Changing prevalence of severe congenital heart disease: a population-based study

Live-Birth Incidence of Isolated D-Transposition of Great Arteries-The Shift in Trends Due to Early Diagnosis

This is a single tertiary population-based study conducted at a center in southwest Romania. We retrospectively compared data obtained in two periods: January 2008-December 2013 and January 2018-December 2023. The global incidence of the transposition of great arteries in terminated cases, in addition to those resulting in live-born pregnancies, remained almost constant. The live-birth incidence decreased. The median gestational age at diagnosis decreased from 29.3 gestational weeks (mean 25.4) to 13.4 weeks (mean 17.2). The second trimester and the overall detection rate in the prenatal period did not significantly change, but the increase was statistically significant in the first trimester. The proportion of terminated pregnancies in fetuses diagnosed with the transposition of great arteries significantly increased (14.28% to 75%, p = 0.019).

Effect of Maternal Race, Residential Rurality, and Social Vulnerability on Critical Congenital Heart Defect Risk

The development of a congenital heart defect (CHD) is multifactorial, with many cases having an unknown etiology. This study explored whether maternal race and lived environment were associated with an infant being born with a critical CHD. A cross-sectional, case-control design was conducted utilizing secondary data analysis. The CHD group (N = 199) consisted of infants diagnosed with a critical CHD within the first year of life identified from hospital databases. The non-CHD group (N = 548) was a random sample of infants selected from the state's vital statistics database. The primary outcome was a critical CHD diagnosis. Maternal race, residential rurality, and the Social Vulnerability Index (SVI) were assessed for associations with a critical CHD using bivariate and multilevel regression models. Bivariate findings reported significance among residential rurality (p < 0.001), SVI ranking overall (p = 0.017), and SVI by theme (theme 1 p =  0.004, theme 2 p < 0.001, theme 3 p = 0.007, and theme 4 p = 0.049) when comparing infants with and without a critical CHD diagnosis. Results of multilevel logistic regression analyses further identified living in a rural residential area compared to urban areas (OR = 7.32; p < 0.001) as a predictor for a critical CHD diagnosis. The findings of lived environmental level associations provides information needed for continued investigation as the burden of a critical CHD continues to impact families, suggesting further research efforts are needed to improve health disparities.

Heart Failure Staging and Indications for Advanced Therapies in Adults with Congenital Heart Disease

Heart failure (HF) is common in adults with congenital heart disease (CHD), and it is the leading cause of death in this population. Adults with CHD presenting with stage D HF have a poor prognosis, and early recognition of signs of advanced HF and referral for advanced therapies for HF offer the best survival as compared with other therapies. The indications for advanced therapies for HF outlined in this article should serve as a guide for clinicians to determine the optimal time for referral. Palliative care should be part of the multidisciplinary care model for HF in patients with CHD.

Lower Socioeconomic Status is Associated with an Increased Incidence and Spectrum of Major Congenital Heart Disease and Associated Extracardiac Pathology

Several studies have suggested an inverse relationship between lower socioeconomic status (SES) and the incidence of congenital heart disease (CHD) among live births. We sought to examine this relationship further in a Canada-wide population study, exploring CHD subtypes, trends, and associated noncardiac abnormalities. Infants born in Canada (less Quebec) from 2008 to 2018 with CHD requiring intervention in the first year were identified using ICD-10 codes through the Canadian Institute for Health Information Discharge Abstract Database. Births of CHD patients were stratified by SES (census-based income quintiles) and compared against national birth proportions using X2 tests. Proportions with extracardiac defects (ED) and nonlethal genetic syndromes (GS) were also explored. From 2008 to 2018, 7711 infants born with CHD were included. The proportions of major CHD distributed across SES quintiles were 27.1%, 20.1%, 19.2%, 18.6%, and 15.0% from lowest to highest, with significant differences relative to national birth proportions (22.0%, 20.0%, 20.6%, 20.7%, and 16.7% from lowest (1) to highest (5)) (p < 0.0001). No temporal trends in the CHD proportions across SES categories were observed over the study period. The distribution across SES quintiles was different only for specific CHD subtypes (double-outlet right ventricle (n = 485, p = 0.03), hypoplastic left heart syndrome (n = 547, p = 0.006), heterotaxy (n = 224, p = 0.03), tetralogy of Fallot (n = 1007, p = 0.008), truncus arteriosus (n = 126, p < 0.0001), and ventricular septal defect (n = 1916, p < 0.0001)), with highest proportions observed in the lowest quintile. The proportion of the total population with ED but not GS was highest in lower SES quintiles (< 0.0001) commensurate with increased proportion of CHD. Our study suggests a negative association between SES and certain CHD lesions and ED.

Pharmacokinetics of a microdosed cocktail of three direct oral anticoagulants in children with congenital heart defects: study protocol for a single-centre clinical trial (DOAC-Child)

INTRODUCTION

Direct oral anticoagulants (DOACs) are direct inhibitors of coagulation factor Xa and are frequently used in adults for different indications such as deep vein thrombosis or non-valvular atrial fibrillation. Paediatric patients might benefit as well from DOACs because the simplicity and convenience of their use is likely to decrease physical and psychological stress related to invasive procedures associated with phenprocoumon and heparin therapy. Thus, it is expected that the future use of DOACs will ultimately improve compliance and overall safety of anticoagulant therapies in paediatric populations. To assure safe and effective use the clinical pharmacology and pharmacokinetics (PK) of these drugs need to be evaluated in children.

METHODS AND ANALYSIS

This study is a single-centre, open-label, clinical trial in a paediatric population with non-cyanotic congenital heart defects. After having obtained informed consent from the parents, each participant will receive a single oral administration of a drinkable solution of a microdose cocktail of three FXa inhibitors consisting of apixaban (12.5 µg), rivaroxaban (12.5 µg), edoxaban (50 µg), plus a microdose of the two probe drugs midazolam (10 µg) and yohimbine (25 µg). Serial blood samples (n=up to 20) will be collected at specified time points before and up to 25 hours after cocktail administration. The primary PK endpoint will be the area under the plasma concentration time curve of apixaban, rivaroxaban and edoxaban. Secondary PK outcomes will be C_max, t_max, t_1/2, Cl/F and V_ss/F. Safety and tolerability of the microdose cocktail will be evaluated as well by a collection of adverse events.

ETHICS

This study has been approved by the responsible Ethics Committee of the Medical Faculty of Heidelberg University.

