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There are conflicting data on how delivery location impacts outcomes in neonates with ductal-dependent heart disease. Our goal was to evaluate the impact of delivery location on hospital length of stay and survival in infants with prenatally diagnosed hypoplastic left heart syndrome (HLHS) after stage 1 palliation (S1P). A multicenter cohort study was performed utilizing the National Pediatric Cardiology Quality Improvement Collaborative dataset for infants with prenatally diagnosed HLHS who underwent S1P from August 2016 to December 2018. Univariate comparisons of demographics, clinical, and outcome data were made and multivariable logistic regression was performed between groups stratified by distance from surgical center. A total of 790 patients from 33 centers were analyzed: 85% were born

Fontan palliation has improved survival for single ventricle patients, but long-term complications persist including cardiovascular dysfunction, neurohormonal abnormalities, and protein-losing enteropathy (PLE). Although chronic inflammation contributes to morbidity, an association between inflammation and vascular dysfunction has not been studied. We assessed inflammation and vascular function in 31 Fontan-palliated patients (52% male, median age 14.3 years), including 10 PLE+. Fontan circulation was associated with altered inflammatory cytokines (TNF-α: mean 2.5 ± 1.4 vs. 0.7 ± 0.2 pg/ml, p0.0001; sTNFR2: 371 ± 108 vs. 2694 ± 884 pg/ml, p0.0001) and vascular dysfunction [log-transformed reactive hyperemia index (lnRHI) 0.28 ± 0.19 vs. 0.47 ± 0.26, p0.01; augmentation index (AI) -2.9 ± 13.8 vs. -16.3 ± 12.0, p = 0.001; circulating endothelial progenitor cells (cEPCs) 5.0 ± 8.1 vs. 22.8 ± 15.9, p = 0.0002)]. Furthermore, PLE+ patients showed greater inflammation (IFN-γ 6.3 ± 2.2 vs. 11.5 ± 7.9 pg/ml, p = 0.01; sTNFR1: 1181 ± 420 vs. 771 ± 350 pg/ml, p = 0.01) and decreased arterial compliance (AI: 5.4 ± 17.1 vs. -6.8 ± 10.2, p = 0.02) than PLE- patients. Circulating EPCs, but not inflammatory cytokines, were inversely associated with arterial stiffness in Fontan patients. In conclusion, chronic inflammation and vascular dysfunction are observed after Fontan operation, with greater inflammation and arterial stiffness in Fontan patients with active PLE. However, there is no clear association between inflammatory cytokines and vascular dysfunction, suggesting these pathophysiologic processes are not mechanistically linked.

To determine the prevalence and influence of clinically significant airway and/or respiratory abnormalities in patients with trisomy 13 and 18 undergoing cardiac surgery.We performed a retrospective, case-control cohort study of all patients with known trisomy 13 or 18 who underwent cardiac operations at our institution from 1994 to 2014. Cases were matched 3:1 by age, surgical date, and cardiac lesion with nontrisomy 13/18 patients. Baseline clinical characteristics and patient outcomes, including postoperative course and management were compared. Descriptive statistics and Wilcoxon rank-sum test or Fisher exact test as appropriate were used to determine significant differences.In the 14 trisomy 13/18 patients who underwent cardiac surgery, there was an increased incidence of postoperative complications. Specifically, 93% had airway or pulmonary complications, including prolonged mechanical ventilation (n = 8), prolonged noninvasive positive pressure ventilation (n = 6), re-intubation (n = 7), tracheitis/pneumonia (n = 6), and tracheostomy (n = 2). The duration of intubation was longer (7.5 vs 2 days; P .0001) as was the duration of noninvasive positive pressure ventilation (8 vs 2 days; P .04) with longer hospital length of stay in the trisomy 13/18 cohort. There was 1 in-hospital mortality, with none in the control group.Although most trisomy 13/18 patients survive cardiac surgery, these patients have an increased incidence of airway complications, requiring longer intensive respiratory support postoperatively that contributes to longer length of stay. Parental guidance before cardiac surgery should include a discussion about postoperative airway management.

BACKGROUND The size of the Fontan population with end-stage heart failure is growing. In this population, heart transplantation has been the only option. This study sought to investigate the efficacy of ventricular assist device (VAD) support in Fontan patients. METHODS We conducted a retrospective study of Fontan patients in the Advanced Cardiac Therapies Improving Outcomes Network. We evaluated patient characteristics, and the clinical and physiologic outcomes after VAD implantation. RESULTS We identified 45 Fontan patients implanted with VAD. The average age of patients was 10 years (interquartile range: 4.5–18) and 30% were female. The majority had a morphologic right ventricle (69%), moderate or greater ventricular dysfunction (83%), and moderate or greater atrioventricular valve regurgitation (65%). The majority of implants were as a bridge to transplantation (76%), and the majority of patients were Interagency Registry for Mechanically Assisted Circulatory Support Profile 2 (56%). The most commonly employed device was the Medtronic HeartWare HVAD (56%). A total of 13 patients were discharged on device support, and 67% of patients experienced adverse events, the most common of which were neurologic (25%). At 1 year after device implantation, the rate of transplantation was 69.5%, 9.2% of patients continued to be VAD supported, and 21.3% of patients had died. Hemodynamically, VAD was effective in decreasing both Fontan and ventricular end-diastolic pressures in some individuals. CONCLUSIONS VAD is effective in supporting patients with end-stage Fontan failure awaiting heart transplantation. Future research should focus on identifying clinical and physiologic characteristics predictive of a favorable response to VAD support.

