Changing Epidemiology of Hypoplastic Left Heart Syndrome: Results of a National Swedish Cohort Study

Maternal-fetal comorbidities and obstetrical outcomes of fetal single ventricle cardiac defects: 10 years' experience with a multidisciplinary management protocol at a single center

OBJECTIVES

To describe and compare maternal and fetal comorbidities and obstetrical outcomes in pregnancies with hypoplastic left and right heart (HLHS and HRH) single ventricle cardiac defects (SVCD) from a single center under a multidisciplinary protocol.

METHOD

A single center retrospective review of fetal SVCD from 2013 to 2022. Maternal-fetal comorbidities, delivery, and postnatal outcomes were compared between HLHS and HRH using descriptive statistics and univariate and multivariate analyses.

RESULTS

Of 181 SVCD pregnancies (131 HLHS; 50 HRH), 9% underwent termination, 4% elected comfort care, 5 died in utero and 147/152 liveborns survived to the first cardiac intervention. Cesarean delivery occurred in 57 cases (37%), planned in 36 and unplanned in 21. Comorbidities, which did not differ between HLHS and HRH, included fetal growth restriction (FGR, 17%), prematurity (14%), maternal hypertension (9%), maternal obesity (50%), fetal extracardiac anomalies and chromosome anomalies (12%, 13%). In multivariate analysis, only earlier gestational age at delivery and oligohydramnios predicted decreased odds of survival at one year.

CONCLUSION

Maternal-fetal comorbidities are common in both HLHS and HRH. Earlier gestational age at delivery and oligohydramnios predict lower postnatal survival. FGR, even with severe early onset, did not significantly impact short- or long-term neonatal survival in single ventricle conditions.

Long-Term Survival After Single-Ventricle Palliation: A Swedish Nationwide Cohort Study

BACKGROUND

Long-term survival after single-ventricle palliation and the effect of dominant ventricle morphology in large, unselected series of patients are scarcely reported.

METHODS AND RESULTS

This nationwide cohort study included all children undergoing operation with single-ventricle palliation during their first year of life in Sweden between January 1994 and December 2019. Data were obtained from institutional records and assessment of underlying cardiac anomaly and dominant ventricular morphology was based on complete review of medical records, surgical reports, and echocardiographic examinations. Data on vital status and date of death were retrieved from the Swedish Cause of Death Register, allowing for complete data on survival. Among 766 included patients, 333 patients (43.5%) were classified as having left or biventricular dominance, and 432 patients (56.4%) as having right ventricular (RV) dominance (of whom 231 patients had hypoplastic left heart syndrome). Follow-up was 98.7% complete (10 patients emigrated). Mean follow-up was 11.3 years (maximum, 26.7 years). Long-term survival was significantly higher in patients with left ventricular compared with RV dominance (10-year survival: 91.0% [95% CI, 87.3%-93.6%] versus 71.1% [95% CI, 66.4%-75.2%]). RV dominance had a significant impact on outcomes after first-stage palliation but was also associated with impaired survival after completed total cavopulmonary connection. In total, 34 (4.4%) patients underwent heart transplantation. Of these 34 patients, 25 (73.5%) had predominant RV morphology.

CONCLUSIONS

This study provides clinically relevant knowledge about the long-term prognosis in patients with different underlying cardiac anomalies undergoing single-ventricle palliation. RV dominance had a significant impact on outcomes after initial surgical treatment but was also associated with impaired survival after completed Fontan circulation.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03356574.

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

Background

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

Aim

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

Methods

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

Results

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

Conclusion

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

[Ethical Attitudes and Handling in Prenatal Conflict Situations - A Survey among Obstetricians and Prenatal Diagnosticians in Germany]

OBJECTIVE

Various studies have shown that belonging to a professional group has an influence on ethical attitudes. The aim of this study was to assess and compare the attitudes and approaches of obstetrical specialists and prenatal diagnosticians in prenatal conflict situations.

METHODS

Explorative cross-sectional online survey among tertiary perinatal care centers and prenatal diagnosticians with DEGUM Level II/III in Germany. The questionnaire included questions on ethical attitudes in the perinatal context and a case presentation of a fetal hypoplastic left heart syndrome.

