Hypoplastic left heart syndrome: Prognosis and management options

Hybrid stage 1 palliation for HLHS: the experience of a tertiary center in a developing country

Background

Hypoplastic left heart syndrome (HLHS) accounts for 2.6% of congenital heart disease and is an invariably fatal cardiac anomaly if left untreated. Approximately 33,750 babies are born annually with HLHS in developing countries. Unfortunately, the majority will not survive due to the scarcity of resources and the limited availability of surgical management.

Aim

To describe and analyze our experience with the hybrid approach in the management of HLHS in a developing country.

Methods

We performed a retrospective single-center study involving all neonates born with HLHS over five years at the Children's Heart Center at the American University of Beirut. The medical records of patients who underwent the hybrid stage 1 palliation were reviewed, and data related to baseline characteristics, procedure details and outcomes were collected to describe the experience at a tertiary care center in a developing country.

Results

A total of 18 patients were diagnosed with HLHS over a five-year period at our institution, with male to female ratio of 1:1. Of those, eight patients underwent the hybrid stage I procedure. The mean weight at the time of the procedure was 3.3 ± 0.3 kg with an average age of 6.4 ± 4 days. The mean hospital length of stay was 27.25 days, with an interquartile range of 33 days. The cohort's follow-up duration averaged 5.9 ± 3.5 years. The surgical mortality was zero. Only one mortality was recorded during the interstage period between stage I and II and was attributed to sepsis. Notably, all surviving patients maintained preserved and satisfactory cardiac function with good clinical status.

Conclusion

Our limited experience underscores the potential of developing countries with proper foundations to adopt the hybrid procedure for HLHS, yielding outcomes on par with those observed in developed countries. This demonstrates the viability of establishing a more balanced global landscape for children with congenital heart disease.

Cardiac tissue engineering for the treatment of hypoplastic left heart syndrome (HLHS)

Hypoplastic left heart syndrome (HLHS) is a deadly congenital heart disease that arises when the left ventricle and outflow tract fail to develop appropriately, inhibiting the adequate perfusion of the rest of the body. Historically, this disease has been treated via a series of surgeries that allows the heart to use a single ventricle. These surgeries are often a palliative measure, and heart transplantation is the only definitive therapy that exists for this condition. It has been hypothesized that stem cell-based regenerative therapies could have a role in promoting cardiac tissue regeneration in HLHS patients who are undergoing palliative surgery. Several clinical trials have demonstrated that introducing pluripotent cells into the heart is safe, feasible, and capable of improving right ventricular ejection fraction (RVEF). However, while these approaches show great promise, there is still room for development. There is a substantial body of pre-clinical work that is focused on generating increasingly large and complex pieces of cardiac tissue in the form of cardiac patches, with the idea that these could be used to rebuild and strengthen the heart in a robust and long-lasting manner. In total, stem cell-based therapies have much to offer when it comes to improving the treatment of HLHS.

Intrauterine Adenosine Administration for the Treatment of Fetal Supraventricular Tachycardia in a Fetus With Aortic Stenosis

Fetal tachyarrhythmia and aortic stenosis (AS) both disrupt fetal hemodynamics, leading to congestive heart failure, hydrops, and intrauterine demise. Traditional transplacental treatments for fetal supraventricular tachycardia (SVT) include digoxin, flecainide, and sotalol. However, the treatment of fetal SVT in the setting of AS has not been described, particularly in cases of refractory SVT. We present a case of a 27-year-old nulliparous female carrying a fetus with fetal AS diagnosed at 25 weeks of gestational age (GA). The patient was not a candidate for in utero valvuloplasty. During ultrasound monitoring at 32 and 6/7 weeks of gestation, fetal SVT with a heart rate of 230-260 beats per minute (bpm) was diagnosed. Maternal digoxin was initiated, and sotalol was subsequently added. Due to persistent fetal SVT and a worsening cardiac function, the patient was treated with direct adenosine administration via cordocentesis successfully terminating the fetal arrhythmia. Despite continued transplacental treatment with digoxin and sotalol throughout the course of pregnancy, the fetal SVT recurred at 35 and 5/7 weeks of gestation prompting delivery. Our case illustrates the use of direct intrauterine adenosine as a novel treatment for refractory fetal SVT in the setting of congenital aortic stenosis and concern about progression to fetal hydrops and fetal demise.

