Outcomes In Pediatric Heart Transplantation Research Articles

(1350) - Using Machine Learning to Assess the Predictive Power of Donor Characteristics in Pediatric Heart Transplant Outcomes

(1350) - Using Machine Learning to Assess the Predictive Power of Donor Characteristics in Pediatric Heart Transplant Outcomes

(162) - Pre-Transplant Psychosocial Evaluation Characteristics and Associations with Pediatric Heart Transplant Outcomes

(162) - Pre-Transplant Psychosocial Evaluation Characteristics and Associations with Pediatric Heart Transplant Outcomes

Impact of prolonged ischemic time on pediatric heart transplantation outcomes: Improved outcomes in the most recent era

BackgroundImpacts of ischemic time (IT) on pediatric heart transplant outcomes are multifactorial. We aimed to analyze the effect of prolonged IT on graft loss after pediatric heart transplantation. We hypothesized that graft survival with prolonged IT has improved across eras. MethodsPatients <18 years old in the Pediatric Heart Transplant Society database (1993-2019) were included (N=6765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, re-transplant, or need for mechanical circulatory support in the first 7 days post-transplant. Descriptive statistical methods were used to compare differences between patient characteristics and IT. Kaplan-Meier survival analysis compared freedom from graft loss, rejection, and infection. Multivariable analysis was performed for graft loss and SGF (hazard and logistic regression modeling, respectively). ResultsDiagnoses were cardiomyopathy (N=3246) and congenital heart disease (CHD; N=3305). CHD were younger, more likely to have an IT >4.5 hours, and more likely to require extracorporeal membrane oxygenation or mechanical ventilation at transplant (all P<0.001). Median IT was 3.6 hours [IQR 2.98 to 4.31; range 0-10.5]. IT was associated with early graft loss (HR 1.012, 95% CI 1.005-1.019), but not when analyzed only in the most recent era. IT was associated with SGF (OR 1.016 95%CI 1.003 - 1.030). ConclusionsDonor IT was independently associated with increased risk of graft loss, albeit with a small effect relative to other risk factors. Graft survival with prolonged IT has improved in the most recent era but the risk of SGF persists.

Survival does not differ by annual center transplant volume-A Pediatric Heart Transplant Society Registry study.

There are conflicting data regarding the relationship between center volume and outcomes in pediatric heart transplantation. Previous studies have not fully accounted for differences in case mix, particularly in high-risk congenital heart disease (CHD) groups. We aimed to evaluate the relationship between center volume and outcomes using the Pediatric Heart Transplant Society (PHTS) Registry and explore how case mix may affect outcomes. A retrospective cohort study of all pediatric patients in the PHTS Registry who received a heart transplant from 2009 to 2018 was performed. Centers were divided into 5 groups based on average yearly transplant volume. The primary outcome was time to death or graft loss and outcomes were compared using Kaplan-Meier analysis. There were 4583 cases among 55 centers included. There was no difference in time to death or graft loss by center volume in the entire cohort (p = .75), in patients with CHD (p = .79) or in patients with cardiomyopathy (p = .23). There was also no difference in time to death or graft loss by center size in patients undergoing transplant after Norwood, Glenn or Fontan (log rank p = .17, p = .31, and p = .10 respectively). There was a statistically significant difference in outcomes by center size in the positive crossmatch group (p < .0001), though no discernible pattern related to high or low center volume. Outcomes are similar among transplant centers of all sizes, including for high-risk patient groups with CHD. Future work is needed to understand how patient-specific risk factors may vary among centers of various sizes and whether this influences patient outcomes.

The effect of socioeconomic status on pediatric heart transplant outcomes at a single institution between 2013 and2022.

Disparities in pediatric heart transplant outcomes based on socioeconomic status (SES) have been previously observed. However, there is a need to reevaluate these associations in contemporary settings with advancements in transplant therapies and increased awareness of health disparities. This retrospective study aims to investigate the relationship between SES and outcomes for pediatric heart transplant patients. Data were collected through a chart review of 176 pediatric patients who underwent first orthotopic heart transplantation (OHT) at a single center from 2013 to 2021. The Area Deprivation Index (ADI), a composite score based on U.S. census data, was used to quantify SES. Cox proportional hazards models and generalized linear models were employed to analyze the association between SES and graft failure, rejection rates, and hospitalization rates. The analysis revealed no statistically significant differences in graft failure rates, rejection rates, or hospitalization rates between low-SES and high-SES pediatric heart transplant patients for our single-center study. There may be patient education, policies, and social resources that can help mitigate SES-based healthcare disparities. Additional multi-center research is needed to identify post-transplant care that promotes patient equity.

