Gestational Age, Birth Weight, and Outcomes Six Years After the Norwood Procedure

Impact of low birth weight on staged single-ventricle palliation

BACKGROUND

To assess the impact of low birth weight on early and late outcomes after staged palliation for single ventricle.

METHODS

Patients after stage 1 palliation for single ventricle in our institution were retrospectively included and divided into two weight groups: 2.5 kg or less (low birth weight) and more than 2.5 kg. The impact of low birth weight on mortality and on the progression to further palliation stages (bidirectional Glenn, stage 2, and total cavopulmonary connection, stage 3) was assessed.

RESULTS

A total of 452 patients were included. Patients with low birth weight (n = 37, 8 %) had more frequently associated prematurity and extracardiac anomalies. Early and inter-stage mortality after stage 1 was higher in patients with low birth weight, so that less of these patients reached the next palliation stage (57 % vs. 77 %, p = 0.01, and 38 % vs. 56 %, p = 0.05, for stage 2 and stage 3, respectively). After 5 years, overall survival was inferior in patients with low birth weight (48 % vs. 73 %, p < 0.001). Survival conditioned by stage 2 palliation was inferior in patients with low birth weight compared to the reference group (76 % vs. 89 % after 5 years, p = 0.04). Low birth weight was a risk factor for death in most patients' subgroups, inclusive those with restricted pulmonary blood flow after a systemic-to-pulmonary shunt procedure.

CONCLUSIONS

During staged palliation of single-ventricle physiology, low birth weight has a detrimental impact on survival extending to beyond stage 2. This study calls for increased vigilance of these patients beyond the first interstage.

Neurodevelopmental outcomes of preterm and growth-restricted neonate with congenital heart defect: a systematic review and meta-analysis

The purpose of the study is to assess the risks of neurodevelopmental morbidity among preterm and growth restricted youth with congenital heart defects (CHD). This systematic review and meta-analysis included observational studies assessing neurodevelopmental outcomes among children with CHD born preterm (i.e., before 37 weeks of gestation) or growth restricted (small-for-gestational age (SGA) with a birthweight < the 10th percentile or with low birthweight (LBW) < 2500 g). Studies were identified in Medline and Embase databases from inception until May 2022, with data extracted by two blinded reviewers. Risk of bias was assessed using the Critical Appraisal Skills Programme cohort checklist. Meta-analysis involved the use of random-effects models. Main outcome measures were neurodevelopmental outcomes including overall cognitive impairment and intellectual disability, IQ, communication, and motor skills scores. From 3573 reports, we included 19 studies in qualitative synthesis and 6 meta-analysis studies. Risk of bias was low in 8/19 studies. Cognitive impairment and intellectual disability were found in 26% (95% CI 20-32, I2 = 0%) and 19% (95% CI 7-35, I2 = 82%) of preterm children with CHD, respectively. Two studies documented a lower IQ score for SGA children who underwent CHD operations in comparison to non-SGA children who also underwent CHD operations. Two studies have reported lower IQ, communication, and motor skills in children with hypoplastic left heart syndrome (HLHS) and low birth weight compared to those with HLHS and expected birth weight.

CONCLUSIONS

Based on a low level of evidence, prematurity and/or growth retardation appear to accentuate specific neurodevelopmental outcomes in certain CHD subgroups. Further evidence is needed to confirm these findings.

TRIAL REGISTRATION

PROSPERO [CRD42020201414].

WHAT IS KNOWN

• Children born with CHD, preterm birth, or growth restriction at birth are independently at higher risk for neurodevelopmental impairment. • The additional effect of preterm birth and/or growth restriction on neurodevelopmental outcomes in children with CHD remains unclear.

WHAT IS NEW

• Prematurity and/or growth retardation appear to accentuate specific neurodevelopmental outcomes in certain CHD subgroups. • Children with CHD, particularly those born preterm or with growth restriction, should undergo lifelong systematic comprehensive neurodevelopmental assessment.

The American Association for Thoracic Surgery (AATS) 2023 Expert Consensus Document: Recommendation for the care of children with trisomy 13 or trisomy 18 and a congenital heart defect

OBJECTIVES

Recommendations for surgical repair of a congenital heart defect in children with trisomy 13 or trisomy 18 remain controversial, are subject to biases, and are largely unsupported with limited empirical data. This has created significant distrust and uncertainty among parents and could potentially lead to suboptimal care for patients. A working group, representing several clinical specialties involved with the care of these children, developed recommendations to assist in the decision-making process for congenital heart defect care in this population. The goal of these recommendations is to provide families and their health care teams with a framework for clinical decision making based on the literature and expert opinions.

