Australian National Standards of Care for Childhood-onset Heart Disease (CoHD Standards). 1st Edition

These first Australian National Standards of Care for Childhood-onset Heart Disease (CoHD Standards) have been developed to inform the healthcare requirements for CoHD services and enable all Australian patients, families and carers impacted by CoHD (paediatric CoHD and adult congenital heart disease [ACHD]) to live their best and healthiest lives. The CoHD Standards are designed to provide the clarity and certainty required for healthcare services to deliver excellent, comprehensive, inclusive, and equitable CoHD care across Australia for patients, families and carers, and offer an iterative roadmap to the future of these services. The CoHD Standards provide a framework for excellent CoHD care, encompassing key requirements and expectations for whole-of-life, holistic and connected healthcare service delivery. The CoHD Standards should be implemented in health services in conjunction with the National Safety and Quality Health Service Standards developed by the Australian Commission on Safety and Quality in Health Care. All healthcare services should comply with the CoHD Standards, as well as working to their organisation's or jurisdiction's agreed clinical governance framework, to guide the implementation of structures and processes that support safe care.

Mother-Infant Dyadic Synchrony and Interaction Patterns After Infant Cardiac Surgery

OBJECTIVE

Parents and their infants with complex congenital heart disease (CHD) face relational challenges, including marked distress, early separations, and infant hospitalizations and medical procedures, yet the prevalence of parent-infant interaction difficulties remains unclear. Using a standardized observational paradigm, this study investigated mother-infant dyadic synchrony, interactional patterns, and associated predictors in mother-infant pairs affected by CHD, compared with typically-developing pairs.

METHODS

In this prospective, longitudinal cohort study, mothers and their infants requiring cardiac surgery before age 6-months (n=110 pairs) and an age- and sex-matched Australian community sample (n=85 pairs) participated in a filmed, free-play interaction at 6.9±1.0 months. Mother-infant dyadic synchrony, maternal and infant interactional patterns, and relational risk were assessed using the Child-Adult Relationship Experimental (CARE) Index. Maternal and infant predictors were assessed at 32 weeks gestation, 3- and 6-months postpartum.

RESULTS

Most mother-infant interactions were classified as "high risk" or "inept" (cardiac: 94%, control: 81%; p=.007). Dyadic synchrony (p<.001), maternal sensitivity (p=.001), and infant cooperativeness (p=.001) were lower for cardiac than control pairs. Higher maternal traumatic stress at 6-months postpartum predicted lower dyadic synchrony for mother-infant pairs affected by CHD (B=-.04, p=.03). Dyadic synchrony was higher among older infants in the total (B=.40, p=.003) but not cardiac sample (B=.24, p=.06).

CONCLUSIONS

Relational difficulties were almost universal among mother-infant pairs affected by CHD and were also high in the Australian community sample. Widespread education initiatives are recommended to increase awareness of heightened mother-infant relational risk in congenital heart care and well-child settings, alongside relationally-focused prevention and early intervention programs.

Advocacy at the Eighth World Congress of Pediatric Cardiology and Cardiac Surgery

The Eighth World Congress of Pediatric Cardiology and Cardiac Surgery (WCPCCS) will be held in Washington DC, USA, from Saturday, 26 August, 2023 to Friday, 1 September, 2023, inclusive. The Eighth World Congress of Pediatric Cardiology and Cardiac Surgery will be the largest and most comprehensive scientific meeting dedicated to paediatric and congenital cardiac care ever held. At the time of the writing of this manuscript, The Eighth World Congress of Pediatric Cardiology and Cardiac Surgery has 5,037 registered attendees (and rising) from 117 countries, a truly diverse and international faculty of over 925 individuals from 89 countries, over 2,000 individual abstracts and poster presenters from 101 countries, and a Best Abstract Competition featuring 153 oral abstracts from 34 countries. For information about the Eighth World Congress of Pediatric Cardiology and Cardiac Surgery, please visit the following website: [www.WCPCCS2023.org]. The purpose of this manuscript is to review the activities related to global health and advocacy that will occur at the Eighth World Congress of Pediatric Cardiology and Cardiac Surgery.Acknowledging the need for urgent change, we wanted to take the opportunity to bring a common voice to the global community and issue the Washington DC WCPCCS Call to Action on Addressing the Global Burden of Pediatric and Congenital Heart Diseases. A copy of this Washington DC WCPCCS Call to Action is provided in the Appendix of this manuscript. This Washington DC WCPCCS Call to Action is an initiative aimed at increasing awareness of the global burden, promoting the development of sustainable care systems, and improving access to high quality and equitable healthcare for children with heart disease as well as adults with congenital heart disease worldwide.

"The usual challenges of work are all magnified": Australian paediatric health professionals' experiences during the COVID-19 pandemic

Background

The COVID-19 pandemic has significantly increased stress and strain on health professionals. With a focus on paediatric cardiac care, this study explored health professionals' concerns about COVID-19, perceptions of the impact of pandemic on healthcare, and experiences of psychological stress.

Methods

Paediatric health professionals working at a large quaternary hospital in Australia were invited to complete a survey between June 2020 and February 2021. Demographic factors, clinical role characteristics, and anxiety and depressive symptoms were assessed. Qualitative data on experiences and perceived effects of the pandemic on paediatric cardiac care were also collected.

Results

228 health professionals (152 nurses, 37 medical doctors, 22 allied and mental health professionals, 17 medical research and administrative staff) participated in the survey (54.4% response rate, 85% women). Half the sample (52.2%) endorsed 'moderate' to 'extreme' worry about COVID-19 and 38% of participants perceived healthcare services as adversely impacted by the pandemic to a 'great' or 'very great' extent. Almost one in five health professionals reported anxiety (18%) and 11% reported depressive symptoms indicative of a need for clinical intervention. Six themes were identified in the qualitative data: (1) Concern about the consequences of visitor restrictions and disrupted patient services, (2) Intensified strain on healthcare workers, (3) Feelings of fear and loss, (4) Social isolation and disconnection, (5) Adapting to change, and (6) Gratitude.