DISSEMINATION

Study results will be presented at international scientific meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

EudraCT 2019-001759-38 16, DRKS00021455.

Current outcomes of live-born children with double outlet right ventricle in Norway

OBJECTIVES

This population-based, comprehensive, retrospective study presented the clinical outcomes of all children born in Norway between 2003 and 2017 with double outlet right ventricle (DORV).

METHODS

All children born with DORV between 2003 and 2017 were identified in the Oslo University Hospital registry. Patients' characteristics, interventions, complications and deaths were recorded. Echocardiographic data were reviewed for classification according to current standards. We investigated time-dependent surgical reintervention and mortality using Kaplan-Meier analyses and determinants of treatment complications, reintervention and death using regression analyses.

RESULTS

Ninety-three children with DORV represented an annual median prevalence of 1.18 per 10 000 births in Norway. Six children received palliative care. With an intention to treat, a surgical route with the primary biventricular repair was followed for 62 children, staged biventricular repair for 15 and univentricular repair for 10 children. Major complications occurred in 1.0% and 6.2% of children following catheter or surgical intervention, respectively. No significant determinants of the complications were identified. Overall survival following treatment was 91.9%, 90.8%, 89.5% and 89.5% and corresponding freedom from surgical reintervention was 88.0%, 79.0%, 74.9% and 69.4% at 1, 2, 5 and 10 years, respectively. The presence of atrioventricular septal defect predicted an increased risk of mortality (hazard ratio: 7.16) but did not increase the risk of surgical reintervention.

CONCLUSIONS

In Norway, most children receive tailored treatment for DORV with low rates of complications, surgical reinterventions and mortality. However, atrioventricular septal defect remains a potential determinant of postoperative death.

Prevalence of congenital heart defects in Europe, 2008-2015: A registry-based study

BACKGROUND

The total prevalence of congenital heart defects (CHDs) varies by populations and over time. Studies that examine trends in the prevalence of CHD in different regions may shed light on our understanding of the occurrence of CHD and the impact of different risk factors.

OBJECTIVES

To examine trends in total and live birth prevalence of nonsyndromic CHD in Europe between the years 2008 and 2015 and to investigate if the decreasing trend reported by previous studies is continuing.

METHODS

Cases of CHD delivered between January 1, 2008 and December 31, 2015 notified to 25 population-based EUROCAT (European Surveillance of Congenital Anomalies) registries in 14 countries, formed the population-based case-series. Prevalence (total/live) rates and 95% confidence intervals were calculated as the number of cases per 10,000 births (live and stillbirths). Time trends in prevalence of all nonsyndromic CHDs and for three CHD severity groups (very severe, severe, and less severe) were plotted using a Poisson regression multilevel approach.

RESULTS

The total prevalence of nonsyndromic CHD was 57.1 per 10,000 births (live births and stillbirths) for the 8-year period and remained stable across the three CHD severity groups while the live birth prevalence was 60.2 per 10,000 births. There was considerable variation in the reported total CHD prevalence and the direction of trends by registry. A decreasing prevalence of CHD was observed for the Norway and England/Wales registries, whereas the CHD prevalence increased for registries in Italy and Croatia.

CONCLUSIONS

The total prevalence of CHD in Europe between the years 2008 and 2015 remained stable for all CHD and across the three CHD severity groups. The decreasing trend reported by previous studies has not continued. However, we found significant differences in the total and live birth prevalence by registry.

Abnormal Extracardiac Development in Fetuses With Congenital Heart Disease

BACKGROUND

Knowledge about extracardiac anomalies (ECA) in fetal congenital heart disease (CHD) can improve our understanding of the developmental origins of various outcomes in these infants. The prevalence and spectrum of ECA, including structural brain anomalies (SBA), on magnetic resonance imaging (MRI) in fetuses with different types of CHD and at different gestational ages, is unknown.

OBJECTIVES

The purpose of this study was to evaluate ECA rates and types on MRI in fetuses with different types of CHD and across gestation.

METHODS

A total of 429 consecutive fetuses with CHD and MRI between 17 and 38 gestational weeks were evaluated. ECA and SBA rates were assessed for each type of CHD and classified by gestational age (<25 or ≥25 weeks) at MRI.

RESULTS

Of all 429 fetuses with CHD, 243 (56.6%) had ECA on MRI, and 109 (25.4%) had SBA. Among the 191 fetuses with normal genetic testing results, the ECA rate was 54.5% and the SBA rate 19.4%. Besides SBA, extrafetal (21.2%) and urogenital anomalies (10.7%) were the most prevalent ECA on MRI in all types of CHD. Predominant SBA were anomalies of hindbrain-midbrain (11.0% of all CHD), dorsal prosencephalon (10.0%) development, and abnormal cerebrospinal fluid spaces (10.5%). There was no difference in the prevalence or pattern of ECA between early (<25 weeks; 45.7%) and late (≥25 weeks; 54.3%) fetal MRI.

CONCLUSIONS

ECA and SBA rates on fetal MRI are high across all types of CHD studied, and ECA as well as SBA are already present from midgestation onward.

Prenatal diagnosis of significant congenital heart disease and elective termination of pregnancy in Nevada

OBJECTIVE

We investigated the relationship between prenatal detection of significant congenital heart disease and elective termination of pregnancy over time in Nevada.

METHODS

We identified those prenatally or post-natally diagnosed with significant congenital cardiovascular malformations in Nevada with birth dates or estimated delivery dates between July 2012 and June 2021.

RESULTS

We identified 1246. Of 1246, 69 underwent fetal demise, 42 had elective termination, and 1135 were live-born. Of the 1135 live-born, 1090 had prenatal care, of which 718 (66%) overall had a prenatal diagnosis of significant congenital heart disease. However, prenatal detection statistically significantly increased over time from 45 to 82%, p = .00001. Termination of pregnancy averaged 10% of those identified within the legal timeframe, and the rate did not statistically significantly increase with increasing prenatal detection rates, p = .56. Of the 42 undergoing elective termination, 23 (55%) had syndromes or comorbidities vs. 280 (25%) of the 1135 live-births, p = .0003.

CONCLUSIONS

In Nevada, despite a statistically significant increase in prenatal detection of significant congenital heart disease over time, termination of pregnancy rates did not increase. Nevertheless, those undergoing elective termination were more likely to have associated syndromes or comorbidities.

