Decreasing number of deaths of infants with hypoplastic left heart syndrome

Fetal cardiac intervention in hypoplastic left heart syndrome with intact or restrictive atrial septum, systematic review, and meta-analysis

To investigate outcomes of fetuses with hypoplastic left heart syndrome (HLHS) with an intact or restrictive atrial septum (I/RAS) managed expectantly or with fetal atrial septal intervention (FASI PubMed, Scopus, and Web of Science were searched systematically from inception until April 2023. Outcomes were classified by those who had FASI and those who had expectant management (EM). To estimate the overall proportion of each endpoint, a meta-analysis of proportions was employed using a random-effects model. Heterogeneity was assessed using the I2 value. Thirty-two studies reporting on 746 fetuses with HLHS and I/RAS met our inclusion criteria. Eleven studies (123 fetuses) were in the FASI group and 21 studies (623 fetuses) were in the EM group. Among the 123 FASI cases, 107 (87%) were reported to be technically successful. The mean gestational age (GA) at diagnosis was comparable between the groups (26.2 weeks FASI vs. 24.4 weeks EM group). The mean GA at FASI was 30.4 weeks (95% CI 28.5, 32.5). The mean GA at delivery was also comparable (37.7 weeks FASI vs. 38.1 weeks EM group). Neonatal outcomes, including live birth, neonatal death, and survival to hospital discharge pooled proportions, were also comparable between groups (live birth: 92% (95% CI 64, 99) FASI versus 93% (95% CI 79, 98) in EM, neonatal death: 32% (95% CI 11, 65) FASI versus 30% (95% CI 21, 41) EM, survival to hospital discharge: 37% (95% CI 25, 52) FASI versus 52% (95% CI 42, 61) EM). Age at neonatal death was higher in the FASI group (mean: 17 days FASI vs. 7.2 days EM group). There was a lower rate of postnatal atrial restrictive septum in the FASI group 38% (95% CI 17, 63) compared to the EM group 88% (95% CI 57, 98). Our review shows variations across centers in the selection criteria and techniques used for FASI. Although survival including livebirth, neonatal death, and survival to hospital discharge did not differ between groups, the procedure may translate into a less restrictive septum at birth. Future multicenter studies are needed to better identify the subset of cases that might have improved outcomes, use standardized definitions, unified techniques, utilize core outcome set, and assess long-term benefits.

Interatrial Septum Stenting for Hypoplastic Left Heart Syndrome in Ex Utero Intrapartum Therapy

Patients with hypoplastic left heart syndrome (HLHS) with intact atrial septum have an increased mortality rate. This presentation occurs in 6% to 10% of cases. We present a patient with fetal diagnosis of HLHS with restrictive atrial septum. We performed a cesarean section at 37 weeks of gestation, and under ex utero intrapartum treatment proceeded with a median sternotomy and transatrial stenting for left atrial decompression due to findings of intact atrial septum on the fetal echocardiogram performed during the procedure. Subsequently, the patient underwent hybrid stage I palliation followed by a comprehensive stage II procedure at five months of age, but unfortunately died from postoperative complications.

Myocardial Biomechanics and the Consequent Differentially Expressed Genes of the Left Atrial Ligation Chick Embryonic Model of Hypoplastic Left Heart Syndrome

Left atrial ligation (LAL) of the chick embryonic heart is a model of the hypoplastic left heart syndrome (HLHS) where a purely mechanical intervention without genetic or pharmacological manipulation is employed to initiate cardiac malformation. It is thus a key model for understanding the biomechanical origins of HLHS. However, its myocardial mechanics and subsequent gene expressions are not well-understood. We performed finite element (FE) modeling and single-cell RNA sequencing to address this. 4D high-frequency ultrasound imaging of chick embryonic hearts at HH25 (ED 4.5) were obtained for both LAL and control. Motion tracking was performed to quantify strains. Image-based FE modeling was conducted, using the direction of the smallest strain eigenvector as the orientations of contractions, the Guccione active tension model and a Fung-type transversely isotropic passive stiffness model that was determined via micro-pipette aspiration. Single-cell RNA sequencing of left ventricle (LV) heart tissues was performed for normal and LAL embryos at HH30 (ED 6.5) and differentially expressed genes (DEG) were identified.After LAL, LV thickness increased by 33%, strains in the myofiber direction increased by 42%, while stresses in the myofiber direction decreased by 50%. These were likely related to the reduction in ventricular preload and underloading of the LV due to LAL. RNA-seq data revealed potentially related DEG in myocytes, including mechano-sensing genes (Cadherins, NOTCH1, etc.), myosin contractility genes (MLCK, MLCP, etc.), calcium signaling genes (PI3K, PMCA, etc.), and genes related to fibrosis and fibroelastosis (TGF-β, BMP, etc.). We elucidated the changes to the myocardial biomechanics brought by LAL and the corresponding changes to myocyte gene expressions. These data may be useful in identifying the mechanobiological pathways of HLHS.

Intramyocardial cell-based therapy with Lomecel-B during bidirectional cavopulmonary anastomosis for hypoplastic left heart syndrome: the ELPIS phase I trial

Aims

Hypoplastic left heart syndrome (HLHS) survival relies on surgical reconstruction of the right ventricle (RV) to provide systemic circulation. This substantially increases the RV load, wall stress, maladaptive remodelling, and dysfunction, which in turn increases the risk of death or transplantation.

Methods and results

We conducted a phase 1 open-label multicentre trial to assess the safety and feasibility of Lomecel-B as an adjunct to second-stage HLHS surgical palliation. Lomecel-B, an investigational cell therapy consisting of allogeneic medicinal signalling cells (MSCs), was delivered via intramyocardial injections. The primary endpoint was safety, and measures of RV function for potential efficacy were obtained. Ten patients were treated. None experienced major adverse cardiac events. All were alive and transplant-free at 1-year post-treatment, and experienced growth comparable to healthy historical data. Cardiac magnetic resonance imaging (CMR) suggested improved tricuspid regurgitant fraction (TR RF) via qualitative rater assessment, and via significant quantitative improvements from baseline at 6 and 12 months post-treatment (P < 0.05). Global longitudinal strain (GLS) and RV ejection fraction (EF) showed no declines. To understand potential mechanisms of action, circulating exosomes from intramyocardially transplanted MSCs were examined. Computational modelling identified 54 MSC-specific exosome ribonucleic acids (RNAs) corresponding to changes in TR RF, including miR-215-3p, miR-374b-3p, and RNAs related to cell metabolism and MAPK signalling.

Conclusion

Intramyocardially delivered Lomecel-B appears safe in HLHS patients and may favourably affect RV performance. Circulating exosomes of transplanted MSC-specific provide novel insight into bioactivity. Conduct of a controlled phase trial is warranted and is underway.Trial registration number NCT03525418.

Hypoplastic Left Heart Syndrome: About a Postnatal Death

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is a congenital heart disease that is associated with high mortality rates in the early neonatal period and during surgical treatments. This is mainly due to missed prenatal diagnosis, delayed diagnostic suspicion, and consequent unsuccessful therapeutic intervention.

CASE REPORT

twenty-six hours after birth, a female newborn died of severe respiratory failure. No cardiac abnormalities and no genetic diseases had been evidenced or documented during intrauterine life. The case became of medico-legal concern for the assessment of alleged medical malpractice. Therefore, a forensic autopsy was performed.

