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Limited data integrating waitlist and postheart transplant (HT) mortality have evaluated outcomes of left ventricular assist device (LVAD)-bridged strategy vs no LVAD according to patient characteristics. We evaluated waitlist and post-HT mortality in LVAD-bridged vs nonbridged patients based on body mass index (BMI). We included linked adults listed for HT in Organ Procurement and Transplant Network/United Network for Organ Sharing and patients receiving durable LVAD as bridge to HT or candidacy in Society of Thoracic Surgeons/Interagency Mechanical Circulatory Support databases (2010–2019). Using BMI at listing or LVAD implant, we categorized patients as underweight (<18.5 kg/m2), normal weight (18.5–24.99 kg/m2), overweight (25–29.99 kg/m2), and obese (≥30 kg/m2). Kaplan–Meier analysis and multivariable Cox proportional hazards models informed the effect of LVAD-bridged and nonbridged strategy by BMI on waitlist, post-HT, and overall mortality (including waitlist and post-HT mortality). Among 11,216 LVAD-bridged and 17,122 nonbridged candidates, bridged candidates were more frequently obese (37.3% vs 28.6%) (p < 0.001). Multivariable analysis indicated increased waitlist mortality in LVAD-bridged vs nonbridged with overweight (Hazard ratio (HR) 1.18, 95% confidence interval (CI) 1.02–1.36) or obesity (HR 1.35, 95%CI 1.17–1.56) in comparison to normal weight candidates (HR 1.02, 95%CI 0.88–1.19) (p -interaction < 0.001). Post-transplant mortality was not statistically different in LVAD-bridged vs nonbridged patients across BMI categories (p -interaction = 0.26). There was a nonsignificant graded increase in overall mortality in LVAD-bridged with overweight (HR 1.53, 95%CI 1.39–1.68) or obesity (HR 1.61, 95%CI 1.46–1.78) compared to nonbridged patients (p -interaction = 0.13). LVAD-bridged candidates with obesity had higher waitlist mortality compared to nonbridged candidates with obesity. Post-transplant mortality was similar in LVAD-bridged and nonbridged patients, but obesity remained associated with increased mortality in both groups. This study may aid clinicians and advanced heart failure patients with obesity in decision-making. [ABSTRACT FROM AUTHOR]

Background: The Pediatric Heart Transplant Society (PHTS) Registry was founded 30 years ago as a collaborative effort among like‐minded providers of this novel life‐saving technique for children with end‐stage heart failure. In the intervening decades, the data from the Registry have provided invaluable knowledge to the field of pediatric heart transplantation. This report of the PHTS Registry provides a comprehensive look at the data, highlighting both the longevity of the registry and one unique aspect of the PHTS registry, allowing for exploration into children with single ventricle anatomy. Methods: The PHTS database was queried from January 1, 1993 to December 31, 2019 to include pediatric (age < 18 years) patients listed for HT. For our analysis, we primarily analyzed patients by era. The early era was defined as children listed for HT from January 1, 1993 to December 31, 2004; middle era January 1, 2005 to December 31, 2009; and recent era January 1, 2010 to December 31, 2019. Outcomes after listing and transplant, including mortality and morbidities, are presented as unadjusted for risk, but compared across eras. Results: Since 1993, 11 995 children were listed for heart transplant and entered into the PHTS Registry with 9755 listed during the study period. The majority of listings occurred within the most recent era. Waitlist survival improved over the decades as did posttransplant survival. Other notable changes over time include fewer patients experiencing allograft rejection or infection after transplant. Waitlist and posttransplant survival have changed dramatically in patients with single ventricle physiology and significantly differ by stage of single ventricle palliation. Summary: Key points from this PHTS Registry summary and focus on patients with single ventricle congenital heart disease in particular, include the changing landscape of candidates and recipients awaiting heart transplant. There is clear improvement in waitlist and transplant outcomes for children with both cardiomyopathy and congenital heart disease alike. [ABSTRACT FROM AUTHOR]

Background The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database now includes >20,000 patients from >180 hospitals. Methods The eighth annual report of INTERMACS updates the first decade of patient enrollment. Results In the current era, >95% of implants are continuous flow devices. Overall survival continues to remain >80% at 1 year and 70% at 2 years. Review of major adverse events shows minimal advantage for patients with ambulatory heart failure pre-implant. Stroke, major infection, and continued inotrope requirement during the first 3 months have a major effect on subsequent survival. Conclusions Greater application of durable devices to patients with ambulatory heart failure will mandate more effective neutralization or prevention of major adverse events. [ABSTRACT FROM AUTHOR]

Impacts 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. Patients <18 years old in the Pediatric Heart Transplant Society database were included (N=6,765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, retransplant, 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). Diagnoses were cardiomyopathy (N = 3,246) and congenital heart disease (CHD; N = 3,305). 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 (interquartile range 2.98-4.31; 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). Donor IT was independently associated with an 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. [ABSTRACT FROM AUTHOR]

Cardiac allograft vasculopathy (CAV) is a leading cause of graft failure in pediatric heart transplant recipients (HTRs). Early statin use has been shown to reduce CAV incidence and all-cause mortality in adult HTRs. We sought to evaluate the contemporary prevalence and trends of statin use in pediatric HTRs and the association between statin use with CAV development and graft failure. Patients aged <17 years at the time of primary heart transplant who survived to ≥3 years without CAV were identified from the Pediatric Heart Transplant Society database (2001-2018). Statin use in the first 3 years posttransplant was defined as consecutive, intermediate, or absent. Kaplan-Meier survival, multivariable modeling, and propensity score–matched analyses evaluated associations between statin use and CAV incidence and graft survival, with subanalyses performed on subjects aged ≥10 years at transplant. Among 3,485 (of which 1,086 aged ≥10 years) HTRs, 584 (17%) received consecutive statin therapy, 647 (19%) received intermediate use, and 2,254 (65%) received no statin therapy. Statin use varied widely between sites, with increasing use in the ≥10-year-old cohort over time. By multivariate analysis, statin use was not associated with graft loss. Consecutive statin use was also not associated with graft survival or freedom from CAV development when compared to absent statin use in unmatched or propensity-matched analyses. While statins remain commonly utilized in pediatric HTRs, early consecutive statin therapy did not decrease CAV incidence or graft loss. The differing effects of statins on CAV development and progression in pediatric vs adult HTRs suggest differing risk and mediating factors and require further study. [ABSTRACT FROM AUTHOR]

Background: Pediatric heart transplant patients are at greatest risk of allograft loss in the first year. We assessed whether machine learning could improve 1‐year risk assessment using the Pediatric Heart Transplant Society database. Methods: Patients transplanted from 2010 to 2019 were included. The primary outcome was 1‐year graft loss free survival. We developed a prediction model using cross‐validation, by comparing Cox regression, gradient boosting, and random forests. The modeling strategy with the best discrimination and calibration was applied to fit a final prediction model. We used Shapley additive explanation (SHAP) values to perform variable selection and to estimate effect sizes and importance of individual variables when interpreting the final prediction model. Results: Cumulative incidence of graft loss or mortality was 7.6%. Random forests had favorable discrimination and calibration compared to Cox proportional hazards with a C‐statistic (95% confidence interval [CI]) of 0.74 (0.72, 0.76) versus 0.71 (0.69, 0.73), and closer alignment between predicted and observed risk. SHAP values computed using the final prediction model indicated that the diagnosis of congenital heart disease (CHD) increased 1 year predicted risk of graft loss by 1.7 (i.e., from 7.6% to 9.3%), need for mechanical circulatory support increased predicted risk by 2, and single ventricle CHD increased predicted risk by 1.9. These three predictors, respectively, were also estimated to be the most important among the 15 predictors in the final model. Conclusions: Risk prediction models used to facilitate patient selection for pediatric heart transplant can be improved without loss of interpretability using machine learning. [ABSTRACT FROM AUTHOR]