Construction and investigation of a circRNA-associated ceRNA regulatory network in Tetralogy of Fallot

Background

As the most frequent type of cyanotic congenital heart disease (CHD), tetralogy of Fallot (TOF) has a relatively poor prognosis without corrective surgery. Circular RNAs (circRNAs) represent a novel class of endogenous noncoding RNAs that regulate target gene expression posttranscriptionally in heart development. Here, we investigated the potential role of the ceRNA network in the pathogenesis of TOF.

Methods

To identify circRNA expression profiles in TOF, microarrays were used to screen the differentially expressed circRNAs between 3 TOF and 3 control human myocardial tissue samples. Then, a dysregulated circRNA-associated ceRNA network was constructed using the established multistep screening strategy.

Results

In summary, a total of 276 differentially expressed circRNAs were identified, including 214 upregulated and 62 downregulated circRNAs in TOF samples. By constructing the circRNA-associated ceRNA network based on bioinformatics data, a total of 19 circRNAs, 9 miRNAs, and 34 mRNAs were further screened. Moreover, by enlarging the sample size, the qPCR results validated the positive correlations between hsa_circ_0007798 and HIF1A.

Conclusions

The findings in this study provide a comprehensive understanding of the ceRNA network involved in TOF biology, such as the hsa_circ_0007798/miR-199b-5p/HIF1A signalling axis, and may offer candidate diagnostic biomarkers or potential therapeutic targets for TOF. In addition, we propose that the ceRNA network regulates TOF progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02217-w.

Postmortem Assessment of Isolated Congenital Heart Defects Remains Essential Following Termination of Pregnancy

OBJECTIVES

To investigate the correlation between prenatal ultrasound (US) and autopsy findings in pregnancies terminated due to isolated congenital heart defects (CHDs), including CHDs associated with heterotaxy syndrome.

MATERIALS AND METHODS

The material consists of 67 fetuses with prenatally detected isolated CHDs or CHDs associated with heterotaxy syndrome at a tertiary center in Norway between 1985 and 2014. The main CHDs were categorized into subdiagnoses of CHDs in accordance with ICD-10. The US and autopsy findings were categorized according to degree of concordance.

RESULTS

Gestational age at termination was 12 + 0-22 + 6 weeks. Hypoplastic left heart syndrome was the most common main diagnosis among the 67 fetuses (32.8%). There was full agreement between US and autopsy findings in 97.4% (222/228) of all subdiagnoses. The discrepant findings in three fetuses had no influence on the decision to terminate the pregnancy.

CONCLUSIONS

The correlation was high between prenatal US and postmortem findings in fetuses with isolated CHDs. Meticulous assessment of cardiac anatomy is particularly necessary when the decision to terminate relies on isolated CHDs. The trend of earlier termination challenges verification of diagnoses at autopsy. Consequently, the fetus should be examined at a tertiary center with fetal medicine specialists, pediatric cardiologists and perinatal pathologists.

From Other Journals: A Review of Recent Articles by Our Editorial Team

In this review we provide a brief description of recently published articles addressing topics relevant to pediatric cardiologists. Our hope is to provide a summary of the latest articles published recently in other journals in our field. The articles address (1) a summary of a scientific statement of the American Heart Association for diagnosis and treatment of myocarditis, (2) development of a perioperative risk score for in-hospital mortality after cardiac surgery in adults with congenital heart disease, (3) using a machine learning algorithm to predict cardiopulmonary deterioration in patients in the interstage period 1-2 h in advance using hospital monitor generated data, (4) risk factors for reoperation after the arterial switch operation, (5) the effect of mitochondrial transplantation for cardiogenic shock in pediatric patients, (6) comparing outcomes of primary or staged repair in tetralogy of Fallot with pulmonary atresia.

Social determinants of health and outcomes for children and adults with congenital heart disease: a systematic review

BACKGROUND

Social determinants of health (SDH) can substantially impact health outcomes. A systematic review, however, has never been conducted on associations of SDH with congenital heart disease (CHD) outcomes. The aim, therefore, was to conduct such a systematic review.

METHODS

Seven databases were searched through May 2020 to identify articles on SDH associations with CHD. SDH examined included poverty, uninsurance, housing instability, parental educational attainment, immigration status, food insecurity, and transportation barriers. Studies were independently selected and coded by two researchers based on the PICO statement.

RESULTS

The search generated 3992 citations; 88 were included in the final database. SDH were significantly associated with a lower likelihood of fetal CHD diagnosis, higher CHD incidence and prevalence, increased infant mortality, adverse post-surgical outcomes (including hospital readmission and death), decreased healthcare access (including missed appointments, no shows, and loss to follow-up), impaired neurodevelopmental outcomes (including IQ and school performance) and quality of life, and adverse outcomes for adults with CHD (including endocarditis, hospitalization, and death).

CONCLUSIONS

SDH are associated with a wide range of adverse outcomes for fetuses, children, and adults with CHD. SDH screening and referral to appropriate services has the potential to improve outcomes for CHD patients across the lifespan.

IMPACT

Social determinants of health (SDH) are associated with a wide range of adverse outcomes for fetuses, children, and adults with congenital heart disease (CHD). This is the first systematic review (to our knowledge) on associations of SDH with congenital heart disease CHD outcomes. SDH screening and referral to appropriate services has the potential to improve outcomes for CHD patients across the lifespan.

Next-generation sequencing in a series of 80 fetuses with complex cardiac malformations and/or heterotaxy

Herein, we report the screening of a large panel of genes in a series of 80 fetuses with congenital heart defects (CHDs) and/or heterotaxy and no cytogenetic anomalies. There were 49 males (61%/39%), with a family history in 28 cases (35%) and no parental consanguinity in 77 cases (96%). All fetuses had complex CHD except one who had heterotaxy and midline anomalies while 52 cases (65%) had heterotaxy in addition to CHD. Altogether, 29 cases (36%) had extracardiac and extra-heterotaxy anomalies. A pathogenic variant was found in 10/80 (12.5%) cases with a higher percentage in the heterotaxy group (8/52 cases, 15%) compared with the non-heterotaxy group (2/28 cases, 7%), and in 3 cases with extracardiac and extra-heterotaxy anomalies (3/29, 10%). The inheritance was recessive in six genes (DNAI1, GDF1, MMP21, MYH6, NEK8, and ZIC3) and dominant in two genes (SHH and TAB2). A homozygous pathogenic variant was found in three cases including only one case with known consanguinity. In conclusion, after removing fetuses with cytogenetic anomalies, next-generation sequencing discovered a causal variant in 12.5% of fetal cases with CHD and/or heterotaxy. Genetic counseling for future pregnancies was greatly improved. Surprisingly, unexpected consanguinity accounts for 20% of cases with identified pathogenic variants.