BACKGROUND The Berlin Heart EXCOR Pediatric (EXCOR) ventricular assist device (VAD) was introduced in North America nearly 2 decades ago. The EXCOR was approved under Humanitarian Device Exemption status in 2011 and received post-market approval (PMA) in 2017 from Food and Drug Administration. Since the initial approval, the field of pediatric mechanical circulatory support has changed, specifically with regard to available devices, anticoagulation strategies, and the types of patients supported. This report summarizes the outcomes of patients supported with EXCOR from the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry. These data were part of the PMA surveillance study (PSS) required by the Food and Drug Administration. METHODS ACTION is a learning collaborative of over 40 pediatric heart failure programs worldwide, which collects data for all VAD implantations as one of its initiatives. All patients in North America with EXCOR implants reported to ACTION from 2018 to 2020 ( n = 72) who had met an outcome were included in the EXCOR PSS group. This was compared with a historical, previously reported Berlin Heart EXCOR study group (Berlin Heart study [BHS] group, n = 320, 2007‒2014). RESULTS Patients in the PSS group were younger, were smaller in weight/body surface area, were more likely to have congenital heart disease , and were less likely to receive a bi-VAD than those in the BHS group. Patients in the PSS group were less likely to be in Interagency Registry for Mechanically Assisted Circulatory Support Profile 1 and were supported for a longer duration. The primary anticoagulation therapy for 92% of patients in the PSS group was bivalirudin . Success, defined as being transplanted, being weaned for recovery, or being alive on a device at 180 days after implantation, was 86% in the PSS group compared with 76% in the BHS group. Incidence of stroke was reduced by 44% and the frequency of pump exchange by 40% in the PSS group compared with those in the BHS group. Similarly, all other adverse events , including major bleeding, were reduced in the PSS group. CONCLUSIONS The PSS data, collected through ACTION, highlight the improvement in outcomes for patients supported with EXCOR compared with the outcomes in a historical cohort. These findings may be the result of changes in patient care practices over time and collaborative learning.

Heart failure metrics specific to the pediatric population are required to successfully implement quality improvement initiatives in children with heart failure. Medication use at the time of discharge following admission for decompensated heart failure has been identified as a potential quality metric in this population. This study aimed to report medication use at discharge in the current era for children admitted with acute decompensated heart failure. All patients

BACKGROUND We aimed to describe the incidence, risk factors, and clinical outcomes of pericardial effusions within 6 months after pediatric heart transplantation (HT). METHODS A single-center retrospective cohort study was performed on all pediatric HT recipients from 2004 to 2018. Logistic regression was used to identify factors associated with pericardial effusions post-HT, and survival was compared using log-rank test. RESULTS During the study period, 97 HTs were performed in 93 patients. Fifty patients (52%) had a ≥small pericardial effusion within 6 months, 16 of which were, or became, ≥moderate in size. Pericardial drain was placed in 8 patients. In univariate analysis, larger recipient body surface area (p = .01) and non-congenital heart disease (p = .002) were associated with pericardial effusion development. Donor/recipient size ratios, post-HT hemodynamics, and rejection did not correlate with pericardial effusion development. In multivariable analysis, non-congenital heart disease (adjusted odds ratio 3.3, p = .01) remained independently associated with development of pericardial effusion. There were no significant differences in post-HT survival between patients with and without ≥small (p = .68) or ≥moderate pericardial effusions (p = .40). CONCLUSIONS Pericardial effusions are common after pediatric HT. Patients with cardiomyopathy, or non-congenital heart disease, were at higher risk for post-HT pericardial effusions. Pericardial effusions increased morbidity but had no effect on mortality in our cohort. The risk factors identified may be used for anticipatory guidance in pediatric HT.

Lymphatic vessel dysplasia is associated with Fontan-associated protein-losing enteropathy. Extra nodal non-Hodgkin lymphomas including mucosa-associated lymphoid tissue (MALT lymphoma) are associated with lymphatic vessel dysplasia. Here, we describe the case of a 7-year-old with Fontan-associated protein-losing enteropathy who developed MALT lymphoma with a clinical course indicative of interaction between these pathologies and improvement in protein-losing enteropathy after MALT lymphoma treatment. This case suggests a pathophysiologic overlap which has implications for the management of Fontan-associated protein-losing enteropathy.

We sought to assess acute hemodynamic changes after implementation of negative extrathoracic pressure (NEP) in spontaneously breathing ambulatory Fontan patients with symptomatic heart failure. We hypothesized that application of NEP would result in an acute decrease in pulmonary artery pressure. Ten patients with clinical evidence of Fontan failure underwent baseline hemodynamic catheterization while breathing spontaneously. Hemodynamic measurements were then repeated after 30 min of continuous NEP. After 30 min of continuous NEP, 4/10 patients had a decrease in their Fontan pressure by 2 mmHg and one patient had a decrease by 1 mmHg. There were three patients that had an increase in Fontan pressure by 2 mmHg. In 7/10 patients, indexed pulmonary vascular resistance decreased by an average of 31%. In symptomatic Fontan patients with a favorable hemodynamic response to NEP during catheterization, potential benefit of longer-term NEP to improve clinical status should be explored.

Background As survival and neuromuscular function in Duchenne Muscular Dystrophy (DMD) improve with glucocorticoid therapy and respiratory advances, the proportion of cardiac deaths is increasing. Little is known about the use and outcomes of advanced heart failure (HF) therapies in this population. Methods A retrospective cohort study of 436 males with DMD was performed, from January 1, 2005-January 1, 2018, with the primary outcome being use of advanced HF therapies including: implantable cardioverter defibrillator (ICD), left ventricular assist device (LVAD), and heart transplantation (HTX). Results Nine subjects had an ICD placed, 2 of whom (22.2%) had appropriate shocks for ventricular tachycardia; 1 and 968 days after implant, and all of whom were alive at last follow-up; median 18 (IQR: 12.5–25.5) months from implant. Four subjects had a LVAD implanted with post-LVAD survival of 75% at 1 year; 2 remaining on support and 1 undergoing HTX. One subject was bridged to HTX with ICD and LVAD and was alive at last follow-up, 53 months after HTX. Conclusion Advanced HF therapies may be used effectively in select subjects with DMD. Further studies are needed to better understand risk stratification for ICD use and optimal candidacy for LVAD implantation and HTX, with hopes of improving cardiac outcomes.