Coarctation Angioplasty in Young Children: Does IMPACT Registry Data Accurately Reflect Clinical Outcomes?

Balloon angioplasty for recoarctation of the aorta is routinely performed in young children and is considered successful when the systolic gradient is reduced to < 10 mmHg. IMPACT defines acute procedural success solely based on a final gradient of < 10 mmHg and stratifies participating institutions based on these acute outcomes. Between February 2012 and December 2020, IMPACT data was analyzed for 110 coarctation interventions. Electronic medical records were reviewed, and primary endpoints were one of the following: (1) final analysis end date (June 2021), (2) patient death, or (3) most recent transcatheter or surgical reintervention. 64 (58.2%) interventions had a post-procedure CA gradient < 10 mmHg. Comparison of clinical patient outcome for acute success demonstrated no significant relationship using IMPACT (p = 0.70) criteria. There was no statistically significant difference between clinical success and failure for: pre- and post-treatment systolic gradients; absolute or percent change in systolic gradient; and pre-treatment aorta diameter. Clinical outcome and patient age did show a significant difference (p = 0.0093) with better clinical outcomes in older patients. Our analysis did not reveal a statistically significant difference between IMPACT criteria for successful treatment of CA and clinical outcome. These findings underscore a need to identify other clinical metrics that better predict outcome following CA balloon angioplasty treatment.

Hypoplastic Left Heart Syndrome: A Review

Hypoplastic left heart syndrome is a rare and poorly understood congenital disorder featuring a univentricular myocardium, invariably resulting in early childhood death if left untreated. The process to palliate this congenital cardiomyopathy is of high complexity and may include invasive interventions in the first week of life. The preferred treatment strategy involves a staged correction with 3 surgical procedures at different points in time. The Norwood procedure is usually performed within the first weeks of life and aims to increase systemic circulation and relieve pulmonary vascular pressure. This procedure is followed by the bidirectional Glenn and the Fontan procedures in later life, which offer to decrease stress in the ventricular chamber. The prognosis of children with this disease has greatly improved in the past decades; however, it is still largely driven by multiple modifiable and nonmodifiable variables. Novel and clever alternatives have been proposed to improve the survival and neurodevelopment of these patients, although they are not used as standard of care in all centers. The neurodevelopmental outcomes among these patients have received particular attention in the last decade in light to improve this very limiting associated comorbidity that compromises quality of life.

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.

Use of Frogs as a Model to Study the Etiology of HLHS

A frog is a classical model organism used to uncover processes and regulations of early vertebrate development, including heart development. Recently, we showed that a frog also represents a useful model to study a rare human congenital heart disease, hypoplastic left heart syndrome. In this review, we first summarized the cellular events and molecular regulations of vertebrate heart development, and the benefit of using a frog model to study congenital heart diseases. Next, we described the challenges in elucidating the etiology of hypoplastic left heart syndrome and discussed how a frog model may contribute to our understanding of the molecular and cellular bases of the disease. We concluded that a frog model offers its unique advantage in uncovering the cellular mechanisms of hypoplastic left heart syndrome; however, combining multiple model organisms, including frogs, is needed to gain a comprehensive understanding of the disease.