Background: A positive crossmatch (+ XM) has traditionally been associated with adverse outcomes following pediatric heart transplantation. However, more recent studies suggest that favorable intermediate‐term outcomes may be achieved despite a + XM. This study's hypothesis is that children with a + XM have similar long‐term survival, but higher rate of complications such as rejection, coronary allograft vasculopathy (CAV), and infection, compared to patients with a negative (−) XM. Methods: The Pediatric Heart Transplant Society Registry (PHTS) database was queried from 2010–2021 for all patients <18 years of age with a known XM. Baseline demographics were compared between + XM and − XM groups using appropriate parametric and non‐parametric group comparisons. Cox Proportional Hazards Modeling was used to identify risk factors for post‐transplant graft loss, rejection, and CAV. Results: Of 4599 pediatric heart transplants during the study period, XM results were available for 3914 (85%), of which 373 (9.5%) had a + XM. Univariate analysis showed lower 10‐year survival for patients with + XM (HR = 1.3, p =.04). Multivariate analyses revealed no significant difference in 10‐year survival in the 2 groups; however, time to first rejection (p =.0001) remained significantly shorter in the + XM group. Conclusions: Pediatric patients transplanted across a + XM experience earlier rejection; however, after multivariate adjustment, + XM is not independently associated with intermediate‐term graft loss. The risk of heart transplantation against a + XM must be balanced with the ongoing risk of waitlist mortality. [ABSTRACT FROM AUTHOR]

Abstract: Heart transplantation remains the best option for long term survival in pediatric patients suffering from end stage cardiomyopathy. Data from the Pediatric Heart Transplant Study indicates an expected 10year survival of 70% following cardiac transplantation among pediatric patients with cardiomyopathy. Despite this successful therapy, mortality prior to cardiac transplantation remains substantial. Over the past decade, mechanical circulatory support has improved survival in patients who deteriorate prior to cardiac transplantation. In a recent analysis, nearly 10% of pediatric heart transplant patients are supported by ventricular assist devices prior to transplant. However, the availability of mechanical devices for small children and infants remains severely limited. A paracorporeal pump for infants and children is currently in clinical trials, and an NHLBI initiative has focused on the development of durable implantable pumps for small pediatric patients. [Copyright &y& Elsevier]

Objectives: The purpose of this study was to evaluate the incidence and prognostic implication of diastolic dysfunction (DD) occurring in the first year after transplant. Background: Diastolic dysfunction is a recognized complication in heart transplant recipients, but its true incidence and natural history has been poorly characterized. We studied the prognostic implication of DD, as defined by elevated filling pressures with normal systolic function, occurring in the first year after transplant. Methods: Between June 1992 and June 2002, all patients who underwent heart transplantation at a single institution were included in the study (231 at 6 weeks and 250 at 6 months and 1 year). Diastolic dysfunction was defined as right atrial pressure (RAP) ≥15 mm Hg (right ventricular [RV] DD) or pulmonary capillary wedge pressure ≥18 mm Hg (left ventricular [LV] DD) with normal systolic function by echocardiogram and without severe mitral or tricuspid insufficiency. In addition, RV DD was defined by a RAP/stroke volume (SV) ratio. Results: The incidence of DD was 22%, 8%, and 12% at 6 weeks, 6 months, and 1 year, respectively. The incidence of LV DD was more frequent than that of RV DD at any time point (p < 0.0001). By multivariable analysis RV DD, as manifested by an elevated RAP/SV, but not LV DD was a strong predictor of cardiac mortality at all time points. Conclusions: Diastolic dysfunction is common early after transplant, and its incidence decreases during the first year. Right ventricular DD, as measured by an elevated RAP/SV ratio, but not LV DD is a strong predictor of cardiac mortality. Further studies are needed to evaluate the functional status of patients with RV or LV DD and whether aggressive medical therapy for early DD could alter outcome. [Copyright &y& Elsevier]

Background: Heart–lung transplantation (Tx) is known to offer a protective effect against acute cardiac rejection. This study was undertaken to evaluate acute and chronic heart and/or lung rejection in the setting of multiple-transplanted organs from the same donor compared with single-organ transplantation. Methods: Acute (treated rejection episodes of heart or lungs) and chronic (allograft vasculopathy in hearts and bronchiolitis obliterans syndrome [BOS] in lungs) rejection events were analyzed in 348 heart transplant (H) recipients, 24 heart–lung (HL) recipients, 82 double-lung (L) recipients and 8 heart–kidney (HK) recipients >18 years of age, who were transplanted between 1990 and 2002. Results: Survival at 3 years differed among groups as follows: HK, 100%; H, 82%; HL, 74%; and L, 70%. The probability of acute rejection within the first 3 months was higher in H recipients than in HL (81% vs 22%; p < 0.0001) or HK (81% vs 12%; p = 0.00009) recipients. Acute cardiac rejection occurred more frequently during the first 2 years in isolated H recipients compared with HL (2.8 vs 0.27 episodes; p < 0.0001) and HK (2.8 vs 0.54; p < 0.001) recipients. Acute lung rejection occurred more frequently in the first 2 years in L than HL (2.4 vs 1.0 episodes; p = 0.02) recipients. Chronic cardiac rejection (allograft vasculopathy) was more likely within 3 years after H compared with HL (32% vs 16%; p = 0.04) or HK (32% vs 0%; p = 0.14). The onset of chronic lung rejection (BOS) within 3 years was similar in HL and L recipients (39% vs 40%; p = 0.9). Conclusions: Recipients of multiple organs from a single donor undergo less acute rejection of the heart or lungs compared with isolated heart or lung transplant recipients. Cardiac allograft vasculopathy is decreased significantly when cardiac transplantation is combined with a lung allograft. A lower incidence of cardiac allograft vasculopathy is observed when cardiac transplantation is combined with a renal allograft, and may prove statistically significant when more cases have been accumulated. These phenomena may result from immune modulation of the recipient by simultaneous transplant of disparate tissues or introduction of immune-modulating hematopoietic elements. [Copyright &y& Elsevier]

We sought to compare heart transplant (HTX) outcomes from patients with a total artificial heart (TAH), biventricular assist device (BiVAD), or left ventricular assist device (LVAD) as a bridge to transplant (BTT). Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS)-Scientific Registry of Transplant Recipients (SRTR) created a dataset with TAH or durable mechanical circulatory support (MCS) who reached HTX between 2006 and 2015. The retrospective analysis compared TAH outcomes with those with a BiVAD or LVAD before HTX. The primary outcome was posttransplant survival at 1, 36, and 60 months. Secondary outcomes included simultaneous heart-kidney transplants, donor characteristics, and mortality risk factors. INTERMACS-SRTR cohort had, at the time of HTX, 2762 patients with LVAD; 205 BiVAD (139 durable and 66 temporary RVAD); 176 TAH (6 prior HeartMate II). Sixty months after HTX, mortality rates were 16.5% in the total group: LVAD 15.2%, BiVAD 22.4%, and TAH 29%. Survival differed between the LVAD, the TAH, and BiVAD but not between the BiVAD and TAH groups. One-year survival and complication rates were similar across groups—there was no difference in survival by donor age in the overall cohort. There was a difference in TTD based on recipient age in the LVAD group but not in BiVAD or TAH groups. Occurrence of HTX-kidney and post-transplant dialysis were higher in the TAH versus LVAD and BiVAD groups. The TAH is an efficacious BTT. Refinements in technology and patient selection may improve outcomes. [ABSTRACT FROM AUTHOR]

Background: Patients after Fontan palliation represent a growing pediatric population requiring heart transplant (HTx) and often have lymphopenia (L) and/or hypogammaglobinemia that may be exacerbated by protein‐losing enteropathy (PLE, P). The post‐HTx effects of this altered immune phenotype are not well studied. Methods: In this study of the Pediatric Heart Transplant Society Registry, 106 Fontan patients who underwent HTx between 2005 and 2018 were analyzed. The impact of lymphopenia and PLE on graft survival, infection, rejection, and malignancy was analyzed at 1 and 5 years post‐HTx. Results: The following combinations of lymphopenia and PLE were noted: +L+P, n = 37; +L−P, n = 23; −L+P, n = 10; and −L−P, n = 36. Graft survival between the groups was similar within the first year after transplant (+L+P: 86%, +L−P: 86%, −L+P: 87%, −L−P: 89%, p =.9). Freedom from first infection post‐HTx was greatest among −L−P patients compared to patients with either PLE, lymphopenia, or both; with a 22.1% infection incidence in the −L−P group and 41.4% in all others. These patients had a significantly lower infection rate in the first year after HTx (+L+P: 1.03, +L−P: 1, −L+P: 1.3, −L−P: 0.3 infections/year, p <.001) and were similar to a non‐single ventricle CHD control group (0.4 infections/year). Neither freedom from rejection nor freedom from malignancy 1 and 5 years post‐HTx, differed among the groups. Conclusions: Fontan patients with altered immunophenotype, with lymphopenia and/or PLE, are at increased risk of infection post‐HTx, although have similar early survival and freedom from rejection and malignancy. These data may encourage alternative immunosuppression strategies and enhanced monitoring for this growing subset of patients. [ABSTRACT FROM AUTHOR]