BACKGROUND The influence of Fontan-associated protein-losing enteropathy's (PLE) severity, duration, and treatment on heart transplant (HTx) outcomes is unknown. We hypothesized that long-standing PLE and PLE requiring more intensive therapy are associated with increased post-HTx mortality. METHODS This 12-center, retrospective cohort study of post-Fontan patients with PLE referred for HTx from 2003 to 2015 involved collection of demographic, medical, surgical, and catheterization data, as well as PLE-specific data, including duration of disease, intensity/details of treatment, hospitalizations, and complications. Factors associated with waitlist and post-HTx outcomes and PLE resolution were sought. RESULTS Eighty patients (median of 5 per center) were referred for HTx evaluation. Of 68 patients listed for HTx, 8 were removed due to deterioration, 4 died waiting, and 4 remain listed. In 52 patients undergoing HTx, post-HTx 1-month survival was 92% and 1-year survival was 83%. PLE-specific factors, including duration of PLE pre-HTx, pre-HTx hospitalizations, need for/frequency of albumin replacement, PLE therapies, and growth parameters had no association with post-HTx mortality. Immunosuppressant regimen was associated with mortality; standard mycophenolate mofetil immunotherapy was used in 95% of survivors compared with only 44% of non-survivors (p = 0.03). Rejection (53%) and infection (42%) post-HTx were common, but not associated with PLE-specific factors. PLE resolved completely in all but 1 HTx survivor at a median of 1 month (interquartile range 1 to 3 months); resolution was not affected by PLE-specific factors. CONCLUSIONS PLE severity, duration, and treatment do not influence post-HTx outcome, but immunosuppressive regimen may have an impact on survival. PLE resolves in nearly all survivors.

Background/Purpose: There is conflicting data on how geographic distance from delivery location to the cardiac surgical center impacts outcomes in neonates with ductal-dependent heart disease. Our goal was to describe national current practices in delivery location of neonates with a prenatal diagnosis of hypoplastic left heart syndrome (HLHS) and evaluate the impact of delivery location and age at admission to the surgical center ICU on post-operative length of hospital stay and transplant-free survival after the Norwood operation. Methods: A multicenter cohort study was performed utilizing the National Pediatric Cardiology Quality Improvement …

Background In a stable, inotrope-dependent pediatric patient with dilated cardiomyopathy, we evaluated the cost-effectiveness of continuous-flow VAD implantation compared to a watchful waiting approach using chronic inotropic therapy. Methods We used a state-transition model to estimate the costs and outcomes of 14-year-old (INTERMACS profile 3) patients receiving either VAD or watchful waiting. We measured benefits in terms of lifetime QALYs gained. Model inputs were taken from the literature. We calculated the ICER, or the cost per additional QALY gained, of VADs and performed multiple sensitivity analyses to test how our assumptions influenced the results. Results Compared to watchful waiting, VADs produce 0.97 more QALYs for an additional $156 639, leading to an ICER of $162 123 per QALY gained from a healthcare perspective. VADs have 17% chance of being cost-effective given a cost-effectiveness threshold of $100 000 per QALY gained. Sensitivity analyses suggest that VADs can be cost-effective if the costs of implantation decrease or if hospitalization costs or mortality among watchful waiting patients is higher. Conclusions As a bridge to transplant, VADs provide a health benefit to children who develop stable, inotrope-dependent heart failure, but immediate implantation is not yet a cost-effective strategy compared to watchful waiting based on commonly used cost-effectiveness thresholds. Early VAD support can be cost-effective in sicker patients and if device implantation is cheaper. In complex conditions such as pediatric heart failure, cost-effectiveness should be just one of many factors that inform clinical decision-making.

AIM To describe the clinical and hemodynamic characteristics of Fontan failure in children listed for heart transplant. METHODS In a nested study of the Pediatric Heart Transplant Society, 16 centers contributed information on Fontan patients listed for heart transplant between 2005and 2013. Patients were classified into four mutually exclusive phenotypes: Fontan with abnormal lymphatics (FAL), Fontan with reduced systolic function (FRF), Fontan with preserved systolic function (FPF), and Fontan with "normal" hearts (FNH). Primary outcome was waitlist and post-transplant mortality. RESULTS 177 children listed for transplant were followed over a median 13 (IQR 4-31) months, 84 (47%) were FAL, 57 (32%) FRF, 22 (12%) FNH, and 14 (8%) FPF. Hemodynamic characteristics differed between the 4 groups: Fontan pressure (FP) was most elevated with FPF (median 22, IQR 18-23, mmHg) and lowest with FAL (16, 14-20, mmHg); cardiac index (CI) was lowest with FRF (2.8, 2.3-3.4, L/min/m2). In the entire cohort, 66% had FP >15 mmHg, 21% had FP >20 mmHg, and 10% had CI

Background: Acute decompensated heart failure (ADHF) is a highly morbid condition among adults. Little is known about outcomes in children with ADHF. We analyzed the Pediatric Cardiac Critical Care Consortium registry to determine the epidemiology, contemporary treatments, and predictors of mortality in critically ill children with ADHF. Methods: Cardiac intensive care unit (CICU) patients ≤18 years of age meeting Pediatric Cardiac Critical Care Consortium criteria for ADHF were included. ADHF was defined as systolic or diastolic dysfunction requiring continuous vasoactive or diuretic infusion, respiratory support, or mechanical circulatory support. Demographics, diagnosis, therapies, complications, and mortality are described for the cohort. Predictors of CICU mortality were identified using logistic regression. Results: Among 26 294 consecutive admissions (23 centers), 1494 (6%) met criteria for analysis. Median age was 0.93 years (interquartile range, 0.1–9.3 years). Patients with congenital heart disease (CHD) comprised 57% of the cohort. Common therapies included the following: vasoactive infusions (88%), central venous catheters (86%), mechanical ventilation (59%), and high flow nasal cannula (46%). Common complications were arrhythmias (19%), cardiac arrest (10%), sepsis (7%), and acute renal failure requiring dialysis (3%). Median length of CICU stay was 7.9 days (interquartile range, 3–18 days) and the CICU readmission rate was 22%. Overall, CICU mortality was 15% although higher for patients with CHD versus non-CHD (19% versus 11%; P Conclusions: ADHF in children is characterized by comorbidities, high mortality rates, and frequent readmission, especially among patients with CHD. Opportunities exist to determine best practices around appropriate use of mechanical support, cardiac arrest prevention, and optimal heart transplantation candidacy to improve outcomes for these patients.

