Trends in Congenital Heart Disease

Susceptibility to congenital heart defects associated with a polymorphism in TBX2 3' untranslated region in the Han Chinese population

BACKGROUND

Tbx2 plays a critical role in determining fates of cardiomyocytes. Little is known about the contribution of TBX2 3' untranslated region (UTR) variants to the risk of congenital heart defect (CHD). Thus, we aimed to determine the association of single-nucleotide polymorphisms (SNPs) in TBX2 3' UTR with CHD susceptibility.

METHODS

We recruited 1285 controls and 1241 CHD children from China. SNPs identification and genotyping were detected using Sanger Sequencing and SNaPshot. Stratified analysis was conducted to explore the association between rs59382073 polymorphism and CHD subtypes. Functional analyses were performed by luciferase assays in HEK-293T and H9c2 cells.

RESULTS

Among five TBX2 3'UTR variants identified, rs59382073 minor allele T carriers had a 1.89-fold increased CHD risk compared to GG genotype (95% CI = 1.48-2.46, P = 4.48 × 10^-7). The most probable subtypes were right ventricular outflow tract obstruction, conotruncal, and septal defect. G to T variation decreased luciferase activity in cells. This discrepancy was exaggerated by miR-3940 and miR-708, while their corresponding inhibitors eliminated it.

CONCLUSION

T allele of rs59382073 in TBX2 3'UTR contributed to greater CHD risk in the Han Chinese population. G to T variation created binding sites for miR-3940 and miR-708 to inhibit gene expression.

Health-Related Physical Fitness and Quality of Life in Children and Adolescents With Isolated Left-to-Right Shunt

Objective: Atrial (ASD) and ventricular septal defects (VSD) represent the most common congenital heart defects (CHD) and are considered simple and curable. This study investigates long-term functional outcomes in children with such defects. Patients and Methods : We examined 147 patients (74 girls, 12.1 ± 3.5 years) with isolated shunts (ASD: 54%, VSD: 46%) for their Health-Related Physical Fitness (HRPF) and Health-Related Quality of Life (HRQoL). Native condition was present in 58 patients, interventional closure of the defect was performed in 42 and surgical closure in 47. For comparison, a healthy control group (CG) of 1,724 children (48.9% girls, 12.8 ± 2.8 years) was recruited within two recent school projects. Results: After adjustment for age and sex, children with ASD and VSD presented lower HRPF (z-score healthy peers: 0.02 ± 0.73, ASD: -0.41 ± 0.73, p < 0.001; VSD: -0.61 ± 0.73, p < 0.001) then healthy peers. Transferred into percentiles, VSD were on the 26th and ASD on the 34th percentile of the healthy peers. HRQoL did not differ between peers and CHD with isolated shunts (healthy peers: 76.1 ± 9.7, ASD: 76.2 ± 9.9, p = 0.999; VSD: 78.7 ± 9.7, p = 0.316). Regarding the surgical history of the shunts (native, percutaneously treated, surgically treated), there were also no difference in-between these three states, nor differed HRPF and HRQoL in-between gender. Conclusions: Children with ASD or VSD have impaired HRPF but normal HRQoL. Early childhood sports promotion could be a good measure to counteract these restrictions in HRPF at an early stage.

Improving medical care and prevention in adults with congenital heart disease-reflections on a global problem-part I: development of congenital cardiology, epidemiology, clinical aspects, heart failure, cardiac arrhythmia

Today most patients with congenital heart defects (CHD) survive into adulthood. Unfortunately, despite relevant residua and sequels, follow-up care of adults with congenital heart disease (ACHD) is not performed in specialized and/or certified physicians or centres. Major problems in the long-term course encompass heart failure, cardiac arrhythmias, heart valve disorders, pulmonary vascular disease, infective endocarditis, aortopathy and non-cardiac comorbidities. Many of them manifest themselves differently from acquired heart disease and therapy regimens from general cardiology cannot be transferred directly to CHD. It should be noted that even simple, postoperative heart defects that were until recently considered to be harmless can lead to problems with age, a fact that had not been expected so far. The treatment of ACHD has many special features and requires special expertise. Thereby, it is important that treatment regimens from acquired heart disease are not necessarily transmitted to CHD. While primary care physicians have the important and responsible task to set the course for adequate diagnosis and treatment early and to refer patients to appropriate care in specialized ACHD-facilities, they should actively encourage ACHD to pursue follow-up care in specialized facilities who can provide responsible and advanced advice. This medical update emphasizes the current data on epidemiology, heart failure and cardiac arrhythmia in ACHD.

Medicines associated with folate-homocysteine-methionine pathway disruption

Folate is vital for cell development and growth. It is involved in one-carbon transfer reactions essential for the synthesis of purines and pyrimidines. It also acts in conjunction with cobalamin (vitamin B₁₂) as a fundamental cofactor in the remethylation cycle that converts homocysteine to methionine. A deficiency in folate or vitamin B₁₂ can lead to elevated homocysteine level, which has been identified as an independent risk factor in several health-related conditions. Adequate folate levels are essential in women of childbearing age and in pregnant women, and folate deficiency is associated with several congenital malformations. Low folate levels can be caused by dietary deficiencies, a genetic predisposition or treatment with medicines that affect folate concentration. Women who are pregnant or of child-bearing age commonly use medicines, so it is important to identify the basic biochemical mechanisms by which medicines interfere with the folate-homocysteine-methionine pathway. This review focuses on prescription medicines associated with folate disruption. It also summarizes their undesirable/toxic effects. Recommendations regarding folate supplementation during medical therapy are also reviewed.

