Brain volume and metabolism in fetuses with congenital heart disease: evaluation with quantitative magnetic resonance imaging and spectroscopy

The Role of Proton Magnetic Resonance Spectroscopy in Neonatal and Fetal Brain Research

The biochemical composition and structure of the brain are in a rapid change during the exuberant stage of fetal and neonatal development. 1H-MRS is a noninvasive tool that can evaluate brain metabolites in healthy fetuses and infants as well as those with neurological diseases. This review aims to provide readers with an understanding of 1) the basic principles and technical considerations relevant to 1H-MRS in the fetal-neonatal brain and 2) the role of 1H-MRS in early fetal-neonatal development brain research. We performed a PubMed search to identify original studies using 1H-MRS in neonates and fetuses to establish the clinical applications of 1H-MRS. The eligible studies for this review included original research with 1H-MRS applications to the fetal-neonatal brain in healthy and high-risk conditions. We ran our search between 2000 and 2023, then added in several high-impact landmark publications from the 1990s. A total of 366 results appeared. After, we excluded original studies that did not include fetuses or neonates, non-proton MRS and non-neurological studies. Eventually, 110 studies were included in this literature review. Overall, the function of 1H-MRS in healthy fetal-neonatal brain studies focuses on measuring the change of metabolite concentrations during neurodevelopment and the physical properties of the metabolites such as T1/T2 relaxation times. For high-risk neonates, studies in very low birth weight preterm infants and full-term neonates with hypoxic-ischemic encephalopathy, along with examining the associations between brain biochemistry and cognitive neurodevelopment are most common. Additional high-risk conditions included infants with congenital heart disease or metabolic diseases, as well as fetuses of pregnant women with hypertensive disorders were of specific interest to researchers using 1H-MRS. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Neonatal Neurocardiac Care: Strategies to Optimize Neurodevelopmental Outcomes in Congenital Heart Disease

Neonates with critical congenital heart disease are at high risk for brain injury and neurodevelopmental disabilities. Neurocardiac care is a developing field, and there are few guidelines for front-line providers regarding neuromonitoring and neuroprotection. Understanding influences on early brain development, risk for seizures and brain injury, and long-term developmental outcomes can help providers formulate appropriate action plans for individual patients. Current evidence suggests that prenatal diagnosis, minimizing medical risk factors, monitoring for brain injury and seizures, providing individualized developmental care, supporting parental mental health, and referral to long-term developmental follow-up are components of care that may improve outcomes.

Longitudinal Trends in Pediatric Survival by Congenital Heart Defect in Texas, 1999 to 2017

BACKGROUND

Despite previously improved survival among children with congenital heart defects (CHDs), U.S. population-level evaluations of survival within recent years are scarce.

OBJECTIVES

The purpose of this study was to describe the survival landscape among children with CHDs in a large population-based birth defects registry overall and by CHD lesion.

METHODS

This population-based cohort study evaluated 1999 to 2017 live births with ≥1 major CHD in the statewide Texas Birth Defects Registry. Variables included CHD lesion, demographics, gestational age at birth (term/preterm), low birthweight (<2,500 g at birth), among others. Kaplan-Meier analyses were used to describe survival to 7 days, 28 days, 1 year, 5 years, and 10 years of life. Kaplan-Meier survival estimates were generated for 1-year survival for CHDs overall by lesion, using log-rank tests assessing differences by exposure.

RESULTS

Of 61,656 children with CHDs, survival was 98.1% and 90.7% at 7 days and 10 years, respectively, and substantially varied by lesion (range, 50.0% to 97.3% 10-year survival). Survival longitudinally improved for complex lesions including hypoplastic left heart syndrome (48.7% 1-year survival for cases born 1999-2004 vs 64.8% in 2014-2017; P < 0.0001). One-year survival differed by maternal race/ethnicity (eg, 58.3% for cases with complex pulmonary atresia born to non-Hispanic Black mothers vs 80.5% for non-Hispanic White mothers, P = 0.01), sex, gestational age, birthweight, and extracardiac defect status.