As survival and neuromuscular function in Duchenne muscular dystrophy (DMD) have improved with glucocorticoid (GC) therapy and ventilatory support, cardiac deaths are increasing. Little is known about risk factors for cardiac and non-cardiac causes of death in DMD. A multi-center retrospective cohort study of 408 males with DMD, followed from January 1, 2005 to December 31, 2015, was conducted to identify risk factors for death. Those dying of cardiac causes were compared to those dying of non-cardiac causes and to those alive at study end. There were 29 (7.1%) deaths at a median age of 19.5 (IQR: 16.9–24.6) years; 8 (27.6%) cardiac, and 21 non-cardiac. Those living were younger [14.9 (IQR: 11.0–19.1) years] than those dying of cardiac [18 (IQR 15.5–24) years, p = 0.03] and non-cardiac [19 (IQR: 16.5–23) years, p = 0.002] causes. GC use was lower for those dying of cardiac causes compared to those living [2/8 (25%) vs. 304/378 (80.4%), p = 0.001]. Last ejection fraction prior to death/study end was lower for those dying of cardiac causes compared to those living (37.5% ± 12.8 vs. 54.5% ± 10.8, p = 0.01) but not compared to those dying of non-cardiac causes (37.5% ± 12.8 vs. 41.2% ± 19.3, p = 0.58). In a large DMD cohort, approximately 30% of deaths were cardiac. Lack of GC use was associated with cardiac causes of death, while systolic dysfunction was associated with death from any cause. Further work is needed to ensure guideline adherence and to define optimal management of systolic dysfunction in males with DMD with hopes of extending survival.

Prostaglandin E (PGE1) is necessary to maintain ductus arteriosus patency in many newborns with congenital heart disease. Because PGE1 therapy commonly leads to fever, and given this population's fragile state, a complete sepsis workup is often performed in febrile, but otherwise asymptomatic, patients. This practice of liberal evaluation with bacterial cultures, empiric antibiotic treatment, and delays in essential surgical intervention may result in poor resource utilization and lead to increased iatrogenic morbidity. This study sought to determine the incidence of fever and culture-positive infection in patients receiving PGE1, and identify diagnostic variables that predict culture-positive infection. The study included a single-center retrospective review of all neonates receiving PGE1 between 2011 and 2014. Logistic regression and receiver operator characteristic analysis were used to identify significant predictors of positive bacterial cultures. Among 435 neonates, 175 (40%) had fevers (≥ 38.3 °C) while concurrently receiving PGE1, but only 9 (2%) had culture-positive infection and 1 (

Influenza B is a common viral illness in childhood. We report a 5-year-old previously healthy girl admitted with facial edema that developed severe acute myocarditis from influenza B infection. As her clinical course progressed, she ultimately developed severe, acute heart failure requiring extracorporeal membrane oxygenation for support.

Purpose PRES is an uncommon complication of organ transplantation. Little is known about its clinical course and risk factors. We sought to examine the natural history and risk factors for PRES in pediatric heart transplant (HTx) recipients. Methods 14-center international retrospective study of 46 pediatric PRES cases between 2000-2018, compared with 1372 HTx recipients without PRES between 2000-2018. Demographic and clinical data were entered into a central database. PRES diagnosis was based on a combination of seizures, headache, altered mental status or focal neurological deficits, and required confirmation, either by MRI or resolution of neurological symptoms after CNI withdrawal. Factors associated with PRES were identified by Cox Proportional Hazard multivariable analysis. Results Median onset of symptoms was 16 days (R, 2-2468 d) after HTx; 23 (50%) developed PRES in the first 2 weeks, 32 (70%) in the first month, and 40 (87%) within the first year after HTx. Symptoms at presentation included seizures (40/46, 87%), altered mental status (27/46, 59%), headache (18/46, 39%), focal neurological deficits (16/46, 35%), and lasted for a median of 4 days (R 1-1772d), with almost all recipients (44/46, 96%) making a full recovery. MRI was obtained in 43/46, showing a vasogenic pattern of edema characteristic of PRES in 37 recipients (80%). Recipients with PRES tended to be older (9.1 y vs 5.9 y, p=0.06). Hypertension (SBP>95%ile) was present in 40/44 (91%) recipients with PRES at presentation, with severe hypertension (SBP>99%ile plus 5mmHG) in 37 (85%). Though all cases occurred in the setting of CNI use (TAC 40, CSA 6), levels were supratherapeutic in only 13/42 (31%). Cox analysis revealed a 5.3x increased hazard for PRES with Glenn (CI 1.54,18.01; p=0.008) and a 3.8x increased hazard with Fontan (1.08,13.00; p=0.038), while age, underlying cardiac diagnosis, BMI, ischemic time and type of CNI did not appear to contribute significantly. Conclusion 2/3 of pediatric PRES cases occur in the first month after HTx with seizures as the most common presenting symptom. An overwhelming majority of patients were severely hypertensive, whereas less than a third had supratherapeutic CNI levels. Almost all recipients recovered fully within days. Recipients with pre-existing Glenn or Fontan have a higher rate of developing PRES after HTx.

Purpose Individuals born with defects resulting in a functionally univentricular heart Fontan-type palliation (FP) are prone to physiologic deterioration requiring advanced cardiac therapies. Given limitations to organ availability and long transplant waiting-list times, mechanical circulatory support (MCS) has become an important tool to permit individuals with a single ventricle circulation to either survive to transplant or may be used for destination therapy. The physiologic and clinical impact of MCS in FP patients are undefined. Methods Centers participating in the ACTION Learning Network entered data on FP patients that received a VAD at their center, between 1/26/12 and 10/1/2019, in the ACTION Outcomes registry. Additional survey data on physiologic variables will be completed by Nov 2019. Results Thirty-nine FP patients were reported to the ACTION registry. Limited clinical variables can be found in table 1. MCS types included intracorporeal continuous flow support (25 patients), paracorporeal support (10), total artificial heart (2) and biventricular assist devices (1). Among supported patients, 23 % (9) died while on support, 10 % (4) are currently alive on support, and 67% (26) were transplanted and are alive while none died post-transplant. Major adverse events included major bleeding (17 episodes), driveline infection (n=1) and other neurologic dysfunction (n=1). There was no stroke or pump thrombosis (table 1). MCS implant improved NYHA functional class (12.5% versus 75% NYHA class 1/2) and decreased severe atrioventricular valve regurgitation (47% versus 30%). Complete clinical and hemodynamic data will be available and presented at the ISHLT meeting. Conclusion This is the first multicenter report of FP outcomes post MCS. MCS results in improved functional status and decreased atrioventricular valve regurgitation in FP patients awaiting transplant without adverse post-transplant outcomes and with good on-device survival. MCS for Fontan patients as both destination and bridge to transplant is a reasonable option.