High prevalence of congenital heart disease at high altitudes in Tibet

BACKGROUND

Previous small sample studies suggested that elevated altitudes might be associated with the incidence of cardiovascular diseases. However, it remains uncertain whether high altitudes (over 3000 m above sea level) are related to congenital heart disease. We therefore explored the prevalence of congenital heart disease in a large cohort of students in the world's largest prefecture-level city with the highest altitude.

METHODS

This cross-sectional study included 84,302 student participants (boys 52.12%, girls 47.88%, with an average age of 10.62 ± 3.33 years). Data were extracted from the screening results among different altitude area schools in Nagqu from June 2016 to August 2017. Students were first screened by performing a physical examination consisting of cardiac auscultations and clinical manifestation screenings. An echocardiography was performed to confirm and identify the subtype of congenital heart disease.

RESULTS

The prevalence of congenital heart disease among students in Nagqu, Tibet, was 5.21‰ (439 cases). The most common congenital heart disease type was patent ductus arteriosus, representing 66.3% of congenital heart diseases diagnosed in this study, followed by atrial septal defect and ventricular septal defect, representing 20.3% and 9.1% of congenital heart diseases, respectively. Students living in higher altitudes were significantly more prone to have congenital heart disease than students in locations with lower altitudes. The prevalence of congenital heart disease in girls was found to be higher than that of boys.

CONCLUSIONS

The correlation between congenital heart disease and increased altitude is noteworthy. This study's results are the first big data epidemiological investigation to confirm that high altitude is a significant environmental risk factor for congenital heart disease, especially patent ductus arteriosus. Furthermore, the results provide additional support to make a diagnostic and treatment plan to prevent congenital heart disease in high altitude areas.

Association of Atrial Septal Defects and Bronchopulmonary Dysplasia in Premature Infants

OBJECTIVE

To evaluate the association between the presence of an atrial septal defect (ASD) and the odds of developing bronchopulmonary dysplasia (BPD) in premature infants.

STUDY DESIGN

We identified a cohort of infants that underwent at least one echocardiogram assessment, birth weight 501-1249 g, and gestational age 23-30 weeks discharged from the neonatal intensive care unit from 2004 to 2016. We used a BPD risk estimator to calculate the predicted risk of developing BPD at 6 postnatal ages within the first 28 days of life. We examined the association between the presence of an ASD and the development of BPD using 2 multivariable logistic regression models for each BPD risk severity on each postnatal day. The first model adjusted for predicted BPD risk and the second added therapeutic interventions for BPD.

RESULTS

Of 20 496 infants from 228 NICUs who met inclusion criteria, 8892 (43%) were diagnosed with BPD and 1314 (6%) had an ASD. BPD was present in 48% of infants with an ASD and 43% of infants without an ASD. In infants with an ASD, the OR of developing BPD was higher after adjusting for predicted risk of BPD plus therapeutic interventions, regardless of postnatal age or predicted BPD risk severity.

CONCLUSIONS

The presence of an ASD was associated with an increased odds of BPD in this cohort. Future trials should consider ASD as a potentially modifiable risk factor in this vulnerable population.

Associations Between Medical History, Cognition, and Behavior in Youth With Down Syndrome: A Report From the Down Syndrome Cognition Project

The cause of the high degree of variability in cognition and behavior among individuals with Down syndrome (DS) is unknown. We hypothesized that birth defects requiring surgery in the first years of life (congenital heart defects and gastrointestinal defects) might affect an individual's level of function. We used data from the first 234 individuals, age 6-25 years, enrolled in the Down Syndrome Cognition Project (DSCP) to test this hypothesis. Data were drawn from medical records, parent interviews, and a cognitive and behavior assessment battery. Results did not support our hypothesis. That is, we found no evidence that either birth defect was associated with poorer outcomes, adjusting for gender, race/ethnicity, and socioeconomic status. Implications for study design and measurement are discussed.

Copenhagen Baby Heart Study: a population study of newborns with prenatal inclusion

Congenital heart diseases (CHDs) are reported in 0.8% of newborns. Numerous factors influence cardiovascular development and CHD prevalence, and possibly also development of cardiovascular disease later in life. However, known factors explain the probable etiology in only a fraction of patients. Past large-scale population-based studies have made invaluable contributions to the understanding of cardiac disease, but none recruited participants prenatally and focused on the neonatal period. The Copenhagen Baby Heart Study (CBHS) is a population-based study of the prevalence, spectrum, and prognosis of structural and functional cardiac abnormalities. The CBHS will also establish normal values for neonatal cardiac parameters and biomarkers, and study prenatal and early childhood factors potentially affecting later cardiovascular disease risk. The CBHS is an ongoing multicenter, prospective study recruiting from second trimester pregnancy (gestational weeks 18-20) (expected n = 25,000). Information on parents, pregnancy, and delivery are collected. After birth, umbilical cord blood is collected for biochemical analysis, DNA purification, and biobank storage. An echocardiographic examination, electrocardiography, and post-ductal pulse oximetry are performed shortly after birth. Infants diagnosed with significant CHD are referred to a specialist or admitted to hospital, depending on CHD severity. CBHS participants will be followed prospectively as part of specific research projects or regular clinical follow-up for CHD. CBHS design and methodology are described. The CBHS aims to identify new mechanisms underlying cardiovascular disease development and new targets for prevention, early detection, and management of CHD and other cardiac diseases presenting at birth or developing later in life.