METHODS

This project was performed under the auspices of the AATS Congenital Heart Surgery Evidence-Based Medicine Taskforce. A Patient/Population, Intervention, Comparison/Control, Outcome process was used to generate preliminary statements and recommendations to address various aspects related to cardiac surgery in children with trisomy 13 or trisomy 18. Delphi methodology was then used iteratively to generate consensus among the group using a structured communication process.

RESULTS

Nine recommendations were developed from a set of initial statements that arose from the Patient/Population, Intervention, Comparison/Control, Outcome process methodology following the groups' review of more than 500 articles. These recommendations were adjudicated by this group of experts using a modified Delphi process in a reproducible fashion and make up the current publication. The Class (strength) of recommendations was usually Class IIa (moderate benefit), and the overall level (quality) of evidence was level C-limited data.

CONCLUSIONS

This is the first set of recommendations collated by an expert multidisciplinary group to address specific issues around indications for surgical intervention in children with trisomy 13 or trisomy 18 with congenital heart defect. Based on our analysis of recent data, we recommend that decisions should not be based solely on the presence of trisomy but, instead, should be made on a case-by-case basis, considering both the severity of the baby's heart disease as well as the presence of other anomalies. These recommendations offer a framework to assist parents and clinicians in surgical decision making for children who have trisomy 13 or trisomy 18 with congenital heart defect.

Hypoplastic Left Heart Syndrome With Low Birth Weight or Prematurity: What Is the Optimal Approach?

BACKGROUND

Hypoplastic left heart syndrome with low birth weight or prematurity comprises a high-risk population with no optimal treatment pathway. Using the Pediatric Health Information System, we compared management approaches across the United States.

METHODS

We analyzed neonates (≤30 days) with birth weight <2500 grams or gestational age <36 weeks between 2012 and 2021. Four strategies were identified: Norwood procedure, ductus arteriosus stent + pulmonary artery banding, pulmonary artery banding + prostaglandin infusion, or comfort care. Outcomes included hospital survival, discharge disposition, staged palliation completion, and 1-year transplant-free survival.

RESULTS

Of 383 infants identified, 36.4% (n = 134) received comfort care, 43.9% (n = 165) Norwood, 12.4% (n = 49) ductal stent + pulmonary artery bands, and 8.8% (n = 34) pulmonary artery bands + prostaglandins. Neonates receiving comfort care had the lowest gestational age (35 weeks; interquartile range [IQR], 31.5-37 weeks) and birth weight (2.0 kg; IQR, 1.5-2.3 kg); 24.6% (33 of 134) had chromosomal anomalies. Infants undergoing primary Norwood had the highest birth weight (2.4 kg; IQR, 2.2-2.5 kg) and gestational age (37 weeks; IQR, 35-38 weeks). Glenn palliation was performed in 66.1% (109 of 165) compared with ductal stent + pulmonary artery band in 18.4% (9 of 49) and pulmonary artery band + prostaglandins in 35.3% (12 of 34). Only 11.3% (6 of 53) born <2 kg survived to 1 year, all after Norwood. Primary Norwood yielded higher hospital and 1-year transplant-free survival than hybrid strategies.

CONCLUSIONS

Comfort care is routinely provided, particularly for infants with low birth weight, gestational age, or chromosomal anomalies. Primary Norwood offered the lowest hospital and 1-year mortality and highest palliation completion rates; birth weight was the most important factor determining 1-year survival.

Impact of Reintervention During Stage 1 Palliation Hospitalization: A National, Multicenter Study

BACKGROUND

Stage 1 palliation (S1P) for hypoplastic left heart syndrome remains associated with high morbidity and mortality. Previous studies on burden of reinterventions did not include patients who remain hospitalized before stage 2 palliation (S2P). This study described the rate of reintervention during S1P hospitalization and sought to determine the impact of reintervention on outcomes.

METHODS

All participants enrolled in phase II of the National Pediatric Cardiology Quality Improvement Collaborative after S1P were included in this study. The primary outcome was the rate of reintervention during hospitalization after S1P and before hospital discharge or S2P. Reintervention was defined as 1 or more unplanned interventional cardiac catheterizations or surgical reoperations.

RESULTS

Between March 1, 2016 and October 1, 2019, 1367 participants underwent S1P and 339 (24.8%) had a reintervention; most commonly to address the source of pulmonary blood flow. Gestational age, weight at S1P, atrioventricular septal defect, heterotaxy, preoperative pulmonary artery bands, hybrid S1P, and an additional bypass run or early extracorporeal membrane oxygenation were significantly associated with reintervention. Participants in the reintervention group experienced higher rates of nearly all postoperative complications, were less likely to be discharged before S2P (57.1% vs 86%; P < .001), and more likely to experience in-hospital mortality (17% vs 5%; P < .001).