CONCLUSIONS

One-year survival improved for most CHDs over recent decades, although survival varies widely by CHD and characteristics. Findings have implications for clinical counseling, population-level resource and research planning, and reinforce the need for mitigation of disparities among individuals with CHDs.

Unraveling the impact of child opportunity and medical factors on neuropsychological outcomes in school-age patients with critical congenital heart disease

We examine the role that medical history and social determinants of health play in predicting school-age intellectual (IQ) and executive functioning (EF) in children with critical congenital heart disease (cCHD). This is a retrospective observational study of 197 patients with cCHD (age 5-18 years) who attended a neuropsychological evaluation through the Cardiac Neurodevelopmental Program. Medical history and social determinants of health (SDOH), measured by the Childhood Opportunity Index (COI 3.0), were obtained via chart review. COI was a significant predictor of school-age IQ and EF. Seizure history and genetic condition were predictors of IQ; inclusion of COI improved the model, predicting an additional 14% of the variance. The Education subdomain of COI, reflecting neighborhood-level educational resources, drove this effect. Aortic obstruction and seizure history were significant predictors of parent-reported EF; inclusion of COI provided modest improvement. Only COI was identified as a predictor of performance-based EF. Social determinants of health are important predictors of school-age functioning in children with cCHD, and efforts to promote positive neurodevelopmental outcomes in this population must consider SDOH. IQ at school-age is related to neighborhood educational resources. This suggests that enhancing educational opportunities in patients with cCHD in lower-resourced communities may promote positive neurodevelopment and reduce disparities.

Neurodevelopmental outcomes in congenital heart disease: modifiable and nonmodifiable substrates

PURPOSE OF REVIEW

Neurodevelopmental impairments are the most common comorbidity among children, adolescents, and adults with congenital heart disease (CHD). Despite significant advances in operative and perioperative care resulting in increased survival, neurodevelopmental impairments remain prevalent in this population. Neurodevelopmental impairments, though subtle, can have a major impact on quality of life, attainment of independence and societal contribution. In this review, we summarize current knowledge on neurodevelopmental outcomes in the CHD population, including neuroimaging findings, known risk factors and opportunities to optimize outcomes.

RECENT FINDINGS

Several risk factors have been identified contributing to neurodevelopmental impairments across the lifespan. These include risk factors originating in the prenatal period and new risk factors that are acquired in adulthood. The risk factors encompass several categories, including genetic abnormalities, aberrant cardiovascular physiology, environmental factors, social determinants of health and mental health. Many risk factors can be considered modifiable, though large multicenter studies identifying the most salient risk factors for neurodevelopmental impairment are lacking.

SUMMARY

In this review, we identify potentially modifiable risk factors for neurodevelopmental impairment in the CHD population that can be studies in future neuroprotective clinical trials.

Head circumference in neonates with septal defects

BACKGROUND

Neurodevelopmental disorders occur in up to 50% of children with CHD. Small head circumference at birth has been associated with impaired neurodevelopment in patients with complex CHD. It is unknown if patients with simple CHD such as septal defects have smaller head circumferences. The objective of this study was to investigate the head circumference at birth in neonates with either an atrial or a ventricular septal defect.

METHODS

This study is part of the Copenhagen Baby Heart Study; a prospective, population-based cohort study of more than 25,000 neonates. The neonates were examined with a comprehensive transthoracic echocardiography within the first 30 days of birth including assessment for atrial or ventricular septal defects. The head circumference at birth in term neonates with septal defects was compared to the head circumference in matched controls, term neonates without septal defects from the same birth cohort.

RESULTS

Neonates with septal defects (n = 1,030; 45.2% male; mean birthweight 3,534g ± 483g) had a mean head circumference of 34.8 cm (95% confidence interval 34.7-34.9 cm), compared to neonates without septal defects (n = 5,150; 45.6% male; mean birthweight 3,546g ± 476g) of 34.7 cm (95% confidence interval 34.7-34.8 cm); p-value 0.07. Mean calculated z-score of head circumferences was 0.05 for neonates with septal defects and -0.01 for neonates without septal defects, p = 0.07. Dividing cases into neonates with atrial septal defects, ventricular septal defects, and those without septal defects did not show differences between groups, p = 0.14.