Social factors like race and insurance affect transplant outcomes. However, little is known in pediatric heart transplantation. We hypothesized that race and insurance coverage impact listing and waitlist outcomes across eras. Data from the Pediatric Heart Transplant Society multi-center registry prospectively collected between January 1, 2000-December 31, 2019 were analyzed. Patients were divided by race as Black, White and other and by insurance coverage at listing (US governmental, US private and non-US single payer systems (UK, Canada). Clinical condition at listing and waitlist outcomes were compared across races and insurance coverages. Categorical variables were compared using a chi-square test and continuous variables using the Wilcoxon rank sum test. Risk factors for waitlist mortality were examined using multiphase parametric hazard modeling. A sensitivity analysis using parametric hazard explored the interaction between race and insurance. At listing, compared to Whites (n = 5391) and others (n = 1167), Black patients (n = 1428) were older, more likely on US governmental insurance and had cardiomyopathy as the predominant diagnosis (p < 0.0001). Black patients were more likely to be higher status at listing, in hospital, on inotropes or a ventricular assist device (p < 0.0001). Black patients had significantly shorter time on the waitlist compared to other races (p < 0.0001) but had higher waitlist mortality (p = 0.0091), driven by the earlier era (2000-2009) (p = 0.0005), most prominently within the US private insurance cohort (p = 0.015). Outcomes were not different in other insurance cohorts or in the recent era (2010-2019). Black children are older and sicker at the time of listing, deteriorate more often and face a higher wait list mortality, despite a shorter waitlist period and favorable clinical factors, with improvement in the recent era associated with the recent US healthcare reforms. The social construct of race appears to disadvantage Black children by limiting referral, consideration or access to pediatric cardiac transplantation. [ABSTRACT FROM AUTHOR]

BACKGROUND Limited data exist describing impact of body mass index (BMI) on post‒left ventricular assist device (post-LVAD) outcomes. We sought to define the relationship between body mass index (BMI) and adverse events (AEs) after LVAD implantation by examining the ISHLT Mechanically Assisted Circulatory Support (IMACS) registry. METHODS Patients implanted with a contemporary continuous flow (CF)-LVAD were stratified into 4 groups using pre-operative BMI: underweight (UW; BMI ≤18.5 kg/m2); non-obese (NO; BMI >18.5 to <30 kg/m2); obese (OB; BMI ≥30 to <40 kg/m2); and morbidly obese (MO; BMI ≥40 kg/m2). Freedom from AEs was evaluated using the Kaplan–Meier method and risk factors for development of first AE were identified using multiphase parametric hazard modeling. AEs included infection, thromboembolic events, bleeding, device malfunction, and neurologic dysfunction. RESULTS Between 2013 and 2015, a total of 9,408 patients underwent implantation of a CF-LVAD, which consisted of 368 (4%) UW, 5,719 (61%) NO, 2,770 (29%) OB, and 444 (5%) MO patients. Survival among the 4 BMI cohorts was similar at 2 years (70.8% to 75.8%, p = 0.24). MO patients were less likely to be free from a non‒VAD-related infection (p < 0.0001) or device-related infection (p = 0.0014) at 2 years (50.3%, 70.7%) when compared with OB (58.3%, 78.7%), NO (65.2%, 81.4%), and UW (68.9%, 77.4%) patients. UW (81.5%) and NO (81.3%) patients were more likely to be free from device malfunction at 2 years when compared with OB (78.3%) and MO (72.6%) (p = 0.0006). Thromboembolic events were rare and more common in the UW cohort (p = 0.026). CONCLUSIONS Although BMI was not correlated with 2-year mortality, an increased rate of infectious and device-related AEs was noted in OB and MO LVAD patients. In a group with few options for transplant, the event morbidity in obese patients can be expected to impact morbidity with longer support durations. [ABSTRACT FROM AUTHOR]

Cardiac allograft vasculopathy (CAV) remains a leading cause of graft loss in pediatric heart transplant (HTx) recipients. Adult literature suggests that aspirin (ASA) use in the early post-HTx period may reduce the risk of CAV. This study aimed to determine the impact of early ASA use on the development of CAV in pediatric HTx recipients. All subjects <17 years of age at time of primary HTx who survived ≥3 years without evidence of CAV were identified for inclusion from the Pediatric Heart Transplant Society database (1996-2019). Early ASA use was defined as ASA started within the first 3 years post-HTx and was classified as continuous or intermittent. Frequency of ASA use was described across centers. Kaplan-Meier method assessed freedom from CAV and overall graft survival. Multiphase parametric hazard analyses and propensity score matched analysis were used to identify independent risk factors. 3,011 patients were included with 387 (13%) receiving continuous ASA, 676 (22%) receiving intermittent ASA, and 1,948 (65%) receiving no ASA. ASA use was highly variable across centers (0%-100%). At baseline patients receiving continuous ASA therapy demonstrated inferior graft survival (p < 0.001) and worse freedom from CAV (p = 0.002), but with lower CAV grades (p = 0.05). In multiphase parametric hazard modeling continuous ASA use was not independently associated with CAV, but remained associated with inferior graft survival. Propensity-matched sub-analysis between continuous and no ASA groups demonstrated no difference in freedom from CAV or overall graft loss. ASA use varies widely across pediatric HTx centers. Early ASA use did not reduce the risk of CAV or graft loss in pediatric heart transplant recipients. [ABSTRACT FROM AUTHOR]

There is limited and conflicting information on waitlist and transplant outcomes for children with myocarditis. Retrospective review included children with myocarditis and dilated cardiomyopathy (DCM) listed for HT from January 01, 1993 to December 31, 2019 in the Pediatric Heart Transplant Society database. Clinical characteristics, waitlist and post-HT outcomes (graft loss, rejection, cardiac allograft vasculopathy, infection and malignancy) for children listed from early (1993-2008) and current era (2009-2019) with myocarditis were evaluated and compared to those with DCM. Of 9755 children listed, 322 (3.3%) had myocarditis and 3178 (32.6%) DCM. Compared to DCM, children with myocarditis in the early and the current era were significantly more likely to be listed at higher urgency; be in intensive care unit; on mechanical ventilation; extracorporeal membrane oxygenation and ventricular assist device (p < 0.05 for all). While unadjusted analysis revealed lower transplant rates and higher waitlist mortality for children with myocarditis, in multivariable analysis, myocarditis was not a risk factor for waitlist mortality. Myocarditis, however, was a significant risk factor for early phase post-HT graft loss (HR 2.46; p = 0.003). Waitlist and post-HT survival for children with myocarditis were similar for those listed and transplanted in the early era to those listed and transplanted in the current era (p > 0.05 for both). Children with myocarditis have a higher acuity of illness at listing and at HT and have inferior post-HT survival compared to children with DCM. Outcomes for children with myocarditis have not improved over the 3 decades and efforts are needed to improve outcomes for this cohort. [ABSTRACT FROM AUTHOR]

Background: Management of infants with pulmonary atresia/intact ventricular septum (PA/IVS) is variable. Because of higher mortality in more severe forms, heart transplant (HT) is an acceptable approach, but waitlist and post‐transplant outcomes are unclear. This study compared outcomes of infants with PA/IVS vs. other single ventricle (SV) anatomies listed for HT. Methods: Data from the Pediatric Heart Transplant Society (1993–2018) were analyzed for survival and risk factors for mortality. Results: Of 1617 SV infants, 300 had PA/IVS (19%) and 1317 had other SV (81%). Overall, 1‐, 5‐, and 10‐year survival was higher among PA/IVS (74%, 65%, 61%) versus other SV infants (62%, 54%, 50%, p =.004). While waitlist mortality was similar between groups (p =.09), PA/IVS was an independent predictor of improved waitlist survival (HR 0.68, p =.03), and PA/IVS infants had higher incidence of waitlist removal (8% vs. 5.5%, p =.03), most commonly for being "too well." Post‐transplant survival was superior among PA/IVS versus other SV infants (1‐ and 5‐year survival 93% and 81% vs. 80% and 71%, p <.0001). Risk factors for PA/IVS waitlist mortality (2008–2018) included extracorporeal membrane oxygenation and mechanical ventilation. Prior aortopulmonary (AP) shunt among PA/IVS infants was associated with improved waitlist survival. Conclusions: Overall survival among PA/IVS infants listed for HT exceeds that of other SV infants with PA/IVS identified as an independent predictor of improved waitlist and post‐transplant survival. Prior AP shunt among listed PA/IVS infants was associated with improved waitlist outcomes, though, which may reflect a listing selection bias. [ABSTRACT FROM AUTHOR]