CONCLUSIONS

Unplanned reintervention during hospitalization after S1P palliation occurred in 25% of participants in a large, registry-based national cohort. Participants who underwent reintervention were more likely to remain as inpatient and were less likely to survive to S2P. Reintervention was associated with a multitude of postoperative complications that affect survival and long-term outcome.

Association Between Birth Weight Z-Scores and Early Outcomes Following Truncus Arteriosus Repair

In infants undergoing truncus arteriosus (TA) repair, we sought to determine associations between fetal growth restrictions as measured by birth weight Z-score and early outcomes. We utilized the Pediatric Health Information System (PHIS) database to identify infants < 90 days old who underwent TA repair from 2004 to 2019. The primary exposure variable was birth weight Z-score, calculated based on gestational age at birth, gender, and birth weight. The primary outcome was postoperative hospital mortality. Secondary outcomes included major complications, prolonged postoperative length of hospital stay (LOS; > 30 days), and hospital readmission within 1 year. Generalized estimating equation (GEE) models were used to identify adjusted associations between birth weight Z-score, small for gestational age (SGA) status, and mortality and included were 1039 subjects. Median birth weight was 2960 g, gestational age at birth was 38 weeks, and birth weight Z-score was - 0.47. SGA was present in 21% of subjects. Hospital mortality occurred in 104 patients (10%). By multivariable analysis, lower birth weight Z-score was associated with higher hospital mortality [for each unit decrease in birth weight Z-score below - 1.0, adjusted OR 1.71 (95% CI 1.10-4.25)]. SGA status was associated with increased hospital mortality (adjusted OR 2.17; 95% CI 1.39-3.40). Birth weight Z-scores and SGA status were not significantly associated with occurrence of cardiac arrest, ECMO use, gastrostomy tube placement, tracheostomy, seizures, infection, prolonged postoperative LOS, or hospital readmission. In infants undergoing TA repair, lower birth weight Z-scores and SGA status were strongly associated with increased hospital mortality.

Early Mortality in Infants Born with Neonatally Operated Congenital Heart Defects and Low or Very-Low Birthweight: A Systematic Review and Meta-Analysis

Mortality outcomes of children with isolated neonatally operated congenital heart defects (CHDs) born with a low (LBW), moderately low (MLBW) or very-low birthweight (VLBW) remain ambiguous. We searched Medline and Embase (inception until October 2021) and included studies that evaluated early mortality. The risk of bias was assessed using the Critical Appraisal Skills Program cohort checklist. Meta-analysis involved random-effects models. We explored variability in mortality across birthweight subgroups, CHD types, and study designs. From 2035 reports, we included 23 studies in qualitative synthesis, and the meta-analysis included 11 studies (1658 CHD cases), divided into 30 subcohorts. The risk of bias was low in 4/11 studies included in the meta-analysis. Summary mortality before discharge or within one month after surgery was 37% (95%CI 27-47). Early mortality varied by birthweight (VLBW 56%, MLBW 15%, LBW 16%; p = 0.003) and CHD types (hypoplastic left heart syndrome (HLHS) 50%, total anomalous pulmonary venous return (TAPVR) 47%, transposition of the great arteries (TGA) 34%, coarctation of the aorta (CoA) 16%; p = 0.13). Mortality was higher in population-based studies (49% vs. 10%; p = 0.006). One-third of infants born with neonatally operated isolated CHDs and LBW, MLBW, or VLBW died within 30 days after surgery. Mortality varied across infant and study characteristics. These results may help clinicians assess neonatal prognosis. PROSPERO registration CRD42020170289.

Prolonged Enteral Tube Feeding in Infants With a Functional Single Ventricle Is Associated With Adverse Outcomes After Fontan Completion

OBJECTIVES

To define the baseline characteristics of long-term tube-fed single ventricle patients, investigate associations between long-term enteral tube feeding and growth, and determine associations with long-term outcomes after Fontan procedure.

STUDY DESIGN

We performed a retrospective cohort study of patients in the Australia and New Zealand Fontan Registry undergoing treatment at the Royal Children's Hospital, the Children's Hospital at Westmead, Royal Melbourne Hospital, and Royal Prince Alfred Hospital from 1981-2018. Patients were defined as tube-fed (TF) or non-tube-fed (NTF) based on enteral tube feeding at age 90 days. Feeding groups were compared regarding BMI trajectory, BMI at last follow-up, and long-term incidence of severe Fontan failure.