Impact of a positive crossmatch on pediatric heart transplant outcomes

BackgroundPediatric heart transplant (HT) candidates experience high waitlist mortality due to a limited donor pool that is constrained in part by anti-HLA sensitization. We evaluated the impact of CDC and Flow donor-specific crossmatch (XM) results on pediatric HT outcomes. MethodsAll pediatric HT between 1999 and 2019 in the OPTN database were included. Donor-specific XM results were sub-categorized based on CDC and Flow results. Primary outcomes were treated rejection in the first year and time to death or allograft loss. Propensity scores were utilized to adjust for differences in baseline characteristics. ResultsA total of 4695 pediatric HT patients with T-cell XM data were included. After propensity score adjustment, a positive T-cell CDC-XM was associated with two times higher odds of treated rejection (OR 2.29 (1.56,3.37)) and shorter time to death/allograft loss (HR 1.50 (1.19,1.88)) compared to a negative Flow-XM. HT recipients who were Flow-XM positive with negative/unknown CDC-XM did not have higher odds of rejection or shorter time to death/allograft loss. An isolated positive B-cell XM was also not associated with worse outcomes. Over the study period XM testing shifted from CDC- to Flow-based assays. ConclusionsA positive donor-specific T-cell CDC-XM was associated with rejection and death/allograft loss following pediatric HT. This association was not observed with a positive T-cell Flow-XM or B-cell XM result alone. The shift away from performing the CDC-XM may result in loss of important prognostic information unless the clinical relevance of quantitative Flow-XM results on heart transplant outcomes is systematically studied.

Atypical infiltrates on endomyocardial biopsy are associated with adverse outcomes in pediatric heart transplantation

The significance of atypical infiltrates (eosinophils or plasma cells) on endomyocardial biopsy (EMB) after pediatric heart transplant (HTx) is not known. We hypothesized that atypical infiltrates are associated with worse post-HTx outcomes. We performed a retrospective cohort study of consecutive patients <21 years old who underwent primary HTx between 2013 and 2017. Multiorgan transplants were excluded. The presence of atypical infiltrates and burden of atypical infiltrates (rare vs predominant) on EMB were recorded. Primary outcome was a composite of cardiac allograft vasculopathy, graft failure (relisting or retransplant), or death. Presence of atypical infiltrates was evaluated: (1) overall using Cox regression with time-dependent covariates and (2) if present by 1 year post-HTx using Kaplan-Meier analysis. Atypical infiltrates were present in 24 out of 95 patients (25%) and were associated with a higher likelihood of reaching the composite outcome (hazard ratio (HR) 6.22, 95% confidence interval (CI) 2.60-14.89, p<0.0001). This persisted when controlling for rejection in multivariable analysis. There was also a greater risk of the composite outcome if ≥2 nonconsecutive EMBs had atypical infiltrates (HR 11.80, 95%CI 3.17-43.84, p=0.0002) or if atypical infiltrates were the predominant feature on EMB (HR 30.58, 95%CI 9.34-100.06, p<0.0001). Patients with atypical infiltrates by 1-year post-HTx had a 5-year freedom from the composite outcome of 48%, compared to 90% if no atypical infiltrates had been present by this timepoint (log rank p=0.002). The presence of atypical infiltrates on EMB is associated with significantly worse outcomes in children following HTx. These patients require closer follow-up to assess for developing graft dysfunction.

Do vasoactive medications impact donor hearts clinical outcomes in pediatric heart transplantation?

There is limited data examining donor vasopressor and/or inotrope medications (vasoactives) on pediatric orthotopic heart transplant (OHT) outcomes. We aim to evaluate the effects of vasoactives on pediatric OHT outcomes. The United Network for Organ Sharing database was retrospectively reviewed from January 2000 to March 2018 for donor hearts. Exclusion criteria included multiorgan transplants and recipient age >18. Donors receiving vasoactives at the time of procurement were compared to donors not on vasoactives, including the number of vasoactives and the type. End-points of interest were survival at 30 days and 1year as well as post-transplant rejection at 1year. Logistic and Cox models were used to quantify survival end-points. Of 6462 donors, 3187 (49.3%) were receiving at least one vasoactive. Comparing any vasoactive medication versus none, there was no difference in 30-day survival (p= .27), 1 year survival (p= .89), overall survival (p= .68), or post-transplant rejection (p= .98). There was no difference in 30-day survival for donors receiving 2 or more vasoactive infusions (p= .89), 1 year survival (p= .53), overall survival (p= .75), or post-transplant rejection at 1year (p= .87). Vasopressin was associated with decreased 30-day mortality (OR=0.22; p= .028), dobutamine with decreased 1-year mortality (OR=0.37; p= .036), overall survival (HR=0.51; p= .003), and decreased post-transplant rejection (HR=0.63; p= .012). There is no difference in pediatric OHT outcomes when the cardiac donor is treated with vasoactive infusions at procurement. Vasopressin and dobutamine were associated with improved outcomes. This information can be used to guide medical management and donor selection.