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals. ispartof: CIRCULATION vol:140 issue:6 pages:E234-E284 ispartof: location:United States status: published

We sought to describe the use and outcomes of small, medium and large premounted stents in patients with congenital heart disease, including incidence of and risk factors for re-intervention and development of in-stent stenosis. Premounted stents offer several advantages over traditional manually crimped bare-metal stents, especially in small patients. There are no data describing the medium-term effectiveness and outcomes of premounted stents in congenital heart disease. We performed a single-center retrospective review of all small, medium and large premounted stents implanted over an 8-year period. Premounted stents were implanted in 71 vessels within 59 patients with a 97 % success rate. Regardless of implantation site, premounted stent implantation resulted in significant improvements in vessel size and pressure gradient (p

Purpose Ventricular assist devices (VADs) have improved wait list survival in children with end-stage heart failure. However, questions remain about the optimal timing of VAD implantation. In this cost-effectiveness analysis, we compared immediate intracorporeal continuous VAD implantation to a watchful waiting approach using continuous inotropic therapy. Methods Using a Markov model, we simulated a cohort of pediatric patients with dilated cardiomyopathy. We used a monthly cycle and 20-year time horizon. We estimated cost and benefits (in terms of quality-adjusted life years, QALYs) from a healthcare perspective discounted at 3% per year. Transition probabilities, costs, and utility weights were taken from published and grey literature, which we supplemented with expert opinion where there were gaps. We calculated the incremental cost-effectiveness ratio (ICER) and performed one-way and probabilistic sensitivity analyses (PSA) using 10,000 Monte Carlo simulations to understand the impact of parameter uncertainty in the main findings. Cost variables were assigned gamma distributions, while transition probabilities and utilities were assigned beta distributions. Results In a base case analysis, the incremental costs and benefits of immediate intracorporeal continuous VAD implantation compared to medical management was $221,269 (2017 US$) and 0.21 QALYs, respectively, resulting in an ICER of $1.04 million per QALY. One-way sensitivity analysis found that the discount rate, the probability of heart transplant among patients on VAD and medical management, and the cost of VAD implantations exerted the most influence on the ICER, though varying any of the parameters to their lowest and highest values did not bring the ICER close a $100,000 per QALY willingness-to-pay (WTP) threshold. The PSA showed a 3% chance of immediate VAD implantation to be cost-effective at a WTP of $500,000 per QALY and a 36% chance at $1 million per QALY. Conclusion Though VADs provide a net health benefit as a bridge to transplant, immediate implantation in children with inotrope-dependent heart failure is not likely to be a cost-effective strategy compared to medical management based on commonly used ICER thresholds. Future analyses should explore the cost-effectiveness of VAD implantation in children with other disease states, diagnoses and device types.

Infections in adult ventricular assist device patients increase subsequent mortality and stroke risk. Less is known about outcomes after infections in younger patients, where diabetes and obesity, risk factors associated with poor outcomes, are less prevalent. The purpose of this study was to examine outcomes after infections in adolescents and young adults with continuous-flow left ventricular assist devices (VAD) bridged to transplant. From Pediatric Interagency Registry for Mechanically Assisted Circulatory Support and Interagency Registry for Mechanical Circulatory Support registries, we identified patients aged 12-29 years with continuous-flow VADs implanted as bridged to transplant from September 2012 to March 2016. The primary predictor variable was first reported infection. The primary outcome was death on VAD support; secondary outcome was clinical stroke. Kaplan-Meier and Cox proportional hazard methods were used to compare outcomes between patients before or without infection and patients after infection. Ninety-two adolescents (12-18 years of age) and 224 young adults (19-29 years of age) with 3,748 patient-months of follow-up were included. Adolescents were smaller (body surface area 1.7 vs. 2.0 m, p < 0.01) and implanted at higher Interagency Registry for Mechanical Circulatory Support profiles (p = 0.005); there were no differences in diabetes and obesity, and survival on VAD was similar (p = 0.22). Among adolescents but not young adults, mortality increased after infection (hazard ratio 8.2, 95% confidence interval 1.6-42.6, p = 0.01). In contrast, stroke risk increased after infection in young adults (hazard ratio 3.1, 95% confidence interval 1.3-7.6, p = 0.01) but not in adolescents. Despite similar underlying risk factors, adolescents have increased mortality after infections, whereas young adults have increased strokes after infections. Both pre- and postimplant factors likely contribute to the discrepancy in outcomes between the two age cohorts.

More children with single ventricle heart disease are surviving after Fontan surgery. This circulation has pervasive effects on multiple organ systems and has unique modes of failure. Many centers have created multidisciplinary programs to care for these patients. Our aim was to survey such programs to better understand current approaches to care. We hypothesized that significant variability in surveillance testing strategy would be present. Eleven academic institutions with established Fontan care programs performing a combined estimated 300 Fontan surgeries per year, with a total population of 1500–2000 Fontan patients, were surveyed using a REDCap survey regarding surveillance testing and basic practice philosophies. Fontan care programs were structured both as consultative services (64%) and as the primary clinical team (9%). Electrocardiograms (73%) and echocardiograms (64%) were most commonly obtained annually. Serum studies, including complete blood count (73%), complete metabolic panel (73%), and Brain-type natriuretic peptide (54%), were most commonly obtained annually. Hepatic testing consisted of liver ultrasound in most centers, obtained biennially (45%) or > every 2 years (45%). Liver biopsy was not routinely recommended (54%). Neurodevelopmental outcomes were assessed at most institutions (54%), with a median frequency of every 3–4 years. There is considerable variability in the surveillance testing regimen and management strategy after a Fontan procedure at surveyed programs. There is an urgent need for surveillance guidelines to reduce variability, define quality metrics, streamline collaborative practice, and prospective research to better understand the complex adaptations of the body to Fontan physiology.