The TRIVIA Cohort for Surgical Management of Tetralogy of Fallot: Merging Population and Clinical Data for Real-World Scientific Evidence

Background

Guidelines for surgical management of tetralogy of Fallot (TOF) are often based on low-quality evidence due to the many challenges of congenital heart disease: heterogeneous cardiac anatomy, consequences from surgical interventions arising years later, and scarcity of hard outcomes. The overarching goal of the Tetralogy of Fallot Research for Improvement of Valve replacement Intervention: A Bridge Across the Knowledge Gap (TRIVIA) study is to evaluate the long-term impact of the surgical management strategies in TOF. The specific objectives are: (1) to describe the long-term outcomes of TOF according to the native anatomy and the presence of genetic conditions, (2) to evaluate the long-term outcomes of surgical repair according to associated residual lesions, and (3) to evaluate the impact of paediatric pulmonary valve replacements on the long-term outcomes.

Methods

The TRIVIA study is a population-based cohort including all subjects with TOF in the province of Québec between 1980 and 2017. It links patient-level granular clinical data with long-term administrative health care data. We will evaluate mortality, cardiovascular interventions, and hospitalizations for adverse cardiovascular events using survival Cox models and marginal mean/rates models for recurrent events, respectively. Multivariate multilevel models will correct for potential confounders, and risk score matching will mitigate the potential of confounding by indication.

Results

The current TRIVIA cohort includes 1001 eligible subjects with TOF with complete lifelong follow-up for > 98%. The median follow-up is 17.1 years, totalling > 17,000 patient-years.

Conclusions

Universal health insurance data combined with granular clinical data enable the development of population-based cohorts, to which contemporary statistical methods are applied to address important research questions in congenital heart disease research.

Global birth prevalence of congenital heart defects 1970-2017: updated systematic review and meta-analysis of 260 studies

Background

Globally, access to healthcare and diagnostic technologies are known to substantially impact the reported birth prevalence of congenital heart disease (CHD). Previous studies have shown marked heterogeneity between different regions, with a suggestion that CHD prevalence is rising globally, but the degree to which this reflects differences due to environmental or genetic risk factors, as opposed to improved detection, is uncertain. We performed an updated systematic review to address these issues.

Methods

Studies reporting the birth prevalence of CHD between the years 1970–2017 were identified from searches of PubMed, EMBASE, Web of Science and Google Scholar. Data on the prevalence of total CHD and 27 anatomical subtypes of CHD were collected. Data were combined using random-effect models. Subgroup and meta-regression analyses were conducted, focused on geographical regions and levels of national income.

Results

Two hundred and sixty studies met the inclusion criteria, encompassing 130 758 851 live births. The birth prevalence of CHD from 1970–2017 progressively increased to a maximum in the period 2010–17 of 9.410/1000 [95% CI (confidence interval) 8.602–10.253]. This represented a significant increase over the fifteen prior years (P = 0.031). The change in prevalence of mild CHD lesions (ventricular septal defect, atrial septal defect and patent ductus arteriosus) together explained 93.4% of the increased overall prevalence, consistent with a major role of improved postnatal detection of less severe lesions. In contrast the prevalence of lesions grouped together as left ventricular outflow tract obstruction (which includes hypoplastic left heart syndrome) decreased from 0.689/1000 (95% CI 0.607–0.776) in 1995–99, to 0.475/1000 (95% CI 0.392–0.565; P = 0.004) in 2010–17, which would be consistent with improved prenatal detection and consequent termination of pregnancy when these very severe lesions are discovered. There was marked heterogeneity among geographical regions, with Africa reporting the lowest prevalence [2.315/1000 (95% CI 0.429–5.696)] and Asia the highest [9.342/1000 (95% CI 8.072–10.704)].

Conclusions

The reported prevalence of CHD globally continues to increase, with evidence of severe unmet diagnostic need in Africa. The recent prevalence of CHD in Asia for the first time appears higher than in Europe and America, where disease ascertainment is likely to be near-complete, suggesting higher genetic or environmental susceptibility to CHD among Asian people.

The applications and potential limitations of right ventricular volumes as surrogate marker in tetralogy of fallot

Cardiac magnetic resonance imaging derived right ventricular (RV) volumes are often necessary for optimal timing of pulmonary valve replacement in patients with tetralogy of Fallot (TOF). This practice is based on previous studies that reported preoperative RV volumetric thresholds that predicted postoperative RV remodeling. As a result, pulmonary valve replacements are being performed even in asymptomatic patients based on RV volumetric thresholds that predict complete postoperative RVOT remodeling. Hence, RV volumes are now being used as surrogate markers/endpoints for future cardiovascular outcomes. Unfortunately, there are no studies showing survival benefit for performing pulmonary valve replacement at smaller RV volumes. This review underscores some of the limitations of using RV volumes as surrogate markers for clinical outcomes, and also highlights knowledge gaps about the pathophysiologic mechanism of cardiovascular death in the TOF population.

Live-Born Major Congenital Heart Disease in Denmark: Incidence, Detection Rate, and Termination of Pregnancy Rate From 1996 to 2013

Importance

The occurrence of major congenital heart disease (CHD) is affected by several variables. Determining the development of the true incidence is critical to the establishment of proper treatment of these patients.

Objective

To evaluate time trends in incidence, detection rate, and termination of pregnancy (TOP) rate of major CHD in fetuses in Denmark and assess the influence of the introduction of general prenatal screening in 2004.

Design, Setting, and Participants

Nationwide, population-based, retrospective observational study in Denmark from 1996 to 2013 that included a consecutive sample of 14 688 live-born children and terminated fetuses diagnosed as having CHD. Patient records on TOP and children with major CHD were reviewed to validate the diagnoses. Major CHD included univentricular heart, transposition of the great arteries, congenitally corrected transposition of the great arteries, truncus arteriosus, interrupted aortic arch, atrioventricular septal defects, double outlet right ventricle, coarctatio of the aorta, Ebstein anomaly, pulmonary atresia with ventricular septal defect, pulmonary atresia with intact ventricular septum, and tetralogy of Fallot. Data were analyzed between January 2017 and March 2018.

Main Outcomes and Measures

Temporal changes in incidence, detection rate, and TOP of major CHD.