CONCLUSION

The head circumference in term neonates with septal defects did not differ from matched controls without septal defects.

Cortical scaling of the neonatal brain in typical and altered development

Theoretically derived scaling laws capture the nonlinear relationships between rapidly expanding brain volume and cortical gyrification across mammalian species and in adult humans. However, the preservation of these laws has not been comprehensively assessed in typical or pathological brain development. Here, we assessed the scaling laws governing cortical thickness (CT), surface area (SA), and cortical folding in the neonatal brain. We also assessed multivariate morphological terms that capture brain size, shape, and folding processes. The sample consisted of 345 typically developing infants, 73 preterm infants, and 107 infants with congenital heart disease (CHD) who underwent brain MRI. Our results show that typically developing neonates and those with CHD follow the cortical folding scaling law obtained from mammalian brains, children, and adults which captures the relationship between exposed SA, total SA, and CT. Cortical folding scaling was not affected by gestational age at birth, postmenstrual age at scan, sex, or multiple birth in these populations. CHD was characterized by a unique reduction in the multivariate morphological term capturing size, suggesting that CHD affects cortical growth overall but not cortical folding processes. In contrast, preterm birth was characterized by altered cortical folding scaling and altered shape, suggesting that the developmentally programmed processes of cortical folding are disrupted in this population. The degree of altered shape was associated with cognitive abilities in early childhood in preterm infants.

Congenital Heart Defects and Apgar Score at Birth, a Nationwide Study

BACKGROUND

Low Apgar scores have been associated with an increased risk of brain injury and neurodevelopmental disorders in newborns with congenital heart defects (CHDs). However, the relation between CHD subtypes and low Apgar scores remains unknown. This study aimed to assess the association between major subtypes of CHD and low (<7) Apgar scores at 5 minutes.

METHODS AND RESULTS

This population-based study included 1 040 474 liveborn singletons in Denmark from 1997 to 2013. The association between CHD and low Apgar scores was estimated by confounder-adjusted, multivariable logistic regression. In mediation analyses, the underlying mechanisms were examined. Low Apgar scores were present in 3.0% of newborns with CHD and in 0.7% of newborns without CHD. Overall, CHD was associated with an increased risk of a low Apgar score (adjusted odds ratio, 2.5 [95% CI, 2.1-3.0]). CHD subtypes associated with the highest risks were anomalous pulmonary venous return (adjusted odds ratio, 5.7 [95% CI, 2.2-14.9]), hypoplastic left heart syndrome (adjusted odds ratio, 5.1 [95% CI, 2.2-11.8]), and transposition of the great arteries (adjusted odds ratio, 3.5 [95% CI, 1.7-7.4]). In mediation analyses, preterm birth explained 25.2% (95% CI, 11.8-38.6) of the association between CHD and low Apgar scores.

CONCLUSIONS

Nearly all CHD subtypes were associated with an increased risk of a low Apgar score. The association was most pronounced in severe and potentially cyanotic types of CHD. These findings suggest that CHD is associated with a complicated fetal-to-neonatal transition and highlight the potential for improvements of this process in infants with CHD.

Foetal cortical expansion is associated with neurodevelopmental outcome at 2-years in congenital heart disease: a longitudinal follow-up study

BACKGROUND

In adolescents and adults with complex congenital heart disease (CHD), abnormal cortical folding is a putative predictor of poor neurodevelopmental outcome. However, it is unknown when this relationship first emerges. We test the hypothesis that it begins in utero, when the brain starts to gyrify and folding patterns first become established.