Background Bacterial infections represent a major cause of morbidity and mortality in heart transplant recipients. However, data describing the epidemiology and outcomes of these infections in children are limited. Methods We analyzed the Pediatric Heart Transplant Study database of patients transplanted between 1993 and 2014 to determine the etiologies, risk factors and outcomes of children with bacterial infections post–heart transplantation. Results Of 4,458 primary transplants in the database, there were 4,815 infections that required hospitalization or intravenous therapy, 2,047 (42.51%) of which were bacterial. The risk of bacterial infection was highest in the first month post-transplant, and the bloodstream was the most common site (24.82%). In the early post-transplant period (<30 days post-transplant), coagulase-negative staphylococci were the most common pathogens (16.97%), followed by Enterobacter sp (11.99%) and Pseudomonas sp (11.62%). In the late post-transplant period, community-acquired pathogens Streptococcus pneumoniae (6.27%) and Haemophilus influenzae (2.82%) were also commonly identified. Patients’ characteristics independently associated with acquisition of bacterial infection included younger age ( p < 0.0001) and ventilator ( p < 0.0001) or extracorporeal membrane oxygenation ( p = 0.03) use at time of transplant. Overall mortality post-bacterial infection was 33.78%, and previous cardiac surgery ( p < 0.001) and multiple sites of infection ( p = 0.004) were independent predictors of death. Conclusions Bacteria were the most common causes of severe infections in pediatric heart transplant recipients and were associated with high mortality rates. The risk of acquiring a bacterial infection was highest in the first month post-transplant, and a large proportion of the infections were caused by multidrug-resistant pathogens. [ABSTRACT FROM AUTHOR]

Heart transplantation (HT) is the gold standard for managing end-stage heart failure. Multiple quality metrics, including length of stay (LOS), have been used in solid organ transplantation. However, limited data are available regarding trends and factors influencing LOS after pediatric HT. We hypothesized that various donor, peri-transplant and recipient factors affect LOS after pediatric HT. We analyzed patients <18years at time of HT from January 2005 to December 2018 in the Pediatric Heart Transplant Society database, and examined LOS trends, defined prolonged LOS (PLOS = LOS>30days after HT), identified factors associated with PLOS and assessed outcomes. Of 4827 patients undergoing HT, 4414 patients were discharged and included for analysis. Overall median LOS was 19days[13,34]. Median LOS was longer in patients with congenital heart disease(CHD = 25days[15,43] than with cardiomyopathy(CM = 17days[12,27] across all ages. Median LOS in age <1year was 26-days[16,45.5] and in age >10year was 16days[11,26]. PLOS was seen in 1313 patients(30%). Patients with PLOS were younger, smaller and had longer CPB times. There was no difference in utilization of VAD at HT between groups, however, ECMO use at listing(8.45% vs 2.93%, p < 0.05) and HT was higher in the PLOS group(9.22% vs 1.58%, p < 0.05). PLOS was more common in patients with previous surgery, CHD, single ventricle physiology, recipient history of cardiac arrest or CPR, end organ dysfunction, lower GFR, use of mechanical ventilation at HT and Status 1A at HT. We present novel findings of LOS distribution and define PLOS after pediatric HT, providing a quality metric for individual programs to utilize and study in their practice. [ABSTRACT FROM AUTHOR]

Background: Obesity and dyslipidemia afflict children of all ages. We explored the prevalence of obesity and dyslipidemia in pediatric heart transplant (HT) recipients and its effects on cardiac allograft vasculopathy (CAV) and survival. Methods: This study included primary HT recipients (≤18 years) transplanted between 01/1996 and 12/2018 included in the Pediatric Heart Transplant Society database. Obesity was categorized according to WHO/CDC guidelines and dyslipidemia according to the National Cholesterol Education Program. Kaplan–Meier analyses for CAV and graft loss stratified for BMI and lipid panels were generated and risk factors identified using multivariate analyses. Results: Among 6291 HT patients (median age [range] at HT = 4.3 [0.6–12.8] years; 45% Female; 68% White), 56% had a normal BMI at HT. Obese patients at HT had an increased risk for graft loss (HR 1.19, 95% CI 1.01–1.4, p =.04). Poor total cholesterol (TC), LDL‐C, and TG were associated with the risk of both CAV (HR 1.79, p <.0001; HR 1.65, p =.0015; HR 1.53, p <.0001, respectively) and graft loss (HR 1.58, p =.0008; HR 1.22, p =.04; HR 1.43, p =.0007, respectively). Conclusions: Pediatric patients who are obese at the time of HT and dyslipidemic at 1 year post‐HT are at an increased risk for CAV and graft loss. Preventative interventions may reduce morbidity and mortality among this cohort. [ABSTRACT FROM AUTHOR]

We sought to evaluate the association between timing of cardiac allograft vasculopathy (CAV) occurrence post-heart transplant (HT) with graft survival and progression of CAV severity in pediatric HT recipients. Data from the Pediatric Heart Transplant Society for pediatric (<18 years old) HT recipients between 1993-2019 with available angiographic data were obtained (N = 5,075). The timing of CAV diagnosis (<3; 3-<5; 5-<10; and ≥10 years post-HT) and severity of disease at each assessment (CAV 1-3) was determined. Associations between CAV timing, graft survival, and CAV progression were evaluated using Kaplan-Meier survival curves, multivariable COX proportional hazard regression analyses, and competing risk analyses. Over a median follow-up period of 4.1 (IQR 1.3-8.3) years, CAV was identified in 17% (885/5,075), 28% (252/885) of which were early-onset CAV. Compared with late onset CAV ≥10 years post-HT, patients with early CAV were older at the time of transplant (8.3 ± 6.2 vs. 3.8 ± 4.8 years, p <.0001). While the five-year graft-survival in the ≥10-year group (79.2%, p = 0.03) was significantly higher than the <3, 3-<5, and 5-<10 years post-HT groups (65.0%-67%) (p = 0.03), overall post-CAV graft survival was not significantly different across the CAV time-points. CAV disease progression did not vary with CAV timing post-HT, with an overall five-year freedom from CAV ≥2 of 75.4% (73.1%-77.6%). Later onset CAV (≥10-years post-HT) was associated with improved five-year graft survival compared with CAV onset at earlier time-points, but similar and poor long-term outcomes. CAV timing post-HT was not associated with progression of CAV disease severity. [ABSTRACT FROM AUTHOR]

Reports focused on adult heart transplant (HTx) recipients with COVID-19 suggest an increased risk of severe disease, however; it is unclear if this holds true for pediatric HTx patients, given the typically milder course of illness in children in general with COVID-19. We sought to rapidly implement a system for multi-center data collection on pediatric HTx candidates and recipients, with the aim of describing the patient population and infection related outcomes. The Pediatric Heart Transplant Society (PHTS) is a multi-center collaboration that seeks to improve the outcomes of children who are listed and undergo HTx. The society consists of pediatric HTx centers in North America (n = 53), UK (n = 2), and Brazil (n = 1). In response to the pandemic, PHTS developed a web-based platform to collect COVID-19 specific data on pediatric HTx candidates and recipients. Non-PHTS centers were also invited to submit data. Data fields included pre-and post-HTx patient characteristics, presumed versus documented infection, need for hospitalization (including ICU and ventilator use), treatments administered, and 30-day outcome (resolution, death, sequelae, and or unresolved) Data collection was initiated on 4/30/20. As of 03/15/21 there were 225 patients [19 pre-HTx and 206 post-HTx, median age 14 years (IQR 7, 18)] reported from 41 centers. Hospitalization occurred in 42% (n = 8) of the pre-HTx and 21% (n=43) of the post-HTx patients. Among the patients listed for HTx, 21% (n = 4) required ICU and 10.5% (n = 2) were mechanically ventilated. Among post-HTx patients, 7% (n = 14) required ICU and 1% (n = 3) were mechanically ventilated. At 30 days, the majority of patients had resolution of symptoms (94.7% pre-HTx, 95.6% post-HTx). One death was reported in a post-HTx patient prior to 30 days from onset of COVID-19 illness. These data demonstrate the ability to rapidly adapt the PHTS data collection infrastructure in response to a novel infection and represent the first known multi-center report of characteristics and early outcomes for patients listed and following pediatric HTx with COVID-19. Hospitalization appears to be more common for both candidates and recipients due to COVID-19 than for the general pediatric population though stays were short and mortality minimal. [ABSTRACT FROM AUTHOR]