RESULTS

Of 390 patients (56(14%) TF, 334(86%) NTF), TF was associated with right ventricular dominance, hypoplastic left heart syndrome, Norwood procedure, increased procedures prior to Fontan, extracardiac conduit Fontan, Fontan fenestration, and atrioventricular valve repair/replacement. TF patients were less likely to be in the higher compared with lowest 0-6 month BMI trajectory (P<0.01,P=0.03), had lower 6month weight-for-age z-scores (P<0.01) and length-for-age z-scores (P=0.01). TF were less likely to be overweight/obese at pediatric follow-up (HR=0.31,95%CI:0.12-0.80;P=0.02) and more likely to be underweight at adult follow-up ((HR=16.51; 5%CI:2.70-101.10;P<0.01).TF compared with NTF was associated with increased risk of severe Fontan failure (HR=4.13;95%CI=1.65,10.31;P<0.01).

CONCLUSIONS

Prolonged infant enteral tube feeding is an independent marker of poor growth and adverse clinical outcomes extending long-term post-Fontan procedure.

Growth and risk of adverse neuro-developmental outcome in infants with congenital heart disease: A systematic review

AIM

Congenital heart disease (CHD) is one of the most common birth defects affecting around 1:100 infants. In this systematic review, we aimed to determine impact of growth on neurodevelopmental outcomes of infants with CHD.

METHODS

Studies that reported association of growth with developmental outcomes in infants with CHD who had surgery, were included. The search strategy was prospectively registered. Relevant studies were identified by electronic searches. The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched from their earliest date to February 2022.

RESULTS

Twenty studies met inclusion criteria. Choice of growth measures, developmental assessment tools and timing of assessment varied widely precluding conduct of a meta-analysis. Seventeen studies reported on infants who had cardio-pulmonary bypass. Birth weight was reported in thirteen studies and was associated with adverse outcome in nine. Head circumference at birth and later predicted developmental outcomes in five. Impaired postnatal growth was associated with adverse developmental outcome in seven studies.

CONCLUSION

Growth in infants with congenital heart disease, specifically single ventricle physiology can predict adverse neurodevelopmental outcome. Included studies showed significant clinical heterogeneity. Uniformity should be agreed by various data registries with routine prospective collection of growth and developmental data.

Cumulative comorbid conditions influence mortality risk after staged palliation for hypoplastic left heart syndrome and variants

OBJECTIVE

Prematurity, low birth weight, genetic syndromes, extracardiac conditions, and secondary cardiac lesions are considered high-risk conditions associated with mortality after stage 1 palliation. We report the impact of these conditions on outcomes from a prospective multicenter improvement collaborative.

METHODS

The National Pediatric Cardiology Quality Improvement Collaborative Phase II registry was queried. Comorbid conditions were categorized and quantified to determine the cumulative burden of high-risk diagnoses on survival to the first birthday. Logistic regression was applied to evaluate factors associated with mortality.

RESULTS

Of the 1421 participants, 40% (575) had at least 1 high-risk condition. The aggregate high-risk group had lower survival to the first birthday compared with standard risk (76.2% vs 88.1%, P < .001). Presence of a single high-risk diagnosis was not associated with reduced survival to the first birthday (odds ratio, 0.71; confidence interval, 0.49-1.02, P = .066). Incremental increases in high-risk diagnoses were associated with reduced survival to first birthday (odds ratio, 0.23; confidence interval, 0.15-0.36, P < .001) for 2 and 0.17 (confidence interval, 0.10-0.30, P < .001) for 3 to 5 high-risk diagnoses. Additional analysis that included prestage 1 palliation characteristics and stage 1 palliation perioperative variables identified multiple high-risk diagnoses, poststage 1 palliation extracorporeal membrane oxygenation support (odds ratio, 0.14; confidence interval, 0.10-0.22, P < .001), and cardiac reoperation (odds ratio, 0.66; confidence interval, 0.45-0.98, P = .037) to be associated with reduced survival odds to the first birthday.

CONCLUSIONS

The presence of 1 high-risk diagnostic category was not associated with decreased survival at 1 year. Cumulative diagnoses across multiple high-risk diagnostic categories were associated with decreased odds of survival. Further patient accrual is needed to evaluate the impact of specific comorbid conditions within the broader high-risk categories.

Preterm Birth Is Associated With Adverse Cardiac Remodeling and Worse Outcomes in Patients With a Functional Single Right Ventricle

OBJECTIVE

To assess the effects of preterm birth on cardiac structure and function and transplant-free survival in patients with hypoplastic left heart syndrome and associated anomalies throughout the staged palliation process.