METHODS

We carried out a prospective, longitudinal case-control study, acquiring foetal MRIs at two timepoints in utero, (Scan 1 = 20-30 Gestational Weeks (GW) and Scan 2 = 30-39 GW), then followed up participants at two years of age to assess neurodevelopmental outcomes. We used normative modelling to chart growth trajectories of surface features across 60 cortical regions in a control population (n = 157), then quantified the deviance of each foetus with CHD (n = 135) and explored the association with neurodevelopmental outcomes at two years of age.

FINDINGS

Differences in cortical development between CHD and Control foetuses only emerged after 30 GW, and lower regional cortical surface area growth was correlated with poorer neurodevelopmental outcomes at two years of age in the CHD group.

INTERPRETATION

This work highlights the third trimester specifically as a critical period in brain development for foetuses with CHD, where the reduced surface area expansion in specific cortical regions becomes consequential in later life, and predictive of neurodevelopmental outcome in toddlerhood.

FUNDING

This research was supported by the NINDS (R01NS114087, K23NS101120) and NIBIB (R01EB031170) of the NIH, PHN Scholar Award, AAN Clinical Research Training Fellowship, BBRF Young Investigator Awards, and the Farb Family Fund.

Placental and Fetal In Utero Growth Among Fetuses With Congenital Heart Disease

Importance

At birth, neonates with congenital heart disease (CHD) have smaller placentas, lower birth weight, and smaller head circumferences compared with healthy neonates. The onset of feto-placental growth disturbances, however, is not well known.

Objective

To compare fetal body volumes, assess differences in the fetal to placental volume ratios (placental growth relative to the fetus), and investigate the association between in utero fetal body and total brain volume in fetuses with and without CHD.

Design, Setting, and Participants

This case-control study enrolled pregnant women with a fetal diagnosis of CHD and those with healthy pregnancies at Children's National Hospital in Washington, DC, from April 2018 to July 2023. Fetal magnetic resonance imaging was obtained up to 2 time points during pregnancy. The fetal to placental ratio was calculated using 3-dimensional magnetic resonance image fetal body volumes and placental volumes.

Exposure

In utero environment CHD.

Main Outcomes and Measures

The main outcomes were the trajectories of body, brain, and placental volumetric growth in fetuses with CHD and in control fetuses. Generalized linear regression and mixed-effects models were applied to identify associations for fetal body volume and fetal to placental volume ratios between CHD and control groups adjusting for fetal sex and gestational age at the time of the magnetic resonance imaging scan.

Results

The study included 108 fetuses (59 male [54.6%]), of which 55 were in the healthy control group (with 55 scans), and 53 had CHD (with 77 scans). Fetal body volumes in fetuses with CHD were smaller compared with control fetuses (β = -193.60 [SE, 44.42]; P < .001) with larger fetal to placental volume ratios (β = 0.23 [SE, 0.10]; P = .02). The total brain volume was smaller in fetuses with CHD compared with control fetuses (β = -10.87 [SE, 5.09]; P = .04).

Conclusions and Relevance

In this case-control study of fetuses with and without CHD, those with CHD demonstrated impaired fetal body growth with higher fetal to placental volume ratios and smaller total brain volume, suggesting that placental failure was associated with growth disturbances in CHD, as demonstrated by the large fetal to placental volume ratios. Additional studies should assess the onset and progression of placental dysfunction and how the timing of placental failure may contribute to neurodevelopmental disability in survivors of CHD.

T2*-Relaxometry MRI to Assess Third Trimester Placental and Fetal Brain Oxygenation and Placental Characteristics in Healthy Fetuses and Fetuses With Congenital Heart Disease

BACKGROUND

Congenital heart disease (CHD) has been linked to impaired placental and fetal brain development. Assessing the placenta and fetal brain in parallel may help further our understanding of the relationship between development of these organs.

HYPOTHESIS

1) Placental and fetal brain oxygenation are correlated, 2) oxygenation in these organs is reduced in CHD compared to healthy controls, and 3) placental structure is altered in CHD.

STUDY TYPE

Retrospective case-control.