Results

Of 14 688 children and fetuses diagnosed with CHD, 2695 (18.4%; 95% CI, 17.8-19.1) had major CHD. A total of 7131 boys (1304 with major CHD) and 6926 girls (920 with major CHD) were included, with a median age of 11 years (interquartile range, 6-15 years). During the study period, the live-birth incidence of CHD was constant at 1.22% (95% CI, 1.18-1.26), whereas it decreased for major CHD. When including TOP, the incidence of major CHD did not change over time. The detection rate of major CHD increased from 4.5% (95% CI, 1.2-7.8) to 71.0% (95% CI, 63.3-78.7) (P < .001). At the end of the study, all cases of double outlet right ventricle, Ebstein anomaly, congenitally corrected transposition of the great arteries, and pulmonary atresia with ventricular septal defect were detected prenatally, whereas coarctation of the aorta had the lowest detection rate (21.7%; 95% CI, 3.5-40.0). The TOP rate increased from 0.6% (95% CI, -0.6 to 1.9) to 39.1% (95% CI, 30.9-47.4) (P < .001) among all major CHD. For prenatally diagnosed major CHD, 57.8% of cases were terminated and the proportion did not change significantly throughout the study. Diagnoses leading to TOP included all major CHD diagnoses.

Conclusions and Relevance

Detection rates of major CHD improved during the study. This has led to increased TOP rates, with a subsequent 39% decrease in the live-birth incidence of major CHD.

Long-term outcomes in adults with repaired tetralogy of Fallot and pulmonary atresia

BACKGROUND

There are limited outcome data in adults with tetralogy of Fallot and pulmonary atresia. The purpose of this study was to describe re-operations and all-cause mortality in adults with tetralogy of Fallot and pulmonary atresia.

METHODS

Retrospective review of adults with repaired tetralogy of Fallot and pulmonary atresia who received care at the Mayo Adult Congenital Heart Disease Clinic, 1990-2016. All-cause mortality was calculated as events per 100 patient-years from the time of first presentation to the Adult Congenital Heart Disease Clinic.

RESULTS

Of the 221 patients, the age at initial tetralogy of Fallot repair was 6 (5-13) years, and the age at first presentation to the clinic was 27 - 8 years. All patients had at least one right ventricular to pulmonary artery conduit re-operation. There were 31 deaths (14%) at mean age of 41 - 14 years. The causes of death were end-stage heart failure (n = 17), sudden cardiac death (n=9), post-operative death after cardiac surgery (n = 2), sepsis with multi-system organ failure (n = 2), and unknown (n = 1). All-cause mortality rate was 1.7 per 100 patient-years. The risk factors for all-cause mortality were older age (>12 years) at the time of repair (hazard ratio 1.41, 95 confidence interval 1.06-2.02, p = 0.033), non-sustained ventricular tachycardia (hazard ratio 1.36, 95 confidence interval 1.17-2.47, p = 0.015), and left ventricular ejection fraction <50% (hazard ratio 1.39, 95 confidence interval 1.08-2.31, p = 0.031).

CONCLUSION

Based on a review of 221 adults with repaired tetralogy of Fallot and pulmonary atresia, all patients had re-operations and all-cause mortality rate was 1.7 events per 100 patient-years. The current study provides important outcomes data for risk stratification in adults with tetralogy of Fallot and pulmonary atresia.

Animal Models of Repaired Tetralogy of Fallot: Current Applications and Future Perspectives

Tetralogy of Fallot is the most common cyanotic congenital heart disease. Despite ongoing improvements in the initial surgical repair, there are lingering concerns regarding the long-term outcomes that may be complicated by right ventricular dysfunction, right ventricular dyssynchrony, and sudden cardiac death. The mechanisms leading to these late complications remain incompletely understood. Experimental animal models have been developed as preclinical steps to gain better insight into the pathophysiology of diseases and to develop new therapeutic strategies. This article summarizes the various types of experimental animal models of repaired tetralogy of Fallot published to date in the literature, with the aim of achieving a greater understanding of the deleterious mechanisms that may lead to these known late and sometimes lethal complications. In addition to analysing the type of animals that can be used according to a given study's objectives, needs, and constraints, the present review also evaluates the type of dysfunction that can be reproduced in our model according to the research objectives, as well as the different types of studies in which these models can be used. In view of all that, we propose a decision algorithm to create an animal model of repaired tetralogy of Fallot. This synthesis should furthermore help in the development of future studies and in the design of new experimental models, thus allowing greater insight into this disease, while not forgetting the ultimate goal of broadening future therapeutic measures to reduce the morbidity and mortality of this prevalent congenital heart disease.

Prenatal diagnosis and prevalence of critical congenital heart defects: an international retrospective cohort study

OBJECTIVES

To assess international trends and patterns of prenatal diagnosis of critical congenital heart defects (CCHDs) and their relation to total and live birth CCHD prevalence and mortality.

SETTING

Fifteen birth defect surveillance programmes that participate in the International Clearinghouse for Birth Defects Surveillance and Research from 12 countries in Europe, North and South America and Asia.

PARTICIPANTS

Live births, stillbirths and elective terminations of pregnancy for fetal anomaly diagnosed with 1 of 12 selected CCHD, ascertained by the 15 programmes for delivery years 2000 to 2014.

RESULTS

18 243 CCHD cases were reported among 8 847 081 births. The median total prevalence was 19.1 per 10 000 births but varied threefold between programmes from 10.1 to 31.0 per 10 000. CCHD were prenatally detected for at least 50% of the cases in one-third of the programmes. However, prenatal detection varied from 13% in Slovak Republic to 87% in some areas in France. Prenatal detection was consistently high for hypoplastic left heart syndrome (64% overall) and was lowest for total anomalous pulmonary venous return (28% overall). Surveillance programmes in countries that do not legally permit terminations of pregnancy tended to have higher live birth prevalence of CCHD. Most programmes showed an increasing trend in prenatally diagnosed CCHD cases.

DISCUSSION AND CONCLUSIONS

Prenatal detection already accounts for 50% or more of CCHD detected in many programmes and is increasing. Local policies and access likely account for the wide variability of reported occurrence and prenatal diagnosis. Detection rates are high especially for CCHD that are more easily diagnosed on a standard obstetric four-chamber ultrasound or for fetuses that have extracardiac anomalies. These ongoing trends in prenatal diagnosis, potentially in combination with newborn pulse oximetry, are likely to modify the epidemiology and clinical outcomes of CCHD in the near future.