STUDY DESIGN

Data from the Single Ventricle Reconstruction trial were used to assess the impact of prematurity on echocardiographic measures at birth, Norwood, Stage II, and 14 months in 549 patients with a single functional right ventricle. Medical history was recorded once a year using medical records or telephone interviews. Cox regression models were applied to analyze transplant-free survival to age 6 years. Causal mediation analysis was performed to estimate the mediating effect of birth weight within this relationship.

RESULTS

Of the 549 participants, 64 (11.7%) were born preterm. Preterm-born participants had lower indexed right ventricle end-diastolic volumes at birth but higher volumes than term-born participants by age 14 months. Preterm-born participants had an increased risk of death or heart transplantation from birth to age 6 years, with an almost linear increase in the observed risk as gestational age decreased below 37 weeks. Of the total effect of preterm birth on transplant-free survival, 27.3% (95% CI 2.5-59.0%) was mediated through birth weight.

CONCLUSIONS

Preterm birth is associated with adverse right ventricle remodeling and worse transplant-free survival throughout the palliation process, in part independently of low birth weight. Further investigation into this vulnerable group may allow development of strategies that mitigate the impact of prematurity on outcomes in patients with hypoplastic left heart syndrome.

Prematurity and Congenital Heart Disease: A Contemporary Review

Congenital heart disease (CHD) is the most commonly reported birth defect in newborns. Neonates with CHD are more likely to be born prematurely, and a higher proportion of preterm neonates have CHD than their term counterparts. The implications of preterm birth on the cardiac and noncardiac organ systems are vast and require special management considerations. The feasibility of surgical interventions in preterm neonates is frequently limited by patient size and delicacy of immature cardiac tissues. Thus, special care must be taken when considering the appropriate timing and type of cardiac intervention. Despite improvements in neonatal cardiac surgical outcomes, preterm and early term gestational ages and low birthweight remain important risk factors for in-hospital mortality. Understanding the risks of early delivery of neonates with prenatally diagnosed CHD may help guide perioperative management in neonates who are born preterm. In this review, we will describe the risks and benefits of early delivery, postnatal cardiac and noncardiac evaluation and management, surgical considerations, overall outcomes, and future directions regarding optimization of perinatal evaluation and management of fetuses and preterm and early term neonates with CHD.

Outcomes Following Norwood Procedures: Analysis of a "Small Volume" Program

BACKGROUND

Institutional survival following Norwood procedures is traditionally correlated with a center's surgical volume. Multiple single and multi-institutional studies conducted at large-volume centers have recently demonstrated improved survival following Norwood procedures. We report both short- and long-term outcomes at a single, small-volume institution and comment on factors potentially influencing outcomes at this institution.

METHODS

All patients undergoing Norwood procedures from January 1, 2005, to January 1, 2020, at our institution were included in this study. Kaplan-Meier survival and Cox regression risk factor analyses were performed in addition to first interstage risk factor scoring to compare observed versus expected survival.

RESULTS

The cohort included 113 patients. Kaplan-Meier freedom from death or transplant was 88%, 80%, and 76% at 1, 5, and 10 years, respectively. Freedom from death following hospital discharge after Norwood procedures was 94%, 87%, and 83% at 1, 5, and 10 years, respectively. The presence of genetic syndromes was a significant risk factor for mortality. First interstage observed-to-expected mortality following discharge was 0.57 (P = .04). Postoperative length of stay was comparable to that reported for the period 2015 to 2018 in the Society of Thoracic Surgeons Database.

CONCLUSIONS

Survival outcomes at this single, small-volume institution were similar to those reported by large-volume centers and multi-institutional collaborative studies. These results may be related to structural and functional features that have been demonstrated to influence outcomes in other studies. These factors are achievable by small-volume programs with sufficient resource allocation.

Fetal Brain Volume Predicts Neurodevelopment in Congenital Heart Disease

BACKGROUND

Neurodevelopmental impairment is common in children with congenital heart disease (CHD), but postnatal variables explain only 30% of the variance in outcomes. To explore whether the antecedents for neurodevelopmental disabilities might begin in utero, we analyzed whether fetal brain volume predicted subsequent neurodevelopmental outcome in children with CHD.

METHODS

Fetuses with isolated CHD and sociodemographically comparable healthy control fetuses underwent fetal brain magnetic resonance imaging and 2-year neurodevelopmental evaluation with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) and the Adaptive Behavior Assessment System, Third Edition (ABAS-3). Hierarchical regression evaluated potential predictors of Bayley-III and ABAS-3 outcomes in the CHD group, including fetal total brain volume adjusted for gestational age and sex, sociodemographic characteristics, birth measures, and medical history.