Conclusion

Timely, tailored policies, supports, and interventions are needed to address health professionals' mental health needs during and beyond the pandemic, to minimize the far-reaching impact of situational stressors.

Insights into the genetic architecture underlying complex, critical congenital heart disease

Congenital heart disease (CHD) has a multifactorial aetiology, raising the possibility of an underlying genetic burden, predisposing to disease but also variable expression, including variation in disease severity, and incomplete penetrance. Using whole genome sequencing (WGS), the findings of this study, indicate that complex, critical CHD is distinct from other types of disease due to increased genetic burden in common variation, specifically among established CHD genes. Additionally, these findings highlight associations with regulatory genes and environmental "stressors" in the final presentation of disease.

The Australian and New Zealand Fontan Registry Quality of Life Study: Protocol for a population-based assessment of quality of life among people with a Fontan circulation, their parents, and siblings

INTRODUCTION

Advances in the care of patients with single-ventricle congenital heart disease have led to a new generation of individuals living with a Fontan circulation. For people with Fontan physiology, physical, psychological and neurodevelopmental challenges are common. The objective of this study is to describe and develop a deeper understanding of the factors that contribute to quality of life (QOL) among children, adolescents and adults living with a Fontan circulation across Australia and New Zealand, their parents and siblings.

METHODS AND ANALYSIS

This article presents the protocol for the Australian and New Zealand Fontan Registry (ANZFR) QOL Study, a cross-sectional, population-based study designed to examine QOL among people of all ages with a Fontan circulation, their parents and siblings. Study eligibility criteria includes (1) individuals with a Fontan circulation aged ≥6 years, at least 12 months post-Fontan procedure and enrolled in the ANZFR; (2) parents of individuals enrolled in the ANZFR; and (3) siblings aged ≥6 years of an individual enrolled in the ANZFR. A novel, online research platform is used to distribute personalised assessments tailored to participant age and developmental stage. A suite of validated psychometric self-report and parent-proxy report instruments capture potential correlates and predictors of QOL, including symptoms of psychological distress, personality attributes, coping and cognitive appraisals, family functioning, healthcare experiences and costs, access to emotional support and socioeconomic factors. Clinical characteristics are captured via self-report and parent-proxy report, as well as the ANZFR. Descriptive analyses and multilevel models will be used to examine QOL across groups and to investigate potential explanatory variables.

ETHICS AND DISSEMINATION

Approval has been obtained from all relevant Human Research Ethics Committees (HRECs), including the Sydney Children's Hospitals Network and the Royal Children's Hospital Melbourne HRECs. Study findings will be published in peer-reviewed journals and presented at national and international meetings and seminars.

Rapidly Enlarging Aortic Root Pseudoaneurysm in a Child With Endocarditis and Repaired Congenital Heart Disease

A child with repaired double outlet right ventricle presented with Staphylococcus aureus bacteremia. Despite unsuspecting echocardiography on admission and clinical improvement on antibiotics, repeat routine echocardiography detected an aortic pseudoaneurysm, requiring a Ross-Konno operation. In repaired congenital heart defects with bacteremia, close echocardiographic surveillance is required to detect aortic pseudoaneurysm. (Level of Difficulty: Intermediate.)

The Ross/Ross-Konno procedure in infancy is a safe and durable solution for aortic stenosis

OBJECTIVE

The objective of this study was to characterize early and midterm outcomes after the Ross/Ross-Konno procedure performed in infancy for severe aortic valve disease.

METHODS

Between January 1995 and December 2018, 35 infants younger than 1 year (13 neonates) underwent a Ross/Ross-Konno procedure. Patients were followed up to a median of 4.1 years (interquartile range [IQR], 2.6-9.5). Primary outcome measures were survival, early morbidity, freedom from reintervention and long-term functional and echocardiographic status.

RESULTS

Median age at operation was 49 days (IQR, 17-135) and weight was 4 kg (IQR, 3.4-5.2). Thirty-one (89%) had undergone a previous procedure, including balloon valvuloplasty in 26 (74%). Thirty (86%) required annular enlargement (Konno incision). Five required concomitant aortic arch surgery (2 neonates, 3 infants). There were no early deaths, and 1 late death at 18 months. Freedom from reoperation was 85% (95% confidence interval [CI], 68%-93%) at 1 year, 76% (95% CI, 54%-88%) at 5 years, and 62% (95% CI, 36%-79%) at 10 years. One modified Konno was performed at 5 years after a Ross in infancy. Ten right ventricle to pulmonary artery conduits have required reintervention (2 percutaneous pulmonary valve implantations). One child required a permanent pacemaker for complete heart block. At latest follow-up, 32 (94%) of 34 survivors were asymptomatic. There was no significant change in neoaortic Z-scores between 6 weeks and latest follow-up.

CONCLUSIONS

The neonatal and infant Ross/Ross-Konno procedure can be performed with low mortality and achieves a stable left ventricular outflow tract. Significant early morbidity reflects the preoperative condition of the patients but definitive surgery of this type can be considered as a primary approach.

Outcomes Following Heterotopic Placement of Right Ventricle to Pulmonary Artery Conduits

BACKGROUND

We sought to evaluate the outcomes following right ventricle to pulmonary artery (RV-PA) conduit placement in pediatric patients, excluding those with a RV-PA conduit for the Ross procedure which is associated with improved conduit durability, partly related to its orthotopic position.

METHODS

Outcomes for 119 patients who underwent RV-PA conduit placement at a single institution from January 2004 to December 2016 were reviewed. Primary outcome measures were reintervention-free survival (RFS) and overall survival. Survival analyses were performed using the Kaplan-Meier method, and risk factors associated with reintervention were evaluated.