POPULATION

Fifty-one human fetuses with CHD (32 male; median [IQR] gestational age [GA] = 32.0 [30.9-32.9] weeks) and 30 from uncomplicated pregnancies with normal birth outcomes (18 male; median [IQR] GA = 34.5 [31.9-36.7] weeks).

FIELD STRENGTH/SEQUENCE

1.5 T single-shot multi-echo-gradient-echo echo-planar imaging.

ASSESSMENT

Masking was performed using an automated nnUnet model. Mean brain and placental T2* and quantitative measures of placental texture, volume, and morphology were calculated.

STATISTICAL TESTS

Spearman's correlation coefficient for determining the association between brain and placental T2*, and between brain and placental characteristics with GA. P-values for comparing brain T2*, placenta T2*, and placental characteristics between groups derived from ANOVA. Significance level P < 0.05.

RESULTS

There was a significant positive association between placental and fetal brain T2* (⍴ = 0.46). Placental and fetal brain T2* showed a significant negative correlation with GA (placental T2* ⍴ = -0.65; fetal brain T2* ⍴ = -0.32). Both placental and fetal brain T2* values were significantly reduced in CHD, after adjusting for GA (placental T2*: control = 97 [±24] msec, CHD = 83 [±23] msec; brain T2*: control = 218 [±26] msec, CHD = 202 [±25] msec). Placental texture and morphology were also significantly altered in CHD (Texture: control = 0.84 [0.83-0.87], CHD = 0.80 [0.78-0.84]; Morphology: control = 9.9 [±2.2], CHD = 10.8 [±2.0]). For all fetuses, there was a significant positive association between placental T2* and placental texture (⍴ = 0.46).

CONCLUSION

Placental and fetal brain T2* values are associated in healthy fetuses and those with CHD. Placental and fetal brain oxygenation are reduced in CHD. Placental appearance is significantly altered in CHD and shows associations with placental oxygenation, suggesting altered placental development and function may be related.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Noncoding variants and sulcal patterns in congenital heart disease: Machine learning to predict functional impact

Neurodevelopmental impairments associated with congenital heart disease (CHD) may arise from perturbations in brain developmental pathways, including the formation of sulcal patterns. While genetic factors contribute to sulcal features, the association of noncoding de novo variants (ncDNVs) with sulcal patterns in people with CHD remains poorly understood. Leveraging deep learning models, we examined the predicted impact of ncDNVs on gene regulatory signals. Predicted impact was compared between participants with CHD and a jointly called cohort without CHD. We then assessed the relationship of the predicted impact of ncDNVs with their sulcal folding patterns. ncDNVs predicted to increase H3K9me2 modification were associated with larger disruptions in right parietal sulcal patterns in the CHD cohort. Genes predicted to be regulated by these ncDNVs were enriched for functions related to neuronal development. This highlights the potential of deep learning models to generate hypotheses about the role of noncoding variants in brain development.

Alteration in Cortical Structure Mediating the Impact of Blood Oxygen-Carrying Capacity on Gross Motor Skills in Infants With Complex Congenital Heart Disease

Congenital heart disease (CHD) is the most common congenital anomaly, leading to an increased risk of neurodevelopmental abnormalities in many children with CHD. Understanding the neurological mechanisms behind these neurodevelopmental disorders is crucial for implementing early interventions and treatments. In this study, we recruited 83 infants aged 12-26.5 months with complex CHD, along with 86 healthy controls (HCs). We collected multimodal data to explore the abnormal patterns of cerebral cortex development and explored the complex interactions among blood oxygen-carrying capacity, cortical development, and gross motor skills. We found that, compared to healthy infants, those with complex CHD exhibit significant reductions in cortical surface area development, particularly in the default mode network. Most of these developmentally abnormal brain regions are significantly correlated with the blood oxygen-carrying capacity and gross motor skills of infants with CHD. Additionally, we further discovered that the blood oxygen-carrying capacity of infants with CHD can indirectly predict their gross motor skills through cortical structures, with the left middle temporal area and left inferior temporal area showing the greatest mediation effects. This study identified biomarkers for neurodevelopmental disorders and highlighted blood oxygen-carrying capacity as an indicator of motor development risk, offering new insights for the clinical management CHD.