RESULTS

The CHD group (n=52) had lower Bayley-III cognitive, language, and motor scores than the control group (n=26), but fetal brain volumes were similar. Within the CHD group, larger fetal total brain volume correlated with higher Bayley-III cognitive, language, and motor scores and ABAS-3 adaptive functioning scores (r=0.32-0.47; all P<0.05), but this was not noted in the control group. Fetal brain volume predicted 10% to 21% of the variance in neurodevelopmental outcome measures in univariate analyses. Multivariable models that also included social class and postnatal factors explained 18% to 45% of the variance in outcome, depending on developmental domain. Moreover, in final multivariable models, fetal brain volume was the most consistent predictor of neurodevelopmental outcome across domains.

CONCLUSIONS

Small fetal brain volume is a strong independent predictor of 2-year neurodevelopmental outcomes and may be an important imaging biomarker of future neurodevelopmental risk in CHD. Future studies are needed to support this hypothesis. Our findings support inclusion of fetal brain volume in risk stratification models and as a possible outcome in fetal neuroprotective intervention studies.

The Effect of Size and Asymmetry at Birth on Brain Injury and Neurodevelopmental Outcomes in Congenital Heart Disease

Poor and asymmetric fetal growth have been associated with neonatal brain injury (BI) and worse neurodevelopmental outcomes (NDO) in the growth-restricted population due to placental insufficiency. We tested the hypothesis that postnatal markers of fetal growth (birthweight (BW), head circumference (HC), and head to body symmetry) are associated with preoperative white matter injury (WMI) and NDO in infants with single ventricle physiology (SVP) and d-transposition of great arteries (TGA). 173 term newborns (106 TGA; 67 SVP) at two sites had pre-operative brain MRI to assess for WMI and measures of microstructural brain development. NDO was assessed at 30 months with the Bayley Scale of Infant Development-II (n = 69). We tested the association between growth parameters at birth with the primary outcome of WMI on the pre-operative brain MRI. Secondary outcomes included measures of NDO. Newborns with TGA were more likely to have growth asymmetry with smaller heads relative to weight while SVP newborns were symmetrically small. There was no association between BW, HC or asymmetry and WMI on preoperative brain MRI or with measures of microstructural brain development. Similarly, growth parameters at birth were not associated with NDO at 30 months. In a multivariable model only cardiac lesion and site were associated with NDO. Unlike other high-risk infant populations, postnatal markers of fetal growth including head to body asymmetry that is common in TGA is not associated with brain injury or NDO. Lesion type appears to play a more important role in NDO in CHD.

Impact of Maternal-Fetal Environment on Mortality in Children With Single Ventricle Heart Disease

BACKGROUND

Children with single ventricle heart disease have significant morbidity and mortality. The maternal–fetal environment (MFE) may adversely impact outcomes after neonatal cardiac surgery. We hypothesized that impaired MFE would be associated with an increased risk of death after stage 1 Norwood reconstruction.

METHODS AND RESULTS

We performed a retrospective cohort study of children with hypoplastic left heart syndrome (and anatomic variants) who underwent stage 1 Norwood reconstruction between 2008 and 2018. Impaired MFE was defined as maternal gestational hypertension, preeclampsia, gestational diabetes, and/or smoking during pregnancy. Cox proportional hazards regression models were used to investigate the association between impaired MFE and death while adjusting for confounders. Hospital length of stay was assessed with the competing risk of in‐hospital death. In 273 children, the median age at stage 1 Norwood reconstruction was 4 days (interquartile range [IQR], 3–6 days). A total of 72 children (26%) were exposed to an impaired MFE; they had more preterm births (18% versus 7%) and a greater percentage with low birth weights <2.5 kg (18% versus 4%) than those without impaired MFE. Impaired MFE was associated with a higher risk of death (hazard ratio [HR], 6.05; 95% CI, 3.59–10.21; P<0.001) after adjusting for age at surgery, Hispanic ethnicity, genetic syndrome, cardiac diagnosis, surgeon, and birth era. Children with impaired MFE had almost double the risk of prolonged hospital stay (HR, 1.95; 95% CI, 1.41–2.70; P<0.001).

CONCLUSIONS

Children exposed to an impaired MFE had a higher risk of death following stage 1 Norwood reconstruction. Prenatal exposures are potentially modifiable factors that can be targeted to improve outcomes after pediatric cardiac surgery.