RESULTS

The median age at the time of conduit placement was 6 months (interquartile range, IQR: 1-14), and the median length of follow-up was 63 months (range: 0-156). During follow-up, 39 patients required conduit-related reintervention, while 6 patients died perioperatively with an overall survival of 90% at 10 years. Among the remaining 113 patients, the RFS at one, five, and ten years was 91% (84%-95%), 72% (60%-80%), and 33% (16%-50%), respectively. The median time to conduit replacement in the series was 43.5 months (IQR: 19.3-76.2). The use of a pulmonary homograft was associated with improved RFS (P = .03), and this was particularly pronounced in comparison with aortic homografts in neonates. Infection was the indication for replacement in only one patient.

CONCLUSIONS

The majority of the conduits placed during the neonatal period required conduit replacement before the age of five years. Endocarditis was not a common indication for replacement. In neonates and infants, we prefer pulmonary homografts for most indications.

Selective serotonin reuptake inhibitor or serotonin-norepinephrine reuptake inhibitors and epidemiological characteristics associated with prenatal diagnosis of congenital heart disease

OBJECTIVE

Identify early pregnancy associations of congenital heart disease (CHD) in a multiethnic cohort.

METHODS

This retrospective observational cohort study compared the general obstetric population to women who gave birth at a referral centre in Australia between 2012 and 2017, after 20 weeks' of gestation, with a pregnancy affected by CHD. We defined mood disorder and anxiety as a history of self-reported or medically diagnosed anxiety, depression, postpartum depression or bipolar disorder.

RESULTS

We compared epidemiological factors between 30 842 general obstetric patients and 470 obstetric patients with a foetus affected by CHD. Multivariate analysis showed independent associations between CHD and use of selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) in the first trimester (relative risk [RR] 4.14, 95% CI 2.58-6.65), history of anxiety or mood disorder with no SSRI/SNRI first trimester (RR 2.20, 95% CI 1.77-2.74), folate and/or pregnancy multivitamin use in the first trimester (RR 0.69, 95% CI 0.55-0.87) and increased risk with maternal age >40 years (RR 2.30, 95% CI 1.57-3.38).

CONCLUSIONS

Our data show maternal mood disorders with and without SSRI or SNRI use, maternal age >40 years and lack of multivitamin/folate use to be independently associated with CHD in pregnancy.

Health-Related Quality of Life in Children, Adolescents, and Adults With a Fontan Circulation: A Meta-Analysis

Background

People with a Fontan circulation experience a range of physical, psychosocial and neurodevelopmental challenges alongside, or caused by, their cardiac condition, with significant consequences for health‐related quality of life (HRQOL). We meta‐analyzed HRQOL outcomes reported by people with a Fontan circulation or their proxies and evaluated predictors of poorer HRQOL.

Methods and Results

Six electronic databases were searched for peer‐reviewed, English‐language articles published before March 2019. Standardized mean differences (SMD) were calculated using fixed and random‐effects models. Fifty articles reporting on 29 unique studies capturing HRQOL outcomes for 2793 people with a Fontan circulation and 1437 parent‐proxies were analyzed. HRQOL was lower in individuals with a Fontan circulation compared with healthy referents or normative samples (SMD, −0.92; 95% CI, −1.36 to −0.48; P<0.001). Lower scores were reported across all HRQOL domains, with the largest differences found for physical (SMD, −0.90; 95% CI, −1.13 to −0.67; P<0.001) and school/work functioning (SMD, −0.71; 95% CI, −0.90 to −0.52; P<0.001). Meta‐regression analyses found no significant predictors of self‐reported physical functioning, but older age at Fontan operation was associated with poorer emotional functioning (β=−0.124; P=0.004), and diagnosis of hypoplastic left heart was associated with poorer social functioning (β=−0.007; P=0.048). Sensitivity analyses showed use of the PedsQL Core Module was associated with lower HRQOL scores compared with the Short‐Form Health Survey‐36.

Conclusions

HRQOL outcomes for people with a Fontan circulation are lower than the general population. Optimal care acknowledges the lifelong impact of the Fontan circulation on HRQOL and offers targeted strategies to improve outcomes for this growing population.

Heterotaxy Is Not a Risk Factor for Adverse Long-Term Outcomes After Fontan Completion

BACKGROUND

Heterotaxy is considered a risk factor for poor outcomes after the Fontan operation. However, long-term data to support this notion are lacking. The aims of this study were to ascertain the long-term outcomes of patients with heterotaxy after hospital discharge after Fontan completion and to compare these outcomes with those of a contemporary nonheterotaxy cohort.

METHODS

A binational Fontan registry (n = 1540) was analyzed to identify patients with heterotaxy and compare them with patients without heterotaxy. The primary composite end point was Fontan failure, encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV.

RESULTS

A total of 109 patients with heterotaxy were identified and they were compared with 1431 nonheterotaxy patients after Fontan completion. There was no difference in unadjusted 15-year freedom from Fontan failure (heterotaxy, 78% vs nonheterotaxy, 85%; P = .2). Patients in the heterotaxy group had a significantly higher cumulative incidence of post-Fontan arrhythmias (P < .001). Propensity-score matching for confounders yielded 73 patients with heterotaxy matched with 439 patients without heterotaxy, in whom 15-year freedom from Fontan failure was also not different (heterotaxy, 76% vs nonheterotaxy, 81%; P = .2). There was no difference in 15-year freedom from Fontan failure in patients with right vs left isomerism (right isomerism, 80% vs left isomerism, 76%; P = .7).

CONCLUSIONS

Although heterotaxy may complicate the pre-Fontan course, once the Fontan procedure is successfully completed, heterotaxy does not appear to be an important risk factor for Fontan failure. Patients with heterotaxy are at a higher risk of post-Fontan arrhythmias compared with patients without heterotaxy.

Long-Term Outcomes of Childhood Left Ventricular Noncompaction Cardiomyopathy: Results From a National Population-Based Study

BACKGROUND

Long-term outcomes for childhood left ventricular noncompaction (LVNC) are uncertain. We examined late outcomes for children with LVNC enrolled in a national population-based study.