Functional status predicts pediatric heart transplant outcomes: A united network for organ sharing (UNOS) database study

Functional status predicts waitlist survival in adult heart transplantation and is an independent predictor of outcomes in pediatric liver transplantation. This has not been studied in pediatric heart transplantation. Study aims were to determine the association of: (1) functional status at listing with waitlist and post-transplant outcomes, and (2) functional status at transplant with post-transplant outcomes in pediatric heart transplantation. Retrospective United Network of Organ Sharing database study of pediatric patients listed for heart transplant between 2005 and 2019 with Lansky Play Performance Scale (LPPS) scores at listing. Standard statistical methods were used to assess relationships between LPPS and outcomes (waitlist and post-transplant). Negative waitlist outcome was defined as death or removal from waitlist due to clinical deterioration. There were 4,169 patients identified, including 1,080 with LPPS 80-100 (normal activity), 1,603 with LPPS 50-70 (mild limitations), and 1,486 with LPPS 10-40 (severe limitations). LPPS 10-40 correlated with negative waitlist outcomes (HR 1.69, CI 1.59-1.80, p < 0.0001). While LLPS at listing had no association with post-transplant survival, those with LPPS 10-40 at transplant had inferior 1-year post-transplant survival compared to those with LPPS ≥50 (92% vs 95%-96%, p=0.0011). Functional status was an independent predictor of post-transplant outcomes in patients with cardiomyopathy. A functional improvement of ≥20 points between listing and transplant (N=770, 24%) was associated with higher 1-year post-transplant survival (HR 1.63, 95% CI: 1.10-2.41, p=0.018). Functional status is associated with waitlist and post-transplant outcomes. Interventions targeting functional impairment may improve pediatric heart transplantation outcomes.

It Takes Two: Outcomes of Pediatric Heart Transplant Candidates With Renal Dysfunction

Associated Factors and Impact of Persistent Renal Dysfunction in Pediatric Heart TransplantationThe Annals of Thoracic SurgeryPreviewWe evaluated the impact of significant renal dysfunction (SRD) on listing and pediatric heart transplantation (PHT) outcomes. Full-Text PDF

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

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

Racial and socioeconomic disparities in pediatric heart transplant outcomes in the era of anti-thymocyte globulin induction.

Black race is associated with worse outcomes across solid organ transplantation. Augmenting immunosuppression through antithymocyte globulin (ATG) induction may mitigate organ rejection and graft loss. We investigated whether racial and socioeconomic outcome disparities persist in children receiving ATG induction. Using the Pediatric Heart Transplant Society registry, we compared outcomes in Black and White children who underwent heart transplant with ATG induction between 2000 and 2020. The primary outcomes of treated rejection, rejection with hemodynamic compromise (HC), and graft loss (death or re-transplant). We explored the association of these outcomes with race and socioeconomic disparity, assessed using a neighborhood deprivation index [NDI] score at 1-year post-transplant (high NDI score implies more socioeconomic disadvantage). The study cohort included 1,719 ATG-induced pediatric heart transplant recipients (22% Black, 78% White). There was no difference in first year treated rejection (Black 24.5%, White 28.1%, p=0.2). During 10 year follow up, the risk of treated rejection was similar; however, Black recipients were at higher risk of HC rejection (p=0.009) and graft loss (p=0.02). Black recipients had a higher mean NDI score (p < 0.001). Graft loss conditional on 1-year survival was associated with high NDI score in both White and Black recipients (p < 0.0001). In a multivariable Cox model, both high NDI score (HR 1.97, 95% CI 1.23-3.17) and Black race (HR 2.22, 95% CI 1.40-3.53) were associated with graft loss. Black race and socioeconomic disadvantage remain associated with late HC rejection and graft loss in children with ATG induction. These disparities represent important opportunities to improve long term transplant outcomes.