Transplant-Amenable Hepatocellular Carcinoma in a Fontan Patient

The Fontan circulation alters a patient's physiology and imparts long-term risks related to chronically elevated systemic venous pressure. An increasing number of patients with Fontan physiology are surviving into adulthood and are at risk of hepatic sequalae. The ideal timeline and method of hepatic surveillance in the Fontan population remains to be defined. In this case, the patient was diagnosed with hepatocellular carcinoma more than 20 years after undergoing the Fontan procedure and was a candidate for combined heart-liver transplant. That her disease progressed prior to organ availability supports the argument for hepatic surveillance in this population.

Outcomes of Pregnancy in Patients With Prior Right Ventricular Outflow Interventions

Background

The purpose of this study was to compare the incidence of pregnancy‐related adverse outcomes (PRAO) between patients with versus without hemodynamically significant right ventricle outflow tract (RVOT).

Methods and Results

This was a retrospective cohort study of all pregnant patients with isolated RVOT lesions undergoing evaluation at the Mayo Clinic, 1990 to 2017. Hemodynamic significance was defined as ≥moderate pulmonary/conduit stenosis (≥3 m/s) and/or ≥moderate regurgitation. Patients with concomitant significant left heart disease were excluded. PRAO was defined as cardiovascular, obstetric, and/or neonatal complications occurring during the pregnancy through 6 weeks postpartum. A total of 224 pregnancies in 114 patients with RVOT lesions were identified; 38 pregnancies occurred in 24 patients with hemodynamically significant RVOT. Forty‐eight (21%) pregnancies ended in spontaneous abortion. Of the 173 completed pregnancies, median gestational age at delivery was 38 (35–40) weeks and median birth weight 2965 (2065–4122) g. Seven pregnancies (4%) were complicated by cardiovascular events, 14 (8%) by obstetric complications, with adverse neonatal outcomes occurring in 38 (22%). There were no maternal deaths. The incidence of spontaneous abortion and PRAO were similar in both the RVOT and hemodynamically significant RVOT groups. As an isolated condition, Tetralogy of Fallot–pulmonary atresia was associated with spontaneous abortion and neonatal complications.

Conclusions

The risk of cardiovascular complications was low in patients with isolated RVOT lesions, and hemodynamically significant RVOT lesions were not associated with either cardiovascular complications or PRAO. Further studies are required to explore the factors responsible for PRAO in patients with Tetralogy of Fallot–pulmonary atresia.

[Congenital heart defects in the Valencian Community 2007-2014: The Population-Based Registry Of Congenital Anomalies]

INTRODUCTION

Congenital heart defects (CHDs) are the most prevalent and severe type of major congenital anomalies (CAs). The objective of this study was to determine the frequency and distribution of CHDs in the Valencian Region from 2007 to 2014, describing common characteristics of the patients and their mothers.

MATERIAL AND METHODS

We retrieved data on CHDs in live births, stillbirths and cases of termination of pregnancy for fetal anomaly between 2007 and 2014 (codes Q20-Q26 in the 10th Revision of the International Classification of Diseases-British Paediatric Association, ICD10-BPA) from the population-based Registry of congenital anomalies of the Valencian Region. We calculated the prevalence per every 10,000 births of CHDs overall and by subtype, analysed temporal trends and the geographic distribution of cases, and documented the presence of associated noncardiac malformations.

RESULTS

We identified 3,671 cases of CHD, corresponding to 38.6% of all CAs. The prevalence was 91.1/10,000 (IC 95%: 88.1-94.0) with a predominance of septal defects, chiefly atrial septal defect (48.5/10,000; IC 95%: 46.4-50.6) and ventricular septal defect (36.1/10,000; IC 95%: 34.3-38.0). We found the highest prevalence in the province of Castellon (137.8/10,000; IC 95%: 127.5-148.1). The sex distribution was 47.3% male and 44.3% female. Of all cases, 90.9% corresponded to live births and 65.6% were diagnosed at birth. The most frequent associated extracardiac malformations were musculoskeletal, and 19.2% of patients had syndromes. The most frequent maternal diseases were diabetes mellitus, hypothyroidism and urinary tract infections.

CONCLUSIONS

The prevalence of CHD and atrial septal defects was higher compared to European data, while the prevalence of ventricular septal defects was similar. Musculoskeletal malformations were the noncardiac CAs most frequently associated with CHDs.

Birth Location of Infants with Critical Congenital Heart Disease in California

The American Academy of Pediatrics classifies neonatal intensive care units (NICUs) from level I to IV based on the acuity of care each unit can provide. Birth in a higher level center is associated with lower morbidity and mortality in high-risk populations. Congenital heart disease accounts for 25-50% of infant mortality related to birth defects in the U.S., but recent data are lacking on where infants with critical congenital heart disease (CCHD) are born. We used a linked dataset from the Office of Statewide Health Planning and Development to access ICD-9 diagnosis codes for all infants born in California from 2008 to 2012. We compared infants with CCHD to the general population, identified where infants with CCHD were born based on NICU level of care, and predicted level IV birth among infants with CCHD using logistic regression techniques. From 2008 to 2012, 6325 infants with CCHD were born in California, with 23.7% of infants with CCHD born at a level IV NICU compared to 8.4% of the general population. Level IV birth for infants with CCHD was associated with lower gestational age, higher maternal age and education, the presence of other congenital anomalies, and the diagnosis of a single ventricle lesion. More infants with CCHD are born in a level IV NICU compared to the general population. Future studies are needed to determine if birth in a lower level of care center impacts outcomes for infants with CCHD.

The implementation of a nationwide anomaly screening programme improves prenatal detection of major cardiac defects: an 11-year national population-based cohort study

OBJECTIVE

To evaluate whether a nationwide prenatal anomaly screening programme improves detection rates of univentricular heart (UVH) and transposition of great arteries (TGA), and whether maternal risk factors for severe fetal heart disease affect prenatal detection.

DESIGN

Population-based cohort study.

SETTING

Nationwide data from Finnish registries 2004-14.

POPULATION

A total of 642 456 parturients and 3449 terminated pregnancies due to severe fetal anomaly.

METHODS

Prenatal detection rates were calculated in three time periods (prescreening, transition and screening phase). The effect of maternal risk factors (obesity, in vitro fertilisation, pregestational diabetes and smoking) was evaluated.

MAIN OUTCOME MEASURES

Change in detection rates and impact of maternal risk factors on screening programme efficacy.