An exploratory fetal MRI study examining the impact of 22q11.2 microdeletion syndrome on early brain growth

BACKGROUND

Improved long-term outcomes, related to advances in surgical and clinical care of infants with congenital heart disease (CHD), has shifted focus onto the accompanying and later-onset cognitive and neuropsychiatric disorders in those who also have 22q11.2 deletion syndrome (22qDS). 22qDS is itself associated with neurodevelopmental impairments and altered brain growth. However, when brain growth in 22qDS first deviates from normal is unknown, and whether impaired brain development is primarily genetics-driven or a secondary consequence of the underlying CHD remains incompletely understood.

METHODS

In this small, exploratory study, we use fetal MRI to assess volumetric brain development in 22qDS by comparing fetal brain morphometry to a set of gestation and sex-matched healthy controls, and a cohort of gestation and sex-matched fetuses with the same CHD diagnoses but without 22q11.2 deletion. Structural T2-weighted fetal brain images were acquired using a 1.5T MRI scanner. MR scanner and sequence parameters were identical in all cohorts. Motion-corrected images underwent segmentation using an automated pipeline developed for fetal brain MRI. Total brain tissue volumes, volumes for four different tissue regions (cortical grey matter, white matter, deep grey matter and cerebellum), cerebrospinal fluid and total intracranial volumes were calculated.

RESULTS

Antenatal imaging was acquired between 29 and 35 weeks gestation. Thirty-three fetuses were included (7 22qDS; 14 isolated CHD; 12 healthy control). White matter volumes were significantly reduced in fetuses with 22qDS compared to control fetuses (p = 0.028), but not to those with CHD without 22q11.2 deletion (p = 0.09). Large effect-sizes were seen between the 22qDS and isolated CHD cohorts (DCohen = 0.81), and between the 22qDS and control cohorts (DCohen = 1.2) for white matter volumes. No significant differences were seen in volumes of other brain regions between groups.

CONCLUSIONS

This exploratory study expands our existing knowledge on neurodevelopmental impairments in 22qDS to the fetal period by highlighting reduced white matter volumes compared to gestation and sex-matched control fetuses during this time-period. Our findings suggest that impaired white matter growth in fetuses with both 22qDS and CHD may not be fully explained by any underlying CHD.

Cerebral Protection in Pediatric Cardiac Surgery

Cardiac surgery, both adult and pediatric, has developed very rapidly and impressively over the past 7 decades. Pediatric cardiac surgery, in particular, has revolutionized the management of babies born with congenital heart disease such that now most patients reach adult life and lead comfortable lives. However, these patients are at risk of cerebral lesions, which may be due to perioperative factors, such as side effects of cardiopulmonary bypass and/or anesthesia, and non-perioperative factors such as chromosomal anomalies (common in children with congenital heart disease), the timing of surgery, number of days on the intensive care unit, length of hospitalization and other hospitalizations in the first year of life. The risk of cerebral lesions is particularly relevant to pediatric cardiac surgery given that cerebral metabolism is about 30% higher in neonates, infants and young children compared to adults, which renders their brain more susceptible to ischemic/hypoxic injury. This issue has been a major concern throughout the history of cardiac surgery such that many preventive measures have been implemented over the years. These measures, however, have had only a modest impact and cerebral lesions continue to be a major concern. This is the subject of this review article, which aims to outline these protective measures, offer possible explanations of why these have not resolved the issue, and suggest possible actions that ought to be taken now.