RESULTS

the macroscopic study of the heart revealed the hypoplasia of the left cardiac cavities with the left ventricle (LV) reduced to a slot and a right ventricular cavity that simulated the presence of a single and unique ventricular chamber. The predominance of the left heart was evident.

CONCLUSIONS

HLHS is a rare condition that is incompatible with life, with very high mortality from cardiorespiratory insufficiency that occurs soon after birth. The prompt diagnosis of HLHS during pregnancy is crucial in managing the disease with surgery.

Novel rare mutation in a conserved site of PTPRB causes human hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a rare but fatal birth defect in which the left side of the heart is underdeveloped. HLHS accounts for 2% to 4% of congenital heart anomalies. Whole genome sequencing (WGS) was conducted for a family trio consisting of a proband and his parents. A homozygous rare variant was detected in the PTPRB (Protein Tyrosine Phosphatase Receptor Type B) gene of the proband by functional annotation and co-segregation analysis. Sanger sequencing was used to confirm genotypes of the variant. The in silico prediction tools, including Mutation Taster, SpliceAI, and CADD, were used to predict the impact of the mutation. The allele frequencies across populations were compared based on multiple databases, including "1000 genomes" and "gnomAD". We used two vectors (pcMINI and pcDNA3.1) to generate a minigene construct to validate the mutational effect at the transcriptional level. Family-based WGS analyses showed that only a homozygous splice acceptor variant (NC_000012.12: g.70636068T>G, NM_001109754.4: c.56-2A>C, NG_029940.2: g.6373A>C) at the exon-intron border of PTPRB gene associates with HLHS. This variant is also within the region with the enhancer activity based on UCSC genome annotation. Genotyping and Sanger sequencing revealed that the proband's parents are heterozygous for this variant. Evolutionary conservation analysis revealed that the site (NC_000012.12: g.70636068) is extremely conserved across species, supporting the evolutionary functional constraints of the ancestral wild type (T). In silico tools universally predicted a deleterious or disease-causing impact of the mutation from T to G. The mutation was not found in the 1000 genomes and gnomAD databases, which indicates that this mutation is very rare in most human populations. A splicing assay indicated that the mutated minigene caused aberrant splicing of mRNA, in which a 3 bp missing in the second exon resulted in the deletion of one amino acid (NP_001103224.1:p.Glu19del) compared to the normal protein of PRPTB (also the VE-PTP). Structure prediction revealed that the deletion occurred within the C-region of the signal peptide of VE-PTP, suggesting signal peptide-related defects as a potential mechanism for the HLHS cellular pathogeny. We report a rare homozygous variant with splicing error in PTPRB associated with HLHS. Previous model species studies revealed conserved functions of PTPRB in cardiovascular and heart development in mice and zebrafish. Our study is the first report to show the association between PTPRB and HLHS in humans.

Statistical shape analysis of the tricuspid valve in hypoplastic left heart sydrome

Hypoplastic left heart syndrome (HLHS) is a congenital heart disease characterized by incomplete development of the left heart. Children with HLHS undergo a series of operations which result in the tricuspid valve (TV) becoming the only functional atrioventricular valve. Some of those patients develop tricuspid regurgitation which is associated with heart failure and death and necessitates further surgical intervention. Repair of the regurgitant TV, and understanding the connections between structure and function of this valve remains extremely challenging. Adult cardiac populations have used 3D echocardiography (3DE) combined with computational modeling to better understand cardiac conditions affecting the TV. However, these structure-function analyses rely on simplistic point-based techniques that do not capture the leaflet surface in detail, nor do they allow robust comparison of shapes across groups. We propose using statistical shape modeling and analysis of the TV using Spherical Harmonic Representation Point Distribution Models (SPHARM-PDM) in order to generate a reproducible representation, which in turn enables high dimensional low sample size statistical analysis techniques such as principal component analysis and distance weighted discrimination. Our initial results suggest that visualization of the differences in regurgitant vs. non-regurgitant valves can precisely locate populational structural differences as well as how an individual regurgitant valve differs from the mean shape of functional valves. We believe that these results will support the creation of modern image-based modeling tools, and ultimately increase the understanding of the relationship between valve structure and function needed to inform and improve surgical planning in HLHS.

Novel Insights into the Etiology, Genetics, and Embryology of Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a relatively rare severe congenital heart defect (CHD) closely linked to other left ventricular outflow tract (LVOT) lesions including bicuspid aortic valve (BAV), one of the most common heart defects. While HLHS, BAV, and other LVOT lesions have a strong genetic underpinning, their genetic etiology remains poorly understood. Findings from a large-scale mouse mutagenesis screen showed HLHS has a multigenic etiology and is genetically heterogenous, explaining difficulties in identifying the genetic causes of HLHS. In Ohia mice, HLHS shows incomplete penetrance. Some mice exhibited small LV with normal aorta, and others a normal LV with hypoplastic aorta, indicating the LV hypoplasia is not hemodynamically driven. In Ohia mutants, HLHS was found to have a digenic modular construction, with mutation in a chromatin modifier causing the small LV phenotype and mutation in Pcdha9 causing the aorta/aortic valve hypoplasia. The Pcdha9 mutation alone can cause BAV, and in the human genome two common deletion copy number variants spanning PCDHA7-10 are associated with BAV. Hence the digenic etiology of HLHS can account for the close association of HLHS, a rare CHD, with BAV, one of the most common CHD. Functional analysis of Ohia HLHS heart tissue showed severe mitochondrial dysfunction in the small LV, while the normal size RV is also affected but milder, suggesting possible role in vulnerability of surgically palliated HLHS patients to heart failure. These findings suggest insights into the genetics of HLHS may yield new therapies for improving outcome for patients with HLHS.

Skeletal model-based analysis of the tricuspid valve in hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a congenital heart disease characterized by incomplete development of the left heart. Children with HLHS undergo a series of operations which result in the tricuspid valve (TV) becoming the only functional atrioventricular valve. Many HLHS patients develop tricuspid regurgitation and right ventricle enlargement which is associated with heart failure and death without surgical intervention on the valve. Understanding the connections between the geometry of the TV and its function remains extremely challenging and hinders TV repair planning. Traditional analysis methods rely on simple anatomical measures which do not capture information about valve geometry in detail. Recently, surface-based shape representations such as SPHARM-PDM have been shown to be useful for tasks such as discriminating between valves with normal or poor function. In this work we propose to use skeletal representations (s-reps), a more feature-rich geometric representation, for modeling the leaflets of the tricuspid valve. We propose an extension to previous s-rep fitting approaches to incorporate application-specific anatomical landmarks and population information to improve correspondence. We use several traditional statistical shape analysis techniques to evaluate the efficiency of this representation: using principal component analysis (PCA) we observe that it takes fewer modes of variation compared to boundary-based approaches to represent 90% of the population variation, while distance-weighted discrimination (DWD) shows that s-reps provide for more significant classification between valves with less regurgitation and those with more. These results show the power of using s-reps for modeling the relationship between structure and function of the tricuspid valve.