RESULTS

The response rate was 57.1% (310/543). 55.5% of the respondents practiced both obstetrics and prenatal diagnostics, 24.5% exclusively prenatal diagnostics, and 14.2% purely obstetrics. 27% agreed with the statement "An uncertain prognosis justifies pregnancy termination". For complex fetal malformations joint interdisciplinary counseling was advocated by 98.3%. Addressing the option of postnatal palliative treatment in a case of a hypoplastic left heart syndrome was accepted by 84.3% across all professional groups, while mentioning fetocide was more frequently cited as an option by prenatal diagnosticians than by obstetricians (57.7% vs. 34.1%).

CONCLUSION

Interdisciplinary prenatal parental counseling in complex fetal malformations is uniformly advocated by prenatal diagnosticians and obstetricians in Germany. However, different ethical attitudes appear among specialists groups with regard to the option of termination of pregnancy.

Hypoplastic Left Heart Syndrome: Signaling & Molecular Perspectives, and the Road Ahead

Hypoplastic left heart syndrome (HLHS) is a lethal congenital heart disease (CHD) affecting 8-25 per 100,000 neonates globally. Clinical interventions, primarily surgical, have improved the life expectancy of the affected subjects substantially over the years. However, the etiological basis of HLHS remains fundamentally unclear to this day. Based upon the existing paradigm of studies, HLHS exhibits a multifactorial mode of etiology mediated by a complicated course of genetic and signaling cascade. This review presents a detailed outline of the HLHS phenotype, the prenatal and postnatal risks, and the signaling and molecular mechanisms driving HLHS pathogenesis. The review discusses the potential limitations and future perspectives of studies that can be undertaken to address the existing scientific gap. Mechanistic studies to explain HLHS etiology will potentially elucidate novel druggable targets and empower the development of therapeutic regimens against HLHS in the future.

Hypoplastic Left Heart Syndrome: A Case Report

Hypoplastic left heart syndrome is a rare critical congenital heart defect constituting a prevalence of 1/3,500 to 1/12,500 live births in which there is obstructions to the blood flow within the left heart. Here we present a case of a full-term 38 weeks male baby with a birth weight of 3.5 kg, and no obvious physical deformity referred to our centre at 22 hours of life for respiratory distress and cyanosis. At 23 hours of life, he was diagnosed with hypoplastic left heart syndrome and kept on Prostaglandin E1 infusion till the 12th day of life. The baby had a large ventricular septal defect and atrial septal defect with a severely hypoplastic left ventricle, hypoplastic aortic root, ascending aorta and post-ductal coarctation of the aorta. The diagnosis was reconfirmed by computed tomography cardiac angiography on the 10th day of life with the same cardiac findings suggestive of hypoplastic left heart syndrome.

Keywords

case reports; congenital heart disease; hypoplastic left heart syndrome.

Preoperative versus postoperative survival in patients with univentricular heart: a nationwide, retrospective study of patients born in 1990-2015

OBJECTIVES

Few data exist on mortality among patients with univentricular heart (UVH) before surgery. Our aim was to explore the results of intention to perform surgery by estimating preoperative vs postoperative survival in different UVH subgroups.

DESIGN

Retrospective.

SETTING

Tertiary centre for congenital cardiology and congenital heart surgery.

PARTICIPANTS

All 595 Norwegian children with UVH born alive from 1990 to 2015, followed until 31 December 2020.

RESULTS

One quarter (151/595; 25.4%) were not operated. Among these, only two survived, and 125/149 (83.9%) died within 1 month. Reasons for not operating were that surgery was not feasible in 31.1%, preoperative complications in 25.2%, general health issues in 23.2% and parental decision in 20.5%. In total, 327/595 (55.0%) died; 283/327 (86.5%) already died during the first 2 years of life. Preoperative survival varied widely among the UVH subgroups, ranging from 40/65 (61.5%) among patients with unbalanced atrioventricular septal defect to 39/42 (92.9%) among patients with double inlet left ventricle. Postoperative survival followed a similar pattern. Postoperative survival among patients with hypoplastic left heart syndrome (HLHS) improved significantly (5-year survival, 42.5% vs 75.3% among patients born in 1990-2002 vs 2003-2015; p<0.0001), but not among non-HLHS patients (65.7% vs 72.6%; p=0.22)-among whom several subgroups had a poor prognosis similar to HLHS. A total of 291/595 patients (48.9%) had Fontan surgery CONCLUSIONS: Surgery was refrained in one quarter of the patients, among whom almost all died shortly after birth. Long-term prognosis was largely determined during the first 2 years. There was a strong concordance between preoperative and postoperative survival. HLHS survival was improved, but non-HLHS survival did not change significantly. This study demonstrates the complications and outcomes encountering newborns with UVH at all major stages of preoperative and operative treatment.