Duchenne muscular dystrophy (DMD) is characterized by myocardial fibrosis and left ventricular (LV) dysfunction. Implantable cardioverter defibrillator (ICD) use has not been characterized in this population but is considered for symptomatic patients with severe LV dysfunction (SLVD) receiving guideline-directed medical therapy (GDMT). We evaluated ICD utilization and efficacy in patients with DMD. Retrospective cohort study of DMD patients from 17 centers across North America between January 2, 2005 and December 31, 2015. ICD use and its effect on survival were evaluated in patients with SLVD defined as ejection fraction (EF)

BACKGROUND: Heart failure results in significant morbidity and mortality for young children with hypoplastic left heart syndrome (HLHS) following the Norwood procedure. METHODS: We studied subjects enrolled in the prospective Single Ventricle Reconstruction (SVR) trial who survived to hospital discharge after the Norwood operation and were followed up to age 6 years. The primary outcome was heart failure, defined as heart transplant listing after Norwood hospitalization, death attributable to heart failure or symptomatic heart failure (NYHA class IV). Multivariate modeling was undertaken using Cox regression methodology to determine variables associated with heart failure. RESULTS: Of the 461 subjects discharged to home following Norwood procedure, 66 (14.3%) met criteria for heart failure. Among these, 15 died from heart failure, 39 were listed for transplant (22 had a transplant, 12 died after listing and 5 were alive and not yet transplanted), and 12 had NYHA Class IV heart failure but were never listed. The median age at heart failure identification was 1.28 yrs (interquartile range 0.30 - 4.69 years). Factors associated with heart failure included post-Norwood lower fractional area change, need for ECMO, non-Hispanic ethnicity, Norwood perfusion type and total support time (p

Autoimmune-mediated bowel disease has been reported after pediatric heart transplantation. Recognition and treatment of these patients has been difficult. We describe a patient who responded to steroids and basiliximab therapy after an inflammatory process secondary to abnormal T-cell activation. Our patient is a 28-month-old female who received a heart transplant at five wk of age. At 24 months post-transplant, she developed fever and bloody stools. Initial investigations were significant for an elevated ESR (>120) and CRP (15.2). Symptoms persisted despite bowel rest and mycophenolate discontinuation. Endoscopic evaluation revealed discontinuous ulcerative disease involving esophagus, terminal ileum, right and left colon, necessitating extensive bowel resection. She had additional airway inflammation leading to a TEF at the site of esophageal ulceration, requiring tracheostomy. Immune evaluation revealed autoimmune dysregulation that responded to parenteral methylprednisolone. Chronic basiliximab therapy allowed for successful weaning of steroids with sustained remission. She has been transitioned to sirolimus and tacrolimus maintenance immunosuppression with plans to discontinue basiliximab once off steroids. In conclusion, bowel disease in the setting of pediatric heart transplantation can be severe and refractory to traditional treatment methods. Tailoring immune therapy to activated T cells can result in remission. Basiliximab therapy was used in our patient to maintain steroid-induced remission, but long-term complications of this disease process are unknown.

Objective To characterize the medical history, disease progression, and treatment of current-era patients with the rare diseases Fontan-associated protein-losing enteropathy (PLE) and plastic bronchitis. Study design A novel survey that queried demographics, medical details, and treatment information was piloted and placed online via a Facebook portal, allowing social media to power the study. Participation regardless of PLE or plastic bronchitis diagnosis was allowed. Case control analyses compared patients with PLE and plastic bronchitis with uncomplicated control patients receiving the Fontan procedure. Results The survey was completed by 671 subjects, including 76 with PLE, 46 with plastic bronchitis, and 7 with both. Median PLE diagnosis was 2.5 years post-Fontan. Hospitalization for PLE occurred in 71% with 41% hospitalized ≥3 times. Therapy varied significantly. Patients with PLE more commonly had hypoplastic left ventricle (62% vs 44% control; OR 2.81, 95% CI 1.43-5.53), chylothorax (66% vs 41%; OR 2.96, CI 1.65-5.31), and cardiothoracic surgery in addition to staged palliation (17% vs 5%; OR 4.27, CI 1.63-11.20). Median plastic bronchitis diagnosis was 2 years post-Fontan. Hospitalization for plastic bronchitis occurred in 91% with 61% hospitalized ≥3 times. Therapy was very diverse. Patients with plastic bronchitis more commonly had chylothorax at any surgery (72% vs 51%; OR 2.47, CI 1.20-5.08) and seasonal allergies (52% vs 36%; OR 1.98, CI 1.01-3.89). Conclusions Patient-specific factors are associated with diagnoses of PLE or plastic bronchitis. Treatment strategies are diverse without clear patterns. These results provide a foundation upon which to design future therapeutic studies and identify a clear need for forming consensus approaches to treatment.

Background— Pediatric data on the impact of pre–heart transplantation (HTx) risk factors on early post-HTx outcomes remain inconclusive. Thus, among patients with previous congenital heart disease or cardiomyopathy, disease-specific risk models for graft loss were developed with the use pre-HTx recipient and donor characteristics. Methods and Results— Patients enrolled in the Pediatric Heart Transplant Study (PHTS) from 1996 to 2006 were stratified by pre-HTx diagnosis into cardiomyopathy and congenital heart disease cohorts. Logistic regression identified independent, pre-HTx risk factors. Risk models were constructed for 1-year post-HTx graft loss. Donor factors were added for model refinement. The models were validated with the use of patients transplanted from 2007 to 2009. Risk factors for graft loss were identified in patients with cardiomyopathy (n=896) and congenital heart disease (n=965). For cardiomyopathy, independent risk factors were earlier year of transplantation, nonwhite race, female sex, diagnosis other than dilated cardiomyopathy, higher blood urea nitrogen, and panel reactive antibody >10%. The recipient characteristic risk model had good accuracy in the validation cohort, with predicted versus actual survival of 97.5% versus 95.3% (C statistic, 0.73). For patients with congenital heart disease, independent risk factors were nonwhite race, history of Fontan, ventilator dependence, higher blood urea nitrogen, panel reactive antibody >10%, and lower body surface area. The risk model was less accurate, with 86.6% predicted versus 92.4% actual survival, in the validation cohort (C statistic, 0.63). Donor characteristics did not enhance model precision. Conclusions— Risk factors for 1-year post-HTx graft loss differ on the basis of pre-HTx cardiac diagnosis. Modeling effectively stratifies the risk of graft loss in patients with cardiomyopathy and may be an adjunctive tool in allocation policies and center performance metrics.