Increased maternal Body Mass Index is associated with congenital heart defects: An updated meta-analysis of observational studies

PURPOSE

To review and summarize the epidemiologic evidence on the association of maternal Body Mass Index (BMI) with risk of congenital heart defects (CHDs) and to assess the possible dose-response patterns.

METHODS

Six electronic databases were searched for eligible studies up to April 2018. The summary risk estimates were calculated using either the fixed-effect models or random-effect models. A dose-response meta-analysis was also performed to capture the shape of the observed association. Subgroup and sensitivity analysis were conducted to explore the potential heterogeneity moderators.

RESULTS

Twenty-nine studies involving 99,205 CHDs cases among 6,467,422 participants were included in the meta-analysis. Mothers who were overweight (odds ratio [OR] = 1.07; 95% confidence intervals [CI]: 1.00-1.13) and obese (OR = 1.32; 95% CI: 1.21-1.43) had a significantly higher risk of total CHDs in their offspring when compared with those with normal weight. When obesity was further divided into class I (OR = 1.15; 95% CI: 1.11-1.20), class II (OR = 1.26; 95% CI: 1.18-1.34) and class III (OR = 1.42; 95% CI: 1.33-1.51) obesity, a significantly increased risk of total CHDs persisted. Different risks for specific CHD phenotypes were also found in different BMI categories. Furthermore, a nonlinear dose-response relationship between maternal BMI and risk of total CHDs was observed. Subgroup and sensitivity analyses identified the most relevant heterogeneity moderators.

CONCLUSION

The increased maternal BMI is associated with the risk of developing CHDs in offspring. Severe obesity can play an independent role in the observed association, but the effect may be mediated by diabetes mellitus. Preventing obesity or excessive weight gain is a priority for CHDs prevention.

Impact of Improved Survival in Congenital Heart Disease on Incidence of Disease

Survival rates and life expectancies for patients with congenital heart disease (CHD) have dramatically increased, and these patients are now reaching reproductive age. As they reproduce, questions pertaining to recurrent risk of disease and the impact on incidence rates have emerged. Recurrence rates for CHD have been estimated at 3% to 5%, although, due to the complex genetics underlying CHD, this range may represent an underestimation of the true risk. Debate still exists on whether the impact of recurrence of disease has been reflected in incidence rates. Although incidence rates have undoubtedly increased, the mechanism underlying this remains unclear; improved detection likely accounts for the majority of the observed increase; however, a true increase may be present simultaneously. Concurrently, certain factors, including improved fetal detection and elective terminations, infertility, increased rates of spontaneous abortion and intrauterine fetal demise in women with CHD, and folic acid supplementation, are leading to decreases in the incidence of CHD. It is likely that the full impact of improved survival and heritability of CHD on incidence rates remains to be seen and will likely be attenuated by other factors acting to decrease incidence.

Effect of Fetal Growth on 1-Year Mortality in Neonates With Critical Congenital Heart Disease

Background Infants with critical congenital heart disease ( CCHD ) are more likely to be small for gestational age (GA). It is unclear how this affects mortality. The authors investigated the effect of birth weight Z score on 1-year mortality separately in preterm (GA <37 weeks), early-term (GA 37-38 weeks), and full-term (GA 39-42 weeks) infants with CCHD . Methods and Results Live-born infants with CCHD and GA 22 to 42 weeks born in California 2007-2012 were included in the analysis. The primary predictor was Z score for birth weight and the primary outcome was 1-year mortality. Multivariable logistic regression was used. Results are presented as adjusted odds ratios and 95% confidence intervals ( CIs ). The authors identified 6903 infants with CCHD . For preterm and full-term infants, only a Z score for birth weight <-2 was associated with increased mortality compared with the reference group ( Z score 0-0.5, adjusted odds ratio, 2.15 [95% CI , 1.1-4.21] and adjusted odds ratio, 3.93 [95% CI , 2.32-6.68], respectively). In contrast, in early-term infants, the adjusted odds ratios for Z scores <-2, -2 to -1, and -1 to -0.5 were 3.42 (95% CI , 1.93-6.04), 1.78 (95% CI , 1.12-2.83), and 2.03 (95% CI , 1.27-3.23), respectively, versus the reference group. Conclusions GA seems to modify the effect of birth weight Z score on mortality in infants with CCHD . In preterm and full-term infants, only the most severe small-for-GA infants ( Z score <-2) were at increased risk for mortality, while, in early-term infants, the risk extended to mild to moderate small-for-GA infants ( Z score <-0.5). This information helps to identify high-risk infants and is useful for surgical planning.

Three-dimensional printing: changing clinical care or just a passing fad?