Mitotic block and epigenetic repression underlie neurodevelopmental defects and neurobehavioral deficits in congenital heart disease

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease associated with microcephaly and poor neurodevelopmental outcomes. Here we show that the Ohia HLHS mouse model, with mutations in Sap130, a chromatin modifier, and Pcdha9, a cell adhesion protein, also exhibits microcephaly associated with mitotic block and increased apoptosis leading to impaired cortical neurogenesis. Transcriptome profiling, DNA methylation, and Sap130 ChIPseq analyses all demonstrate dysregulation of genes associated with autism and cognitive impairment. This includes perturbation of REST transcriptional regulation of neurogenesis, disruption of CREB signaling regulating synaptic plasticity, and defects in neurovascular coupling mediating cerebral blood flow. Adult mice harboring either the Pcdha9 mutation, which show normal brain anatomy, or forebrain-specific Sap130 deletion via Emx1-Cre, which show microcephaly, both demonstrate learning and memory deficits and autism-like behavior. These findings provide mechanistic insights indicating the adverse neurodevelopment in HLHS may involve cell autonomous/nonautonomous defects and epigenetic dysregulation.

Unique model of chronic hypoxia in fetal lambs demonstrates abnormal contrast-enhanced ultrasound brain perfusion

BACKGROUND

Children with congenital heart disease (CHD) demonstrate long-term neurodevelopmental impairments. We investigated contrast-enhanced ultrasound (CEUS) cerebral perfusion in a fetal animal model exposed to sub-physiologic oxygen at equivalent levels observed in human fetuses with CHD.

METHODS

Fifteen fetal lambs [hypoxic animals (n = 9) and normoxic controls (n = 6)] maintained in an extrauterine environment underwent periodic brain CEUS. Perfusion parameters including microvascular flow velocity (MFV), transit time, and microvascular blood flow (MBF) were extrapolated from a standardized plane; regions of interest (ROI) included whole brain, central/thalami, and peripheral parenchymal analyses. Daily echocardiographic parameters and middle cerebral artery (MCA) pulsatility indices (PIs) were obtained.

RESULTS

Hypoxic lambs demonstrated decreased MFV, increased transit time, and decreased MBF (p = 0.026, p = 0.016, and p < 0.001, respectively) by whole brain analyses. MFV and transit time were relatively preserved in the central/thalami (p = 0.11, p = 0.08, p = 0.012, respectively) with differences in the peripheral parenchyma (all p < 0.001). In general, cardiac variables did not correlate with cerebral CEUS perfusion parameters. Hypoxic animals demonstrated decreased MCA PI compared to controls (0.65 vs. 0.78, respectively; p = 0.027).

CONCLUSION

Aberrations in CEUS perfusion parameters suggest that in environments of prolonged hypoxia, there are regional microvascular differences incompletely characterized by MCA interrogation offering insights into fetal conditions which may contribute to patient outcomes.

IMPACT

This work utilizes CEUS to study cerebral microvascular perfusion in a unique fetal animal model subjected to chronic hypoxic conditions equal to fetuses with congenital heart disease. CEUS demonstrates altered parameters with regional differences that are incompletely characterized by MCA Doppler values. These findings show that routine MCA Doppler interrogation may be inadequate in assessing microvascular perfusion differences. To our knowledge, this study is the first to utilize CEUS to assess microvascular perfusion in this model. The results offer insight into underlying conditions and physiological changes which may contribute to known neurodevelopmental impairments in those with congenital heart disease.

Preoperative autonomic failure in neonates with critical congenital heart disease

BACKGROUND

Neonates with critical congenital heart disease (cCHD) undergo a complicated transition to ex-utero life. However, continuous monitoring of autonomic tone using heart rate variability is currently lacking.

MATERIALS AND METHODS

We retrieved continuous electrocardiograms from the time of admission or from 10 days prior to surgery for neonates with dextro-transposition of the great arteries (d-TGA) and hypoplastic left heart syndrome (HLHS). Beat-to-beat intervals (RRi) were calculated and divided into 10-min epochs. Spectral metrics, including low-frequency (LF) and high-frequency (HF) powers, as well as detrended fluctuation analysis metrics (αS, αL, RMSS, and RMSL), were computed for RRi within each epoch and averaged over 24 h. The relationship between RRi metrics and time to surgery was analyzed using linear mixed-effects models, adjusting for prenatal and postnatal factors.