RESULTS

In total, 483 cases of UVH and 184 of TGA were detected. The prenatal detection rate of UVH increased from 50.4% to 82.8% and of TGA from 12.3% to 41.0% (P < 0.0001). Maternal risk factors did not affect prenatal detection rate, but detection rate differed substantially by region.

CONCLUSIONS

A nationwide screening programme improved overall UVH and TGA detection rates, but regional differences were observed. Obesity or other maternal risk factors did not affect the screening programme efficacy. The establishment of structured guidelines and recommendations is essential when implementing the screening programme. In addition, a prospective screening register is highly recommended to ensure high quality of screening.

TWEETABLE ABSTRACT

Implementation of a nationwide prenatal anomaly screening improved detection rates of UVH and TGA.

Prevalence of Congenital Heart Disease at Live Birth in China

OBJECTIVE

To investigate the prevalence of congenital heart disease (CHD) in China based on a large prospective multicenter screening study.

STUDY DESIGN

A total of 122 765 consecutive infants born at 18 hospitals throughout China between August 1, 2011, and November 30, 2012, were included. Cases of CHD were identified by echocardiography, clinical assessment, and telephone follow-up.

RESULTS

The overall prevalence of CHD was 8.98 per 1000 live births (critical, 1.46; serious, 1.47; significant, 5.00; nonsignificant, 1.07), including 7.15 in male infants and 11.11 in female infants. The most common CHD was ventricular septal defect (3.3), followed by atrial septal defect (1.7), patent ductus arteriosus (0.78), pulmonary stenosis (0.73), tetralogy of Fallot (0.47), and transposition of the great arteries (0.35). Female predominance was observed for all CHD and mild CHD (significant and nonsignificant), and male predominance was observed for the critical CHDs. The proportion of preterm newborns was substantially higher among the major CHD cases (critical and serious) compared with normal newborns. There were appreciably more low birth weight infants among the critical CHD cases compared with normal newborns. Significantly higher rates of ventricular septal defect and atrioventricular septal defect were found in infants born to mothers aged ≥35 years. Extracardiac anomalies were found in 9.3% of CHD cases. The risk of CHD was increased by approximately 3-fold when a first-degree relative had CHD.

CONCLUSIONS

Our estimates are concordant with data from Western studies. This screening study may provide more accurate and complete information on the overall prevalence of CHD in China.

National trends in Fontan operation and in-hospital outcomes in the USA

Background

National prevalence and outcomes of Fontan operation in the USA is unknown. Study objective was to determine trends (temporal change) in the annual volume of Fontan operations, in-hospital mortality, postoperative complications and type of hospital discharge.

Methods

Review of the Nationwide Inpatient Sample for patients that underwent Fontan operation from 2001 to 2014 using the International Classification of Diseases-Ninth Revision, Clinical Modification procedure code for Fontan operation, that is, 35.94. To evaluate for change in patients’ demographics over the years, we divided the patient population into four groups based on procedure year (2001–2004, 2005–2008, 2009–2011 and 2012–2014).

Results

An estimated 15 934 Fontan operations were performed in the USA from 2001 to 2014. Median (Q1–Q3) age was 3 (2–4) years and 39.8% were female. Hypoplastic left heart syndrome was the most common (29%) congenital heart disease diagnosis. An estimated 1175 procedures were performed in 2001 and 1340 in 2014, but there was no significant change in the number of procedures per year (p=0.47). There was significant decline in in-hospital mortality from 4.5% (53/1175) in 2001 to 1.1% (15/1340) in 2014 (p=0.009). When we compared event rates between 2001–2004 and 2012–2014 periods, there was significant decline in postoperative cardiac complications (12.6% (459/3640) to 8% (378/4706), p=0.007) and respiratory complications (17.1% (623/3640) to 10.2% (481/4706), p<0.001). However, there was increase in the number of patients discharged to home with healthcare assistance or transferred to another acute care facility (5.8% (211/3640) to 9.4% (443/4706), p=0.01) and inflation-adjusted hospitalisation cost (US$46 978 to US$60 383, p<0.001), but no significant change in length of stay (p=0.73).

Conclusion

On the average, 1062 Fontan operations are performed annually in the USA with no change in volume of procedures but a decrease in in-hospital mortality and postoperative complications over a 15-year period.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Epidemiology of congenital heart diseases in Bogotá, Colombia, from 2001 to 2014: Improved surveillance or increased prevalence?

Introducción. Las cardiopatías congénitas son alteraciones estructurales y funcionales del corazón, sistema circulatorio y grandes vasos que se desarrollan durante la embriogénesis cardiaca. A nivel mundial dichos defectos son una causa importante de morbi-mortalidad en la población infantil.Objetivo. Determinar la prevalencia de cardiopatías congénitas en la ciudad de Bogotá, durante el periodo de 2001 a 2014 y evaluar la tendencia en el tiempo.Material y métodos. Se analizaron 405.408 recién nacidos del Programa de Vigilancia y Seguimiento de Niños con Anomalías Congénitas de la Secretaría de Salud de Bogotá calculando la prevalencia de las cardiopatías congénitas a través de un registro diario de nacimientos y su evaluación clínica y paraclínica. Se clasificaron en aisladas, complejas y asociada y se halló la prevalencia por año. Se evaluó la mortalidad en las primeras horas de vida.Resultados. La prevalencia de cardiopatías congénitas fue de 15,1 por cada 10.000 recién nacidos en todo el período, pero se evidenciaron valores por encima de 20x10.000 en los últimos 3 años. Del total, 46% fueron de sexo femenino, 53,16% de sexo masculino y 0.33% indeterminado. De los nacidos malformados, 397 cardiopatías fueron aisladas, 142 asociadas a otras malformaciones extracardiacas y 74 complejas.Conclusiones. Las cardiopatías tienen gran impacto en la salud de la población infantil y aunque la prevalencia es menor que en otros países, esto puede deberse a subregistro a nivel nacional. Se nota un aumento en la prevalencia en los últimos 3 años que puede corresponder a la implementación de los programas de vigilancia nacional y local. Sugerimos continuar el desarrollo de programas que incrementen e incentiven el tamizaje y registro de estas patologías. 

Perinatal outcomes and congenital heart defect prognosis in 53313 non-selected perinatal infants

Objective

To evaluate perinatal outcomes and congenital heart defect (CHD) prognosis in a non-selected population.

Methods

The population-based surveillance data used in this assessment of CHDs were based on birth defect surveillance data collected from 2010–2012 in Liuyang City, China. Infants living with CHDs were followed up for 5 years to determine their prognosis. Prevalence, prenatal diagnosis, perinatal outcomes, and total and type-specific prognosis data were assessed using SPSS 18.0.