PURPOSE OF REVIEW

Advances in medical imaging and three-dimensional (3D) reconstruction software have enabled a proliferation of 3D modeling and 3D printing for clinical applications. In particular, 3D printing has garnered an extraordinary media presence over the past few years. There is growing optimism that 3D printing can address patient specificity and complexity for improved interventional and surgical planning. Will this relatively untested technology bring about a paradigm shift in the clinical environment, or is it just a transient fad?

RECENT FINDINGS

Case studies and series centered around 3D printing are omnipresent in clinical and engineering journals. These primarily qualitative studies support the potential efficacy of the emerging technology. Few studies analyze the value of 3D printing, weighing its potential benefits against increasing costs (e.g., institutional overhead, labor, and materials).

SUMMARY

Clinical integration of 3D printing is growing rapidly, and its adoption into clinical practice presents unique workflow challenges. There are numerous clinical trials on the horizon that will finally help to elucidate the measured impact of 3D printing on clinical outcomes through quantitative analyses of clinical and economic metrics. The contrived integration of 3D printing into clinical practice seems all but certain as the value of this technology becomes more and more evident.

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System

Congenital heart defects (CHDs) are the most common cause of childhood morbidity and early mortality. Prenatal detection of the underlying molecular mechanisms of CHDs is crucial for inventing new preventive and therapeutic strategies. Mutant mouse models are powerful tools to discover new mechanisms and environmental stress modifiers that drive cardiac development and their potential alteration in CHDs. However, efforts to establish the causality of these putative contributors have been limited to histological and molecular studies in non-survival animal experiments, in which monitoring the key physiological and hemodynamic parameters is often absent. Live imaging technology has become an essential tool to establish the etiology of CHDs. In particular, ultrasound imaging can be used prenatally without surgically exposing the fetuses, allowing maintaining their baseline physiology while monitoring the impact of environmental stress on the hemodynamic and structural aspects of cardiac chamber development. Herein, we use the High-Frequency Ultrasound (30/45) system to examine the cardiovascular system in fetal mice at E18.5 in utero at the baseline and in response to prenatal hypoxia exposure. We demonstrate the feasibility of the system to measure cardiac chamber size, morphology, ventricular function, fetal heart rate, and umbilical artery flow indices, and their alterations in fetal mice exposed to systemic chronic hypoxia in utero in real time.

Interpreting the various associations of MiRNA polymorphisms with susceptibilities of cardiovascular diseases: Current evidence based on a systematic review and meta-analysis

BACKGROUND

To interpret the various associations between miRNA polymorphisms and cardiovascular diseases (CVD).

METHODS

Literature search has identified relevant studies up to June 2016. A meta-analysis was performed followed the guidelines from the Cochrane review group and the PRISMA statement. Studies were identified by searching the Cochrane Library, EMBASE, PUBMED and WHO clinical trials registry center. A meta-analysis has been done with a fixed/random-effect model using STATA 14.0, which also has been used to estimate the publication bias and meta-regression.

RESULTS

The results from 11 case-control studies were included. The miR-146a G/C makes a contribution to the causing of CVD as recessive genetic model. And the miR-499 G/A raised the risks of cardiomyopathy, however it could still accelerate the procedure of CVD combined with myocardial infraction. At this point, we consider that it could deepen the adverse of outcomes from coronary artery disease (CAD), but it's hard to draw an association between miR-499 G/A and CAD. At last the miR-196a2 T/C demonstrated a contrary role between development problem and metabolic issues, which protects the development procedure and impairs the metabolism to cause different disease phenotypes.

CONCLUSION

Despite inter-study variability, the polymorphisms from miR-146a, miR-499 and miR-196a2 have impacts on cardiovascular disease. Each type of miRNA has individual role in either cardiac development or the origins of CVD.

Transplant-Free Survival and Interventions at 6 Years in the SVR Trial

BACKGROUND

In the SVR trial (Single Ventricle Reconstruction), 1-year transplant-free survival was better for the Norwood procedure with right ventricle-to-pulmonary artery shunt (RVPAS) compared with a modified Blalock-Taussig shunt in patients with hypoplastic left heart and related syndromes. At 6 years, we compared transplant-free survival and other outcomes between the groups.

METHODS

Medical history was collected annually using medical record review, telephone interviews, and the death index. The cohort included 549 patients randomized and treated in the SVR trial.

RESULTS

Transplant-free survival for the RVPAS versus modified Blalock-Taussig shunt groups did not differ at 6 years (64% versus 59%, P=0.25) or with all available follow-up of 7.1±1.6 years (log-rank P=0.13). The RVPAS versus modified Blalock-Taussig shunt treatment effect had nonproportional hazards (P=0.009); the hazard ratio (HR) for death or transplant favored the RVPAS before stage II surgery (HR, 0.66; 95% confidence interval, 0.48-0.92). The effect of shunt type on death or transplant was not statistically significant between stage II to Fontan surgery (HR, 1.36; 95% confidence interval, 0.86-2.17; P=0.17) or after the Fontan procedure (HR, 0.76; 95% confidence interval, 0.33-1.74; P=0.52). By 6 years, patients with RVPAS had a higher incidence of catheter interventions (0.38 versus 0.23/patient-year, P<0.001), primarily because of more interventions between the stage II and Fontan procedures (HR, 1.72; 95% confidence interval, 1.00-3.03). Complications did not differ by shunt type; by 6 years, 1 in 5 patients had had a thrombotic event, and 1 in 6 had had seizures.

