increased long-term mortality. Notably, the time of 8 am to 11 am was not associated with a change in survival (HR: 1.04; 95% CI, 0.96-1.14; P = 0.3). Given the independent association of donor timing and survival after adjustment in a large national cohort, further investigation into the role of donor circadian rhythm and donor procurement time is warranted in preclinical and clinical studies. Understanding the underlying mechanisms of this observation could potentially lead to the development of effective treatments and donor procurement processes that prepare the organs for transplantation in a better condition.

Trends in survival after heart transplantation based on Social Vulnerability Index in the United States

IntroductionThe association of social vulnerability (SV) and cardiac transplant survival remains poorly defined, particularly related to long-term outcomes. The purpose of this study was to define the impact of SV on survival among heart transplant recipients with at least 1-year of survival post-transplant. MethodsHeart transplant recipients were identified using the United Network for Organ Sharing database between 6/1/06-12/31/20. The Center for Disease Control’s Social Vulnerability Index (SVI) database was used to stratify patients based on SVI into three groups: Low: <25; Average: 26-74; High: 75+. The groups were analyzed with comparative statistics, and unadjusted survival was assessed using Kaplan-Meier methods. To determine the independent association between SVI and survival, a multivariable Cox proportional hazard model was created. ResultsThere were 27,740 recipients identified. High SVI patients more commonly identified as Black individuals and had a higher incidence of diabetes, pre-transplant intensive care unit admission and need for concomitant kidney transplant (p<0.05 for all). Additionally, High SVI patients had the longest length of stay post-transplant (21.4 days) (p<0.05). High and Average SVI patients had inferior 3-year, 5-year, and 10-year survival versus Low SVI patients (p<0.05). After adjustment, Average (hazard ratio [HR]:1.12) and High (HR:1.16) SVI were independently associated with an increased risk of mortality on multivariable analysis (both p<0.001). ConclusionHigh or average SVI is independently associated with increased mortality following heart transplantation in patients with 1-year conditional survival. These findings demonstrate that disparities persist among heart transplant recipients during long-term follow up.

Reversibility of precapillary pulmonary hypertension and outcomes after heart transplantation bridged with left ventricular assist devices: Insight from the United Network for Organ Sharing

BackgroundIn light of the updated lowered threshold for diagnosing pulmonary hypertension (PH), the reversibility of precapillary PH with left ventricular assist device (LVAD) and the associated post-heart transplantation (HT) outcomes remain unclear. MethodsUsing data from the United Network for Organ Sharing database, we aimed to investigate predictors of persistent precapillary PH in HT recipients bridged with LVAD and examine the interrelated post-HT survival using the updated pulmonary vascular resistance (PVR) cutoff of >2 Wood units for precapillary PH. ResultsAmong 2169 HT recipients bridged with LVAD, 1299 had PVR >2 at baseline; 551 (42.4%) of whom normalized their PVR ≤2 and 748 (57.6%) remained with elevated PVR >2 after LVAD implantation. Female sex (adjusted odds ratio [aOR]; 2.22, 95% confidence interval [CI], 1.61-3.07; P < .001) and inotrope treatment at listing (aOR, 1.31; 95% CI, 1.03-1.66; P = .028) were associated with persistently elevated PVR after LVAD. Conversely, longer duration of LVAD support (aOR, 0.74; 95% CI, 0.65-0.84; P < .001) and use of HeartMate II (aOR, 0.74; CI, 0.59-0.93; P = .011) were found to be protective against persistently elevated PVR after LVAD. Persistently elevated PVR >2 after LVAD was associated with increased risk of death compared with those who normalized their PVR (adjusted hazard ratio [aHR], 1.26; 95% CI, 1.01-1.57; P = .037). However, the normalized PVR post-LVAD group had comparable survival with those with PVR ≤2 at baseline (aHR, 0.76; 95% CI, 0.57-1.02; P = .07). ConclusionsMany recipients of HT bridged with LVAD remain with PVR >2 after LVAD implantation, which is associated with increased risk of death after HT compared with patients with normalized PVR after LVAD.

Trends and outcomes of heart transplantation in adults with congenital heart disease.

Heart transplantation for adult congenital heart disease is complicated and associated with challenging pretransplant support, long waiting, and high early post-transplant mortality. We explored if surgical and medical advances, and allocation system changes have affected outcomes. From United Network for Organ Sharing database, adults with congenital heart disease listed for heart transplantation were queried. To explore practice and outcome trends, patients were divided into 4 eras (eras1-3: nearly 3 equal periods from 1992-2018, era-4: after 2018, corresponding with new allocation system). Univariate and multivariable analysis was performed to evaluate outcomes. 2737 patients were listed. There was gradual increase in listed and transplanted patients, along with significant increase in use of mechanical support, simultaneous kidney and liver transplantation. While proportion of transplanted remained constant, there was decrease in proportion delisted/died after listing (p = 0.01) and waiting list duration (p = 0.01), especially in era-4. 30-days post-transplant mortality remains high, however, it has significantly improved starting era-3 (p = 0.01). Current survival at 1-year and 5-years is 85% and 65%, with improvement mainly related to decreased early death. On multivariable analysis, factors associated with survival were lower glomerular filtration rate (HR = 0.99, p = 0.042), bilirubin (HR = 1.17, p < 0.001), and mechanical ventilation (HR = 2.3, p = 0.004). Heart transplantation in adults with congenital heart disease is increasing, along with added complexity, higher usage of pretransplant mechanical support and simultaneous organ transplantation. Despite that, more complex patients don't experience worse outcomes. Early mortality improved but remains high. New donor allocation system allowed shorter waiting time and higher proportion transplanted without altering early mortality.

Outcomes following concomitant multiorgan heart transplantation from circulatory death donors: The United States experience

BackgroundDonation after circulatory death (DCD) has reemerged as a method of expanding the donor heart pool. Given the high waitlist mortality of multiorgan heart candidates, we evaluated waitlist outcomes associated with willingness to consider DCD offers and post-transplant outcomes following DCD transplant for these candidates. MethodsUsing the United Network for Organ Sharing database, we identified adult multiorgan heart candidates and recipients between 1/1/2020 and 3/31/2023. Among candidates that met inclusion criteria, we compared the cumulative incidence of transplant, with waitlist death/deterioration as a competing risk, by willingness to consider DCD offers. Among recipients of DCD vs. brain death (DBD) transplants, we compared perioperative outcomes and post-transplant survival. ResultsOf 1,802 heart-kidney, 266 heart-liver, and 440 heart-lung candidates, 15.8%, 12.4% and 31.1%, respectively, were willing to consider DCD offers. On adjusted analysis, willingness to consider DCD offers was associated with higher likelihood of transplant for all multiorgan heart candidates and decreased likelihood of waitlist deterioration for heart-lung candidates. Of 1,100 heart-kidney, 173 heart-liver, and 159 heart-lung recipients, 5.4%, 2.3%, and 2.5%, respectively, received DCD organs. Recipients of DCD and DBD heart-kidney transplants had similar likelihood of perioperative outcomes and 1-year survival. All other DCD multiorgan heart recipients have survived to last follow-up. ConclusionsMultiorgan heart candidates who were willing to consider DCD offers had favorable waitlist outcomes, and heart-kidney recipients of DCD transplants had similar post-transplant outcomes to recipients of DBD transplants. We recommend the use of DCD organs to increase the donor pool for these high-risk candidates.