Abstract 9536: The Influence of Social Determinants of Health and Race on Pediatric Heart Transplant Outcomes

Introduction: While traditional registry-based analyses have outlined that Black children have worse post-heart transplant (HT) outcomes, it is not entirely clear if such differences persist after accounting for social determinants of health (SDOH). Hypothesis: After accounting for SDOH, Black children from distressed communities will continue to have worse post-HT outcomes compared to White children. Methods: All children in the Pediatric Heart Transplant Society (PHTS) database that underwent HT in the U.S. from January 2010 - December 2020 were included. Recipient zip codes from PHTS and the Scientific Registry of Transplant Recipients databases were used to create a pediatric specific community risk score for each transplanted recipient. Lower risk communities (quartiles 1 and 2) were labelled prosperous and the higher risk (quartiles 3 and 4) as distressed communities. The effects of community risk and self-identified race on post-HT rejection, cardiac allograft vasculopathy (CAV) and graft loss were evaluated unadjusted and after adjusting for donor and recipient risk factors. Results: Of 3680 children transplanted, 1911 (51.9%) lived in prosperous and 1769 (48.1%) in distressed communities. Unadjusted analysis revealed that Black children from distressed communities had higher rejection (p=0.0013), CAV (p=0.0011) and graft loss (p&lt;0.0001) (Figure) . In multivariable adjusted analysis, Black children from distressed communities experienced increased rejection (HR 1.33, 95%CI 1.03-1.71), CAV (HR 2.06, 95%CI 1.21-3.51) and graft loss (HR 1.66, 95%CI 1.12-2.46), while white children did not experience increased rejection (HR 0.99, 95%CI 0.86-1.14), CAV (HR 0.95, 95%CI 0.69-1.32) or graft loss (HR 1.17, 95%CI 0.92-1.48). Conclusions: This study found that SDOH independently affects post-HT outcomes for Black, but not White children. More studies will be necessary to identify the root causes to be able to address these racial disparities.

Racial and Socioeconomic Disparities in Pediatric Heart Transplant Outcomes in the Era of Anti-Thymocyte Globulin Induction

<h3>Purpose</h3> A recent multicenter pediatric study using antithymocyte globulin (ATG) induction found a reduced risk of first yr rejection in Black heart transplant (tx) recipients. We investigated this finding in the broader field and studied the effects of race and socioeconomic disparity on outcomes in ATG-induced children. <h3>Methods</h3> Using the Pediatric Heart Transplant Society registry, we compared outcomes in Black and White children 1-17 yrs old who underwent heart tx with ATG induction between 2000-2020. The primary outcomes of treated rejection, rejection with hemodynamic compromise (HC), and graft loss (death or re-transplant) were studied over 1- and 10-yr time intervals as well as late outcomes conditional on 1-yr survival<i>.</i> We explored the association of these outcomes with race and socioeconomic disparity, assessed using neighborhood deprivation index [NDI] score at 1-yr post-tx (high NDI score implies more socioeconomic disadvantage). <h3>Results</h3> The study cohort included 1719 ATG-induced pediatric heart tx recipients (23% Black, 77% White). There was no racial difference in incidence of first yr treated rejection (Black 24.5%, White 28.1%, p = 0.2). During the 10 yr follow up, the risk of treated rejection was similar between Black and White recipients; however, Black recipients were at higher risk of HC rejection (p = 0.009) and graft loss (p = 0.02, log rank test). Black recipients had a higher mean NDI score (0.43 vs 0.36, p < 0.001). A higher risk of graft loss was associated with high NDI score in both White and Black recipients (p < 0.001, Fig). In a multivariable Cox model, both high NDI score (HR 2.03, 95% CI 1.38-2.98) and Black race (HR 1.99, 95% CI 1.36-2.93) were associated with graft loss. <h3>Conclusion</h3> Black race and socioeconomic disadvantage remain associated with HC rejection and graft loss after the first post-transplant year in pediatric heart tx patients with ATG induction. These disparities represent important opportunities to improve long term tx outcomes in children.