CONCLUSIONS

By 6 years, the hazards of death or transplant and catheter interventions were not different between the RVPAS versus modified Blalock-Taussig shunt groups. Children assigned to the RVPAS group had 5% higher transplant-free survival, but the difference did not reach statistical significance, and they required more catheter interventions. Both treatment groups have accrued important complications.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Web-Based Motor Intervention to Increase Health-Related Physical Fitness in Children With Congenital Heart Disease: A Study Protocol

Objective: Exercise interventions are underutilized in children with congenital heart disease (CHD) especially when the primary outcome is not peak oxygen uptake. Most of the studies are restricted to a low sample size and proximity of the patients to the study centers. Now eHealth approaches bear a promising but also challenging opportunity to transmit such intervention programs to participants, and check progress and compliance from remote. This study will aim to improve health-related physical fitness (HRPF) with a 24 weeks web-based exercise intervention. Methods and Design: The current study is planned as a randomized control trial (RCT) with a crossover design and the aim to improve functional outcome measures. It also estimates adherence and feasibility in patients with CHD in this web-based exercise/motor intervention over 24 weeks. Primary outcome will be the improvement of HRPF. Secondary outcomes are, functional and structural arterial stiffness measures and health-related quality of life. Thus, 70 children from 10 to 18 years with CHD of moderate and complex severity will be recruited and allocated randomly 1:1 in two study arms after baseline testing for their HRPF, arterial stiffness measures and health-related quality of life. For 24 weeks, participants in the intervention arm will receive three weekly exercise video clips of 20 min each. Every video clip comprises 20 child-oriented exercises which have to be executed for 30 s followed by a recovery period of 30 s. Each session will start with 3-4 warming-up exercises, followed by 10-12 strength and flexibility exercises, and ending with 3-4 min of cool down or stretching tasks. Continuous video clips will be streamed from a web-based e-Learning platform. The participant simply has to imitate the execution and follow some short advices. After each session, a brief online survey will be conducted to assess perceived exertion and feasibility. Discussion: The study will help to determine the efficacy and applicability of a web-based exercise intervention in children with CHD in regard to functional outcome measures. In addition, it will outline the effectiveness of remote monitoring, which provides a cost effective approach to reach patients with CHD that are low in prevalence and often do not live in close proximity to their tertiary center. Trial Registration: https://ClinicalTrials.gov Identifier: NCT03488797.

ACTB Loss-of-Function Mutations Result in a Pleiotropic Developmental Disorder

ACTB encodes β-actin, an abundant cytoskeletal housekeeping protein. In humans, postulated gain-of-function missense mutations cause Baraitser-Winter syndrome (BRWS), characterized by intellectual disability, cortical malformations, coloboma, sensorineural deafness, and typical facial features. To date, the consequences of loss-of-function ACTB mutations have not been proven conclusively. We describe heterozygous ACTB deletions and nonsense and frameshift mutations in 33 individuals with developmental delay, apparent intellectual disability, increased frequency of internal organ malformations (including those of the heart and the renal tract), growth retardation, and a recognizable facial gestalt (interrupted wavy eyebrows, dense eyelashes, wide nose, wide mouth, and a prominent chin) that is distinct from characteristics of individuals with BRWS. Strikingly, this spectrum overlaps with that of several chromatin-remodeling developmental disorders. In wild-type mouse embryos, β-actin expression was prominent in the kidney, heart, and brain. ACTB mRNA expression levels in lymphoblastic lines and fibroblasts derived from affected individuals were decreased in comparison to those in control cells. Fibroblasts derived from an affected individual and ACTB siRNA knockdown in wild-type fibroblasts showed altered cell shape and migration, consistent with known roles of cytoplasmic β-actin. We also demonstrate that ACTB haploinsufficiency leads to reduced cell proliferation, altered expression of cell-cycle genes, and decreased amounts of nuclear, but not cytoplasmic, β-actin. In conclusion, we show that heterozygous loss-of-function ACTB mutations cause a distinct pleiotropic malformation syndrome with intellectual disability. Our biological studies suggest that a critically reduced amount of this protein alters cell shape, migration, proliferation, and gene expression to the detriment of brain, heart, and kidney development.

Trends of Out-of-Hospital Sudden Cardiac Death Among Children and Young Adults

BACKGROUND AND OBJECTIVES

Previous estimates of sudden cardiac death in children and young adults vary significantly, and population-based studies in the United States are lacking. We sought to estimate the incidence, causes, and mortality trends of sudden cardiac death in children and young adults (1-34 years).

METHODS

Demographic and mortality data based on death certificates for US residents (1-34 years) were obtained (1999-2015). Cases of sudden death and sudden cardiac death were retrieved by using the International Classification of Diseases, 10th Revision codes.