Challenges exist with heterotaxy due to the complexity of heart disease, abnormal venous connections, and infection risks. This study aims to understand heart transplant outcomes for children with heterotaxy. All children with congenital heart disease listed for transplant from 1993 to 2018 were included. Those with and without heterotaxy were compared. Waitlist outcomes and survival post-listing and transplant were analyzed. Post-transplant risk factors were identified using multiphase parametric hazard modeling. There were 4814 children listed, of whom 196 (4%) had heterotaxy. Heterotaxy candidates were older (5.8 ± 5.7 vs 4.2 ± 5.5 years, p < 0.01), listed at a lower urgency status (29.8% vs 18.4%, p < 0.01), more commonly single ventricle physiology (71.3% vs 59.2%, p < 0.01), and less often supported by mechanical ventilation (22% vs 29.1%, p < 0.05) or extracorporeal membrane oxygenation (3.6% vs 7.5%, p < 0.05). There were no differences in waitlist outcomes of transplant, death, or removal. Overall, post-transplant survival was worse for children with heterotaxy: one-year survival 77.2% vs 85.1%, with and without heterotaxy, respectively. Heterotaxy was an independent predictor for early mortality in the earliest era (1993-2004), HR 2.09, CI 1.16-3.75, p = 0.014. When stratified by era, survival improved with time. Heterotaxy patients had a lower freedom from infection and from severe rejection, but no difference in vasculopathy or malignancy. Mortality risk associated with heterotaxy is mitigated in the recent transplant era. Early referral may improve waitlist outcomes for heterotaxy patients who otherwise have a lower status at listing. Lower freedom from both infection and severe rejection after transplant in heterotaxy highlights the challenges of balancing immune suppression. [ABSTRACT FROM AUTHOR]

Plastic bronchitis is a rare post‐Fontan complication with limited treatment options. Heart transplantation has evolved as a potential curative option, but outcomes have not been well‐defined. This study aims to assess contemporary waitlist and post‐transplant outcomes in patients with plastic bronchitis. All Fontan patients were identified in the PHTS database (2010 ‐ 2018). Waitlist and post‐transplant outcomes were compared between Fontan patients with and without plastic bronchitis. Competing outcomes and Kaplan‐Meier analyses were used to assess the impact of plastic bronchitis on waitlist and post‐transplant survival. A secondary analysis excluded those with PLE from the comparison cohort. Of 645 Fontan patients listed for heart transplant, 69 (11%) had plastic bronchitis. At listing, patients with plastic bronchitis were younger (8.9 vs 11.1 years, P =.02), but had few other differences in baseline characteristics. A fewer Fontan patients with plastic bronchitis were listed in the more recent era (46 [15.4%] in 2010‐2014 vs 23 [6.6%] in 2015‐2018, P <.01). Overall, there was no difference in waitlist (P =.30) or post‐transplant (P =.66) survival for Fontan patients with and without plastic bronchitis. The results were similar after excluding patients with PLE. Contrary to prior reports, this relatively large series showed that plastic bronchitis did not have a negative impact on survival to or after heart transplantation in Fontan patients. Our study also found a 50% reduction in listing in the current era, which may indicate evolution in management of Fontan patients. [ABSTRACT FROM AUTHOR]

Examines the effects of diltiazem therapy on cyclosporine blood levels in cardiac transplant patients. Long-term cyclosporine dose; Medication cost following cardiac transplantation; Interaction between diltiazem and cyclosporine.

Racial disparities have been reported among pediatric patients waitlisted for and undergoing heart transplantation but have not been studied further upstream in the transplant candidate evaluation process. We retrospectively studied our single‐center experience in order to investigate any potential biases in the evaluation process. Results of the heart transplant evaluation in children ≤18 years old at our institution were analyzed. Primary outcome was final disposition to waitlist or not. Race was defined by family self‐identification. Descriptive and comparative statistical analyses were performed. From 2013 to 2019, 133 unique patients were referred for listing consideration. While Black patients comprised 44% of the referral population and had more markers of socioeconomic disadvantage, they comprised 43% of the patients who were listed for transplantation with no significant difference between these proportions (p =.96). Black and White patients made up a similar proportion of patients deemed too well or too ill for listing. Black patients had lower annual household income estimates and rates of household marriage. Despite identifying significant social challenges in 27 patients (18 of them Black), only five patients (3 Black and 2 White) were turned down for listing due to social barriers. While limited by the small number of patients turned down for social barriers, our transplant evaluation process does not appear to result in racial disparities in access to listing. Further studies are needed using national cohorts to explore possible racial disparities upstream from waitlisting and transplantation, such as during the referral and evaluation. [ABSTRACT FROM AUTHOR]

Coronary allograft vasculopathy (CAV) is a leading cause of mortality after heart transplantation (HT) in children. Variation in CAV screening practices may impact detection rates and patient outcomes. Among 50 Pediatric Heart Transplant Society (PHTS) sites from 2001 to 2016, coronary evaluations were classified as angiography or non-invasive testing, and angiograms were designated as routine or symptom based. CAV detection rates stratified by routine vs symptom-based angiograms were calculated. Freedom from CAV and mortality after CAV diagnosis, stratified by study indication, were calculated. A total of 3,442 children had 13,768 coronary evaluations; of these, 97% (n = 13,012) were for routine surveillance, and only 3% (n = 333) were for cause. Over the study period, CAV was detected in 472 patients (14%). Whereas 58% (n = 29) of PHTS sites evaluate by angiography alone, 42% reported supplementing with a non-invasive test, although only 423 non-invasive studies were reported. Angiographic detection of CAV was higher for symptom-based testing than for routine testing (29% vs 4%, p < 0.0001), although routine testing identified a majority of cases (88%; n = 414). The 10-year freedom from CAV was 77% overall. Once CAV is detected, 5-year graft survival was 58%, with lower survival for patients diagnosed after symptoms angiogram than after routine angiogram (30% vs 62%; p < 0.0001). Development of a robust model for CAV risk should allow low-risk patients to undergo less frequent invasive angiography without adverse impact on CAV detection rates or outcomes. [ABSTRACT FROM AUTHOR]

Regional outcomes after implantation of continuous-flow left ventricular assist devices (LVADs) have not been described. We examined differences in patient selection, survival, and adverse events across 3 geographic regions of the world: the Americas, Asia-Pacific, and Europe. Using data from The International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support registry, all adult patients implanted with a continuous-flow LVADs were included in this International Society for Heart and Lung Transplantation Mechanically Assisted Circulatory Support analysis (n = 15,560), of whom, 9,988 (64%) received axial-flow devices and 5,572 (36%) received centrifugal-flow devices. There were significant interregional differences in the rate of implantation of patients aged >70 years (Americas: 14%, Asia-Pacific: 1%, Europe: 5%; p < 0.0001), morbidly obese (Americas: 5%, Asia-Pacific: 1%, Europe: 1%; p < 0.0001), male (Americas: 79%, Asia-Pacific: 77%, Europe: 85%; p < 0.0001), and implanted as destination therapy (Americas: 48%, Asia-Pacific: 4%, Europe: 22%; p < 0.0001). The rates of centrifugal pump usage varied by region (Americas: 30%, Asia-Pacific: 34%, Eu: 74%; p < 0.0001). Survival rates varied by region and the type of pump flow, with survival at 12 and 48 months (axial flow vs centrifugal flow) being 82% vs 82% and 52% vs 53 in Americas; 92% vs 86% and 83% vs 74% in Asia-Pacific; and 80% vs 75% and 69% vs 53% in Europe, respectively (regional survival p < 0.0001). There are marked global differences in LVAD recipient characteristics, device utilization, and post-operative care. These heterogeneities along with differences in patient management and transplantation rates may impact long-term survival. Regional differences in adverse event incidence warrant further investigation. [ABSTRACT FROM AUTHOR]