Altered white matter connectivity in children with congenital heart disease with single ventricle physiology

Children born with congenital heart disease (CHD) have seen a dramatic decrease in mortality thanks to surgical innovations. However, there are numerous risk factors associated with CHD that can disrupt neurodevelopment. Recent studies have found that psychological deficits and structural brain abnormalities persist into adulthood. The goal of the current study was to investigate white matter connectivity in early school-age children (6-11 years), born with complex cyanotic CHD (single ventricle physiology), who have undergone Fontan palliation, compared to a group of heart-healthy, typically developing controls (TPC). Additionally, we investigated associations between white matter tract connectivity and measures on a comprehensive neuropsychological battery within each group. Our results suggest CHD patients exhibit widespread decreases in white matter connectivity, and the extent of these decreases is related to performance in several cognitive domains. Analysis of network topology showed that hub distribution was more extensive and bilateral in the TPC group. Our results are consistent with previous studies suggesting perinatal ischemia leads to white matter lesions and delayed maturation.

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.

Leftward and Posterior Deviation of the Septum Primum Predicts Morbidity in Patients with Hypoplastic Left Heart Syndrome

Leftward posterior deviation of the atrial septum primum (LDSP) has been reported in up to 64% of patients with hypoplastic left heart syndrome (HLHS) but there are no published data on its impact on neonatal outcomes. We reviewed the prevalence of LDSP and its correlation with neonatal outcomes in our institution. This was a single-center retrospective study of neonates with HLHS from 2001 to 2019. Echocardiograms were reviewed and the presence or absence of LDSP was noted. To quantify the degree of deviation in patients with LDSP, a new measurement, the deviation index (DI) was calculated using both the subcostal long and short-axis views. Of ninety-four patients with HLHS, fifty-seven (61%) patients were noted to have LDSP. There was no statistically significant difference in gestational age (GA), birth weight (BW), or mortality between patients with and without LDSP. Patients with LDSP had an increased incidence of unplanned reoperation (p < 0.01), post-operative cardiac catheterization (p < 0.05), and post-operative infection (p < 0.05). After correction for GA, BW, HLHS subtype, and type of surgery, LDSP predicted reoperation (OR = 3.6, p < 0.01), catheterization (OR = 2.7, p = 0.05), and infection (OR = 3.4, p < 0.05). Higher degree of deviation predicted reoperation (DI > 0.17), catheterization (DI > 0.07), and infection (DI > 0.12). There was excellent inter-observer reproducibility of the DI (ICCabsolute-agreement = 0.82, ICCconsistency = 0.90). Patients with LDSP have a higher prevalence of post-operative morbidity. The degree of deviation was found to be predictive of post-operative complications. Pre-operative echocardiographic evaluation of LDSP in patients with HLHS may be helpful in risk stratification and counseling.

Identifying gaps in parental support for families of children with hypoplastic left heart syndrome

PURPOSE

The purpose of this study is to identify gaps in support for parents of children with Hypoplastic Left Heart Syndrome.

DESIGN AND METHODS

Using a mixed-methods approach, the researchers first studied the parental and care team experience through interviews of Hypoplastic Left Heart Syndrome mothers and members of the inter-professional care team and then conducted an international survey of 690 Hypoplastic Left Heart Syndrome primary caregivers to validate the qualitative findings.

RESULTS

Parental and care team interviews revealed three main gaps in parental support, including lack of open communication, unrealistic parental expectations, and unclear inter-professional team roles. Survey results found that parents whose children were diagnosed with Hypoplastic Left Heart Syndrome after birth indicated significant dissatisfaction with the care team's open communication and welcoming of feedback (p = 0.008). As parents progress through the stages of surgical intervention, they also indicate significant dissatisfaction with the care team's anticipation of parental emotional needs and provision of coping resources (p = 0.003).

CONCLUSIONS

Parental support interventions should focus on providing resources to help parents cope, helping the care team model open communication, and welcoming feedback on the parental experience.

PRACTICE IMPLICATIONS

Interventions should be piloted with parents who are in the later stages of the surgical intervention timeline or whose children were diagnosed after birth as they are the populations who perceived the least support within this study.