RESULTS

A total of 1 452 808 subjects aged 1 to 34 years died in the United States, of which 31 492 (2%) were due to sudden cardiac death. The estimated incidence of sudden cardiac death is 1.32 per 100 000 individuals and increased with age from 0.49 (1-10 years) to 2.76 (26-34 years). During the study period, incidence of sudden cardiac death declined from 1.48 to 1.13 per 100 000 (P < .001). Mortality reduction was observed across all racial and ethnic groups with a varying magnitude and was highest in children aged 11 to 18 years. Significant disparities were found, with non-Hispanic African American individuals and individuals aged 26 to 34 years having the highest mortality rates. The majority of young children (1-10 years) died of congenital heart disease (n = 1525, 46%), whereas young adults died most commonly from ischemic heart disease (n = 5075, 29%).

CONCLUSIONS

Out-of-hospital sudden cardiac death rates declined 24% from 1999 to 2015. Disparities in mortality exist across age groups and racial and ethnic groups, with non-Hispanic African American individuals having the highest mortality rates.

[Research advances in the mechanism of congenital heart disease induced by pregestational diabetes mellitus]

Congenital heart disease (CHD) is the most common birth defect at present and has a complex etiology which involves the combined effect of genetic and environmental factors. Pregestational diabetes mellitus is significantly associated with the development of CHD, but the detailed mechanism remains unknown. This article reviews the research advances in the molecular mechanism of CHD caused by pregestational diabetes mellitus.

Increased arterial stiffness in children with congenital heart disease

Objective Central systolic blood pressure (SBP) is a measure of arterial stiffness and strongly associated with atherosclerosis and end-organ damage. It is a stronger predictor of cardiovascular events and all-cause mortality than peripheral SBP. In particular, for children with congenital heart disease, a higher central SBP might impose a greater threat of cardiac damage. The aim of the study was to analyse and compare central SBP in children with congenital heart disease and in healthy counterparts. Patients and methods Central SBP was measured using an oscillometric method in 417 children (38.9% girls, 13.0 ± 3.2 years) with various congenital heart diseases between July 2014 and February 2017. The test results were compared with a recent healthy reference cohort of 1466 children (49.5% girls, 12.9 ± 2.5 years). Results After correction for several covariates in a general linear model, central SBP of children with congenital heart disease was significantly increased (congenital heart disease: 102.1 ± 10.2 vs. healthy reference cohort: 100.4 ± 8.6, p < .001). The analysis of congenital heart disease subgroups revealed higher central SBP in children with left heart obstructions (mean difference: 3.6 mmHg, p < .001), transpositions of the great arteries after arterial switch (mean difference: 2.2 mmHg, p = .017) and univentricular hearts after total cavopulmonary connection (mean difference: 2.1 mmHg, p = .015) compared with the reference. Conclusion Children with congenital heart disease have significantly higher central SBP compared with healthy peers, predisposing them to premature heart failure. Screening and long-term observations of central SBP in children with congenital heart disease seems warranted in order to evaluate the need for treatment.

Gestational Age and Outcomes in Critical Congenital Heart Disease

BACKGROUND AND OBJECTIVES

It is unknown how gestational age (GA) impacts neonatal morbidities in infants with critical congenital heart disease (CCHD). We aim to quantify GA-specific mortality and neonatal morbidity in infants with CCHD.

METHODS

Cohort study using a database linking birth certificate, infant hospital discharge, readmission, and death records, including infants 22 to 42 weeks' GA without chromosomal anomalies (2005-2012, 2 988 925 live births). The International Classification of Diseases, Ninth Revision diagnostic and procedure codes were used to define CCHD and neonatal morbidities (intraventricular hemorrhage, retinopathy, periventricular leukomalacia, chronic lung disease, necrotizing enterocolitis). Adjusted absolute risk differences (ARDs) with 95% confidence intervals (CIs) were calculated.

RESULTS

We identified 6903 out of 2 968 566 (0.23%) infants with CCHD. The incidence of CCHD was highest at 29 to 31 weeks' GA (0.9%) and lowest at 39 to 42 weeks (0.2%). Combined neonatal morbidity or mortality in infants with and without CCHD was 82.8% and 57.9% at <29 weeks and declined to 10.9% and 0.1% at 39 to 42 weeks' GA. In infants with CCHD, being born at 34 to 36 weeks was associated with a higher risk of death or morbidity than being born at 37 to 38 weeks (adjusted ARD 9.1%, 95% CI 5.5% to 12.7%), and being born at 37 to 38 weeks was associated with a higher risk of death or morbidity than 39 to 42 weeks (adjusted ARD 3.2%, 95% CI 1.6% to 4.9%).

CONCLUSIONS

Infants born with CCHD are at high risk of neonatal morbidity. Morbidity remains increased across all GA groups in comparison with infants born at 39 to 42 weeks. This substantial risk of neonatal morbidity is important to consider when caring for this patient population.

Risk Factors for Mortality in Reoperations for Pediatric and Congenital Heart Surgery in a Developing Country

BACKGROUND

The survival of patients with congenital heart disease has increased in the recent years, because of enhanced diagnostic capabilities, better surgical techniques, and improved perioperative care. Many patients will require reoperation as part of staged procedures or to treat grafts deterioration and residual or recurrent lesions. Reoperations favor the formation of cardiac adhesions and consequently increase surgery time; however, the impact on morbidity and operative mortality is certain. The objective of the study was to describe the risk factors for mortality in pediatric patients undergoing a reoperation for congenital heart disease.