Double Jeopardy: Prematurity and Congenital Heart Disease-What's Known and Why It's Important

This article is based on a composite of talks presented during the Double Jeopardy: Prematurity and Congenital Heart Disease Plenary Session at NeoHeart 2020, a global virtual conference.Prematurity and low weight remain significant risk factors for mortality after neonatal cardiac surgery despite a steady increase in survival. Newer and lower weight thresholds for operability are constantly generated as surgeons gather proficiency, technical mastery, and experience in performing complex procedures on extremely small infants. The relationship between birth weight and survival after cardiac surgery is nonlinear with 2 kilograms (kg) being an inflection point below which marked decline in survival occurs.The prevalence of congenital heart disease (CHD) in premature infants is more than twice that in term born infants. Increased risk of preterm birth in infants with CHD is most commonly due to spontaneous preterm birth and remains poorly understood.Advances in Neonatal-Perinatal medicine have led to a marked improvement in survival of neonates born prematurely over the last several decades. However, the risk of severe morbidities including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia and necrotizing enterocolitis remains significant in extremely low birth weight infants. Premature infants with CHD are at a greater risk of prematurity related morbidities than premature infants without CHD. Interventions that have been successful in decreasing the risk of these morbidities are addressed.

An introduction to and review of cardiac neurodevelopment: the risks and recommended approaches

PURPOSE OF REVIEW

To introduce the reader to the current understanding of the neurocognitive profile of congenital heart disease (CHD) survivors, the risk factors that may influence outcomes, and to the recommendations for cardiac neurodevelopmental care.

RECENT FINDINGS

A growing body of literature has shown that survivors of CHD are at increased risk for neurodevelopmental impairments. Multiple elements influence each patient's risk, which likely begins in utero and extends to perioperative management, surgical considerations, and long-term clinical care. Additionally, sociodemographic factors may compound these risks. Serial developmental follow-up is recommended for children with critical CHD.

SUMMARY

Though there are some clinical factors that increase risk, based on the high rate of developmental impairments for children with CHD, serial evaluations are recommended. Multidisciplinary and multicenter collaboration is ongoing and will facilitate moving this field forward to improve neurodevelopmental outcomes for children with CHD.

Myocardial Calcification and the Demise of an Infant With Surgically Treated Hypoplastic Left Heart Syndrome

A term female infant with hypoplastic left heart syndrome underwent Norwood palliation including aortic and pulmonary amalgamation with arch reconstruction, atrial septectomy, and right ventricle to pulmonary artery conduit. Postoperatively, she experienced hypoxemia and lactic acidosis although echocardiogram showed adequate conduit function. She was placed on veno-arterial extracorporeal membrane oxygenation (ECMO) on postoperative day two with improvement. ECMO decannulation was attempted with subsequent cardiac arrest and ultimate failure to resuscitate, eleven days after surgery. Autopsy confirmed clinical findings and evidence of surgical intervention with a patent conduit and neo-aorta. Multiple subendocardial right ventricular dystrophic calcifications involving the outflow tract were identified grossly and histologically with foci of associated myonecrosis. Myocardial calcification may lead to abnormal heart wall motion by increasing rigidity and compromising myocyte function or compromising the conduction system. In this patient, right ventricular turbulence caused by systolic and diastolic flow patterns, including mild tricuspid regurgitation, may have played a role in inducing dystrophic calcification along with surgery and ECMO dependence. Compromised myocyte function from calcifications, right ventricular hypertrophy, lung immaturity, and persistent pulmonary hypertension were likely sources of cardiac strain leading to the patient's demise. This case represents a previously unreported complication of hypoplastic left heart syndrome treatment.

Antenatal and Perioperative Mechanisms of Global Neurological Injury in Congenital Heart Disease

Congenital heart defects (CHD) is one of the most common types of birth defects. Thanks to advances in surgical techniques and intensive care, the majority of children with severe forms of CHD survive into adulthood. However, this increase in survival comes with a cost. CHD survivors have neurological functioning at the bottom of the normal range. A large spectrum of central nervous system dysmaturation leads to the deficits seen in critical CHD. The heart develops early during gestation, and CHD has a profound effect on fetal brain development for the remainder of gestation. Term infants with critical CHD are born with an immature brain, which is highly susceptible to hypoxic-ischemic injuries. Perioperative blood flow disturbances due to the CHD and the use of cardiopulmonary bypass or circulatory arrest during surgery cause additional neurological injuries. Innate patient factors, such as genetic syndromes and preterm birth, and postoperative complications play a larger role in neurological injury than perioperative factors. Strategies to reduce the disability burden in critical CHD survivors are urgently needed.