Hypoplastic left heart syndrome (HLHS): molecular pathogenesis and emerging drug targets for cardiac repair and regeneration

INTRODUCTION

Hypoplastic left heart syndrome (HLHS) is a severe developmental defect characterized by the underdevelopment of the left ventricle along with aortic and valvular defects. Multiple palliative surgeries are required for survival. Emerging studies have identified potential mechanisms for the disease onset, including genetic and hemodynamic causes. Genetic variants associated with HLHS include transcription factors, chromatin remodelers, structural proteins, and signaling proteins necessary for normal heart development. Nonetheless, current therapies are being tested clinically and have shown promising results at improving cardiac function in patients who have undergone palliative surgeries.

AREAS COVERED

We searched PubMed and clinicaltrials.gov to review most of the mechanistic research and clinical trials involving HLHS. This review discusses the anatomy and pathology of HLHS hearts. We highlight some of the identified genetic variants that underly the molecular pathogenesis of HLHS. Additionally, we discuss some of the emerging therapies and their limitations for HLHS.

EXPERT OPINION

While HLHS etiology is largely obscure, palliative therapies remain the most viable option for the patients. It is necessary to generate animal and stem cell models to understand the underlying genetic causes directly leading to HLHS and facilitate the use of gene-based therapies to improve cardiac development and regeneration.

A Rare Combination of Chromosomal Abnormalities in an Infant With Turner Syndrome and Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a fatal congenital complex heart defect where the heart's left side is critically undeveloped. However, its pathogenesis remains unknown. We report a unique case of HLHS because of the rare combination of two abnormalities in the cell lines: partial monosomy X (Turner syndrome) and partial trisomy 14 (14q11.2 microduplication syndrome).

Clinical trials in cardiac xenotransplantation: Are we ready to overcome barriers?

Heart allotransplantation has become one of the methods of choice in the treatment of severe heart failure. In the face of its difficulties, such as the unmet balance between organ supply and demand, the use of xenotransplantation (XTx) might be an attractive option shortly, even more with the ongoing progress achieved regarding the avoidance of hyperacute rejection and primary organ disfunction, maintenance of xenograft function and control of xenograft growth. To make possible this translational challenge, some points must be taken into account indeed, and they are the equipoise of human benefit and animal suffering, the risk of unknown infections, a well prepared informed consent, ethical and religious beliefs, and the role of cardiac XTx in a ventricular assistance device era.

Ventriculocoronary Fistulas with Hypoplastic Left Heart in a Neonate: Imaging with Cardiac CT

Fistulous communications between the ventricular cavities and the coronary arterial tree can be found in the presence of hypoplasia of the left ventricle, especially when the ventricular septum is intact and mitral stenosis and aortic atresia subtype are present. The cardiac CT provides excellent anatomic information especially in the evaluation of extracardiac vessels and coronary arteries. In this case study, we report a newborn with ventriculocoronary fistulas (VCFs) with the hypoplastic left disease diagnosed with cardiac CT. Transthoracic echocardiography of a term baby showed hypoplastic left heart syndrome (HLHS) with mitral stenosis and aortic atresia. The patient immediately underwent a Sano variation of the Norwood procedure. On the postoperative second day, the clinical status of the patient deteriorated. A prospective electrocardiogram-gated axial technique was performed within a single heartbeat for the patient and large VCFs were detected and a second operation were performed to close the VCFs that failed. On the nineteenth day after the operation, the baby passed away. According to us, cardiac CT can also be performed free-breathing and without anesthesia in the neonatal period for the definition of complex cardiac anatomy with the lower radiation dose from the latest scanners, radiation risk of CT should be weighed against the anesthesia risk of cardiac MRI and intraoperative risk of conventional cardiac angiography. Pre-operative cardiac CT may increase surgical success.