METHODS

Historic cohort of patients who underwent reoperation after pediatric cardiac surgery from January 2009 to December 2015. Operations with previous surgical approach different to sternotomy were excluded from the analysis.

RESULTS

In seven years, 3,086 surgeries were performed, 481 were reoperations, and 238 patients fulfilled the inclusion criteria. Mean number of prior surgeries was 1.4 ± 0.6. Median age at the time of reoperation was 6.4 years. The most common surgical procedures were staged palliation for functionally univentricular heart (17.6%). Median cross-clamp time was 66 minutes. Younger age at the moment of resternotomy, longer cross-clamp time, and Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery (STAT) Mortality Categories risk category greater than three were risk factors for mortality. The number of resternotomies was not associated with mortality. Mortality prior to hospital discharge was 4.6%, and mortality after discharge but prior to 30 days after surgery was 0.54%. Operative mortality was 5.1%.

CONCLUSIONS

Resternotomy in pediatric cardiac surgery is a safe procedure in our center.

A Path to Implement Precision Child Health Cardiovascular Medicine

Congenital heart defects (CHDs) affect approximately 1% of live births and are a major source of childhood morbidity and mortality even in countries with advanced healthcare systems. Along with phenotypic heterogeneity, the underlying etiology of CHDs is multifactorial, involving genetic, epigenetic, and/or environmental contributors. Clear dissection of the underlying mechanism is a powerful step to establish individualized therapies. However, the majority of CHDs are yet to be clearly diagnosed for the underlying genetic and environmental factors, and even less with effective therapies. Although the survival rate for CHDs is steadily improving, there is still a significant unmet need for refining diagnostic precision and establishing targeted therapies to optimize life quality and to minimize future complications. In particular, proper identification of disease associated genetic variants in humans has been challenging, and this greatly impedes our ability to delineate gene–environment interactions that contribute to the pathogenesis of CHDs. Implementing a systematic multileveled approach can establish a continuum from phenotypic characterization in the clinic to molecular dissection using combined next-generation sequencing platforms and validation studies in suitable models at the bench. Key elements necessary to advance the field are: first, proper delineation of the phenotypic spectrum of CHDs; second, defining the molecular genotype/phenotype by combining whole-exome sequencing and transcriptome analysis; third, integration of phenotypic, genotypic, and molecular datasets to identify molecular network contributing to CHDs; fourth, generation of relevant disease models and multileveled experimental investigations. In order to achieve all these goals, access to high-quality biological specimens from well-defined patient cohorts is a crucial step. Therefore, establishing a CHD BioCore is an essential infrastructure and a critical step on the path toward precision child health cardiovascular medicine.

An interspecies heart-to-heart: Using Xenopus to uncover the genetic basis of congenital heart disease

PURPOSE OF REVIEW

Given the enormous impact congenital heart disease has on child health, it is imperative that we improve our understanding of the disease mechanisms that underlie patient phenotypes and clinical outcomes. This review will outline the merits of using the frog model, Xenopus, as a tool to study human cardiac development and left-right patterning mechanisms associated with congenital heart disease.

RECENT FINDINGS

Patient-driven gene discovery continues to provide new insight into the mechanisms of congenital heart disease, and by extension, patient phenotypes and outcomes. By identifying gene variants in CHD patients, studies in Xenopus have elucidated the molecular mechanisms of how these candidate genes affect cardiac development, both cardiogenesis as well as left-right patterning, which can have a major impact on cardiac morphogenesis. Xenopus has also proved to be a useful screening tool for the biological relevance of identified patient-mutations, and ongoing investigations continue to illuminate disease mechanisms.

SUMMARY

Analyses in model organisms can help to elucidate the disease mechanisms underlying CHD patient phenotypes. Using Xenopus to disentangle the genotype-phenotype relationships of well-known and novel disease genes could enhance the ability of physicians to efficaciously treat patients and predict clinical outcomes, ultimately improving quality of life and survival rates of patients born with congenital heart disease.

Genetics and Genomics of Congenital Heart Disease

Congenital heart disease is the most common birth defect, and because of major advances in medical and surgical management, there are now more adults living with congenital heart disease (CHD) than children. Until recently, the cause of the majority of CHD was unknown. Advances in genomic technologies have discovered the genetic causes of a significant fraction of CHD, while at the same time pointing to remarkable complexity in CHD genetics. This review will focus on the evidence for genetic causes underlying CHD and discuss data supporting both monogenic and complex genetic mechanisms underlying CHD. The discoveries from CHD genetic studies draw attention to biological pathways that simultaneously open the door to a better understanding of cardiac development and affect clinical care of patients with CHD. Finally, we address clinical genetic evaluation of patients and families affected by CHD.

Clinical Factors Associated with Cerebral Metabolism in Term Neonates with Congenital Heart Disease

OBJECTIVE

To determine associations between patient and clinical factors with postnatal brain metabolism in term neonates with congenital heart disease (CHD) via the use of quantitative magnetic resonance spectroscopy.