Placental and fetal characteristics of the Ohia mouse line recapitulate outcomes in human hypoplastic left heart syndrome

Congenital heart defects (CHDs) are the most common birth defect worldwide. The morbidity and mortality associated with these defects is compounded by increased frequency of fetal growth abnormalities. In the Ohia mouse model of hypoplastic left heart syndrome (HLHS), the double homozygous genotype is embryonically lethal at mid-pregnancy; a time in which optimal establishment of the placenta is crucial to fetal survival. We aimed to characterize placental and fetal growth and development in the double heterozygous genotype (Sap130^m/+Pcdha9^m/+). There was a shift in frequency of fetuses with reduced weight near term in the Sap130^m/+Pcdha9^m/+ fetuses compared to wildtype, driven by lower fetal weight in male fetuses compared to female. This shift in fetal weight distribution in the Sap130^m/+Pcdha9^m/+ fetuses was associated with reduced labyrinth region area (P < 0.001) and reduced fetal capillary density (P < 0.001) in the placentas, the latter being significantly lower in male Sap130^m/+Pcdha9^m/+ placentas compared to female. mRNA expression of several nutrient transporters was also lower in placentas from males compared to placentas from females, irrespective of genotype. Overall, this data shows that whilst the double heterozygous fetuses do not carry heart defects, placental development and function is impaired, particularly in males. Such differences are similar to findings in studies of human placentas and highlights the importance of this mouse model in continuing to understand the developmental links and disruptions to the heart-placenta axis.

Feeding infants with complex congenital heart disease: a modified Delphi survey to examine potential research and practice gaps

OBJECTIVE

To determine clinical consensus and non-consensus in regard to evidence-based statements about feeding infants with complex CHD, with a focus on human milk. Areas of non-consensus may indicate discrepancies between research findings and practice, with consequent variation in feeding management.

MATERIALS AND METHODS

A modified Delphi survey validated key feeding topics (round 1), and determined consensus on evidence-based statements (rounds 2 and 3). Patients (n=25) were an interdisciplinary group of clinical experts from across the United States of America. Descriptive analysis used SPSS Statistics (Version 26.0). Thematic analysis of qualitative data provided context for quantitative data.

RESULTS

Round 1 generated 5 key topics (human milk, developing oral feeding skills, clinical feeding practice, growth failure, and parental concern about feeding) and 206 evidence-based statements. The final results included 110 (53.4%) statements of consensus and 96 (46.6%) statements of non-consensus. The 10 statements of greatest consensus strongly supported human milk as the preferred nutrition for infants with complex CHD. Areas of non-consensus included the adequacy of human milk to support growth, need for fortification, safety, and feasibility of direct breastfeeding, issues related to tube feeding, and prevention and treatment of growth failure.

CONCLUSIONS

The results demonstrate clinical consensus about the importance of human milk, but reveal a need for best practices in managing a human milk diet for infants with complex CHD. Areas of non-consensus may lead to clinical practice variation. A sensitive approach to these topics is needed to support family caregivers in navigating feeding concerns.

Single-Cell RNA Sequencing and Quantitative Proteomics Analysis Elucidate Marker Genes and Molecular Mechanisms in Hypoplastic Left Heart Patients With Heart Failure

Objective

To probe markers and molecular mechanisms of the hypoplastic left heart (HLH) by single-cell RNA sequencing (scRNA-seq) and quantitative proteomics analysis.

Methods

Following data preprocessing, scRNA-seq data of pluripotent stem cell (iPSC)-derived cardiomyocytes from one HLH patient and one control were analyzed by the Seurat package in R. Cell clusters were characterized, which was followed by a pseudotime analysis. Markers in the pseudotime analysis were utilized for functional enrichment analysis. Quantitative proteomics analysis was based on peripheral blood samples from HLH patients without heart failure (HLH-NHF), HLH patients with heart failure (HLH-HF), and healthy controls. Hub genes were identified by the intersection of pseudotime markers and differentially expressed proteins (DE-proteins), which were validated in the GSE77798 dataset, RT-qPCR, and western blot.

Results

Cardiomyocytes derived from iPSCs were clustered into mesenchymal stem cells, myocardium, and fibroblast cells. Pseudotime analysis revealed their differentiation trajectory. Markers in the three pseudotime clusters were significantly associated with distinct biological processes and pathways. Finally, three hub genes (MMP2, B2M, and COL5A1) were identified, which were highly expressed in the left (LV) and right (RV) ventricles of HLH patients compared with controls. Furthermore, higher expression levels were detected in HLH patients with or without HF than in controls.

Conclusion

Our findings elucidate marker genes and molecular mechanisms of HLH, deepening the understanding of the pathogenesis of HLH.

Attrition between the superior cavopulmonary connection and the Fontan procedure in hypoplastic left heart syndrome

OBJECTIVE

We investigated the incidence and predictors of failure to undergo the Fontan in children with hypoplastic left heart syndrome who survived superior cavopulmonary connection.

METHODS

The cohort consists of all patients with hypoplastic left heart syndrome who survived to hospital discharge after superior cavopulmonary connection between 1988 and 2017. The primary outcome was attrition, which was defined as death, nonsuitability for the Fontan, or cardiac transplantation before the Fontan. Subjects were excluded if they were awaiting the Fontan, were lost to follow-up, or underwent biventricular repair. The study period was divided into 4 eras based on changes in operative or medical management. Attrition was estimated with 95% confidence intervals, and predictors were identified using adjusted, logistic regression models.

RESULTS

Of the 856 hospital survivors after superior cavopulmonary connection, 52 died, 7 were deemed unsuitable for Fontan, and 12 underwent or were awaiting heart transplant. Overall attrition was 8.3% (71/856). Attrition rate did not change significantly across eras. A best-fitting multiple logistic regression model was used, adjusting for superior cavopulmonary connection year and other influential covariates: right ventricle to pulmonary artery shunt at Norwood (P < .01), total support time at superior cavopulmonary connection (P < .01), atrioventricular valve reconstruction at superior cavopulmonary connection (P = .02), performance of other procedures at superior cavopulmonary connection (P = .01), and length of stay after superior cavopulmonary connection (P < .01).

CONCLUSIONS

In this study spanning more than 3 decades, 8.3% of children with hypoplastic left heart syndrome failed to undergo the Fontan after superior cavopulmonary connection. This attrition rate has not decreased over 30 years. Use of a right ventricle to pulmonary artery shunt at the Norwood procedure was associated with increased attrition.

Stem Cell Therapy for Hypoplastic Left Heart Syndrome: Mechanism, Clinical Application, and Future Directions

Hypoplastic left heart syndrome is a type of congenital heart disease characterized by underdevelopment of the left ventricle, outflow tract, and aorta. The condition is fatal if aggressive palliative operations are not undertaken, but even after the complete 3-staged surgical palliation, there is significant morbidity because of progressive and ultimately intractable right ventricular failure. For this reason, there is interest in developing novel therapies for the management of right ventricular dysfunction in patients with hypoplastic left heart syndrome. Stem cell therapy may represent one such innovative approach. The field has identified numerous stem cell populations from different tissues (cardiac or bone marrow or umbilical cord blood), different age groups (adult versus neonate-derived), and different donors (autologous versus allogeneic), with preclinical and clinical experience demonstrating the potential utility of each cell type. Preclinical trials in small and large animal models have elucidated several mechanisms by which stem cells affect the injured myocardium. Our current understanding of stem cell activity is undergoing a shift from a paradigm based on cellular engraftment and differentiation to one recognizing a primarily paracrine effect. Recent studies have comprehensively evaluated the individual components of the stem cells' secretomes, shedding new light on the intracellular and extracellular pathways at the center of their therapeutic effects. This research has laid the groundwork for clinical application, and there are now several trials of stem cell therapies in pediatric populations that will provide important insights into the value of this therapeutic strategy in the management of hypoplastic left heart syndrome and other forms of congenital heart disease. This article reviews the many stem cell types applied to congenital heart disease, their preclinical investigation and the mechanisms by which they might affect right ventricular dysfunction in patients with hypoplastic left heart syndrome, and finally, the completed and ongoing clinical trials of stem cell therapy in patients with congenital heart disease.