Results

In total, 190 CHD cases were identified among the 53313 included perinatal infants (PIs), indicating a CHD prevalence of 35.64 per 10000 PIs in this non-selected population. The five most frequently identified types of CHDs were ventricular septal defects (VSDs, 38.95%), atrial septal defects (ASDs, 15.79%), cardiomegaly (7.89%), tetralogy of Fallot (TOF, 5.79%), and atrioventricular septal defects (AVSDs, 5.26%). Of the 190 CHD cases, 110 (57.89%) were diagnosed prenatally, 30 (15.79%) were diagnosed with associated malformations, and 69 (36.32%) resulted in termination of pregnancy (TOP). Moreover, 15 (7.89%) PIs died within 7 days after delivery, and 42 (22.10%) died within 1 year. In contrast, 79 (41.58%) were still alive after 5 years. When TOP cases were included, the 5-year survival rate of PIs with prenatally detected CHDs was lower than that of PIs with postnatally detected CHDs (25.45% vs. 63.75%). The CHD subtype associated with the highest rate of infant (less than 1 year old) mortality was transposition of the great arteries (100%). The subtypes associated with higher 5-year survival rates were patent ductus arteriosus (80%), ASD (63.33%), VSD (52.70%) and AVSD (50%).

Conclusions

The rates of prenatal CHD detection and TOP were high in this study population, and the 5-year survival rate of PIs with CHDs was low. The government should strengthen efforts to educate pediatricians regarding this issue and provide financial assistance to improve the prognosis of infants living with CHDs, especially during the first year of life.

Ethnic and socioeconomic variation in incidence of congenital heart defects

INTRODUCTION

Ethnic differences in the birth prevalence of congenital heart defects (CHDs) have been reported; however, studies of the contemporary UK population are lacking. We investigated ethnic variations in incidence of serious CHDs requiring cardiac intervention before 1 year of age.

METHODS

All infants who had a cardiac intervention in England and Wales between 1 January 2005 and 31 December 2010 were identified in the national congenital heart disease surgical audit and matched with paediatric intensive care admission records to create linked individual child records. Agreement in reporting of ethnic group by each audit was evaluated. For infants born 1 January 2006 to 31 December 2009, we calculated incidence rate ratios (IRRs) for CHDs by ethnicity and investigated age at intervention, antenatal diagnosis and area deprivation.

RESULTS

We identified 5350 infants (2940 (55.0%) boys). Overall CHD incidence was significantly higher in Asian and Black ethnic groups compared with the White reference population (incidence rate ratios (IRR) (95% CIs): Asian 1.5 (1.4 to 1.7); Black 1.4 (1.3 to 1.6)); incidence of specific CHDs varied by ethnicity. No significant differences in age at intervention or antenatal diagnosis rates were identified but affected children from non-White ethnic groups were more likely to be living in deprived areas than White children.

CONCLUSIONS

Significant ethnic variations exist in the incidence of CHDs, including for specific defects with high infant mortality. It is essential that healthcare provision mitigates ethnic disparity, including through timely identification of CHDs at screening, supporting parental choice and effective interventions. Future research should explore the factors underlying ethnic variation and impact on longer-term outcomes.

Proarrhythmic remodelling of the right ventricle in a porcine model of repaired tetralogy of Fallot

Objective

The growing adult population with surgically corrected tetralogy of Fallot (TOF) is at risk of arrhythmias and sudden cardiac death. We sought to investigate the contribution of right ventricular (RV) structural and electrophysiological remodelling to arrhythmia generation in a preclinical animal model of repaired TOF (rTOF).

Methods and results

Pigs mimicking rTOF underwent cardiac MRI functional characterisation and presented with pulmonary regurgitation, RV hypertrophy, dilatation and dysfunction compared with Sham-operated animals (Sham). Optical mapping of rTOF RV-perfused wedges revealed a significant prolongation of RV activation time with slower conduction velocities and regions of conduction slowing well beyond the surgical scar. A reduced protein expression and lateralisation of Connexin-43 were identified in rTOF RVs. A remodelling of extracellular matrix-related gene expression and an increase in collagen content that correlated with prolonged RV activation time were also found in these animals. RV action potential duration (APD) was prolonged in the epicardial anterior region at early and late repolarisation level, thus contributing to a greater APD heterogeneity and to altered transmural and anteroposterior APD gradients in rTOF RVs. APD remodelling involved changes in Kv4.3 and MiRP1 expression. Spontaneous arrhythmias were more frequent in rTOF wedges and more complex in the anterior than in the posterior RV.

Conclusion

Significant remodelling of RV conduction and repolarisation properties was found in pigs with rTOF. This remodelling generates a proarrhythmic substrate likely to facilitate re-entries and to contribute to sudden cardiac death in patients with rTOF.

Myocardial Response to Milrinone in Single Right Ventricle Heart Disease

OBJECTIVES

Empiric treatment with milrinone, a phosphodiesterase (PDE) 3 inhibitor, has become increasingly common in patients with single ventricle heart disease of right ventricular (RV) morphology (SRV); our objective was to characterize the myocardial response to PDE3 inhibition (PDE3i) in the pediatric population with SRV.

STUDY DESIGN

Cyclic adenosine monophosphate levels, PDE activity, and phosphorylated phospholamban (PLN) were determined in explanted human ventricular myocardium from nonfailing pediatric donors (n = 10) and pediatric patients transplanted secondary to SRV. Subjects with SRV were further classified by PDE3i treatment (n = 13 with PDE3i and n = 12 without PDE3i).

RESULTS

In comparison with nonfailing RV myocardium (n = 8), cyclic adenosine monophosphate levels are lower in patients with SRV treated with PDE3i (n = 12, P = .021). Chronic PDE3i does not alter total PDE or PDE3 activity in SRV myocardium. Compared with nonfailing RV myocardium, SRV myocardium (both with and without PDE3i) demonstrates equivalent phosphorylated PLN at the protein kinase A phosphorylation site.

CONCLUSIONS

As evidenced by preserved phosphorylated PLN, the molecular adaptation associated with SRV differs significantly from that demonstrated in pediatric heart failure because of dilated cardiomyopathy. These alterations support a pathophysiologically distinct mechanism of heart failure in pediatric patients with SRV, which has direct implications regarding the presumed response to PDE3i treatment in this population.