METHODS

The National Australian Childhood Cardiomyopathy Study includes all children in Australia with primary cardiomyopathy diagnosed before 10 years of age between 1987 and 1996. Outcomes for subjects with LVNC with a dilated phenotype (LVNC-D) were compared with outcomes for those with dilated cardiomyopathy. Propensity-score analysis was used for risk factor adjustment.

RESULTS

There were 29 subjects with LVNC (9.2% of all cardiomyopathy subjects), with a mean annual incidence of newly diagnosed cases of 0.11 per 100 000 at-risk individuals. Congestive heart failure was the initial symptom in 24 of 29 subjects (83%), and 27 (93%) had LVNC-D. The median age at diagnosis was 0.3 (interquartile interval, 0.08-1.3) years. The median duration of follow-up was 6.8 (interquartile interval, 0.7-24.0) years for all subjects and 24.7 (interquartile interval, 23.3 - 27.7) years for surviving subjects. Freedom from death or transplantation was 48% (95% confidence interval [CI], 30-65) at 10 years after diagnosis and 45% (95% CI, 27-63) at 15 years. In competing-risk analysis, 21% of subjects with LVNC were alive with normal left ventricular systolic function, and 31% were alive with abnormal function at 15 years. Propensity-score matching between subjects with LVNC-D and those with dilated cardiomyopathy suggested a lower freedom from death/transplantation at 15 years after diagnosis in the subjects with LVNC-D (LVNC-D, 46% [95% CI, 26-66] versus dilated cardiomyopathy, 70% [95% CI, 42-97]; P=0.08). Using propensity-score inverse probability of treatment-weighted Cox regression, we found evidence that LVNC-D was associated with a greater risk of death or transplantation (hazard ratio, 2.3; 95% CI, 1.4-3.8; P=0.0012).

CONCLUSIONS

Symptomatic children with LVNC usually present in early infancy with a predominant dilated phenotype. Long-term outcomes are worse than for matched children with dilated cardiomyopathy.

Impact of High-Risk Characteristics in Hypoplastic Left Heart Syndrome

BACKGROUND

Management of hypoplastic left heart syndrome (HLHS) presents many challenges. We describe our institutional outcomes for management of patients with HLHS over the past 12 years and highlight our strategy for those with highly restrictive/intact interatrial septum (R/I-IAS).

METHODS

Eighty-eight neonates with HLHS underwent surgical treatment, divided equally into Era-I (n = 44, April 2006 to February 2013) and Era-II (n = 44, March 2013 to June 2018). Up to 2013, all patients with R/I-IAS were delivered at an adjacent adult hospital and then moved to our hospital for intensive care and management. From 2014, these patients were delivered at a co-located theatre in our hospital with immediate atrial septectomy. The hybrid approach was occasionally used with preference for the Norwood procedure for suitable candidates.

RESULTS

One-year survival after Norwood procedure was 62.5% and 80% for Era-I and Era-II (P = not significant (ns)), respectively, and 41% of patients were categorized as high risk using conventional criteria. Survival at 1 year differed significantly between high-risk and standard-risk patients (P = 0.01). For high-risk patients, survival increased from 42% to 65% between eras (P = ns). In the R/I-IAS subgroup (n = 15), 11 underwent Norwood procedure after emergency atrial septectomy. Of these, seven born at the adjacent adult hospital had 40% survival to stage II versus 60% for the four born at the colocated theatre. Delivery in a colocated theatre reduced the birth-to-cardiopulmonary bypass median time from 445 (150-660) to 62 (52-71) minutes.

CONCLUSION

Reported surgical outcomes are comparable to multicenter reports and international databases. Proactive management for risk factors such as R/I-IAS may contribute to improved overall outcomes.

School-Age Developmental and Educational Outcomes Following Cardiac Procedures in the First Year of Life: A Population-Based Record Linkage Study

The purpose of the study was to evaluate school-age developmental and educational outcomes for children with and without a cardiac procedure in the first year of life to improve understanding of longer-term neurodevelopmental outcomes in children who have had a cardiac procedure for congenital heart disease, the most common serious congenital anomaly. A population-based cohort study using record linkage of state-wide data was undertaken, evaluating children born in New South Wales, Australia, 2001-2007. Those with and without a cardiac procedure in the first year of life with a linked developmental (Australian version Early Development Instrument testing result, age 4-6 years) and/or educational outcome (Australian National Assessment Program result, age 7-9 years) were included. Perinatal, perioperative and sociodemographic factors were examined using multivariable logistic regression models. Of 468,329 eligible children, 768 had a cardiac procedure in the first year of life and 582 were included. For those with a cardiac procedure and developmental outcome (n = 260), 13.1% were classified as having 'special needs' compared to 4.4% without a cardiac procedure. Of those with an educational outcome, after adjusting for perinatal, perioperative and demographic variables, children with a cardiac procedure (n = 396) were twice as likely to score below National Minimum Standard in school literacy and numeracy tests compared to their peers. Significant predictors included low birthweight, parent not completing school and having > 4 re-hospitalisations in their first six years. The developmental and educational trajectory of children who have had a cardiac procedure in their first year remains altered into primary school years. While perioperative factors did not impact outcomes, ongoing health and sociodemographic factors were important in identifying those children at greatest risk.

Need for Routine Screening of Health-Related Quality of Life in Families of Young Children with Complex Congenital Heart Disease

OBJECTIVES

To assess health-related quality of life (HRQOL) in families of young children with complex congenital heart disease (CHD), and identify the demographic, clinical, and psychosocial factors that place these children and their mothers at greater risk of vulnerability.

STUDY DESIGN

This cross-sectional study took place from June 2015 to October 2016 at The Sydney Children's Hospitals Network Cardiac Service, Australia. Mothers of a child aged 1-5 years with either single ventricle CHD or CHD requiring neonatal biventricular repair were invited to participate. Eighty-seven mothers completed a suite of validated measures, including the Pediatric Quality of Life Inventory, which assessed the outcomes of child and maternal HRQOL.