Novel insights into the genetic landscape of congenital heart disease with systems genetics

We recently conducted a large-scale mouse mutagenesis screen and uncovered a central role for cilia in the pathogenesis of congenital heart disease (CHD). Though our screen was phenotype based, most of the genes recovered were cilia-related, including genes encoding proteins important for ciliogenesis, cilia-transduced cell signaling, and vesicular trafficking. Also unexpected, many of the cilia related genes recovered are known direct protein-protein interactors, even though each gene was recovered independently in unrelated mouse lines. These findings suggest a cilia-based protein-protein interactome network may provide the context for congenital heart disease pathogenesis. This could explain the incomplete penetrance and variable expressivity of human CHD, and account for its complex non-Mendelian etiology. Supporting these findings in mice, a preponderance of cilia and cilia related cell signaling genes were observed among de novo pathogenic variants identified in a CHD patient cohort. Further clinical relevance unfolded with the observation of a high prevalence of respiratory cilia dysfunction in CHD patients. This was associated with increased postsurgical respiratory complications. Together these findings highlight the importance of cilia in CHD pathogenesis and suggest possible clinical translation with instituting pulmonary therapy to improve outcome for CHD patients undergoing congenital cardiac surgeries.

Trajectory of right ventricular indices is an early predictor of outcomes in hypoplastic left heart syndrome

BACKGROUND

Children with hypoplastic left heart syndrome (HLHS) have risk for mortality and/or transplantation. Previous studies have associated right ventricular (RV) indices in a single echocardiogram with survival, but none have related serial measurements to outcomes. This study sought to determine whether the trajectory of RV indices in the first year of life was associated with transplant-free survival to stage 3 palliation (S3P).

METHODS

HLHS patients at a single center who underwent stage 1 palliation (S1P) between 2000 and 2015 were reviewed. Echocardiographic indices of RV size and function were obtained before and following S1P and stage 2 palliation (S2P). The association between these indices and transplant-free survival to S3P was examined.

RESULTS

There were 61 patients enrolled in the study with 51 undergoing S2P, 20 S3P, and 18 awaiting S3P. In the stage 1 perioperative period, indexed RV end-systolic area increased in patients who died or needed transplant following S2P, and changed little in those surviving to S3P (3.37 vs -0.04 cm² /m² , P = .017). Increased indexed RV end-systolic area was associated with worse transplant-free survival. (OR = 0.815, P = .042). In the interstage period, indexed RV end-diastolic area increased less in those surviving to S3P (3.6 vs 9.2, P = .03).

CONCLUSION

Change in indexed RV end-systolic area through the stage 1 perioperative period was associated with transplant-free survival to S3P. Neither the prestage nor poststage 1 indexed RV end-systolic area was associated with transplant-free survival to S3P. Patients with death or transplant before S3P had a greater increase in indexed RV end-diastolic area during the interstage period. This suggests earlier serial changes in RV size which may provide prognostic information beyond RV indices in a single study.

Economic implications of outpatient cardiac catheterisation in infants with single ventricle congenital heart disease

BACKGROUND

Resource utilisation for infants with single ventricle CHD remains high without well-studied ways to decrease economic burden. Same-day discharge following cardiac catheterisation has been shown to be safe and effective in children with CHD, but those with single ventricle physiology are commonly excluded. The purpose of this study was to investigate the economic implications of planned same-day discharge following cardiac catheterisation versus universal overnight hospital admission in infants with single ventricle CHD.

METHODS AND RESULTS

A probabilistic decision-tree analysis with sensitivity analyses was performed. All included patients were categorised into four possible outcomes; discharge, readmission following discharge (within 48 hours), observation and prolonged hospitalisation. Baseline probabilities of each node of the tree were then combined with the cost data to evaluate the comparative dominance of one decision (immediately discharge) versus the other decision (routinely admit). Patients discharged on the same day as the procedure accrued the lowest attributed hospital cost ($5469), while patients readmitted to the hospital had the highest attributed cost ($11,851). Currently, no other studies have assessed the cost of hospitalisation following cardiac catheterisation in this population. Thus, we allowed for a wide range of cost variation, but same-day discharge dominated the decision outcome with a lower economic burden.

CONCLUSION

Same-day discharge following routine cardiac catheterisation in patients with single ventricle physiology is less costly compared to universal overnight admission. This demonstrates an important cost-limiting step in a complex population of patients who have high resource utilisation.

Safety of outpatient cardiac catheterisation in infants with single-ventricle or shunt-dependent biventricular congenital heart disease

OBJECTIVE

We aimed to investigate the incidence and causes of readmission of infants with single-ventricle and shunt-dependent biventricular CHD following routine, outpatient cardiac catheterisation.

BACKGROUND

Cardiac catheterisation is commonly performed in patients with single-ventricle and shunt-dependent biventricular CHD for haemodynamic assessment and surgical planning. Best practices for post-procedural care in this population are unknown, and substantial variation exists between centres. Outpatient catheterisation reduces parental anxiety and decreases cost. Our institutional strategy is to discharge patients following a 4- to 6-hour post-procedure observation period.

METHODS

Retrospective cohort study using the Society of Thoracic Surgeons Database identified patients 23 hours. There were no differences in baseline characteristics between discharged and admitted patients. Patients who underwent intervention were more likely to be admitted. Patients with hypoplastic left heart syndrome did not have major adverse events or readmissions. No intra- or peri-procedural deaths occurred.

CONCLUSIONS

Outpatient cardiac catheterisation may be a safe option for infants with single-ventricle and shunt-dependent biventricular CHD, with low readmission rates and minimal morbidity.

Launching a New Strategy for Multidisciplinary Management of Single-Ventricle Heart Defects

Children born with single-ventricle heart defects, particularly hypoplastic left heart syndrome, have a lifetime high risk of mortality and comorbidities. They have complex medical challenges in addition to their cardiac needs, including growth and feeding complications and neurodevelopmental issues. These concerns require a coordinated effort among specialties to help patients maximize their potential. Additionally, because many complex heart defects are diagnosed prenatally, coordination of care between the pre- and postnatal care teams is imperative. Nursing leadership improves program coordination and efficiency. The purpose of this article is to describe the development and implementation of our hospital's synchronized, multidisciplinary team to support children with single-ventricle heart defects and their families. (Critical Care Nurse. 2018;38[1]:60-71).

The HAND1 frameshift A126FS mutation does not cause hypoplastic left heart syndrome in mice

Aims

To test if a human Hand1 frame shift mutation identified in human samples is causative of hypoplastic left heart syndrome (HLHS).