Factors influencing the choice-of-care pathway and survival in the fetus with hypoplastic left heart syndrome in New Zealand: a population-based cohort study

OBJECTIVES

To better understand the relative influence of fetal and maternal factors in determining the choice-of-care pathway (CCP) and outcome in the fetus with hypoplastic left heart syndrome (HLHS).

DESIGN

A retrospective, population-based study of fetuses with HLHS from a national dataset with near-complete case ascertainment from 20 weeks' gestation. Fetal cardiac and non-cardiac factors were recorded from the patient record and maternal factors from the national maternity dataset. The primary endpoint was a prenatal decision for active treatment after birth (intention-to-treat). Factors associated with a delayed diagnosis (≥24 weeks' gestation) were also reviewed. Secondary endpoints included proceeding to surgical treatment, and 30-day postoperative mortality in liveborns with an intention-to-treat.

SETTING

New Zealand population-wide.

PARTICIPANTS

Fetuses with a prenatal diagnosis of HLHS between 2006 and 2015.

RESULTS

Of 105 fetuses, the CCP was intention-to-treat in 43 (41%), and pregnancy termination or comfort care in 62 (59%). Factors associated with intention-to-treat by multivariable analysis included a delay in diagnosis (OR: 7.8, 95% CI: 3.0 to 20.6, p<0.001) and domicile in the maternal fetal medicine (MFM) region with the most widely dispersed population (OR: 5.3, 95% CI: 1.4 to 20.3, p=0.02). Delay in diagnosis was associated with Māori maternal ethnicity compared with European (OR: 12.9, 95% CI: 3.1 to 54, p<0.001) and greater distance from the MFM centre (OR: 3.1, 95% CI: 1.2 to 8.2, p=0.02). In those with a prenatal intention-to-treat, a decision not to proceed to surgery was associated with maternal ethnicity other than European (p=0.005) and the presence of major non-cardiac anomalies (p=0.01). Thirty-day postoperative mortality occurred in 5/32 (16%) and was more frequent when there were major non-cardiac anomalies (p=0.02).

CONCLUSIONS

Factors associated with the prenatal CCP relate to healthcare access. Anatomic characteristics impact treatment decisions after birth and early postoperative mortality. The association of ethnicity with delayed prenatal diagnosis and postnatal decision-making suggests systemic inequity and requires further investigation.

Congenital heart disease: changes in recorded birth prevalence and cardiac interventions over the past half-century in Sweden

AIMS

Our objective was to assess changes in the birth prevalence of CHD over a half-century in a high-resource, nationwide setting, as well as changes in the prevalence of cardiac interventions in this population.

METHODS AND RESULTS

The Swedish National Patient and Cause of Death registers were linked to estimate the annual rates of CHD and cardiac interventions among live-born infants from 1970 to 2017. Additionally, separate estimates were obtained by lesion complexity, from mild to the most complex forms of CHD. Overall, the numbers of live-born infants with a CHD identified varied from 624 to 2459 annual cases, with rates increasing steadily from 5.7 to an average of 20 per 1000 live births at the end of the study period, and with a more pronounced increase from 1996 to 2005. The largest increase over time was observed for mild CHD lesions. Overall, the proportion of cardiac interventions among patients with CHD declined from 40.7% in 1970 to below 15.0% after 2014. However, in the most complex CHD lesion groups, overall cardiac interventions increased from 57.1 to 76.8% in patients with conotruncal defects and from 32.8 to 39.5% in those with severe non-conotruncal defects.

CONCLUSION

The live-birth prevalence of CHD in Sweden more than tripled during the past half-century, most likely resulting from more accurate diagnostic capabilities. The largest increase over time was observed among patients with simple defects. During the same period, overall cardiac interventions decreased whereas interventions for the most complex CHD groups increased.

The Alberta Congenital Anomalies Surveillance System: a 40-year review with prevalence and trends for selected congenital anomalies, 1997-2019

INTRODUCTION

Current published long-term provincial or territorial congenital anomaly data are lacking for Canada. We report on prevalence (per 1000 total births) and trends in 1997-2019, in Alberta, Canada, for selected congenital anomalies. Associated risk factors are also discussed.

METHODS

We used data from the Alberta Congenital Anomalies Surveillance System (ACASS) to calculate the prevalence and perform chi-square linear trend analyses.