RESULTS

Sixty percent of children with single ventricle CHD and 25% of children with biventricular repair had total Pediatric Quality of Life Inventory scores within the at-risk range. Lower child HRQOL was strongly associated with single ventricle CHD (β = -0.38; P < .001), physical comorbidity (β = -0.32; P = .001), feeding difficulties (β = -0.26; P = .008), and greater maternal psychological stress (β = -0.18; P = .045), accounting for 52% of the variance in child HRQOL. Lower maternal HRQOL was strongly associated with poorer family functioning (β = 0.61; P < .001), greater maternal psychological stress (β = -0.23; P = .004), child physical comorbidity (β = -0.17; P = .01), and a 'difficult' child temperament (β = -0.14; P = .01), accounting for 73% of the variance in maternal HRQOL.

CONCLUSIONS

Lower HRQOL is common in young children with complex CHD, particularly single ventricle CHD. Several predictors of HRQOL are potentially modifiable, offering possible pathways for prevention and early intervention. Routine screening is a necessary first step toward developing models of care to improve HRQOL in this population.

Two Ventricles Are Not Better Than One in the Fontan Circulation: Equivalent Late Outcomes

BACKGROUND

A subset of patients who underwent Fontan operations has two adequate-sized ventricles, but an anatomic biventricular circulation cannot be achieved because of complex morphology or for technical reasons. This study sought to determine whether these patients with two-ventricle Fontan circulation had superior outcomes compared with those with a single ventricle.

METHODS

A binational Fontan Registry of patients (n = 1,377) was analyzed to identify those patients with two adequate ventricles. This cohort was compared with patients with single-ventricle Fontan circulation. The primary end point was a composite end point called "Fontan failure" encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV.

RESULTS

A total of 79 Fontan patients with two adequate ventricles (2V) were compared with 1,291 single ventricle (1V) Fontan patients. Median follow-up for the entire cohort was 11.5 years (interquartile range, 5.1 to 18.8 years). There was no difference in unadjusted 15-year freedom from Fontan failure (2V: 81% [95% confidence interval (CI), 69% to 94%] vs 1V: 86% [95% CI, 83% to 88%], p = 0.4). Propensity-score matching for potential confounding factors yielded 75 two-ventricle Fontan patients matched with 604 single-ventricle Fontan patients, in which 15-year freedom from Fontan failure was also not different (2V: 79% [95% CI, 67% to 94%] vs 1V: 87% [95% CI, 84% to 91%], p = 0.3).

CONCLUSIONS

The two-ventricle Fontan circulation does not have better outcomes compared with the single-ventricle Fontan circulation. Late outcomes may depend more on other characteristics of the Fontan circulation. This finding is relevant when the Fontan procedure is being considered as an alternative to anatomic repair in patients with complex two-ventricle morphologies.

Genetic burden and associations with adverse neurodevelopment in neonates with congenital heart disease

BACKGROUND

Up to 20% of children with congenital heart disease (CHD) undergoing cardiac surgery develop neurodevelopmental disabilities (NDD), with some studies reporting persistent impairment. Recent large-scale studies have demonstrated shared genetic mechanisms contributing to CHD and NDD. In this study, a targeted approach was applied to assess direct clinical applicability of this information.

METHODS

A gene panel comprising 148 known CHD and/or NDD genes was used to sequence 15 patients with CHD + NDD, 15 patients with CHD, and 15 healthy controls. The number and types of variants between the 3 groups were compared using Poisson log-linear regression, and the SNP-set (Sequence) Kernel Association Test-Optimized was used to conduct single-gene and gene-pathway burden analyses.

RESULTS

A significant increase in rare (minor allele frequency < 0.01) and novel variants was identified between the CHD + NDD cohort and controls, P < .001 and P = .001, respectively. There was also a significant increase in rare variants in the CHD cohort compared with controls (P = .04). Rare variant burden analyses implicated pathways associated with "neurotransmitters," "axon guidance," and those incorporating "RASopathy" genes in the development of NDD in CHD patients.

CONCLUSIONS

These findings suggest that an increase in novel and rare variants in known CHD and/or NDD genes is associated with the development of NDD in patients with CHD. Furthermore, burden analyses point toward rare variant burden specifically in pathways related to brain development and function as contributors to NDD. Although promising variants and pathways were identified, further research, utilizing whole-genome approaches, is required prior to demonstrating clinical utility in this patient group.

A Screening Approach to Identify Clinically Actionable Variants Causing Congenital Heart Disease in Exome Data

BACKGROUND

Congenital heart disease (CHD)-structural abnormalities of the heart that arise during embryonic development-is the most common inborn malformation, affecting ≤1% of the population. However, currently, only a minority of cases can be explained by genetic abnormalities. The goal of this study was to identify disease-causal genetic variants in 30 families affected by CHD.

METHODS

Whole-exome sequencing was performed with the DNA of multiple family members. We utilized a 2-tiered whole-exome variant screening and interpretation procedure. First, we manually curated a high-confidence list of 90 genes known to cause CHD in humans, identified predicted damaging variants in genes on this list, and rated their pathogenicity using American College of Medical Genetics and Genomics-Association for Molecular Pathology guidelines.

RESULTS

In 3 families (10%), we found pathogenic variants in known CHD genes TBX5, TFAP2B, and PTPN11, explaining the cardiac lesions. Second, exomes were comprehensively analyzed to identify additional predicted damaging variants that segregate with disease in CHD candidate genes. In 10 additional families (33%), likely disease-causal variants were uncovered in PBX1, CNOT1, ZFP36L2, TEK, USP34, UPF2, KDM5A, KMT2C, TIE1, TEAD2, and FLT4.

