The Fontan operation was first performed in 1968. Since then, this operation has been performed on thousands of patients worldwide. Results vary from very good for many decades to very bad with a ...pleiad of complications and early death. A good understanding of the physiology is necessary to further improve results. The Fontan connection creates a critical bottleneck with obligatory upstream congestion and downstream decreased flow; these two features are the basic cause of the majority of the physiologic impairments of this circulation. The ventricle, while still the engine of the circuit, cannot compensate for the major flow restriction of the Fontan bottleneck: the suction required to compensate for the barrier effect cannot be generated, specifically not in a deprived heart. Except for some extreme situations, the heart therefore no longer controls cardiac output nor can it significantly alter the degree of systemic venous congestion. Adequate growth and development of the pulmonary arteries is extremely important as pulmonary vascular impedance will become the major determinant of Fontan outcome. Key features of the Fontan ventricle are early volume overload and overgrowth, but currently chronic preload deprivation with increasing filling pressures. A functional decline of the Fontan circuit is expected and observed as pulmonary vascular resistance and ventricular filling pressure increase with time. Treatment strategies will only be successful if they open up or bypass the critical bottleneck or act on immediate surroundings (impedance of the Fontan neoportal system, fenestration, enhanced ventricular suction).
The first human mutations in GATA6 were described in a cohort of patients with persistent truncus arteriosus, and the phenotypic spectrum has expanded since then. This study underscores the broad ...phenotypic spectrum by presenting two patients with de novo GATA6 mutations, both exhibiting complex cardiac defects, pancreatic, and other abnormalities. Furthermore, we provided a detailed overview of all published human genetic variation in/near GATA6 published to date and the associated phenotypes (n = 78). We conclude that the most common phenotypes associated with a mutation in GATA6 were structural cardiac and pancreatic abnormalities, with a penetrance of 87 and 60%, respectively. Other common malformations were gallbladder agenesis, congenital diaphragmatic hernia, and neurocognitive abnormalities, mostly developmental delay. Fifty‐eight percent of the mutations were de novo, and these patients more often had an anomaly of intracardiac connections, an anomaly of the great arteries, and hypothyroidism, compared with those with inherited mutations. Functional studies mostly support loss‐of‐function as the pathophysiological mechanism. In conclusion, GATA6 mutations give a wide range of phenotypic defects, most frequently malformations of the heart and pancreas. This highlights the importance of detailed clinical evaluation of identified carriers to evaluate their full phenotypic spectrum.
Atrial arrhythmias are the most common complication encountered in the growing and aging population with congenital heart disease.
This study sought to assess the types and patterns of atrial ...arrhythmias, associated factors, and age-related trends.
A multicenter cohort study enrolled 482 patients with congenital heart disease and atrial arrhythmias, age 32.0 ± 18.0 years, 45.2% female, from 12 North American centers. Qualifying arrhythmias were classified by a blinded adjudicating committee.
The most common presenting arrhythmia was intra-atrial re-entrant tachycardia (IART) (61.6%), followed by atrial fibrillation (28.8%), and focal atrial tachycardia (9.5%). The proportion of arrhythmias due to IART increased with congenital heart disease complexity from 47.2% to 62.1% to 67.0% in patients with simple, moderate, and complex defects, respectively (p = 0.0013). Atrial fibrillation increased with age to surpass IART as the most common arrhythmia in those ≥50 years of age (51.2% vs. 44.2%; p < 0.0001). Older age (odds ratio OR: 1.024 per year; 95% confidence interval CI: 1.010 to 1.039; p = 0.001) and hypertension (OR: 2.00; 95% CI: 1.08 to 3.71; p = 0.029) were independently associated with atrial fibrillation. During a mean follow-up of 11.3 ± 9.4 years, the predominant arrhythmia pattern was paroxysmal in 62.3%, persistent in 28.2%, and permanent in 9.5%. Permanent atrial arrhythmias increased with age from 3.1% to 22.6% in patients <20 years to ≥50 years, respectively (p < 0.0001).
IART is the most common presenting atrial arrhythmia in patients with congenital heart disease, with a predominantly paroxysmal pattern. However, atrial fibrillation increases in prevalence and atrial arrhythmias progressively become permanent as the population ages.
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As COVID-19 continues to affect the global population, it is crucial to study the impact of the disease in vulnerable populations. This study of a diverse, international cohort aims to provide ...timely, experiential data on the course of disease in paediatric patients with congenital heart disease (CHD).
Data were collected by capitalising on two pre-existing CHD registries, the International Quality Improvement Collaborative for Congenital Heart Disease:
and the Congenital Cardiac Catheterization Project on Outcomes. 35 participating sites reported data for all patients under 18 years of age with diagnosed CHD and known COVID-19 illness during 2020 identified at their institution. Patients were classified as low, moderate or high risk for moderate or severe COVID-19 illness based on patient anatomy, physiology and genetic syndrome using current published guidelines. Association of risk factors with hospitalisation and intensive care unit (ICU) level care were assessed.