Trends in Preterm Delivery among Singleton Gestations with Critical Congenital Heart Disease

OBJECTIVE

To examine state-wide population trends in preterm delivery of children with critical congenital heart disease (CHD) over an 18-year period. We hypothesized that, coincident with early advancements in prenatal diagnosis, preterm delivery initially increased compared with the general population, and more recently has decreased.

STUDY DESIGN

Data from the Texas Public Use Data File 1999-2016 was used to evaluate annual percent preterm delivery (<37 weeks) in critical CHD (diagnoses requiring intervention at <1 year of age). We first evaluated for pattern change over time using joinpoint segmented regression. Trends in preterm delivery were then compared with all Texas livebirths. We then compared trends examining sociodemographic covariates including race/ethnicity, sex, and neighborhood poverty levels.

RESULTS

Of 7146 births with critical CHD, 1339 (18.7%) were delivered preterm. The rate of preterm birth increased from 1999 to 2004 (a mean increase of 1.69% per year) then decreased between 2005 and 2016 (a mean decrease of -0.41% per year). This represented a faster increase and then a similar decrease to that noted in the general population. Although the greatest proportion of preterm births occurred in newborns of Hispanic ethnicity and non-Hispanic black race, newborns with higher neighborhood poverty level had the most rapidly increasing rate of preterm delivery in the first era, and only a plateau rather than decrease in the latter era.

CONCLUSIONS

Rates of preterm birth for newborns with critical CHD in Texas first were increasing rapidly, then have been decreasing since 2005.

Maternal Predictors of Disparate Outcomes in Children With Single Ventricle Congenital Heart Disease

Background Significant variability in morbidity and mortality persists for children with functionally single ventricle congenital heart disease (SV-CHD) despite standardization in medical and surgical care. We hypothesized that maternal health factors may be associated with an increased risk of poor outcomes in children with SV-CHD. Methods and Results This retrospective, observational, cohort study included term maternal-infant pairs with a diagnosis of SV-CHD who underwent surgical palliation from 2006 to 2015 at Primary Children's Hospital. Pairs lacking maternal variables of interest or infant follow-up data were excluded. The association of maternal risk factors of abnormal pre-pregnancy body mass index, abnormal gestational weight gain (<7 or >20 kg), hypertensive disorders, and gestational diabetes mellitus with death/transplant and hemodynamics were analyzed using regression models. Of 190 infants, 135 (71%) maternal-infant dyads had complete data for inclusion. Death or transplant occurred in 48 infants (36%) during an average follow-up of 2.2 years (0.1-11.7 years). Abnormal gestational weight gain was associated with an increased risk of death and/or transplant in logistic regression (odds ratio, 3.22; 95% CI, 1.32-7.86; P=0.01), but not Cox regression (hazard ratio, 1.9; 95% CI, 1.0-3.7; P=0.055). Mean pulmonary artery pressures were higher in the setting of abnormal gestational weight gain (16.5±2.9 versus 14.7±3.0 mm Hg; P<0.001), and abnormal pre-pregnancy body mass index (15.7±3.5 versus 14.2±2.1 mm Hg; P<0.001) in the systemic right ventricle group. Conclusions Abnormal gestational weight gain (excessive or inadequate) is a novel risk factor for worse outcomes in SV-CHD. The fetoplacental environment may alter the trajectory of vascular development to impact outcomes in infants with SV-CHD.

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.

Right ventricular failure in congenital heart disease

PURPOSE OF REVIEW

We aim to review select literature pertaining to congenital heart disease (CHD)-induced right ventricular (RV) function and failure.

RECENT FINDINGS

We review recent findings pertaining to children and adults with repaired tetralogy of Fallot (rTOF), systemic RV and hypoplastic left heart syndrome (HLHS). We emphasize pathophysiological mechanisms contributing to RV dysfunction in these conditions, the risk factors for adverse outcomes and the continuing challenges in treating these patients. We discuss how recent pathology findings, as well as developments in imaging and computer modeling have broadened our understanding of the pathophysiology of these conditions. We further review developments in the molecular and cellular basis of RV failure; and in particular, the RV molecular response to stress in repaired tetralogy of Fallot (rTOF). We highlight some of the genetic complexities in HLHS and how these may influence the long-term outcomes in these patients.

SUMMARY

Recent literature has led to new understandings in the pathology, pathophysiology, risk factors for adverse outcomes, molecular and genetic basis for RV dysfunction and failure in CHD. Although these findings provide new therapeutic targets, the treatment of RV failure at this time remains limited.