Methods and results

HLHS is a poorly understood single ventricle congenital heart defect that affects two to three infants in every 10 000 live births. The aetiologies of HLHS are largely unknown. The basic helix-loop-helix transcription factor HAND1 is required for normal heart development. Interrogation of HAND1 sequence from fixed HLHS tissues identified a somatic frame-shift mutation at Alanine 126 (NP_004812.1 p.Ala126Profs13X defined as Hand1A126fs). Hand1A126fs creates a truncated HAND1 protein that predictively functions as dominant negative. To determine if this mutation is causative of HLHS, we engineered a conditional Hand1A126fs mouse allele. Activation of this allele with Nkx2.5Cre results in E14.5 lethality accompanied by cardiac outflow tract and intraventricular septum abnormalities. Using αMHC-Cre or Mef2CAHF-Cre to activate Hand1A126fs results in reduced phenotype and limited viability. Left ventricles of Hand1A126FS mutant mice are not hypoplastic.

Conclusions

Somatically acquired Hand1A126FS mutation is not causative of HLHS. Hand1A126FS mutation does exhibit embryonic lethal cardiac defects that reflect a dominant negative function supporting the critical role of Hand1 in cardiogenesis.

The Genetic Landscape of Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is one of the most lethal congenital heart defects, and remains clinically challenging. While surgical palliation allows most HLHS patients to survive their critical heart disease with a single-ventricle physiology, many will suffer heart failure, requiring heart transplantation as the only therapeutic course. Current paradigm suggests HLHS is largely of hemodynamic origin, but recent findings from analysis of the first mouse model of HLHS showed intrinsic cardiomyocyte proliferation and differentiation defects underlying the left ventricular (LV) hypoplasia. The findings of similar defects of lesser severity in the right ventricle suggest this could contribute to the heart failure risks in surgically palliated HLHS patients. Analysis of 8 independent HLHS mouse lines showed HLHS is genetically heterogeneous and multigenic in etiology. Detailed analysis of the Ohia mouse line accompanied by validation studies in CRISPR gene-targeted mice revealed a digenic etiology for HLHS. Mutation in Sap130, a component of the HDAC repressor complex, was demonstrated to drive the LV hypoplasia, while mutation in Pcdha9, a protocadherin cell adhesion molecule played a pivotal role in the valvular defects associated with HLHS. Based on these findings, we propose a new paradigm in which complex CHD such as HLHS may arise in a modular fashion, mediated by multiple mutations. The finding of intrinsic cardiomyocyte defects would suggest hemodynamic intervention may not rescue LV growth. The profound genetic heterogeneity and oligogenic etiology indicated for HLHS would suggest that the genetic landscape of HLHS may be complex and more accessible in clinical studies built on a familial study design.

Regional Differences in Cost and Length of Stay in Neonates with Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a highly resource-intensive diagnosis. Geographic variation in cost and length of stay (LOS) in HLHS is not well described. Neonates diagnosed with HLHS between 2000 and 2012 were identified using the Kids' Inpatient Database. Hospitalizations were stratified into two groups: (1) birth and (2) secondary. United States regional differences in hospital charges and LOS were compared using adjusted linear regression. Of 2431 birth hospitalizations, 449 neonates (18.5%) died while inpatient and mortality rates differed by region (p = 0.02). After birth, 40.5% (n = 985) of neonates were transferred; transfers were most common in the Midwest (p < 0.0001). Adjusted average LOS was shortest in the West and longest in the South (26.1 days; 95% CI 24.0, 35.1 vs. 34.9 days; 95% CI 31.8, 38.1). Average adjusted charges were lowest in the Northeast ($324,600; 95% CI $271,400, $377,900) and highest in the West ($400,500; 95% CI $346,700, $454,300, p = 0.05). Among 1895 secondary hospitalizations, 24.9% of neonates died as inpatients, and the average adjusted LOS was shortest in the West (26.8 days; 95% CI 23.9, 29.7) and longest in the South (38.5 days; 95% CI 34.4, 42.4). Average adjusted charges were lowest in the Northeast ($326,900; 95% CI $270,700, $383,100) and highest in the South ($505,900; 95% CI $450,200, $561,500, p < 0.0001). Significant geographic variations in mortality, LOS, and hospital charges exist in care of US HLHS neonates. Reducing variation in care should remain a priority in national quality efforts in congenital heart disease.

Congenital heart defects: the 10-year experience at a single center

Objective: We aimed to evaluate congenital heart disease (CHD) cases according to EUROCAT subgroup classification that were diagnosed during the prenatal period in our center.Methods: CHDs that were prenatally diagnosed using ultrasonography and confirmed by fetal echocardiography were reviewed over a 10-year period. Subgroup classification was finalized at the post-partum period in terms of the EUROCAT guide 1.3. Congenital heart defect subtypes and obstetric outcomes (gestational week at delivery, birth weight, gender, extracardiac structural abnormalities, karyotype results if performed) were analyzed.Results: The data of 180 cases with CHD were examined. Left ventricular outflow tract obstruction (LVOT) was the most common CHD subtype (57/180; 31.6%), which included 48, five, and four cases of hypoplastic left heart syndrome (HLHS), coarctation of the aorta, and aortic valve atresia/stenosis, respectively. Eighteen pregnancies were terminated; the most common CHD subtype among patients of terminated pregnancies was hypoplastic left heart syndrome (HLHS) (n = 7, 38.8%). The most common extracardiac malformations were a single umbilical artery, esophageal atresia, and situs inversus in our study group. Eighteen of the 96 (18.75%) neonates with CHD died during the neonatal period. The most common CHD subtype was HLHS (7/18; 38%) among the newborns who died after birth.Conclusion: Prenatal diagnosis of a CHD and subgroup classification is very important for clinical decision making, including prenatal management, recommendations for termination of the pregnancy, postnatal management of the patient, and for early referral to pediatric cardiology and cardiovascular surgery centers.

Cerebral Abscess in Young Adult with Hypoplastic Left Heart Syndrome

BACKGROUND

Cerebral abscesses are rare, potentially life-threatening entities that result from local spread or hematogenous dissemination to the brain. Prompt diagnosis and initiation of treatment is key in lowering morbidity and preventing mortality associated with cerebral abscesses. Congenital heart diseases with right-to-left intracardiac shunts can be complicated by brain abscesses via paradoxical embolism of infected microthrombi. Hypoplastic left heart syndrome (HLHS) is a rare congenital heart disease characterized by an underdeveloped left heart that uses intracardiac shunting to achieve adequate systemic circulation. We present the first reported case of a cerebral abscess in a patient with HLHS. The pathophysiology of HLHS and how it predisposes patients to development of cerebral abscesses is discussed.

CASE DESCRIPTION

A 25-year-old male was transferred to our institution complaining of headache, nausea, and vomiting. The patient was not an intravenous (IV) drug user, and serologic testing was negative for human immunodeficiency virus. Magnetic resonance imaging revealed a 2.6-cm left occipital abscess, which was surgically resected without complication, and the patient was treated with IV antibiotics.

CONCLUSION

HLHS is a rare congenital cardiac malformation. The long-term outcome of patients with this condition continues to improve as treatment paradigms evolve. As such, patients with HLHS are living longer, and their potential to develop cerebral abscesses secondary to their unique systemic circulation is increasing with improved life expectancy. Surgeons and physicians should maintain a high index of suspicion for cerebral abscess in the setting of HLHS.