Hypoplastic left heart syndrome with anomalous origin of right pulmonary artery

Classic hypoplastic left heart syndrome is a rare but fatal congenital heart disease associated with variable underdevelopment of the left side of the heart. Complex forms of hypoplastic left heart syndrome have been reported to coexist with anomalous pulmonary venous drainage, transposition of the great arteries, or pulmonary valve dysplasia. We report a case of hypoplastic left heart syndrome with anomalous origin of the right pulmonary artery from the ascending aorta a rare association not reported in the literature. Preoperative comprehensive echocardiography is essential for diagnosis and accurate recognition of such rare anatomic variations.

Palliative Care?! But This Child's Not Dying: The Burgeoning Partnership Between Pediatric Cardiology and Palliative Care

The field of pediatric cardiology has witnessed major changes over the past few decades that have considerably altered patient outcomes, including decreasing mortality rates for many previously untreatable conditions. Despite this, some pediatric cardiology programs are increasingly choosing to partner with their institutional palliative care teams. Why is this? The field of palliative care also has experienced significant shifts over a similar period of time. Today's palliative care is focused on improving quality of life for any patient with a serious or life-threatening condition, regardless of where they might be on their disease trajectory. Research has clearly demonstrated that improved outcomes can be achieved for a variety of patient cohorts through early integration of palliative care; recent evidence suggests that the same may be true in pediatric cardiology. All pediatric cardiologists need to be aware of what pediatric palliative care has to offer their patients, especially those who are not actively dying. This manuscript reviews the evolution of palliative care and provides a rationale for its integration into the care of children with advanced heart disease. Readers will gain a sense of how and when to introduce palliative care to their families, as well as insight into what pediatric palliative care teams have to offer. Additional research is required to better delineate optimal partnerships between palliative care and pediatric cardiology so that we may promote maximal quality of life for patients concurrently with continued efforts to push the boundaries of quantity of life.

Maternal Fontan procedure is a predictor of a small-for-gestational-age neonate: a 10-year retrospective study

BACKGROUND

Women with single ventricle cardiac physiologic condition who have undergone Fontan procedures are surviving well into reproductive age and historically have been discouraged from pregnancy, despite the paucity of data regarding maternal and neonatal outcomes.

OBJECTIVE

Our primary objective was to investigate, in a large cohort, the maternal and neonatal outcomes of pregnant women who have undergone the Fontan procedure and to understand maternal and neonatal sequelae of their pregnancies.

STUDY DESIGN

This single-center retrospective cohort study involves pregnant women with a Fontan palliation who delivered at UCLA Medical Center over a 10-year period (2007-2017). All pregnancies were evaluated for differences in maternal and neonatal characteristics.

RESULTS

We identified 37 distinct pregnancies in 24 women with a Fontan procedure. The physiologic pregnancy-related increase in cardiac output is blunted substantially in Fontan circulation. Third-trimester cardiac index positively correlated to birthweight z-score (R²=0.48; P=.038) but not to small for gestational age (R²=0.13; P=.339). The most common cardiac complications in pregnancies of >24 weeks gestation were sustained arrhythmia (37.5%) and decompensated heart failure (21%). The 37 pregnancies comprised 25 live births (67.6%), 1 fetal death (2.7%), 9 spontaneous abortions (24%), and 2 pregnancy terminations (5.4%). Of the live births, 60% were preterm at an average gestational age of 34.9±3.7 weeks. Newborn infants were delivered via cesarean in 53%, operative vaginal delivery in 28%, and spontaneous vaginal delivery in 20%. Forty percent of neonates were born small (<10th percentile) for gestational age; 44.0% of all neonates were admitted to the neonatal intensive care unit.

CONCLUSION

Women with a single ventricle and Fontan circulation can have a successful pregnancy, although they are at increased risk for arrhythmias and heart failure. The decreased cardiac reserve in these pregnancies blunts the normal increase in maternal cardiac output, which is associated with preterm delivery and small-for-gestational-age neonates. Further studies are needed to determine to what extent the impaired rise in maternal cardiac output reduces uteroplacental perfusion, placental exchange, fetal growth, and onset of parturition.