Background: Cardiac transplant recipients have been regarded as not medically fit to fly an airplane. Recently, the Federal Aviation Administration decided to re-examine this policy and, in response, this study was undertaken to determine the risk of death from any cause and sudden-onset death in heart transplant recipients during the 12 months after an annual evaluation.Methods: Of 6,510 patients undergoing primary orthotopic cardiac transplantation enrolled in the Cardiac Transplant Research Database (CTRD), 4,978 patients survived for at least 1 year and formed the basis of this study. Risk factors for death from any causes and sudden-onset death (a composite of causes of death that could conceivably result in a pilot’s incapacitation) were determined during the 12-month period after an anniversary evaluation. Patients were re-entered into the analysis at each evaluation, resulting in a total of 23,575 anniversary evaluations.Results: The presence of coronary allograft vasculopathy (CAV), left ventricular systolic dysfunction, history of rejection, malignancy, infection and pre-transplant insulin-dependent diabetes were associated with an increased risk of death from any cause and sudden-onset death during the 12-month period after an evaluation. Based on the absence of these risk factors, a group of heart transplant recipients could be defined with a 12-month risk of death from any cause of 1.0% and of sudden-onset death of 0.3% (which is identical to the mortality rate of a matched population from the U.S. life-table).Conclusion: Using these identified risk factors, a group of heart transplant recipients can be defined that are potentially medically certifiable to fly without compromising aviation safety. [Copyright &y& Elsevier]

Heart transplantation from ABO incompatible (ABOi) donors has evolved into a progressively accepted therapy in young children. We assessed the recent practice of ABOi listing impact on waitlist and post-transplant outcomes. Using the Pediatric Heart Transplant Society registry, we compared clinical presentation, waitlist parameters, and post-transplant survival of children < 2 years of age listed for ABOi vs ABO compatible (ABOc) heart transplant between January 2010 and June 2018 with sub-analysis of blood group O recipients. Among 2,039 patients, ABOi listing increased significantly with time from 49% (2010) to 72% (2017). ABOi-listed patients had lower age and body surface area, and higher proportion of congenital heart disease, mechanical ventilation, and high urgency status (all p < 0.01). Use of mechanical circulatory support was similar between groups. Of 1,288 patients reaching transplant, 239 (18.6%) received an ABOi organ (15%–40%/year). Death while waiting, removal from the waitlist, and waitlist survival were similar between groups. Time to transplant was significantly shorter for ABOi listing in blood group O patients (p < 0.02), approaching significance (p = 0.057) for all blood groups. Post-transplant survival was similar except for lower survival of patients listed ABOc but transplanted ABOi. These patients showed increasing need for mechanical circulatory support and high urgency listing while waiting. In the current era, primary listing for ABOi heart transplant has become routine for the majority of children < 2 years old, resulting in shorter waitlist time, especially in blood group O. Post-transplant survival is similar despite ABOi-listed children still showing a higher risk profile. [ABSTRACT FROM AUTHOR]

Educational development is an important component of quality of life for children with heart transplant. Aims include determining prevalence of and risk factors for modified education placement in a large representative sample of pediatric heart transplant recipients. Participants included 1495 patients (age 6‐18 years) from the PHTS database. Data on education placement and clinical predictors were collected at listing and at 1 and 3 years post‐transplant. At listing, 88% of patients were in typical education placement, while 12% were in modified education. Males (P =.02), those with CHD (P <.0001), those with non‐private insurance (P <.0001), and those with longer hospital stay (P =.001) were more likely to be in a modified education placement at time of listing. Age, race, listing status, mechanical support, and waitlist time were not significantly associated with placement. The prevalence of typical education placement was similar (87% at 1‐year and 86% at 3‐year) post‐transplant. Predictors of modified education placement at 3‐year follow‐up included placement at listing (OR = 12.9 [95% CI 7.6‐21.9], P <.0001), non‐private insurance (OR = 2.0 [95% CI 1.3‐3.2], P =.001), CHD (OR = 1.8 [95% CI 1.1‐2.7, P =.01), history of post‐transplant infection (OR = 1.9 [95% CI 1.2‐2.9, P =.007), and number of post‐transplant infections (OR = 1.3 [95% CI 1.1‐1.5, P =.002). Among pediatric heart transplant recipients, males, those with non‐private insurance, those with CHD, and those who experience post‐transplant infections are at greatest risk for modified academic placement, which persists for several years post‐transplant and deserves targeted intervention. [ABSTRACT FROM AUTHOR]

Ventricular assist device (VAD) patients often experience infections, which increase the risk of stroke and mortality. Using the definitions of the International Society for Heart and Lung Transplantation (ISHLT), we have characterized differences in clinical outcomes for categories of infection: VAD-specific (e.g., pump component related); VAD-related (e.g., bloodstream infection, BSI); and non-VAD infections (e.g., pneumonia). Querying of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) identified 16,597 continuous-flow VAD recipients. Categories of infection were tested in multivariate models to determine the risk of stroke and death. After implant, 7,046 patients (42%) developed an infection at a median of 69 (interquartile range 12 to 272) days. A majority were non-VAD infections (49%), followed by VAD-related (26%) and VAD-specific infections (25%). BSIs were the most common form of VAD-related infection (92%), and the majority (59%) had no associated infection, that is, idiopathic bacteremia. Internal pump component infections were rare (0.003 event per patient-year [EPPY]). Infected VAD patients had a higher prevalence of stroke compared to patients without an infection (18% vs 11%, p < 0.001). The lowest stroke rate occurred after a VAD-specific infection (0.11 EPPY) compared with VAD-related (0.17 EPPY) and non-VAD infections (0.15 EPPY, p < 0.001). Hemorrhagic strokes were more common than ischemic strokes in all infection groups and highest after a VAD-related infection (0.13 EPPY). One-year survival after an infection was 87% in VAD-specific infections, as compared with VAD-related (71%) and non-VAD infections (72%, p < 0.001). The ISHLT categorization of VAD infections unveils notable differences in associated risk of stroke and mortality. A re-assessment of transplant prioritization for eligible infected VAD patients may be useful to increase transplant-related survival benefit. [ABSTRACT FROM AUTHOR]

BACKGROUND The reported ventricular assist device (VAD) experience in the pediatric congenital heart disease (CHD) population is limited. We sought to describe contemporary use and outcomes of VADs in children with CHD and compare these outcomes to those of non-CHD children. METHODS Patients enrolled in the Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) between September 19, 2012 through June 30, 2017 were included. CHD was classified as biventricular vs single ventricle (Stages 1, 2, or 3). Outcomes were compared between groups and multivariable analysis was used to identify factors associated with mortality on the device. RESULTS Among the 471 patients enrolled, 108 (24%) had CHD (45 biventricular and 63 single ventricle). CHD patients were younger (5.7 ± 5.7 years vs 9.8 ± 6.5 years; p < 0.0001) and smaller (0.8 ± 0.5 m2 vs 1.2 ± 0.7 m2; p < 0.0001) compared with non-CHD patients. CHD patients were more likely to receive a paracorporeal continuous-flow VAD (36.1% vs 12.9%; p < 0.0001) and less likely to receive an implantable continuous-flow VAD (27.8% vs 55.0%; p < 0.0001) compared with non-CHD patients. After 6 months on a VAD, CHD patients had higher mortality (36.4% vs 12.1%) and a lower transplantation rate (29.1% vs 59.9%) than non-CHD patients (p < 0.0001). In the multivariable analysis, CHD was the factor most strongly associated with mortality on VAD (hazard ratio [HR] = 2.9; p < 0.0001), whereas the factors implantable continuous-flow device and high-volume center were protective (HR = 0.3, p < 0.0001, and HR = 0.6, respectively; p = 0.02). CONCLUSIONS VAD use in children with CHD is associated with increased mortality and decreased transplant rates compared to children without CHD. For the subgroup of children with CHD who received implantable continuous-flow VADs, survival rates were higher and comparable to those of children without CHD. Increased experience correlated with better survival in pediatric VADs. [ABSTRACT FROM AUTHOR]

Background We sought to better understand the patient population who receive a temporary total artificial heart (TAH) as bridge to transplant or as bridge to decision by evaluating data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database. Methods We examined data related to survival, adverse events, and competing outcomes from patients who received TAHs between June 2006 and April 2017 and used hazard function analysis to explore risk factors for mortality. Results Data from 450 patients (87% men; mean age, 50 years) were available in the INTERMACS database. The 2 most common diagnoses were dilated cardiomyopathy (50%) and ischemic cardiomyopathy (20%). Risk factors for right heart failure were present in 82% of patients. Most patients were INTERMACS Profile 1 (43%) or 2 (37%) at implantation. There were 266 patients who eventually underwent transplantation, and 162 died. Overall 3-, 6-, and 12-month actuarial survival rates were 73%, 62%, and 53%, respectively. Risk factors for death included older age (p = 0.001), need for pre-implantation dialysis (p = 0.006), higher creatinine (p = 0.008) and lower albumin (p < 0.001) levels, and implantation at a low-volume center (≤10 TAHs; p < 0.001). Competing-outcomes analysis showed 71% of patients in high-volume centers were alive on the device or had undergone transplantation at 12 months after TAH implantation vs 57% in low-volume centers (p = 0.003). Conclusions Patients receiving TAHs have rapidly declining cardiac function and require prompt intervention. Experienced centers have better outcomes, likely related to patient selection, timing of implantation, patient care, and device management. Organized transfer of knowledge to low-volume centers could improve outcomes. [ABSTRACT FROM AUTHOR]