Regenerative medicine therapy for single ventricle congenital heart disease

One of the most complex forms of congenital heart disease (CHD) involving single ventricle physiology is hypoplastic left heart syndrome (HLHS), characterized by underdevelopment of the left ventricle (LV), mitral and aortic valves, and narrowing of the ascending aorta. The underdeveloped LV is incapable of providing long-term systemic flow, and if left untreated, the condition is fatal. Current treatment for this condition consists of three consecutive staged palliative operations: the first is conducted within the first few weeks of birth, the second between 4 to 6 months, and the third and final surgery within the first 4 years. At the conclusion of the third surgery, systemic perfusion is provided by the right ventricle (RV), and deoxygenated blood flows passively to the pulmonary vasculature. Despite these palliative interventions, the RV, which is ill suited to provide long-term systemic perfusion, is prone to eventual failure. In the absence of satisfying curative treatments, stem cell therapy may represent one innovative approach to the management of RV dysfunction in HLHS patients. Several stem cell populations from different tissues (cardiac and non-cardiac), different age groups (adult- vs. neonate-derived), and different donors (autologous vs. allogeneic), are under active investigation. Preclinical trials in small and large animal models have elucidated several mechanisms by which these stem cells affect the injured myocardium, and are driving the shift from a paradigm based upon cellular engraftment and differentiation to one based primarily on paracrine effects. Recent studies have comprehensively evaluated the individual components of the stem cells' secretomes, shedding new light on the intracellular and extracellular pathways at the center of their therapeutic effects. This research has laid the groundwork for clinical application, and there are now several trials of stem cell therapies in pediatric populations that will provide important insights into the value of this therapeutic strategy in the management of HLHS and other forms of CHD. This article reviews the many stem cell types applied to CHD, their preclinical investigation and the mechanisms by which they might affect RV dysfunction in HLHS patients, and finally, the completed and ongoing clinical trials of stem cell therapy in patients with CHD.

Regional differences in right versus left congenital heart disease diagnoses in neonates in the United States

BACKGROUND

Differences in the prevalence of left and right congenital heart defects (CHD) across the United States are unclear. This study evaluated the overall prevalence and the distribution of right versus left CHD across US regions and divisions in neonates.

METHODS

Newborns born from 2000 to 2014 diagnosed with CHD were identified using the National Inpatient Sample. Heart defects were stratified into right, left, and "neither" subtypes. The risk of right and left heart diagnoses between US Census regions and divisions was compared using multivariable binomial regression, adjusting for infant, and hospital characteristics.

RESULTS

Two hundred forty thousand four hundred fifty-five newborns were included and 38,185 (15.9%) were classifiable as having either right or left subtypes. Between 2000 and 2014, the prevalence of right defects increased from 1.65 to 2.88 cases/1,000 live born infants (p < .0001), left defects increased from 0.47 to 0.75 cases/1,000 live born infants (p < .0001), and "neither" defects increased from 10.82 to 20.09 cases/1,000 live born infants (p < .0001). Newborns in the Northeast (RD_adj .03, 95% CI .02, .03), Midwest (RD_adj .02, 95% CI .02, .03), and South (RD_adj .02, 95% CI .02, .02) were significantly more likely to have a right heart defect diagnosis compared to the West. When stratified by division, New England states had a significantly higher prevalence of right defects compared to the Pacific (RD_adj .09, 95% CI .06, 0.11). No differences in the prevalence of left defects were seen.

CONCLUSIONS

The prevalence of CHD diagnoses at birth in the US has increased, and regional differences in the prevalence of right defects appear to exist.

The Medical Home at 50: Are Children With Medical Complexity the Key to Proving Its Value?

The medical home has been widely promoted as a model of primary care with the potential to transform the health care delivery system. Although this model was initially focused on children with chronic conditions, the American Academy of Pediatrics has endorsed a generalization of the model, promoting the statement, "Every child deserves a medical home." Recently, other major professional and governmental organizations have embraced this more inclusive vision, and the medical home concept has been promoted in provisions of the Affordable Care Act. Yet, rigorous evaluations of the value of the medical home, within pediatrics and beyond, have been limited, and the results have been mixed. Early results from large demonstration projects in adults have generally noted modest improvements in quality without accompanying reductions in cost. At this critical period in health care, with widespread interest in health care delivery and payment reform, these results present a potential threat to the medical home. Understanding possible reasons for these early findings is crucial to sustaining the spread of the medical home beyond its first 50 years. With this aim, we review the history of the medical home and trends in child health, and we explore the concepts of value and complexity as they pertain to pediatric health care delivery. We propose that, because of the demographic characteristics and economics of child health and current policy imperatives with regard to health care, a strong value proposition for the medical home in pediatrics involves children with medical complexity.

Hospital Inpatient Costs for Single Ventricle Patients Surviving the Fontan Procedure

We estimated the inpatient resource use for a Fontan patient from birth to adulthood and explored factors that might induce cost differences (2014 US dollar). Inpatient costing records from 4 hospitals with greatest numbers of Fontan patients in Australia and New Zealand were linked with the Fontan registry database. Inpatient records between July 1995 and September 2014 for 420 Fontan patients were linked, and the most frequent primary diagnoses were hypoplastic left heart syndrome (20.7%), tricuspid atresia (19.7%), and double inlet left ventricle (17.1%). The mean hospital cost for a Fontan patient from birth to 18 years of age was estimated to be $390,601 (95% confidence interval [CI] $264,703 to $516,499), corresponding to 164 (95% CI 98 to 231) inpatient days. The cost incurred from birth through to Fontan completion (the staged procedures period) was $219,482 (95% CI $202,410 to $236,553) and the cost thereafter over 15 years was $146,820 (95% CI $44,409 to $249,231), corresponding to 82 (95% CI 72 to 92) and 65 (95% CI 18 to 112) inpatient days, respectively. Costs were higher in male and hypoplastic left heart syndrome patients in the staged procedures period (p <0.001). Having fenestration was associated with higher costs in the staged procedures period (p <0.001) and lower cost after Fontan over 15 years (p = 0.66). In conclusion, patients with single ventricle congenital heart disease continue to demand considerable inpatient resources after the staged procedures period. Over 40% of the pediatric hospital costs for Fontan patients were estimated to occur after the last planned surgery.

Hand factor ablation causes defective left ventricular chamber development and compromised adult cardiac function

Coordinated cardiomyocyte growth, differentiation, and morphogenesis are essential for heart formation. We demonstrate that the bHLH transcription factors Hand1 and Hand2 play critical regulatory roles for left ventricle (LV) cardiomyocyte proliferation and morphogenesis. Using an LV-specific Cre allele (Hand1^LV-Cre), we ablate Hand1-lineage cardiomyocytes, revealing that DTA-mediated cardiomyocyte death results in a hypoplastic LV by E10.5. Once Hand1-linage cells are removed from the LV, and Hand1 expression is switched off, embryonic hearts recover by E16.5. In contrast, conditional LV loss-of-function of both Hand1 and Hand2 results in aberrant trabeculation and thickened compact zone myocardium resulting from enhanced proliferation and a breakdown of compact zone/trabecular/ventricular septal identity. Surviving Hand1;Hand2 mutants display diminished cardiac function that is rescued by concurrent ablation of Hand-null cardiomyocytes. Collectively, we conclude that, within a mixed cardiomyocyte population, removal of defective myocardium and replacement with healthy endogenous cardiomyocytes may provide an effective strategy for cardiac repair.