Human genotyping and an experimental model reveal NPR-C as a possible contributor to morbidity in coarctation of the aorta

Coarctation of the aorta (CoA) is a common congenital cardiovascular (CV) defect characterized by a stenosis of the descending thoracic aorta. Treatment exists, but many patients develop hypertension (HTN). Identifying the cause of HTN is challenging because of patient variability (e.g., age, follow-up duration, severity) and concurrent CV abnormalities. Our objective was to conduct RNA sequencing of aortic tissue from humans with CoA to identify a candidate gene for mechanistic studies of arterial dysfunction in a rabbit model of CoA devoid of the variability seen with humans. We present the first known evidence of natriuretic peptide receptor C (NPR-C; aka NPR3) downregulation in human aortic sections subjected to high blood pressure (BP) from CoA versus normal BP regions (validated to PCR). These changes in NPR-C, a gene associated with BP and proliferation, were replicated in the rabbit model of CoA. Artery segments from this model were used with human aortic endothelial cells to reveal the functional relevance of altered NPR-C activity. Results showed decreased intracellular calcium ([Ca²⁺]_i) activity to C-type natriuretic peptide (CNP). Normal relaxation induced by CNP and atrial natriuretic peptide was impaired for aortic segments exposed to elevated BP from CoA. Inhibition of NPR-C (M372049) also impaired aortic relaxation and [Ca²⁺]_i activity. Genotyping of NPR-C variants predicted to be damaging revealed that rs146301345 was enriched in our CoA patients, but sample size limited association with HTN. These results may ultimately be used to tailor treatment for CoA based on mechanical stimuli, genotyping, and/or changes in arterial function.

Upcycling umbilical cords: bridging regenerative medicine with neonatology

Preterm birth is a major health concern that affects 10% of all worldwide deliveries. Many preterm infants are discharged from the hospital with morbidities that lead to an increased risk for neurodevelopmental impairment, recurrent hospitalizations, and life-long conditions. Unfortunately, the treatment of these conditions is palliative rather than curative, which calls for novel and innovative strategies. Progress in regenerative medicine has offered therapeutic options for many of these conditions. Specifically, human umbilical cord mesenchymal stem cells (MSCs) and cord blood (UCB) cells have shown promise in treating adult-onset diseases. Unlike bone-marrow and embryonic derived stem cells, umbilical cord-derived cells are easily and humanely obtained, have low immunogenicity, and offer the potential of autologous therapy. While there are several studies to uphold the efficacy of umbilical cord MSCs in adult therapies, there remains an unmet need for the investigation of its use in treating neonates. The purpose of this review is to provide a summary of current information on the potential therapeutic benefits and clinical applicability of umbilical cord MSCs and UCB cells. Promising preclinical studies have now led to a research movement that is focusing on cell-based therapies for preterm infants.

Children with hypoplastic left heart syndrome have lower quality of life than healthy controls and children with other illnesses

OBJECTIVE

Previous studies suggest that children with congenital cardiac diagnoses report lower quality of life when compared with healthy norms. A few studies have evaluated quality of life specifically in children born with hypoplastic left heart syndrome, a condition requiring several surgeries before age three. The aim of this study was to use an empirically validated and standardised measure - the Pediatric Quality of Life Inventory - to evaluate quality of life in children with hypoplastic left heart syndrome and compare the findings with similar, medically complicated samples.

METHODS

The parent-report Pediatric Quality of Life Inventory was administered, and demographic information was collected through an internet portal. A total of 121 caregivers of children with hypoplastic left heart syndrome responded. The sample included children aged 2-18 years (M=10.81 years). Independent sample t-tests were used to compare our sample with published norms of healthy children and children with acute or chronic illnesses.