The study included 339 COVID-19 cases in paediatric patients with CHD from 35 sites worldwide. Of these cases, 84 patients (25%) required hospitalisation, and 40 (12%) required ICU care. Age <1 year, recent cardiac intervention, anatomical complexity, clinical cardiac status and overall risk were all significantly associated with need for hospitalisation and ICU admission. A multivariable model for ICU admission including clinical cardiac status and recent cardiac intervention produced a c-statistic of 0.86.
These observational data suggest risk factors for hospitalisation related to COVID-19 in paediatric CHD include age, lower functional cardiac status and recent cardiac interventions. There is a need for further data to identify factors relevant to the care of patients with CHD who contract COVID-19 illness.
There is little information about congenital heart surgery outcomes in developing countries. The International Quality Improvement Collaborative for Congenital Heart Surgery in Developing World ...Countries uses a registry and quality improvement strategies with nongovernmental organization reinforcement to reduce mortality. Registry data were used to evaluate impact.
Twenty-eight sites in 17 developing world countries submitted congenital heart surgery data to a registry, received annual benchmarking reports, and created quality improvement teams. Webinars targeted 3 key drivers: safe perioperative practice, infection reduction, and team-based practice. Registry data were audited annually; only verified data were included in analyses. Risk-adjusted standardized mortality ratios (SMRs) and standardized infection ratios among participating sites were calculated.
Twenty-seven sites had verified data in at least 1 year, and 1 site withdrew. Among 15,049 cases of pediatric congenital heart surgery, unadjusted mortality was 6.3% and any major infection was 7.0%. SMRs for the overall International Quality Improvement Collaborative for Congenital Heart Surgery in Developing World Countries were 0.71 (95% confidence interval CI 0.62-0.81) in 2011 and 0.76 (95% CI 0.69-0.83) in 2012, compared with 2010 baseline. SMRs among 7 sites participating in all 3 years were 0.85 (95% CI 0.71-1.00) in 2011 and 0.80 (95% CI 0.66-0.96) in 2012; among 14 sites participating in 2011 and 2012, the SMR was 0.80 (95% CI 0.70-0.91) in 2012. Standardized infection ratios were similarly reduced.
Congenital heart surgery risk-adjusted mortality and infections were reduced in developing world programs participating in the collaborative quality improvement project and registry. Similar strategies might allow rapid reduction in global health care disparities.
Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency (21OHD) has a worldwide incidence of 1 in 15-20,000. Affected individuals have adrenal insufficiency and androgen excess; ...the androgen excess begins during fetal life, typically resulting in 46,XX disordered sexual development. In 21OHD, 17-hydroxyprogesterone (17OHP), the steroid proximal to 21-hydroxylase, accumulates. Most industrialized countries have newborn screening programs that measure 17OHP; such screening has permitted rapid detection of newborns with 21OHD, saving lives previously lost to mineralocorticoid deficiency and salt wasting. However, newborn screening is plagued by false positives. 17OHP is above most "cutoff values" in the first 24 h of life, is high in otherwise normal premature infants, and in many term infants with physiologic stress from unrelated diseases. In addition, newborn 17OHP may be elevated in other forms of CAH, including 11-hydroxylase deficiency, 3β-hydroxysteroid dehydrogenase deficiency, and P450 oxidoreductase deficiency. In 21OHD, some of the accumulated intra-adrenal 17OHP is converted to 21-deoxycortisol (21-deoxy) by 11β-hydroxylase (CYP11B1); 21-deoxy is not elevated in premature infants or in other forms of CAH, and hence is a more specific marker for 21OHD. However, 21-deoxy assays have not been generally available until recently, hence experience is limited. We urge clinical investigators, commercial reference laboratories, and newborn screening programs to investigate replacing 17OHP with 21-deoxy as the analyte of choice for studies of 21OHD.
It has been reported that folic acid supplementation before and/or during pregnancy could reduce the risk of congenital heart defects (CHDs). However, the results from limited epidemiologic studies ...have been inconclusive. We investigated the associations between maternal folic acid supplementation, dietary folate intake, and the risk of CHDs.
A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. After exclusion of stillbirths and multiple births, a total of 94 births were identified with congenital heart defects, and 9,993 births without any birth defects. Unconditional logistic regression was used to estimate the associations.
Compared to non-users, folic acid supplement users before pregnancy had a reduced risk of overall CHDs (OR: 0.42, 95% CI: 0.21-0.86, Ptrend = 0.025) after adjusted for potential confounders. A protective effect was observed for certain subtypes of CHDs (OR: 0.37, 95% CI: 0.16-0.85 for malformation of great arteries; 0.26, 0.10-0.68 for malformation of cardiac septa; 0.34, 0.13-0.93 for Atrial septal defect). A similar protective effect was also seen for multiple CHDs (OR: 0.49, 95% CI: 0.26-0.93, Ptrend = 0.004). Compared with the middle quartiles of dietary folate intake, lower dietary folate intake (<149.88 μg/day) during pregnancy were associated with increased risk of overall CHDs (OR: 1.63, 95% CI: 1.01-2.62) and patent ductus arteriosus (OR: 1.85, 95% CI: 1.03-3.32). Women who were non-user folic acid supplement and lower dietary folate intake have almost 2-fold increased CHDs risk in their offspring.