The left ventricle of the heart drives blood flow throughout the body. Impaired left ventricle function, associated either with heart failure or with certain, severe cardiac birth defects, constitutes a significant cause of mortality. Understanding how heart muscle grows is vital to developing improved treatments for these diseases. Unfortunately, genetic tools necessary to study the left ventricle have been lacking. Here we engineer the first mouse line to enable specific genetic study of the left ventricle. We show that, unlike in the adult heart, the embryonic left ventricle is remarkably tolerant of cell death, as remaining cells have the capacity to proliferate and to restore heart function. Conversely, disruption of two related genes, Hand1 and Hand2, within the left ventricle causes cells to assume the wrong identity, and to consequently overgrow and impair cardiac function. Ablation of these mutant cells rescues heart function. We conclude that selective removal of defective heart muscle and replacement with healthy cells may provide an effective therapy to treat heart failure.

Image Segmentation and Modeling of the Pediatric Tricuspid Valve in Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a single-ventricle congenital heart disease that is fatal if left unpalliated. In HLHS patients, the tricuspid valve is the only functioning atrioventricular valve, and its competence is therefore critical. This work demonstrates the first automated strategy for segmentation, modeling, and morphometry of the tricuspid valve in transthoracic 3D echocardiographic (3DE) images of pediatric patients with HLHS. After initial landmark placement, the automated segmentation step uses multi-atlas label fusion and the modeling approach uses deformable modeling with medial axis representation to produce patient-specific models of the tricuspid valve that can be comprehensively and quantitatively assessed. In a group of 16 pediatric patients, valve segmentation and modeling attains an accuracy (mean boundary displacement) of 0.8 ± 0.2 mm relative to manual tracing and shows consistency in annular and leaflet measurements. In the future, such image-based tools have the potential to improve understanding and evaluation of tricuspid valve morphology in HLHS and guide strategies for patient care.

Postoperative management of heart failure in pediatric patients

Low cardiac output syndrome (LCOS) is a well-described entity occurring in 25-65% of pediatric patients undergoing open-heart surgery. With judicious intensive care management of LCOS, most patients have an uncomplicated postoperative course, and within 24 h after cardiopulmonary bypass, the cardiac function returns back to baseline. Some patients have severe forms of LCOS not responsive to medical management alone, requiring temporary mechanical circulatory support to prevent end-organ injury and to decrease myocardial stress and oxygen demand. Occasionally, cardiac function does not recover and heart transplantation is necessary. Long-term mechanical circulatory support devices are used as a bridge to transplantation because of limited availability of donor hearts. Experience in usage of continuous flow ventricular assist devices in the pediatric population is increasing.

Transcriptional Impact of Rare and Private Copy Number Variants in Hypoplastic Left Heart Syndrome

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is a heterogeneous, lethal combination of congenital malformations characterized by severe underdevelopment of left heart structures, resulting in a univentricular circulation. The genetic determinants of this disorder are largely unknown. Evidence of copy number variants (CNVs) contributing to the genetic etiology of HLHS and other congenital heart defects has been mounting. However, the functional effects of such CNVs have not been examined, particularly in cases where the variant of interest is found in only a single patient.

METHODS AND RESULTS

Whole-genome SNP microarrays were employed to detect CNVs in two patient cohorts (N = 70 total) predominantly diagnosed with some form of nonsyndromic HLHS. We discovered 16 rare or private variants adjacent to or overlapping 20 genes associated with cardiovascular or premature lethality phenotypes in mouse knockout models. We evaluated the impact of selected variants on the expression of nine of these genes through quantitative PCR on cDNA derived from patient heart tissue. Four genes displayed significantly altered expression in patients with an overlapping or proximal CNV verses patients without such CNVs.

CONCLUSION

Rare and private genomic imbalances perturb transcription of genes that potentially affect cardiogenesis in a subset of nonsyndromic HLHS patients.

Survival of Children With Hypoplastic Left Heart Syndrome

OBJECTIVE

To examine the survival of infants with hypoplastic left heart syndrome (HLHS) and potential influence of demographic and clinical characteristics on survival using population-based data.

METHODS

Infants with nonsyndromic HLHS (n = 212) born between 1979 and 2005 were identified through the Metropolitan Atlanta Congenital Defects Program. Vital status was ascertained through 2009 based on linkage with vital records. We estimated Kaplan-Meier survival probabilities stratified by select demographic and clinical characteristics.

RESULTS

The overall survival probability to 2009 was 24% and significantly improved over time: from 0% in 1979-1984 to 42% in 1999-2005. Survival probability was 66% during the first week, 27% during the first year of life, and 24% during the first 10 years. Survival of very low and low birth weight or preterm infants and those born in high-poverty neighborhoods was significantly poorer. For children with information on surgical intervention (n = 88), the overall survival was 52%, and preterm infants had significantly poorer survival (31%) compared with term infants (56%). For children who survived to 1 year of age, long-term survival was ∼90%.

CONCLUSIONS

Survival to adolescence of children with nonsyndromic HLHS born in metropolitan Atlanta has significantly improved in recent years, with those born full term, with normal birth weight, or in a low-poverty neighborhood having a higher survival probability. Survival beyond infancy to adolescence is high. A better understanding of the growing population of survivors with HLHS is needed to inform resource planning.

Effects of race, ethnicity, and gender on surgical mortality in hypoplastic left heart syndrome

Information is limited regarding the effect of race, ethnicity, and gender on the outcomes of the three palliative procedures for hypoplastic left heart syndrome (HLHS). This study examined the effects of race, ethnicity, gender, type of admission, and surgical volume on in-hospital mortality associated with palliative procedures for HLHS between 1998 and 2007 using data from the University HealthSystem Consortium. According to the data, 1,949 patients underwent stage 1 palliation (S1P) with a mortality rate of 29 %, 1,279 patients underwent stage 2 palliations (S2P) with a mortality rate of 5.4 %, and 1,084 patients underwent stage 3 palliation (S3P) with a mortality rate of 4.1 %. The risk factors for increased mortality with S1P were black and "other" race, smaller surgical volume, and early surgical era. The only risk factors for increased mortality with S2P were black race (11 % mortality; odds ratio [OR], 3.19; 95 % confidence interval [CI] 1.69-6.02) and Hispanic ethnicity (11 % mortality; OR 3.30; 95 % CI 1.64-6.64). For S2P, no racial differences were seen in the top five surgical volume institutions, but racial differences were seen in the non-top-five surgical volume institutions. Mortality with S1P was significantly higher for patients discharged after birth (37 vs 24 %; p = 0.004), and blacks were more likely to be discharged after birth (12 vs 5 % for all other races; p < 0.001). No racial differences with S3P were observed. The risk factors for increased mortality at S1P were black and "other" race, smaller surgical volume, and early surgical era. The risk factors for increased in-hospital mortality with S2P were black race and Hispanic ethnicity.