Increasing Donor-Recipient Weight Mismatch is Associated with Shorter Waitlist Duration and No Increased Morbidity or Mortality

<h3>Purpose</h3> Infants awaiting pediatric heart transplantation (PHT) experience long waitlist duration and high mortality due to donor shortage. Using UNOS database, we explored if increasing donor-recipient weight ratio (DRWR) >2.0 (recommended cutoff) was associated with adverse outcomes. <h3>Methods</h3> Between 2007-20, 1392 infants received PHT. We divided cohort to 3 groups: A (DRWR ≤1.0,n=239,17%), B (DRWR 1.0-2.0,n=947,68%), C (DRWR >2.0,n=206,15%). Group characteristics and PHT outcomes were analyzed. <h3>Results</h3> DRWR ranged between 0.5-4.1. Underlying pathology (congenital vs. cardiomyopathy), gender, race, renal function, and mechanical circulatory support were comparable between groups. Group C patients were more likely to be ventilated, to receive ABO incompatible heart, and to have longer donor ischemic time. Waitlist duration was significantly shorter for Group C (33 vs. 50 days,p<0.1). Early outcomes for groups A,B,C were the following (respectively): operative death (6%,4%,3%,p=0.29), primary graft dysfunction (5%,3%,3%,p=0.30), renal failure (10%,7%,7%,p=0.42), stroke (3%,4%,1%,p=0.36). DRWR group was not associated with mortality in either congenital (OR=0.819,95%CI=0.523-1.282) or cardiomyopathy (OR=1.221,95%CI=0.780-1.912) patients and only pre-PHT ECMO was associated with mortality (OR=4.400,95%CI=2.761-7.010). Additionally, survival at 1 year (87%,87%,85%,p=0.80) and 5 years (76%,78%,77%,p=0.80) was comparable between the DRWR groups. <h3>Conclusion</h3> Infants who received PHT with DRWR >2.0 (up to 4.1) experienced shorter waitlist duration with no demonstrable increase in peritransplant complications, operative or late mortality. Historic practice to avoid DRWR>2.0 due to complications (e.g. hypertension-related stroke, graft dysfunction, death) is not currently supported in infants and stretching DRWR acceptance criteria would decrease PHT waitlist duration and potentially improve waitlist complications and mortality.

External Evaluation of a Single Center Precision Tacrolimus Dosing Model for Pediatric Heart Transplant

<h3>Purpose</h3> Extensive variability in tacrolimus pharmacokinetics (PK) influences attainment of therapeutic immunosuppression following pediatric heart transplant. Population PK (popPK) model-based personalized dosing of tacrolimus can reduce the need for tacrolimus titration and improve long-term pediatric heart transplant outcomes. The objective of this study was to externally evaluate a previously described single-center popPK model for personalized tacrolimus therapy. <h3>Methods</h3> A multicenter, retrospective analysis utilized demographics, tacrolimus dosing and concentration data, and laboratory values collected from pediatric inpatients during the first 6 weeks post-transplant, or until discharge, from three sites. PopPK analysis used the modeling software NONMEM v7.2. Observed concentration data were compared to data simulated with our single-center popPK model, using median prediction error (MPE, a measure of bias, <15% acceptable) and median absolute prediction error (MAPE, a measure of accuracy, <30% acceptable). <h3>Results</h3> A total of 285 children: 115 female, 196 white, 32 black, were included. Median age and creatinine clearance were 9.1 years and 101 mL/min/1.73m², respectively. Fluconazole use was rare, occurring in only 6 subjects. When utilizing all data the MPE and MAPE (interquartile range) were acceptable, at -3% (-25%, 10%) and 18% (5%, 49%), respectively, and not different by institution. However, when allowed only 3 concentrations (i.e. the minimum number to adequately predict future concentrations in our prior single-center study) the model poorly predicted future concentrations at all sites (MPE=31%; MAPE=47%). MPE and MAPE varied by site, ranging from 7 to 61% and 30 to 63%, respectively. Including site as a covariate in the popPK model improved predictions (MPE=21%; MAPE=37%) and decreased variability in predictive ability between sites (MPE: 11 to 34%; MAPE: 32 to 45%). <h3>Conclusion</h3> Our single-center popPK model did not adequately predict tacrolimus concentrations from external institutions. Study site appears to drive some of the poor model performance. Future directions include identifying study site differences that influence model performance, as well as identifying additional patient-specific factors affecting tacrolimus dosing requirements.

Effect of ischemic time on pediatric heart transplantation outcomes: is it the same for all allografts?