STUDY DESIGN

Neonates with CHD were enrolled prospectively to undergo pre- and postoperative 3T brain magnetic resonance imaging. Short-echo single-voxel magnetic resonance spectroscopy of parietal white matter was used to quantify metabolites related to brain maturation (n-acetyl aspartate, choline, myo- inositol), neurotransmitters (glutamate and gamma-aminobutyric acid), energy metabolism (glutamine, citrate, glucose, and phosphocreatine), and injury/apoptosis (lactate and lipids). Multivariable regression was performed to search for associations between (1) patient-specific/prenatal/preoperative factors with concurrent brain metabolism and (2) intraoperative and postoperative factors with postoperative brain metabolism.

RESULTS

A total of 83 magnetic resonance images were obtained on 55 subjects. No patient-specific, prenatal, or preoperative factors associated with concurrent metabolic brain dysmaturation or elevated lactate could be identified. Chromosome 22q11 microdeletion and age at surgery were predictive of altered concurrent white matter phosphocreatine (P < .0055). The only significant intraoperative association found was increased deep hypothermic circulatory arrest time with reduced postoperative white matter glutamate and gamma-aminobutyric acid (P < .0072). Multiple postoperative factors, including increased number of extracorporeal membrane oxygenation days (P < .0067), intensive care unit, length of stay (P < .0047), seizures in the intensive care unit (P < .0009), and home antiepileptic use (P < .0002), were associated with reduced postoperative white matter n-acetyl aspartate.

CONCLUSION

Multiple postoperative factors were found to be associated with altered brain metabolism in term infants with CHD, but not patient-specific, preoperative, or intraoperative factors.

The association of maternal lymphatic markers and critical congenital heart defects in the fetus-A population based case-control study

The objective ot this study was to investigate whether lymphatic markers measured in women during the second trimester are associated with critical congenital heart defects (CCHDs) in offspring. This is a retrospective cohort study of pregnant women who participated in the California Prenatal Screening Program. CCHD data in the offspring was captured by linking birth certificate data with hospital patient discharge records. Second trimester samples were assayed for vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF) AA/BB, and PDGF AB. Logistic models were used to evaluate the association between lymphatic biomarkers and CCHD. Models were adjusted for other serum biomarkers and maternal characteristics. Results are presented in odds ratios (OR) with 95% confidence intervals (CI). We identified 93 cases with CCHDs and 194 controls without CCHDs. The crude and adjusted OR for log (ln) VEGF was 1.07 (95%CI 0.94-1.22) and 1.08 (95%CI 0.94-1.24), respectively; for ln PDGF AB/BB was 0.93 (95%CI 0.6-1.35) and 0.58 (95%CI 0.32-1.05), respectively. There was a significant association between ln PDFG AA and CCHDs (crude OR 1.83 (95%CI 1.05-3.2); adjusted OR 2.41 (95%CI 1.06-5.44)). Levels of circulating PDGF AA were highest in cases with hypoplastic left heart syndrome (HLHS) (mean 8.78 +/- 1.54 pg/ml). In this study, increased mid-pregnancy maternal serum levels of PDGF AA were associated with CCHDs in offspring. The highest PDGF AA levels were found in mothers of fetuses with HLHS. These findings may be useful in screening for CCHDs and offer insight into their association with nuchal translucency.

Intracoronary Cardiac Progenitor Cells in Single Ventricle Physiology: The PERSEUS (Cardiac Progenitor Cell Infusion to Treat Univentricular Heart Disease) Randomized Phase 2 Trial

RATIONALE

Patients with single ventricle physiology are at high risk of mortality resulting from ventricular dysfunction. The preliminary results of the phase 1 trial showed that cardiosphere-derived cells (CDCs) may be effective against congenital heart failure.

OBJECTIVE

To determine whether intracoronary delivery of autologous CDCs improves cardiac function in patients with single ventricle physiology.

METHODS AND RESULTS

We conducted a phase 2 randomized controlled study to assign in a 1:1 ratio 41 patients who had single ventricle physiology undergoing stage 2 or 3 palliation to receive intracoronary infusion of CDCs 4 to 9 weeks after surgery or staged reconstruction alone (study A). The primary outcome measure was to assess improvement in cardiac function at 3-month follow-up. Four months after palliation, controls had an alternative option to receive late CDC infusion on request (study B). Secondary outcomes included ventricular function, heart failure status, somatic growth, and health-related quality of life after a 12-month observation. At 3 months, the absolute changes in ventricular function were significantly greater in the CDC-treated group than in the controls (+6.4% [SD, 5.5] versus +1.3% [SD, 3.7]; P=0.003). In study B, a late CDC infusion in 17 controls increased the ventricular function at 3 months compared with that at baseline (38.8% [SD, 7.7] versus 34.8% [SD, 7.4]; P<0.0001). At 1 year, overall CDC infusion was associated with improved ventricular function (41.4% [SD, 6.6] versus 35.0% [SD, 8.2]; P<0.0001) and volumes (P<0.001), somatic growth (P<0.0001) with increased trophic factors production, such as insulin-like growth factor-1 and hepatocyte growth factor, and quality of life, along with a reduced heart failure status (P<0.0001) and cardiac fibrosis (P=0.014) relative to baseline.

CONCLUSIONS

Intracoronary infusion of CDCs after staged palliation favorably affected cardiac function by reverse remodeling in patients with single ventricle physiology. This impact may improve heart failure status, somatic growth, and quality of life in patients and reduce parenting stress for their families.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01829750.