Emergency laparotomy for necrotising enterocolitis in a newborn with hypoplastic left heart syndrome

Necrotising enterocolitis (NEC) and congenital heart disease are two distinct disease processes, but they appear to be inter-related, particularly in patients with the congenital heart condition known as hypoplastic left heart syndrome (HLHS). Both NEC and HLHS are causes of significant morbidity and mortality in the neonatal population. As medical and surgical advances allow for the palliation and correction of complex heart lesions at an earlier gestational age and lower birth weight, the already high-risk of NEC in this population is likely to increase. In this article, we report a case of a neonate with unpalliated HLHS who underwent emergency laparotomy for NEC. We also discuss the pathophysiology of these two diseases and the perioperative care of this rare group of patients.

Laparoscopic antireflux surgery in infants with single ventricle physiology: a review

Laparoscopic fundoplication and gastrostomy tube placement have grown in popularity within the pediatric population for treatment of gastroesophageal reflux disease and failure to thrive, respectively. One population that has an increased need for gastric surgery in infancy is patients with congenital heart defects, especially those with "single ventricle physiology." The most common defect included in this population is hypoplastic left heart syndrome (HLHS). Because of the abnormal physiology present in this condition, there are concerns with regard to the use of laparoscopic procedures for gastric surgery in patients treated with a three-staged reconstruction. We review the staged reconstruction of infants with HLHS, address safety concerns of interstage noncardiac procedures on this patient population, and review the current literature regarding outcomes of laparoscopic gastric surgery on patients with single ventricle physiology.

Staged palliation of hypoplastic left heart syndrome: trends in mortality, cost, and length of stay using a national database from 2000 through 2009

Staged surgical palliation has revolutionized the care of patients with hypoplastic left heart syndrome (HLHS), although the outcomes of survival and cost at a national level remain unclear. This study sought to evaluate (1) trends in HLHS surgical outcomes including in-hospital mortality, length of stay (LOS), and cost, and (2) patient and hospital risk factors associated with these outcomes. Hospitalizations for patients with HLHS, including stage I, II, and III palliations, were analyzed using the Kids' Inpatient Database from 2000 through 2009. Trends in mortality, LOS, and cost were analyzed and chi-squared tests were used to test association between categorical variables. Patient and hospital characteristics associated with death were analyzed using logistic regression and associations with LOS were analyzed using ordinary least squared regression. There were 16,923 hospital admissions in patients with HLHS of which 5,672 (34%) included surgical intervention. Total (3,201-5,102) and surgery-specific admissions (1,165-1,618) increased from 2000 to 2009. Mortality decreased 14% per year in stage III palliations (odds ratio [OR] 0.86; 95% confidence interval [CI]: 0.79-0.94) and 6% per year for stage I palliations (OR 0.94; 95% CI 0.90-0.99) but not for stage II palliations (OR 1.01; 95% CI; 0.89-1.14). Length of stay increased for stage I and II palliations; however, per-patient hospital cost decreased in 2009. In conclusion, recent decrease in per patient cost for staged surgical palliation for HLHS has correlated temporally with improved mortality.

The use of reconstructive surgery to improve quality of life and survival in prenatal hypoplastic left heart syndrome

Outcomes for hypoplastic left heart syndrome have improved substantially in the era of prenatal diagnosis. Current stage 1 survival rates are in excess of 90% in the absence of risk factors. However, fetuses with an intact atrial septum continue to have poor postnatal survival. Accurate diagnosis of these fetuses with an intact atrial septum relies upon careful assessment of the patent foramen ovale, pulmonary venous Doppler flow patterns and branch pulmonary artery Doppler flow patterns. Prenatal and perinatal interventions, such as the placement of an atrial stent in utero or delivery at a center where a stent may be placed immediately after birth to relieve left atrial hypertension, may improve survival in this particularly high-risk group.

Effect of acculturation and distance from cardiac center on congenital heart disease mortality

BACKGROUND AND OBJECTIVE

Despite improvements in congenital heart disease (CHD) survival over the past 4 decades, ethnic disparities persist. Several studies have shown higher postoperative CHD adjusted mortality in black and Hispanic children. Others noted that non-English-speaking language at home was associated with appointment noncompliance, which the parents attributed to misunderstanding and living too far from a health center. The purpose of this study was to determine the effect of home distance to a cardiac center, or having a Latin American-born parent, on first-year mortality in infants with severe CHD.

METHODS

Infants with severe CHD, having an estimated first-year mortality >25%, born 1996-2003, were identified from the Texas Birth Defects Registry and linked to state and national vital records. We examined the effects of defect type; birth weight; gestational age; extracardiac anomalies; infant gender; maternal race/ethnicity, marital status, and education; residence in a Texas county bordering Mexico; home distance to cardiac center; and parental birth country on first-year survival.

RESULTS

Overall first-year survival was 59.9%, and no race/ethnic differences were noted; however, survival was significantly (P < .05) lower for Hispanic infants with hypoplastic left heart syndrome. Neither home distance to a cardiac center nor parental birth country was related to first-year survival; however, survival was noted to be lower in Texas counties bordering Mexico, counties that have high rates of poverty.

CONCLUSIONS

Further studies are needed to determine if these disparities in survival of infants with severe CHD are attributable to delays in referral to a cardiac center.

Medical transport of children with complex chronic conditions

One of the most notable trends in child health has been the increase in the number of children with special health care needs, including those with complex chronic conditions. Care of these children accounts for a growing fraction of health care resources. We examine recent developments in health care, especially with regard to medical transport and prehospital care, that have emerged to adapt to this remarkable demographic trend. One such development is the focus on care coordination, including the dissemination of the patient-centered medical home concept. In the prehospital setting, the need for greater coordination has catalyzed the development of the emergency information form. Training programs for prehospital providers now incorporate specific modules for children with complex conditions. Another notable trend is the shift to a family-centered model of care. We explore efforts toward regionalization of care, including the development of specialized pediatric transport teams, and conclude with recommendations for a research agenda.

Inpatient costs and charges for surgical treatment of hypoplastic left heart syndrome

OBJECTIVE

Hypoplastic left heart syndrome (HLHS) is one of the most serious congenital cardiac anomalies. Typically, it is managed with a series of 3 palliative operations or cardiac transplantation. Our goal was to quantify the inpatient resource burden of HLHS across multiple academic medical centers.

METHODS

The University HealthSystem Consortium is an alliance of 101 academic medical centers and 178 affiliated hospitals that share diagnostic, procedural, and financial data on all discharges. We examined inpatient resource use by patients with HLHS who underwent a staged palliative procedure or cardiac transplantation between 1998 and 2007.

RESULTS

Among 1941 neonates, stage 1 palliation (Norwood or Sano procedure) had a median length of stay (LOS) of 25 days and charges of $214,680. Stage 2 and stage 3 palliation (Glenn and Fontan procedures, respectively) had median LOS and charges of 8 days and $82,174 and 11 days and $79,549, respectively. Primary neonatal transplantation had an LOS of 87 days and charges of $582,920, and rescue transplantation required 36 days and $411,121. The median inpatient wait time for primary and rescue transplants was 42 and 6 days, respectively. Between 1998 and 2007, the LOS for stage 1 palliation increased from 16 to 28 days and inflation-adjusted charges increased from $122,309 to $280,909, largely because of increasing survival rates (57% in 1998 and 83% in 2007).

CONCLUSIONS

Patients with HLHS demand considerable inpatient resources, whether treated with the Norwood-Glenn-Fontan procedure pathway or cardiac transplantation. Improved survival rates have led to increased hospital stays and costs.