ObjectiveIncreased blood lactate levels reflect tissue oxygen debt and might be indicative of low cardiac output. We hypothesized that the rate of increase in serum lactate would be an ideal marker to discriminate between infants at high and low risk of a poor outcome after surgical repair of congenital heart disease using cardiopulmonary bypass.MethodsIn the present prospective, observational study in a pediatric cardiac intensive care unit, infants (aged

Although nutritional status affects survival after heart transplant (HTx) in adults and older children, its effect on outcomes in young children is unknown. This study aimed to assess the effect of pre-HTx nutrition on outcomes in this population.Children aged 0 to 2 years old listed for HTx from 1997 to 2011 were identified from the Organ Procurement and Transplantation Network database. Nutritional status was classified according to percentage of ideal body weight at listing and at HTx. Logistic regression analysis evaluated the risk of waitlist mortality. Cox proportional hazard models assessed the effect of nutrition on post-HTx survival.Of 1,653 children evaluated, 899 (54%) had normal nutrition at listing, 445 (27%) were mildly wasted, 203 (12%) were moderate or severely wasted, and 106 (6%) had an elevated weight-to-height (W:H) ratio. Moderate or severe wasting (adjusted odds ratio, 1.9; 95% confidence interval, 1.3-2.7) and elevated W:H (adjusted odds ratio, 1.7; 95% confidence interval, 1.1-2.6) were independent risk factors for waitlist mortality. HTx was performed in 1,167 patients, and 1,016 (87%) survived to 1-year post-HTx. Nutritional status at listing or at HTx was not associated with increased post-HTx mortality. Nutritional status did not affect the need for early reoperation, dialysis, or the incidences of infection, stroke, or rejection before hospital discharge.Moderate or severe wasting and an elevated W:H are independent risk factors for waitlist mortality in patients aged2 years but do not affect post-HTx mortality. Optimization of pre-HTx nutritional status constitutes a strategy to reduce waitlist mortality in this age range.

Assess liver stiffness using ultrasound point shear wave elastography (US P-SWE) in children before and after the Fontan operation. Eighteen children undergoing the Fontan operation were prospectively enrolled. Eight US P-SWE measurements were obtained from the right hepatic lobe before surgery, and at multiple postoperative time points. Temporally related inferior vena cava pressure (IVC) data was collected from medical records, when available. Changes in mean liver shear wave speed (SWS) were assessed using a mixed-effect model with post hoc Tukey correction. Changes in IVC pressure were evaluated using the Wilcoxon signed-rank test. A p value less than 0.05 was considered significant. Mean age at enrolment was 33.5 ± 10.5 months. Baseline mean liver SWS was normal at 1.18 ± 0.29 m/s, increased to 2.28 ± 0.31 m/s at 2.5 ± 1.2 days (p

Although the dramatically improved survival of children with single‐ventricle heart disease with Fontan circulation in the recent era is a tremendous accomplishment in pediatric cardiology and cardiac surgery, it has been accompanied by a growing realization that Fontan circulation is largely a

Plastic bronchitis (PB) is a poorly understood disease that can complicate any underlying pulmonary disease. However, it appears to most often occur in patients with surgically palliated congenital heart disease, particularly after the Fontan procedure. Few data exist about the prevalence and etiology of PB in this population. In an effort to establish data about prevalence, we conducted a retrospective study of an existing Fontan surgery database (n = 654) comprised of data, including sex, age at date of surgery, alive/dead status, New York Heart Association classification at last follow-up, right-ventricular end-diastolic pressure and pulmonary artery pressure before Fontan surgery, and the presence of a Fontan fenestration. An initial medical record review of 173 patients in the database who were followed at the University of Michigan identified seven patients with PB resulting in an estimated prevalence of 4 %. Subsequently, 14 % of 211 surveyed patients reported that they presently expectorate mucus or fibrin plugs (casts). Demographic and clinical variables did not differ between patients with or without possible PB. Collectively, these findings suggest that Fontan patients presently with PB may range from 4 to 14 %, indicating potential under-diagnosis of the disease. There were no remarkable physical or hemodynamic indicators that differentiated patients with or without possible PB. These data also highlight the need for more elaborate, prospective studies to improve our understanding of PB pathogenesis so that more definitive diagnostic criteria for this devastating disease can be established and its prevalence more accurately determined.

Coronary allograft vasculopathy is the current leading cause for late graft loss following cardiac transplantation. Its pathogenesis is multifactorial, including immune, constitutional and genetic factors, metabolism, infection, as well as potential injury from routine immunosuppressive therapy. Children represent a patient group with unique differences: their pretransplant history rarely includes ischemic heart disease and risk factors for atherosclerotic heart disease, but many are presensitized from use of allograft material during reconstructive cardiac surgeries. Compared with older children and adults, infants and young children show significantly lower rates of graft vasculopathy that may be related to the relative immaturity of their immune system. This review summarizes the current concepts of coronary allograft vasculopathy derived mainly from animal models and adult clinical observations. It provides an overview of confirmed risk factors and explains their interactions. The characteristics and unique clinical findings among pediatric transplant recipients will be explored within the context of recent, albeit limited, scientific investigations.

Numerous data sets collect information on patients with paediatric cardiovascular disease, including paediatric heart failure and transplant patients. This review discusses methodologies available for linking and integrating information across data sets, which may help facilitate answering important questions in the field of paediatric heart failure and transplant that cannot be answered with individual data sets or single-centre data alone.