RESULTS

From 1997 to 2019, the overall prevalence of neural tube defects was stable, at 0.74 per 1000 total births. The same was true for spina bifida (0.38), orofacial clefts (1.99), more severe CHDs (transposition of the great arteries, 0.38; tetralogy of Fallot, 0.33; and hypoplastic left heart syndrome, 0.32); and gastroschisis (0.38). Anencephaly, cleft palate and anorectal malformation significantly decreased with a prevalence of 0.23, 0.75 and 0.54 per 1000 total births, respectively. Significantly increasing trends were reported for anotia/microtia (0.24), limb reduction anomalies (0.73), omphalocele (0.36) and Down syndrome (2.21) and for hypospadias and undescended testes (4.68 and 5.29, respectively, per 1000 male births).

CONCLUSION

Congenital anomalies are an important public health concern with significant social and societal costs. Surveillance data gathered by ACASS for over 40 years can be used for planning and policy decisions and the evaluation of prevention strategies. Contributing genetic and environmental factors are discussed as is the need for continued surveillance and research.

Hypoplastic Left Heart Syndrome Across the Lifespan: Clinical Considerations for Care of the Fetus, Child, and Adult

Hypoplastic left heart syndrome (HLHS) is the most common anatomic lesion in children born with single ventricle physiology and is characterized by the presence of a dominant right ventricle and a hypoplastic left ventricle along with small left-sided heart structures. Diagnostic subgroups of HLHS reflect the extent of inflow and outflow obstruction at the aortic and mitral valves, specifically stenosis or atresia. If left unpalliated, HLHS is a uniformly fatal lesion in infancy. Following introduction of the Norwood operation, early survival has steadily improved over the past four decades, mirroring advances in operative and peri-operative management as well as reflecting refinements in patient surveillance and interstage clinical care. Notably, survival following staged palliation has increased from 0% to a 5-year survival of 60-65% for children in some centres. Despite the prevalence of HLHS in childhood with relatively favourable surgical outcomes in contemporary series, this cohort is only now reaching early adult life and longer-term outcomes have yet to be elucidated. In this article we focus on contemporary clinical management strategies for patients with HLHS across the lifespan, from fetal to adult life. Nomenclature and diagnostic considerations are discussed and current literature pertaining to putative genetic etiologies is reviewed. The spectrum of fetal and pediatric interventional strategies, both percutaneous and surgical, are described. Clinical, patient-reported and neurodevelopmental outcomes of HLHS are delineated. Finally, note is made of current areas of clinical uncertainty and suggested directions for future research are highlighted.

Prevalence and Infant Mortality of Major Congenital Malformations Stratified by Birthweight

BACKGROUND

Low birthweight and major congenital malformations (MCMs) are key causes of infant mortality.

OBJECTIVES

The aim of this study was to explore the prevalence of MCMs in infants with low and very low birthweight and analyze the impact of MCMs and birthweight on infant mortality.

METHODS

We determined prevalence and infant mortality of 28 life-threatening MCMs in very-low-birthweight (<1,500 g, VLBW), low-birthweight (1,500-2,499 g, LBW), or normal-birthweight (≥2,500 g, NBW) infants in a cohort of 2,727,002 infants born in Germany in 2006-2017, using de-identified administrative data of the largest statutory public health insurance system in Germany.

RESULTS

The rates of VLBW, LBW, and NBW infants studied were 1.3% (34,401), 4.0% (109,558), and 94.7% (2,583,043). MCMs affected 0.5% (13,563) infants, of whom >75% (10,316) had severe congenital heart disease. The prevalence (per 10,000) of any/cardiac MCM was increased in VLBW (286/176) and LBW (244/143), as compared to NBW infants (38/32). Infant mortality rates were significantly higher in infants with an MCM, as opposed to infants without an MCM, in each birthweight group (VLBW 28.5% vs. 11.5%, LBW 16.7% vs. 0.9%, and NBW 8.6% vs. 0.1%). For most MCMs, observed survival rates in VLBW and LBW infants were lower than expected, as calculated from survival rates of VLBW or LBW infants without an MCM, and NBW infants with an MCM.

CONCLUSIONS

Infants with an MCM are more often born with LBW or VLBW, as opposed to infants without an MCM. Many MCMs carry significant excess mortality when occurring in VLBW or LBW infants.

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.

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.