Studies have shown that the optimal ischemia time (IT) threshold in pediatric heart transplantation (PHT) is up to 4h, independent of other donor organ factors. The purpose of this study was to examine the relationship between IT and donor left ventricular ejection fraction (LVEF) and study their impact on PHT outcomes. This is a retrospective cohort study of PHT (<18years) identified in UNOS between January 2000 and March 2020. Post-transplantation survival analysis of patients receiving donor hearts with IT<4, 4-6, and >6h was performed using Kaplan-Meier curves. Cohort was divided according to donor LVEF median value, and survival was analyzed. Cox regression was performed. Median LVEF was 65% in the study cohort (6669 PHT). Overall, IT>6h was associated with worse survival compared to <4h regardless of donor LVEF. For allografts with LVEF<65%, IT=4-6h was associated with worse survival compared with IT<4h (p=.006) but had similar survival compared with IT>6h (p=.315). For allografts with LVEF≥65%, IT=4-6h had similar survival compared with <4h (p=.175) but improved survival compared with >6h (p=.003). After adjusting for donor and recipient variables, Cox regression showed that IT=4-6h was not associated with increased mortality for LVEF≥65%. The IT threshold of 4h does not apply to all allografts. Recipients of hearts with LVEF≥65% can tolerate an IT up to 6h without any detriment to survival. Routine acceptance of these donor hearts could mitigate longer waiting times and poor donor availability for many candidates.

Center Variation in Indication and Short-Term Outcomes after Pediatric Heart Transplantation: Analysis of a Merged United Network for Organ Sharing - Pediatric Health Information System Cohort.

The relationship between center-specific variation in indication for pediatric heart transplantation and short-term outcomes after heart transplantation is not well described. We used merged patient- and hospital-level data from the United Network for Organ Sharing and the Pediatric Health Information Systems to analyze outcomes according to transplant indication for a cohort of children (≤ 21years old) who underwent heart transplantation between 2004 and 2015. Outcomes included 30-day mortality, transplant hospital admission mortality, and hospital length of stay, with multivariable adjustment performed according to patient and center characteristics. The merged cohort reflected 2169 heart transplants at 20 U.S. centers. The median number of transplants annually at each center was 11.6, but ranged from 3.5 to 22.6 transplants/year. Congenital heart disease was the indication in the plurality of cases (49.2%), with cardiomyopathy (46%) and myocarditis (4.8%) accounting for the remainder. There was significant center-to-center variability in congenital heart disease as the principal indication, ranging from 15% to 66% (P < 0.0001). After adjustment, neither center volume nor proportion of indications for transplantation were associated with 30-day or transplant hospital admission mortality. In this large, merged pediatric cohort, variation was observed at center level in annual transplant volume and prevalence of indications for heart transplantation. Despite this variability, center volume and proportion of indications represented at a given center did not appear to impact short-term outcomes.

Relationship of ventricular assist device support duration with pediatric heart transplant outcomes

There is wide variability in the timing of heart transplant (HTx) after pediatric VAD implant. While some centers wait months before listing for HTx, others accept donor heart offers within days of VAD surgery. We sought to determine if HTx within 30 days versus ≥ 30 after VAD impacts post-HTx outcomes. Children on VAD pre-HTx were extracted from the Pediatric Heart Transplant Study database. The primary endpoints were post-HTx length of hospital stay (LOS) and one-year survival. Confounding was addressed by propensity score weighting using inverse probability of treatment. Propensity scores were calculated based on age, blood type, primary cardiac diagnosis, decade, VAD type, and allosensitization status. A total of 1064 children underwent VAD prior to HTx between 2000 to 2018. Most underwent HTx ≥ 30 days post-VAD (70%). Infants made up 22% of both groups. Patients ≥ 12 years old were 42% of the < 30 days group and children 1 to 11 years comprised 47% of the ≥ 30 days group (p < 0.001). There was no difference in the prevalence of congenital heart disease vs. cardiomyopathy (p=0.8) or high allosensitization status (p=0.9) between groups. Post-HTx LOS was similar between groups (p=0.11). One-year survival was lower in the < 30 days group (adjusted mortality HR 1.76, 95% CI 1.11-2.78, p=0.016). A longer duration of VAD support prior to HTx is associated with a one-year survival benefit in children, although questions of patient complexity, post-VAD complications and the impact on causality remain. Additional studies using linked databases to understand these factors will be needed to fully assess the optimal timing for post-VAD HTx.

The Dark Side of Chasing the Perfect Donor. Is it Time for Us to Change Cardiac Transplant Program Performance Metrics?

The Dark Side of Chasing the Perfect Donor. Is it Time for Us to Change Cardiac Transplant Program Performance Metrics?