Background Pediatric ventricular assist device (VAD) support as bridge to transplant has improved waitlist survival, but the effects of pre-implant status and VAD-related events on post-transplant outcomes have not been assessed. This study is a linkage analysis between the PediMACS and Pediatric Heart Transplant Study databases to determine the effects of VAD course on post-transplant outcomes. Methods Database linkage between October 1, 2012 and December 31, 2015 identified 147 transplanted VAD patients, the primary study group. The comparison cohort was composed of 630 PHTS patients without pre-transplant VAD support. The primary outcome was post-transplant survival, with secondary outcomes of post-transplant length of stay, freedom from infection and freedom from rejection. Results At implant, the VAD cohort was INTERMACS Profile 1 in 33 (23%), Profile 2 in 89 (63%) and Profile 3 in 14 (10%) patients. The VAD cohort was older, larger, and less likely to have congenital heart disease ( p < 0.0001). However, they had greater requirements for inotrope and ventilator support and increased liver and renal dysfunction ( p < 0.0001), both of which normalized at transplant after device support. Importantly, there were no differences in 1-year post-transplant survival (96% vs 93%, p = 0.3), freedom from infection (81% vs 79%, p = 0.9) or freedom from rejection (71% vs 74%, p = 0.87) between cohorts. Conclusions Pediatric VAD patients have post-transplant outcomes equal to that of medically supported patients, despite greater pre-implant illness severity. Post-transplant survival, hospital length of stay, infection and rejection were not affected by patient acuity at VAD implantation or VAD-related complications. Therefore, VAD as bridge to transplant mitigates severity of illness in children. [ABSTRACT FROM AUTHOR]

Background Adult congenital heart disease (ACHD) prevalence is increasing worldwide, with advanced heart failure (HF) as a leading cause of death. Limited data are available on durable mechanical circulatory support (MCS) in ACHD patients. Methods ACHD patients from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database were identified and propensity matched with non-ACHD patients using risk factors from the INTERMACS Seventh Annual Report. We compared these groups for the primary outcome of post-MCS mortality. We also investigated adverse event rates, functional status, and health-related quality of life. Results ACHD ( n = 128) and non-ACHD ( n = 512) patients were appropriately matched by baseline characteristics. ACHD patients had a longer length of stay at MCS implant (24 vs 19 days, p = 0.006) but similar rates of post-MCS adverse events and hospitalization. There were similar improvements in functional status and health related quality of life post-MCS in both groups. ACHD patients had significantly higher mortality post-MCS exclusively during the first 5 months after implant ( p = 0.003) and a lower probability of receiving a transplant ( p = 0.003). Risk factors for early mortality were biventricular or total artificial heart device implant and age > 50 years. Conclusions ACHD patients experience a higher early mortality after MCS but have similar adverse event rates and similar improvements in functional capacity and quality of life compared with non-ACHD patients. These data support expansion of MCS use in selected ACHD patients. [ABSTRACT FROM AUTHOR]

Abstract: Data are lacking on RSB intensity and outcomes after pediatric heart transplantation. PHTS centers received a survey on RSB practices from 2005 to present. PHTS data were obtained for 2010‐2013 and integrated with center‐matched survey responses for analysis. Survey response rate was 82.6% (38/46). Centers were classified as low‐, moderate‐, and high‐intensity programs based on RSB frequency (0—more than 8 RSB/y). RSB intensity decreased with increasing time from HT. Age at HT impacted RSB intensity mostly in year 1, with little to no impact in later years. Most centers have not replaced RSB with non‐invasive methods, but many added ECHO and biomarker monitoring. Higher RSB intensity was not associated with decreased 4‐year mortality (P=.63) or earlier detection of moderate to severe (ISHLT grade 2R/3R) cellular rejection (RSBMSR) in the first year (P=.87). First‐year RSBMSR incidence did not differ with intensity or age at HT. Significant variability exists in RSB intensity, but with no impact on timing and incidence of RSBMSR or 4‐year mortality. Reduction in RSB frequency may be safe in certain patients after pediatric HT. [ABSTRACT FROM AUTHOR]

Background Induction therapy is increasingly being used in pediatric heart transplantation. General versus risk-adapted use remains controversial. We aimed to determine the impact of induction therapy on outcomes after stratifying patients by diagnosis and risk. Methods The Pediatric Heart Transplant Study (PHTS) database was used to identify patients (age ≤18 years) who underwent transplantation between January 1, 2001 and December 31, 2014. Patients were excluded if they survived <48 hours or received multiple induction agents. Patients were stratified using a multivariable model to predict 1-year mortality. Patients within the top 25% risk of predicted mortality were defined as high risk (HR) and the bottom 75% as low risk (LR). Results Of the 2,860 patients studied, 1,370 received anti-lymphocyte antibody (ALA), 707 received an interleukin-2 receptor antagonist (IL-2RA) and 783 received no induction (NI) therapy. Overall, patients with NI had lower survival ( p < 0.01); however, multivariable analysis did not demonstrate an association with graft loss. Freedom from rejection was greater among LR congenital heart disease (CHD) and all cardiomyopathy (CMP) patients who received induction therapy ( p < 0.01, for both), as confirmed in a multivariable analysis for CMP patients. Frequency of graft vasculopathy was higher in LR CMP patients who received NI. Freedom from infection was lower with IL-2RA in the LR groups. Conclusions Pediatric heart transplant survival has improved in the recent era, in concert with increased use of induction therapy. Although induction therapy is associated with decreased rejection, it was not found to directly influence survival on multivariable analysis. Lower risk patients may benefit the most from induction therapy, particularly IL-2RA, which may be correlated with decreased infection and rejection in this cohort. [ABSTRACT FROM AUTHOR]

Heart transplantation has become a standard therapy option for advanced heart failure. The translation of heart transplantation from innovative experiments to long-term clinical success has married prescient insights with discipline and organization in the domains of surgical techniques, organ preservation, immunosuppression, organ donation and transplantation logistics, infection control, and long-term graft surveillance. This review explores the key milestones of the past 50 years of heart transplantation and discusses current challenges and promising innovations on the clinical horizon. [ABSTRACT FROM AUTHOR]

Background Management of existing mitral valve (MV) disease in patients undergoing left ventricular assist device (LVAD) implantation remains controversial. Methods Among continuous-flow LVAD patients with moderate to severe mitral regurgitation entered into the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database between April 2008 and March 2014 ( n = 4,930), outcomes were compared between patients who underwent MV repair (MVr, n = 252), MV replacement (MVR, n = 11) and no MV procedure (no MVP, n = 4,667). Impact on survival was analyzed by stratified actuarial and hazard function multivariable methodology. Post-operative functional capacity and quality of life were assessed. Results Patients who underwent MVPs had higher pre-operative pulmonary vascular resistance (3.6 ± 2.9 vs 2.9 ± 2.6 Wood units; p = 0.0006) and higher pulmonary artery systolic pressures (55.1 ± 13.8 vs 51.5 ± 14.0 mm Hg; p = 0.0003). Two-year survival was 76% for patients with concomitant MVr, 57% for those with MVR and 71% for those with no MVP ( p = 0.15). By multivariable analysis, neither MVr nor MVR affected early or late survival. Although improvements in post-operative functional status as evaluated by 6-minute walk distances were comparable across groups, visual analog score assessments of quality of life suggested a benefit of concomitant MVPs at 1-year post-implant (79.00 ± 1.73 vs 74.45 ± 0.51; p = 0.03), with fewer re-admissions observed for MVP patients ( p < 0.0001). Conclusions Concomitant MVPs are not associated with increased survival overall. However, MVPs are associated with benefits in terms of reduced hospital re-admission and improved quality of life in select patients. [ABSTRACT FROM AUTHOR]