RESULTS

Children with hypoplastic left heart syndrome were rated as having significantly lower overall quality-of-life scores (M=59.69) compared with published norms of children without medical diagnoses (M=83.00) and those with acute (M=78.70) or chronic (M=77.19) illnesses (p<0.001). Children with hypoplastic left heart syndrome complicated by a stroke or seizure (15%) reported the lowest quality of life. The results held for all subscales (p<0.001).

CONCLUSIONS

Children with hypoplastic left heart syndrome appear to be a significantly vulnerable population with difficulties in functioning across psychosocial domains and across the age span. Further research is required to facilitate early identification of the need for resources for these children and families, especially for children who experience additional medical complications.

Effectiveness of interstage home monitoring on healthcare outcomes in infants with hypoplastic left heart syndrome: a systematic review protocol

REVIEW QUESTION

What is the effectiveness of home monitoring on interstage survival rates, weight gain, hospital admissions and cost savings in infants with hypoplastic left heart syndrome?

Survival, by Birth Weight and Gestational Age, in Individuals With Congenital Heart Disease: A Population-Based Study

BACKGROUND

Congenital heart disease (CHD) survival estimates are important to understand prognosis and evaluate health and social care needs. Few studies have reported CHD survival estimates according to maternal and fetal characteristics. This study aimed to identify predictors of CHD survival and report conditional survival estimates.

METHODS AND RESULTS

Cases of CHD (n=5070) born during 1985-2003 and notified to the Northern Congenital Abnormality Survey (NorCAS) were matched to national mortality information in 2008. Royston-Parmar regression was performed to identify predictors of survival. Five-year survival estimates conditional on gestational age at delivery, birth weight, and year of birth were produced for isolated CHD (ie, CHD without extracardiac anomalies). Year of birth, gestational age, birth weight, and extracardiac anomalies were independently associated with mortality (all P≤0.001). Five-year survival for children born at term (37-41 weeks) in 2003 with average birth weight (within 1 SD of the mean) was 96.3% (95% CI, 95.6-97.0). Survival was most optimistic for high-birth-weight children (>1 SD from the mean) born post-term (≥42 weeks; 97.9%; 95% CI, 96.8-99.1%) and least optimistic for very preterm (<32 weeks) low-birth-weight (<1 SD from mean) children (78.8%; 95% CI, 72.8-99.1).

CONCLUSIONS

Five-year CHD survival is highly influenced by gestational age and birth weight. For prenatal counseling, conditional survival estimates provide best- and worst-case scenarios, depending on final gestational age and birth weight. For postnatal diagnoses, they can provide parents with more-accurate predictions based on their baby's birth weight and gestational age.

Neurodevelopmental functioning in children being evaluated for heart transplant prior to 2 years of age

Cardiac defects represent the most common type of birth defect and children with these abnormalities are known to experience a variety of developmental and neuropsychological delays. Children receiving heart transplants may be at the highest risk for delays as they tend to represent the most severely ill patients with heart disease. This study investigates neurocognitive and adaptive functioning in 20 children under 2 years of age who were undergoing evaluation for heart transplant, comparing their performance to that of normative samples. The results indicate delays across various domains of neurocognition, including general cognitive, receptive language, expressive language, fine motor, and gross motor skills. In addition, adaptive and social-emotional functioning fell significantly below that of normative samples. No significant differences were found when comparing the test performance of patients with congenital heart defects (n = 12) to patients with cardiomyopathy (n = 8). Secondary analyses investigating the impact of genetic conditions, premature birth, and non-English language dominance showed minor changes in results across some domains, although this may have been due, at least in part, to decreased power to detect differences. Overall, this study's results support the need for early evaluation, intensive intervention (e.g., speech, occupational, and physical therapy), and continued monitoring of these patients' neurodevelopmental/neuropsychological functioning over time. Future research should examine longitudinal changes in development using both pre- and post-transplant data and should investigate the impact of early intervention.