Prenatal diagnosis of congenital heart defects: echocardiography

Congenital heart defects (CHD) are the most common congenital anomaly, and the majority can be diagnosed during prenatal life. Prenatal detection rates remain highly variable, as most CHD occur in low risk pregnancies and therefore depend on the maternal obstetric provider to recognize fetal cardiac abnormality on obstetric screening anatomic ultrasound. Fetuses with abnormal findings on obstetric screening anatomic ultrasound and/or risk factors for cardiac disease should be referred for evaluation with fetal echocardiography. Fetal echocardiography should be performed by specialized sonographers and interpreted by physicians with knowledge of evolving fetal cardiac anatomy and physiology throughout gestation. A fetal echocardiography examination, which can be done from the late first trimester onward, utilizes a standardized and systemic approach to diagnose fetuses with CHD or other forms of primary or secondary cardiac disease. The field of fetal cardiology has advanced past the accurate prenatal diagnosis of simple and complex CHD, as fetal echocardiography enables understanding of dynamic fetal cardiac physiology and consideration of potential fetal/neonatal treatment. The greatest impact of fetal echocardiography remains identification of critical CHD before birth to allow immediate cardiac management after delivery to decrease neonatal morbidity and mortality. Analyzing the severity of abnormal cardiac physiology in various forms of CHD before birth allows the fetal cardiologist to prognosticate effects on the developing fetus, predict risk of postnatal hemodynamic instability, guide delivery planning through multidisciplinary collaboration, and anticipate how the disease will impact the neonate after delivery.

Role of gated cardiac computed tomographic angiography in the evaluation of postsurgical complications after stage I Norwood procedure and its implications on management: a comparative study with two-dimensional echocardiography

BACKGROUND

The Norwood procedure is the first part of a three-stage surgical palliation for patients with functionally single ventricle anatomy. Complications after the stage I operation are not uncommon. Transthoracic echocardiography (TTE) is traditionally the mainstay for evaluation.

OBJECTIVE

The purpose of our study is to compare gated cardiac computed tomographic angiography (CCTA) with TTE when evaluating for postoperative complications after stage I Norwood procedure and to describe management implications.

MATERIALS AND METHODS

A retrospective chart review of all patients over a 4-year period who underwent nonelective urgent CCTA for suspected complications related to stage I Norwood procedure was performed. Elective CCTA studies before stage II palliation were excluded. Patient demographics, CCTA and TTE findings, as well as interventions performed, were recorded.

RESULTS

Thirty-four patients were included. The mean age at CCTA was 63 days (range: 4-210 days). All patients had a recent TTE with a mean time interval between TTE and CCTA of 2 days. CCTA detected 56 abnormalities in 30 patients, with 23 directly related to postsurgical complications, including shunt-related complications (10/23, 43%), Damus-Kaye-Stansel anastomotic narrowing (2/23, 9%) and neo-aortic arch/branch vessel abnormalities (11/23, 48%). These complications were managed as follows: surgery (9, 39%), catheter-based intervention (7, 30%), medical (4, 17%) and no change in management (3, 13%). TTE did not detect 8/23 (35%) findings found on CCTA, of which 75% were either managed with surgery (4/8, 50%) or catheter-based intervention (2/8, 25%).

CONCLUSION

CCTA plays an important role in detecting surgical complications after stage I Norwood procedure and demonstrates additional findings that have direct management implications.

Survival in Children With Congenital Heart Disease: Have We Reached a Peak at 97%?

Background

Despite advances in pediatric health care over recent decades, it is not clear whether survival in children with congenital heart disease (CHD) is still increasing.

Methods and Results

We identified all patients with CHD using nationwide Swedish health registries for 1980 to 2017. We examined the survival trends in children with CHD; we investigated the mortality risk in patients with CHD compared with matched controls without CHD from the general population using Cox proportional regression models and Kaplan–Meier survival analysis. Among 64 396 patients with CHD and 639 012 matched controls without CHD, 3845 (6.0%) and 2235 (0.3%) died, respectively. The mean study follow‐up (SD) was 11.4 (6.3) years in patients with CHD. The mortality risk was 17.7 (95% CI, 16.8–18.6) times higher in children with CHD compared with controls. The highest mortality risk was found during the first 4 years of life in patients with CHD (hazard ratio [HR], 19.6; 95% CI, 18.5–20.7). When stratified by lesion group, patients with non‐conotruncal defects had the highest risk (HR, 97.2; 95% CI, 80.4–117.4). Survival increased substantially according to birth decades, but with no improvement after the turn of the century where survivorship reached 97% in children with CHD born in 2010 to 2017.