CONCLUSIONS

The pathogenesis of CHD could be explained using our high-confidence CHD gene list for variant filtering in a subset of cases. Furthermore, our unbiased screening procedure of family exomes implicates additional genes and variants in the pathogenesis of CHD, which suggest themselves for functional validation. This 2-tiered approach provides a means of (1) identifying clinically actionable variants and (2) identifying additional disease-causal genes, both of which are essential for improving the molecular diagnosis of CHD.

Tell me once, tell me soon: parents' preferences for clinical genetics services for congenital heart disease

PURPOSE

As the molecular basis of congenital heart disease (CHD) comes into sharper focus, cardiac genetics services are likely to play an increasingly important role. This study aimed to identify parents' preferences for, and willingness to participate in, clinical genetics services for CHD.

METHODS

A discrete choice experiment was developed to assess parents' preferences for pediatric cardiogenetics services based on four attributes: appointment format, health professionals involved, waiting time, and information format. Data were analyzed using a mixed logit model.

RESULTS

One hundred parents with a living child diagnosed with CHD requiring surgical intervention between 2000 and 2009 completed the discrete choice experiment. Parents expressed a clear preference for cardiac genetics services featuring (i) a single appointment, (ii) the presence of a clinical geneticist and a genetic counselor, (iii) both verbal (oral) and Web-based information about CHD and genetics, and (iv) availability of an appointment within 2 weeks. If offered such conditions, 93% of respondents indicated that they would attend. The choice of service was most strongly influenced by the presence of both a clinical geneticist and a genetic counselor.

CONCLUSION

Parents of children with CHD favor a single, timely genetics appointment with both a geneticist and a genetic counselor present. If appointments offered match these preferences, uptake is likely to be high.

Long-Term Outcomes of Hypertrophic Cardiomyopathy Diagnosed During Childhood: Results From a National Population-Based Study

BACKGROUND

Late survival and symptomatic status of children with hypertrophic cardiomyopathy have not been well defined. We examined long-term outcomes for pediatric hypertrophic cardiomyopathy.

METHODS

The National Australian Childhood Cardiomyopathy Study is a longitudinal population-based cohort study of children (0-10 years of age) diagnosed with cardiomyopathy between 1987 and 1996. The primary study end point was time to death or cardiac transplantation.

RESULTS

There were 80 patients with hypertrophic cardiomyopathy, with a median age at diagnosis of 0.48 (interquartile range, 0.1, 2.5) years. Freedom from death/transplantation was 86% (95% confidence interval [CI], 77.0-92.0) 1 year after presentation, 80% (95% CI, 69.0-87.0) at 10 years, and 78% (95% CI, 67.0-86.0) at 20 years. From multivariable analyses, risk factors for death/transplantation included symmetrical left ventricular hypertrophy at the time of diagnosis (hazard ratio, 4.20; 95% CI, 1.60-11.05; P=0.004), Noonan syndrome (hazard ratio, 2.88; 95% CI, 1.02-8.08; P=0.045), higher posterior wall thickness z score (hazard ratio, 1.45; 95% CI, 1.22-1.73; P<0.001), and lower fractional shortening z score (hazard ratio, 0.84; 95% CI, 0.74-0.95; P=0.005) during follow-up. Nineteen (23%) subjects underwent left ventricular myectomy. At a median of 15.7 years of follow-up, 27 (42%) of 63 survivors were treated with β-blocker, and 13 (21%) had an implantable cardioverter-defibrillator.

CONCLUSIONS

The highest risk of death or transplantation for children with hypertrophic cardiomyopathy is within 1 year after diagnosis, with low attrition rates thereafter. Many subjects receive medical, surgical, or device therapy.

Advances in the Genetics of Congenital Heart Disease: A Clinician's Guide

Our understanding of the genetics of congenital heart disease (CHD) is rapidly expanding; however, many questions, particularly those relating to sporadic forms of disease, remain unanswered. Massively parallel sequencing technology has made significant contributions to the field, both from a diagnostic perspective for patients and, importantly, also from the perspective of disease mechanism. The importance of de novo variation in sporadic disease is a recent highlight, and the genetic link between heart and brain development has been established. Furthermore, evidence of an underlying burden of genetic variation contributing to sporadic and familial forms of CHD has been identified. Although we are still unable to identify the cause of CHD for most patients, recent findings have provided us with a much clearer understanding of the types of variants and their individual contributions and collectively mark an important milestone in our understanding of both familial and sporadic forms of disease.

Congenitally corrected transposition: complex anatomic repair or Fontan pathway?

Background Successful anatomic repair of congenitally corrected transposition of the great arteries achieves excellent outcomes. Several centers report excellent long-term survival with the Fontan pathway as well. We have selectively applied both approaches depending on individual patient morphology, with anatomic repair preferred but utilizing the Fontan pathway when high technical complexity or operative risk is anticipated. Methods Hospital records over an 18-year period (1998-2016) were reviewed to identify patients with congenitally corrected transposition of the great arteries who underwent surgical management. Physiological repairs and hypoplastic ventricles were excluded. Patient- and procedure-related variables were reviewed. Results We identified 19 patients. Group 1 consisted of 12 anatomic repairs, of which 10 (83.3%) required prior interim staging procedures. Mean age at anatomic repair was 2.6 ± 1.3 years, mean follow-up was 8.7 ± 5.3 years. Nine (75%) patients experienced important complications and 4 (33.3%) required reintervention during follow-up. There were no deaths; one patient required heart transplantation. Group 2 (7 patients) underwent Fontan palliation. Mean age at Fontan completion was 7.2 ± 3.8 years, mean follow-up was 6.3 ± 4 years. There was no reintervention, death, or transplant. Conclusion Patients with congenitally corrected transposition of the great arteries and two adequate-sized ventricles do well with both anatomic repair and the Fontan pathway in the medium term. Excellent outcomes with reduced early complication and reintervention rates can be achieved for this cohort of patients when a strategy of avoiding complex anatomic repair in favor of the Fontan pathway is used.