Our study suggested that folic acid supplementation before pregnancy was associated with a reduced risk of CHDs, lower dietary folate intake during pregnancy was associated with increased risk. The observed associations varied by CHD subtypes. A synergistic effect of dietary folate intake and folic acid supplementation was also observed.
Abstract
Aims
The New York Heart Association functional classification (NYHA class) is often used to describe the functional capacity of adults with congenital heart disease (ACHD), albeit with ...limited evidence on its validity in this heterogeneous population. We aimed to validate the NYHA functional classification in ACHD by examining its relation to objective measures of limitation using cardiopulmonary exercise testing (CPET) and mortality.
Methods and results
This study included all ACHD patients who underwent a CPET between 2005 and 2015 at the Royal Brompton, in whom functional capacity was graded according to the NYHA classification. Congenital heart diagnoses were classified according to the Bethesda score. Time to all-cause mortality from CPET was recorded in all 2781 ACHD patients (mean age 33.8 ± 14.2 years) enrolled in the study. There was a strong relation between NYHA class and peak oxygen consumption (peak VO2), ventilation per unit in carbon dioxide production (VE/VCO2) slope and the Bethesda classification (P < 0.0001). Although a large number of ‘asymptomatic’ (NYHA class 1) patients did not achieve a ‘normal’ peak VO2, the NYHA class was a strong predictor of mortality, with an 8.7-fold increased mortality risk in class 3 compared with class 1 (hazard ratio 8.68, 95% confidence interval: 5.26–14.35, P < 0.0001).
Conclusion
Despite underestimating the degree of limitation in some ACHD patients, NYHA classification remains a valuable clinical tool. It correlates with objective measures of exercise and the severity of underlying cardiac disease, as well as mid- to long-term mortality and should, thus, be into incorporated the routine assessment and risk stratification of these patients.
The diagnosis and management of congenital heart disease (CHD), the most common inborn defect, has been a tremendous success story of modern medicine. In the 1950s, survival of children born with CHD ...was only approximately 15%, whereas nowadays more than 90% of these children survive well into adulthood. Consequently, the prevalence of patients with CHD has shifted away from infancy and childhood towards adulthood. Adult CHD cardiology is now encompassing not only young or middle‐aged adults but also patients with CHD over 60 years old. Many adult patients are afflicted by residual haemodynamic lesions and also face additional opportunities and/or challenges such as pregnancy, acquired heart disease, non‐cardiac pathology etc., necessitating integrated care and all medical disciplines. We are faced with a “tsunami” in terms of adult CHD numbers, disease heterogeneity and complexity of work and interventions needed. We need to secure resources, welcome more people in our field, learn from “marching with our patients”, and educate better patients, public and ourselves so that every single patient with CHD, born anywhere in the world, may reach their full life potential.
Our understanding of the development of congenital heart disease (CHD) across the lifespan has evolved. These include the evidence for the change in demographics of CHD, the observations that ...lifelong complications of CHD result in CHD as a lifespan disease, and the concept of long windows of exposure to risk that start in foetal life and magnify the expression of risk in adulthood. These observations set the stage for trajectories as an emerging construct to target health‐service interventions. The lifelong cardiovascular and systemic complications of CHD make the long‐term care of these patients challenging for cardiologists and internists alike. A life‐course approach is thus required to facilitate our understanding of the natural history and to orient our clinical efforts. Three specific examples are illustrated: neurocognition; cancer resulting from exposure to low‐dose ionizing radiation; and cardiovascular disease acquired in ageing adults. As patients grow, they do not just want to live longer, they want to live well. With the need to move beyond the mortality outcome, a shift in paradigm is needed. A life‐course health development framework is developed for CHD. Trajectories are used as a complex construct to illustrate the patient’s healthcare journey. There is a need to define disease trajectories, wellness trajectories and ageing trajectories in this population. Disease trajectories for repaired tetralogy of Fallot, transposition of the great arteries and the Fontan operation are hypothetically constructed. For clinicians, the life‐course horizon helps to frame the patient’s history and plan for the future. For researchers, life‐course epidemiology offers a framework that will help increase the relevance of clinical enquiry and improve study design and analyses. A health‐service policy framework is proposed for a growing number of conditions that start in the before birth and extend as long as contemporary survival now permits. Ultimately, the goal is the precision delivery of health services that enables lifelong health management, organization of developmental health services, and integration of vertical and horizontal health‐service delivery.
Content List ‐ Read more articles from the symposium: “The 99th Berzelius symposium: The Cardiac Patient from Birth to Adulthood”.
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