Conclusions

Survival in children with CHD has increased substantially since the 1980s; however, no significant improvement has been observed this century. Currently, >97% of children with CHD can be expected to reach adulthood highlighting the need of life‐time management.

Detailed Echocardiographic Measurements of Individual Chamber in a Chinese Cohort of Hypoplastic Left Heart Syndrome and Comparison with Normal Fetuses via Z-score Modeling

Hypoplastic left heart syndrome (HLHS) is a rare, but exceptionally serious, congenital heart defect. We aimed to explore the best-fitted Z-score models for individual chamber dimension and to draw a comparison between fetuses with HLHS and the normal Chinese cohort. We made measurements of 1674 healthy fetuses and 79 fetuses with HLHS, undertaking echocardiography. Normal fetal cardiovascular Z-score formulae were established by curve-fitting with 5 algorithmic functions and weighted regression of absolute residuals. Classic linear models were fitted for left ventricular diameter against gestational age, and log-transformed linear-power models-were statistically better for left ventricular length, diameter of left atrium and ascending aorta. Fetuses with HLHS manifested significantly lower Z-score means (≤3.5) for these 4 parameters and the vast majority (∼90%) lay beyond -2. Overall, cardiovascular Z-score equations were reliably constructed in a larger Chinese cohort, and their application should benefit evaluation and diagnosis of HLHS.

Transplantation-free survival after Norwood surgery for hypoplastic left heart syndrome with aortic atresia: A Swedish national cohort study

BACKGROUND

Norwood surgery has been available in Sweden since 1993. In this national cohort study, we analysed transplantation-free survival after Norwood surgery for hypoplastic left heart syndrome with aortic atresia.

METHODS

Patients were identified from the complete national cohort of live-born with hypoplastic left heart syndrome/aortic atresia 1993-2010. Analysis of survival after surgery was performed using Cox proportional hazards models for the total cohort and for birth period and gender separately. Thirty-day mortality and inter-stage mortality were analysed. Patients were followed until September 2016.

RESULTS

The 1993-2010 cohort consisted of 208 live-born infants. Norwood surgery was performed in 121/208 (58%). The overall transplantation-free survival was 61/121 (50%). The survival was higher in the late period (10-year survival 63%) than in the early period (10-year survival 40%) (p = 0.010) and lower for female (10-year survival 34%) than for male patients (10-year survival 59%) (p = 0.002). Inter-stage mortality between stages I and II decreased from 23 to 8% (p = 0.008). For male patients, low birthweight in relation to gestational age was a factor associated with poor outcome.

CONCLUSION

The survival after Norwood surgery for hypoplastic left heart syndrome/aortic atresia improved by era of surgery, mainly explained by improved survival between stages I and II. Female gender was a significant risk factor for death or transplantation. For male patients, there was an increased risk of death when birthweight was lower than expected in relation to gestational age.

Changing Epidemiology of Hypoplastic Left Heart Syndrome: Results of a National Swedish Cohort Study

Background Norwood surgery provides a palliative surgical option for hypoplastic left heart syndrome and has been available in Sweden since 1993. The practice of prenatal ultrasound screening was gradually implemented in the same era, resulting in an increased prenatal detection rate. Our primary aims were to study changes in the incidence of live births, prenatal detection rate, and the termination of pregnancies over time. The secondary aims were to study the proportion of live-borns undergoing surgery and to identify factors that influenced whether surgery was or was not performed. Methods and Results Neonates with hypoplastic left heart syndrome with aortic atresia born 1990-2010 were identified through national databases, surgical files, and medical records. The fetal incidence was estimated from the period when prenatal screening was rudimentary. The study period was divided into the presurgical, early surgical, and late surgical periods. The incidence was calculated as the overall yearly incidence for each time period and sex separately. Factors influencing whether surgery was performed were analyzed using Cox-logistic regression. The incidence at live birth decreased from 15.4 to 8.4 per 100 000. The prenatal detection rate increased from 27% to 63%, and terminations increased from 19% to 56%. The odds of having surgery was higher in the late period and higher in the group with prenatal diagnosis. Conclusions We observed a decrease in incidence of live-borns with hypoplastic left heart syndrome aortic atresia. There was in increase in prenatal detection rate and an increase in termination of pregnancy. The proportion of live-borns who underwent surgery increased between time periods.