The Lymphatic Circulation in Adaptations to the Fontan Circulation

Failing Fontan continues to be major problem for patients on the univentricular pathway. Failing Fontan is often complicated by chylothorax, plastic bronchitis and protein loosing enteropathy. The role of lymphatic circulation in Fontan circulation is still being researched. Newer imaging modalities give insight into the role of abnormal dilatation and retrograde flow in lymphatic channels post Fontan. Interventional strategies targeting abnormal lymphatic channels, provides an alternative management strategy for patients with failing Fontan. This review focuses on the role of lymphatic system in adaptations to Fontan circulation.

The promises and challenges of exome sequencing in familial, non-syndromic congenital heart disease

BACKGROUND

Exome sequencing is an established strategy to identify causal variants in families with two or more members affected by congenital heart disease (CHD). This unbiased approach, in which both rare and common variants are identified, makes it suitable to research complex, heterogeneous diseases such as CHD.

METHODS AND RESULTS

Exome sequencing was performed on two affected members of a three generation family with atrial septal defects (ASD), suggesting a dominant inheritance pattern. Variants were filtered using two bioinformatics pipelines and prioritised according to in silico prediction programs. Segregation studies and functional analyses were used to assess co-segregation with disease and effects on protein function, respectively. Following the data and in silico analyses, ten candidate variants were prioritised. Of these, SRPK2 (c.2044C>T[p.Arg682Trp]) and NOTCH1 (c.3835C>T[p.Arg1279Cys]), co-segregated with disease in the family; however, previous functional analyses on SRPK2 make this an unlikely candidate. Functional analyses in the variant (c.3835C>T[p.Arg1279Cys]) of the known CHD gene NOTCH1 demonstrated a non-significant decrease in signalling activity.

CONCLUSION

This study demonstrates both the potential, as well as the challenges, of applying exome sequencing to complex diseases such as CHD. While in silico evidence and segregation analyses in the NOTCH1 p.Arg1279Cys variant are highly suggestive of pathogenicity, the minimal change in signalling capacity suggests that other variants may be required for CHD development. This study highlights the difficulties of applying exome sequencing in familial, non-syndromic CHD in the clinical environment and a cautionary note in the interpretation of apparently causal abnormalities in silico without supportive functional data.

Developmental outcomes at 3 years of age following major non-cardiac and cardiac surgery in term infants: A population-based study

OBJECTIVE

The objective of this study was to determine whether there remain developmental differences between term infants at 3 years of age following major non-cardiac surgery (NCS) and cardiac surgery (CS) compared with healthy control infants in New South Wales (NSW), Australia.

STUDY DESIGN

Between 2006 and 2008, term infants who required NCS or CS within the first ninety days of life were enrolled in a prospective population-based study. Their developmental outcome was then compared with a cohort of healthy term infants. Infants initially assessed at 1 year of age were then re-assessed at 3 years of age using the Bayley scales of infant and toddler development (version-

III) RESULTS

Of the 539 term infants assessed at 1 year of age, 417 returned for the 3-year assessment, with 378 complete assessments. The mean scores for the infants who underwent CS (P < 0.001) were significantly lower in all subscales of the assessment compared with the controls, while the mean scores for the infants who underwent NCS were significantly lower in three of the subscales (P < 0.05). The infants who underwent CS scored significantly lower in four of the subscales (P < 0.05), compared with the infants who underwent NCS.

CONCLUSION

The second phase of this unique population-based study provides further data on the outcomes of infants who underwent major NCS and CS. Major surgery in infants continues to be associated with developmental delay at 3 years of age compared with control infants; however the majority of the delay is mild. The risk remains higher in CS group with the pattern and severity of delay similar to that observed in the first study.

Redefining Expectations of Long-Term Survival After the Fontan Procedure

Background—

The life expectancy of patients undergoing a Fontan procedure is unknown.

Methods and Results—

Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975–1995), 271 lateral tunnels (1988–2006), and 532 extracardiac conduits (1997–2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%–93%) for AP and 97% (95% confidence interval [CI], 94%–99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%–82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P <0.001; 95% CI, 2.4–16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%–76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P <0.001; 95% CI, 2.0–7.1). Ten-year freedom from failure was 79% (95% CI, 61%–89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%–95%) for other morphologies.

Conclusions—

The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

Long-Term Outcomes of Dilated Cardiomyopathy Diagnosed During Childhood

Background—

Existing studies of childhood dilated cardiomyopathy deal mainly with early survival. This population-based study examines long-term outcomes for children with dilated cardiomyopathy.

Methods and Results—

The diagnosis of dilated cardiomyopathy was based on clinical, echocardiographic, and pathological findings. The primary study end point included time to the combined outcome of death or cardiac transplantation. There were 175 patients 0 to <10 years of age at the time of diagnosis. Survival free from death or transplantation was 74% (95% confidence interval, 67–80) 1 year after diagnosis, 62% (95% confidence interval, 55–69) at 10 years, and 56% (95% confidence interval, 46–65) at 20 years. In multivariable analysis, age at diagnosis <4 weeks or >5 years, familial cardiomyopathy, and lower baseline left ventricular fractional shortening Z score were associated with increased risk of death or transplantation, as was lower left ventricular fractional shortening Z score during follow-up. At 15 years after diagnosis, echocardiographic normalization had occurred in 69% of surviving study subjects. Normalization was related to higher baseline left ventricular fractional shortening Z score, higher left ventricular fractional shortening Z score during follow-up, and greater improvement in left ventricular fractional shortening Z score. Children with lymphocytic myocarditis had better survival and a higher rate of echocardiographic normalization. At the latest follow-up, 100 of 104 of survivors (96%) were free of cardiac symptoms, and 83 (80%) were no longer receiving pharmacotherapy.