We present a case of coronary ectasia and LAD coronary artery aneurysm with angiographic characteristics of Kawasaki disease in a three-yr-old girl two-yr status post-orthotopic heart transplant. Coronary anomalies were noted during initial screening coronary angiography two yr after transplant. Subsequent review of the donor echocardiogram revealed that the LMCA had been mildly dilated prior to transplant. In the absence of any symptoms consistent with Kawasaki disease in the transplant recipient, this appears to be a case of Kawasaki disease in the organ donor manifesting with coronary anomalies in the transplant recipient. The patient has done well clinically, and repeat coronary angiography has revealed partial regression of coronary anomalies. Given multiple reports in the literature of persistent abnormalities of coronary artery morphology and function after Kawasaki disease, close monitoring is warranted, with consideration of potential coronary protective medical therapies.

PLE is an important cause of morbidity and mortality in patients who have undergone Fontan palliation. While multiple PLE therapies have been reported, none has proved consistently effective. Patients who do not respond to "standard" PLE therapies face poor long-term outcomes. We report here a significant response to dopamine infusion in three patients with chronic, refractory PLE. We hypothesize that this response may be at least partially due to a dopamine effect on lymphatic receptors rather than to an augmentation of cardiac output.

At 6 years of age, patients with hypoplastic left heart syndrome had mean age-adjusted z -scores for weight and height below the normative population, and body mass index was similar to the normative population. Males had the greatest increase in z -scores for body mass index. Trial registration ClinicalTrials.gov: NCT00115934.

Post-Fontan protein-losing enteropathy (PLE) is associated with significant morbidity and mortality. Although heart transplantation (HTx) can be curative, PLE may increase the risk of morbidity before and after HTx. This study analyzed the influence of PLE influence on waiting list and post-HTx outcomes in a pediatric cohort.Fontan patients listed for HTx and enrolled in the Pediatric Heart Transplant Study from 1999 to 2012 were stratified by a diagnosis of PLE, and the association of PLE with waiting list and post-HTx mortality, rejection, and infection was analyzed.Compared with non-PLE Fontan patients (n = 260), PLE patients listed for HTx (n = 96) were older (11.9 years vs 7.6 years; p = 0.003), had a larger body surface area (1.1 m(2) vs 0.9 m(2); p = 0.0001), had lower serum bilirubin (0.5 vs 0.9 mg/dl; p = 0.01), lower B-type natriuretic peptide (59 vs 227 pg/ml; p = 0.006), and were less likely to be on a ventilator (3% vs 13%; p = 0.006). PLE patients had lower waiting list mortality than non-PLE Fontan patients (p0.0001). There were no intergroup differences for post-HTx survival or times to the first infection or rejection. PLE was not independently associated with increased post-HTx mortality at any time point.In this multicenter cohort, the diagnosis of PLE alone was not associated with increased waiting list mortality or post-HTx morbidity or mortality. Given the limitations of our data, this analysis suggests that PLE patients in the pediatric age group have outcomes similar to their non-PLE counterparts. Additional multicenter studies of PLE patients with targeted collection of PLE-specific information will be necessary to fully delineate the risks conferred by PLE for HTx.

Background The onset of plastic bronchitis ( PB ) can be debilitating in survivors of Fontan surgery. The rarity of this complication makes designing studies to understand risk factors for PB challenging. This 2‐center case‐control study aimed to describe patient outcomes and to assess the association of antecedent patient factors with PB development. Methods and Results Using center registries, PB patients (n=25) were matched 1:2 to non‐ PB Fontans (n=43) by date of Fontan surgery and center. The groups were compared for baseline characteristics. Association of patient characteristics with PB was assessed using logistic regression and of potential risk factors with onset of PB using time‐to‐event analyses. The median time from Fontan to PB diagnosis was 2.5 years. Overall, 12/25 PB patients died or underwent heart transplant; the median transplant‐free survival was 8.3 years after diagnosis. Factors associated with developing PB included post‐surgical chylothorax (44% PB versus 10% control; odds ratio [ OR ] 7.3; P =0.003), chest tube ( CT ) duration at stage 2 ( P =0.04) and Fontan ( P =0.004), and postoperative ascites (36% PB versus 12% control; OR 4.2; P =0.003). CT drainage >13 days at Fontan was associated with earlier PB onset ( P =0.04). Early‐onset PB was associated with an increased risk of death ( OR 5.0; P =0.002). Conclusions PB is a life‐threatening disorder. A longer duration of CT drainage after surgery, chylothorax, and development of ascites are all associated with developing PB . Understanding the pathophysiology of peri‐operative complications in individual patients and using targeted interventions may delay the onset of the PB phenotype.

We report the use of an absorbable pulmonary artery band to limit postoperative cyanosis due to severe pulmonary arteriovenous fistulae in a 5-year-old girl with post-Fontan palliation takedown to a two-ventricle repair. At 1-year postoperatively, her fistulae had nearly resolved with no distortion of her pulmonary artery anatomy. This case demonstrates a novel approach to limiting cyanosis while pulmonary arteriovenous fistulae resolved after redirection of hepatic blood flow to the affected lung.

Pediatric pharmacotherapy is often challenging due to the paucity of available clinical data on the safety and efficacy of medications that are commonly used in children. This quandary is even more prevalent in children with rare diseases. Although extrapolations for dosing and administration are often made from available adult data with similar disease states, this translation becomes even more problematic in rare pediatric diseases. Understanding of disease pathophysiology is typically poor, and few, if any, effective therapies have been studied and identified. One condition that illustrates these issues is plastic bronchitis, a rare, most often pediatric disease that is characterized by the production of obstructive bronchial airway casts. This illness primarily occurs in children with congenital heart disease, often after palliative surgery. Plastic bronchitis is a highly clinically relevant and therapeutically challenging problem with a high mortality rate, and, to date, a generally accepted effective pharmacotherapy regimen has not been identified. Furthermore, the disease is ill defined, which makes timely identification and treatment of children with plastic bronchitis difficult. The pharmacotherapies currently used to manage this disease are largely anecdotal and vary between the use of macrolide antibiotics, mucolytics, bronchodilators, and inhaled fibrinolytics in a myriad of combinations. The purpose of this review is twofold: first, to highlight the dilemma of treating plastic bronchitis, and second, to bring attention to the continuing need for studies of drug therapies used in children so that safe and effective drug regimens can be established, particularly for rare diseases, which often have no treatment options.