Background The effect of age at transplant on rejection detected by routine surveillance biopsy (RSB) in pediatric heart transplant (HT) recipients is unknown. We hypothesized there would be low diagnostic yield and decreased prevalence of rejection detected on RSB in infants (age <1 year) when compared with children (age 1 to 9 years) and adolescents (age 10 to 18 years). Methods We utilized Pediatric Heart Transplant Study (PHTS) data from 2010 to 2013 to analyze moderate-to-severe (ISHLT Grade 2R/3R) cellular rejection (MSR) detected only on RSB (RSBMSR). Results RSB detected 280 of 343 (81.6%) episodes of MSR. RSBMSR was detected in all age groups even >5 years after HT. Infant RSBMSR had a greater proportion ( p = 0.0025) occurring >5 years after HT (39.2 vs 18.4 vs 10.8%) and a lower proportion ( p = 0.0009) occurring in the first year after HT (25.5 vs 60.6 vs 51.7%) compared with children and adolescents, respectively. Freedom from RSBMSR was 87 ± 7% in infants, 76 ± 6% in children and 73 ± 7% in adolescents 4 years after HT. In 1-year survivors who had RSBMSR in the first year after HT, the risk of RSBMSR occurring in Years 2 to 4 was significantly ( p < 0.0001) greater than patients without RSBMSR in the first year (hazard ratio 21.28, 95% confidence interval 10.87 to 41.66), regardless of recipient age. Conclusions RSBMSR exists in all age groups after pediatric HT with long-term follow-up. The prevalence in infant recipients is highest >5 years after HT. Those with RSBMSR in the first year after HT are at a high risk for recurrent rejection regardless of age at HT. [ABSTRACT FROM AUTHOR]

Background: Nonsurgical bleeding is the most common adverse event in patients with continuous-flow left ventricular assist devices (LVADs) and is caused by arteriovenous malformations. We hypothesized that deregulation of an angiogenic factor, angiopoietin-2 (Ang-2), in patients with LVADs leads to increased angiogenesis and higher nonsurgical bleeding.Methods: Ang-2 and thrombin levels were measured by ELISA and Western blotting, respectively, in blood samples from 101 patients with heart failure, LVAD, or orthotopic heart transplantation. Ang-2 expression in endothelial biopsy was quantified by immunofluorescence. Angiogenesis was determined by in vitro tube formation from serum from each patient with or without Ang-2-blocking antibody. Ang-2 gene expression was measured by reverse transcription-polymerase chain reaction in endothelial cells incubated with plasma from each patient with or without the thrombin receptor blocker vorapaxar.Results: Compared with patients with heart failure or those with orthotopic heart transplantation, serum levels and endothelial expression of Ang-2 were higher in LVAD patients (P=0.001 and P<0.001, respectively). This corresponded to an increased angiogenic potential of serum from patients with LVADs (P<0.001), which was normalized with Ang-2 blockade. Furthermore, plasma from LVAD patients contained higher amounts of thrombin (P=0.003), which was associated with activation of the contact coagulation system. Plasma from LVAD patients induced more Ang-2 gene expression in endothelial cells (P<0.001), which was reduced with thrombin receptor blockade (P=0.013). LVAD patients with Ang-2 levels above the mean (12.32 ng/mL) had more nonsurgical bleeding events compared with patients with Ang-2 levels below the mean (P=0.003).Conclusions: Our findings indicate that thrombin-induced Ang-2 expression in LVAD patients leads to increased angiogenesis in vitro and may be associated with higher nonsurgical bleeding events. Ang-2 therefore may contribute to arteriovenous malformation formation and subsequent bleeding in LVAD patients. [ABSTRACT FROM AUTHOR]

Background Continuous-flow (CF) ventricular assist devices (VADs) have largely replaced pulsatile-flow VADs in adult patients. However, there are few data on CF VADs among pediatric patients. In this study we aimed to describe the overall use, patients’ characteristics and outcomes of CF VADs in this population. Methods The Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS) is a national registry for U.S. Food and Drug Adminstration (FDA)-approved VADs in patients <19 years of age. Patients undergoing placement of durable CF VADs between September 2012 and June 2015 were included and outcomes were compared with those of adults from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). Results CF VADs were implanted in 109 patients at 35 hospitals. The median age at implantation was 15 years (2.8 to 18.9 years) and median weight was 62 kg (range 16 to 141 kg). The underlying disease was cardiomyopathy in 89 (82%) patients. The INTERMACS level at time of implant was Level 1 in 20 (19%), Level 2 in 64 (61%) and Levels 3 to 7 in 21 (20%) patients. Most were implanted as LVADs ( n = 102, 94%). Median duration of support was 2.3 months (range <1 day to 28 months). Serious adverse event rates were low, including neurologic dysfunction (early event rate 4.1 per 100 patient-months with 2 late events). Competing outcomes analysis at 6 months post-implant indicated 61% transplanted, 31% alive with device in place and 8% death before transplant. These outcomes compared favorably with the 3,894 adults supported with CF VADs as a bridge to transplant. Conclusions CF VADs are commonly utilized in older children and adolescents, with excellent survival rates. Further study is needed to understand impact of patient and device characteristics on outcomes in pediatric patients. [ABSTRACT FROM AUTHOR]

Background Pulmonary blood flow during Stage 1 (Norwood) palliation for hypoplastic left heart syndrome (HLHS) is achieved via modified Blalock–Taussig shunt (MBT) or right ventricle to pulmonary artery conduit (RVPA). Controversy exists regarding the differential impact of shunt type on outcome among those who require transplantation early in life. In this study we explored waitlist and post-transplant outcomes within this sub-population stratified by shunt type. Methods Eligible patients were enrolled through the Pediatric Heart Transplant Study (PHTS) database. Patients included those listed for heart transplantation at 1 of 35 participating centers, all of whom were <6 years of age and with a diagnosis of HLHS (and variants) status post Stage 1 palliation with MBT or RVPA. Standard risk factors for death were analyzed using multivariable hazards modeling. Results Between 2010 and 2013, 190 patients were identified. Compared with the RVPA group ( n = 111), the MBT group ( n = 79) was less likely to have undergone a Glenn palliation (41% vs 73%, p < 0.001), were younger at listing (median age 1.3 vs 1.8 years, p = 0.05), had lower median weight (7.9 vs 9.4 kg, p = 0.02), and were more likely to be mechanically ventilated at listing (35% vs 22%, p = 0.04). There were no significant differences in median waitlist time (1.7 vs 2.6 months, p = 0.2) or rate of transplantation (61% vs 60%, p = 1.0). Among waitlisted patients, 3-month survival was less for MBT compared with RVPA patients (74% vs 91%, p = 0.02). Patients who had not yet achieved Glenn palliation before listing had lower waitlist 3-month survival (76% vs 90%, p = 0.02). In MBT infants <1 year old, there was a trend toward improved survival in those with Glenn palliation compared to those without (100% vs 68%, p = 0.08). Early post-transplant mortality rates were similar between the RVPA and MBT groups ( p = 0.4) with overall survival 84% at 1 year. Conclusions Among HLHS patients, the need for transplant before Glenn palliation is associated with poorer waitlist survival. Waitlist survival is poorer in the MBT group, with this difference driven by pre-Glenn MBT infants. Post-transplant outcomes were unaffected by shunt type. [ABSTRACT FROM AUTHOR]

Background The Cardiac Transplant Research Database (CTRD) collected data from 26 U.S. institutions from January 1, 1990 to December 31, 2008 providing the opportunity for construction of a comprehensive multivariable model of risk for death after transplantation. We analyzed risk factors for death over 19 years of experience to determine how risk profiles have changed over time and how they interact with age. Methods A multivariable parametric hazard model for death was created for 7,015 patients entered into the CTRD. Variables collected over 19 years of experience were examined as potential risk factors and tested for interaction with date of transplantation to determine if their relative risk (RR) changed over time. Results The hazard for death post-transplant occurred in 2 phases: an early phase of acute risk lasting <1 year, and a late phase of relatively low, gradually increasing risk (<0.1 event/year). In the early phase, predictive models showed that ventricular assist device (VAD) at the time of transplant did not increase the RR of death for recipient transplant at 30 years of age, but the RR of death was increased by 60% ( p = 0.04) at 60 years of age. Of the late-phase variables found to be risk factors, the RR of age, date of transplant and pulmonary vascular resistance changed with respect to transplant year. The overall risk of death dropped importantly over the study period, but the RR of all other variables remained unchanged. RR was 2.6 ( p < 0.0001) for 25-year-old African-American (AA) versus non-AA recipients and 1.6 for 60-year-old AA recipients ( p = 0.02). Conclusion Over 19 years, the baseline risk of death has decreased, but the specific risk factors and the magnitudes of their RR have remained unchanged. Therefore, despite advances in clinical management and improvement in overall survival, the risk profile for death after cardiac transplantation is similar to that in 1990. [ABSTRACT FROM AUTHOR]