Conclusions—

Death or transplantation occurred in 26% of patients with childhood dilated cardiomyopathy within 1 year of diagnosis and ~1% per year thereafter. Risk factors for death or transplantation include age at diagnosis, familial cardiomyopathy, and severity of left ventricular dysfunction. The majority of surviving subjects are well and free of cardiac medication.

Early developmental outcomes following major noncardiac and cardiac surgery in term infants: a population-based study

OBJECTIVE

To ascertain developmental differences between term infants after major noncardiac surgery and cardiac surgery compared with healthy control infants in New South Wales, Australia.

STUDY DESIGN

This prospective population-based cohort study enrolled infants between August 1, 2006, and December 31, 2008, who required major noncardiac surgery within the first 90 days of life. Developmental outcomes were compared in these children, cohorts of term infants requiring cardiac surgery, and healthy controls. Infants were assessed at 1 year of age using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III).

RESULTS

Of the 784 infants enrolled, 688 (90.2%) of infants alive at 1 year were assessed. Of these, 539 infants were term and were included in the present analysis. Compared with controls, the infants who underwent cardiac surgery had significantly lower (P < .001) mean scores in all 5 BSID-III subscales, and the infants who underwent noncardiac surgery had significantly lower (P < .05) mean scores in 4 of the 5 BSID-III subscales. The greatest difference was in the incidence of gross motor delay in both the cardiac surgery group (OR, 0.25; 95% CI, 0.16-0.41) and the noncardiac surgery group (OR, 0.41; 95% CI, 0.26-0.63).

CONCLUSION

This unique population-based prospective study compared the developmental outcomes of infants who underwent major noncardiac surgery and cardiac surgery. Major surgery in infants was found to be significantly associated with developmental delay at 1 year of age compared with control infants. These data have important implications for interventions and clinical review in the first year of life.

Hypoplastic left heart syndrome in context

Hypoplastic left heart syndrome is a rare condition requiring major cardiac surgery during the neonatal period to sustain life, with subsequent procedures culminating in completion of the Fontan circulation - the common pathway for all 'single ventricle' conditions. Algorithms for care of these children are now well defined with predictable medium-term outcomes with the majority achieving a Fontan circulation. Hypoplastic left heart syndrome is one of a group of conditions that require complex surgery as a neonate and require a similar perioperative approach. Antenatal diagnosis is common in this patient subgroup, and there is a significant body of work that can be drawn on to inform parental choice.

Somatic mutations in NKX2–5, GATA4, and HAND1 are not a common cause of tetralogy of Fallot or hypoplastic left heart

The majority of congenital heart disease (CHD) occurs as a sporadic finding, with a minority of cases associated with a known genetic abnormality. Combinations of genetic and environmental factors are implicated, with the recent and intriguing hypothesis that an apparently high rate of somatic mutations might explain some sporadic CHD. We used samples of right ventricular myocardium from patients undergoing surgical repair of tetralogy of Fallot (TOF) and hypoplastic left heart (HLH) to examine the incidence of somatic mutation in cardiac tissue. TOF is a common form of cyanotic CHD, occurring in 3.3 per 10,000 live births. HLH is a rare defect in which the left side of the heart is severely under-developed. Both are severe malformations whose genetic etiology is largely unknown. We carried out direct sequence analysis of the NKX2–5 and GATA4 genes from fresh frozen cardiac tissues and matched blood samples of nine TOF patients. Analysis of NKX2–5, GATA4, and HAND1 was performed from cardiac tissue of 24 HLH patients and three matched blood samples. No somatic or germline mutations were identified in the TOF or HLH patients. Although limited by sample size, our study suggests that somatic mutations in NKX2–5 and GATA4 are not a common cause of isolated TOF or HLH.

Fetal and post-natal diagnosis of major congenital heart disease: implications for medical and psychological care in the current era

AIM

The fetal or post-natal diagnosis of major congenital cardiac abnormality has important medical and psychological consequences.

METHODS

We reviewed infants who underwent cardiac surgery in the first year of life at the Heart Centre for Children, The Children's Hospital at Westmead during 2009. The aims of this study were to: (i) examine the key features of cardiac diagnosis and clinical outcome, and (ii) consider how these data can inform priorities for the delivery of clinical services.

RESULTS

Over the 12-month study period, a first cardiac surgical procedure was performed on 195 infants, with 85 infants (44%) diagnosed in the antenatal period. Of the total sample, a subset of 90 babies (46%) underwent their first procedure in the neonatal period, with 62% having had a fetal diagnosis. Major intracardiac lesions including truncus arteriosus (100%), single ventricular lesions (83%), pulmonary atresia with ventricular septal defect (78%) and transposition of the great arteries (53%) were diagnosed prior to birth. Improved haemodynamic stability at initial presentation was found in those with a fetal diagnosis. The overall mortality rate for all patients was 6.1% at 12 months, with a higher mortality in infants with single ventricle.

CONCLUSIONS

The contemporary paradigm of care for infants with major congenital heart disease requires a multidisciplinary approach to care, with improvements in clinician-clinician and clinician-family communication, and psychological support and education for families. Changes in the allocation of resources are required to meet this model of best practice.

GATA4 mutations in 357 unrelated patients with congenital heart malformation

Congenital heart disease (CHD) represents one of the most common birth defects, but the genetic causes remain largely unknown. Mutations in GATA4, encoding a zinc finger transcription factor with a pivotal role in heart development, have been associated with CHD in several familial cases and a small subset of sporadic patients. To estimate the pathogenetic role of GATA4 in CHD, we screened for mutations in 357 unrelated patients with different congenital heart malformations. In addition to nine synonymous changes, we identified two known (A411V and D425N) and two novel putative mutations (G69D and P163R) in five patients with atrial or ventricular septal defects that were not seen in control subjects. The four mutations did not show altered GATA4 transcriptional activity in synergy with the transcription factors NKX2-5 and TBX20. Our data expand the spectrum of mutations associated with cardiac septal defects but do not support GATA4 mutations as a common cause of CHD.