RESULTS

The study included 10 neonates with HLHS and 23 with d-TGA. RRi metrics were available for 110 days. In the unadjusted models, LF power (Estimate: -4.4×10-3, P = 0.02), HF power (-4.1 x 10-2, 5 x 10-5), RMSS(-3.7 x 10-4, 8.7 x 10-3), and RMSL(-1.4× 10-3, 0.02) were all negatively associated with time to surgery, with HF power showing the strongest association. After adjusting for covariates, HF power retained its significant negative association with time (-0.04, P = 0.03). The cCHD diagnosis did not significantly influence RRi metrics.

CONCLUSIONS

In neonates with cCHD, there is a progressive decline in autonomic function leading up to surgery. RRi metrics may serve as valuable indicators of deteriorating physiology in these patients.

Lung volumes are increased in fetuses with transposition of the great arteries on intrauterine MRI

Fetal brain size is decreased in some children with complex CHDs, and the distribution of blood and accompanying oxygen and nutrients is regionally skewed from early fetal life dependent on the CHD. In transposition of the great arteries, deoxygenated blood preferentially runs to the brain, whereas the more oxygenated blood is directed towards the lungs and the abdomen. Knowledge of whether this impacts intrauterine organ development is limited. We investigated lung, liver, and total intracranial volume in fetuses with transposition of the great arteries using MRI.Eight fetuses with dextro-transposition and without concomitant disease or chromosomal abnormalities and 42 fetuses without CHD or other known diseases were scanned once or twice at gestational age 30 through 39 weeks. The MRI scans were conducted on a 1.5T system, using a 2D balanced steady-state free precession sequence. Slices acquired covered the entire fetus, slice thickness was 10 mm, pixel size 1.5 × 1.5 mm, and scan duration was 30 sec.The mean lung z score was significantly larger in fetuses with transposition compared with those without a CHD; mean difference is 1.24, 95% CI:(0.59;1.89), p < 0.001. The lung size, corrected for estimated fetal weight, was larger than in the fetuses without transposition; mean difference is 8.1 cm3/kg, 95% CI:(2.5;13.7 cm3/kg), p = 0.004.In summary, fetuses with dextro-transposition of the great arteries had both absolute and relatively larger lung volumes than those without CHD. No differences were seen in liver and total intracranial volume. Despite the small number of cases, the results are interesting and warrant further investigation.

Structural Covariance Networks in the Fetal Brain Reveal Altered Neurodevelopment for Specific Subtypes of Congenital Heart Disease

BACKGROUND

Altered structural brain development has been identified in fetuses with congenital heart disease (CHD), suggesting that the neurodevelopmental impairment observed later in life might originate in utero. There are many interacting factors that may perturb neurodevelopment during the fetal period and manifest as structural brain alterations, such as altered cerebral substrate delivery and aberrant fetal hemodynamics.

METHODS AND RESULTS

We extracted structural covariance networks from the log Jacobian determinants of 435 in utero T2 weighted image magnetic resonance imaging scans, (n=67 controls, 368 with CHD) acquired during the third trimester. We fit general linear models to test whether age, sex, expected cerebral substrate delivery, and CHD diagnosis were significant predictors of structural covariance. We identified significant effects of age, sex, cerebral substrate delivery, and specific CHD diagnosis across a variety of structural covariance networks, including primary motor and sensory cortices, cerebellar regions, frontal cortex, extra-axial cerebrospinal fluid, thalamus, brainstem, and insula, consistent with widespread coordinated aberrant maturation of specific brain regions over the third trimester.

CONCLUSIONS

Structural covariance networks offer a sensitive, data-driven approach to explore whole-brain structural changes without anatomical priors. We used them to stratify a heterogenous patient cohort with CHD, highlighting similarities and differences between diagnoses during fetal neurodevelopment. Although there was a clear effect of abnormal fetal hemodynamics on structural brain maturation, our results suggest that this alone does not explain all the variation in brain development between individuals with CHD.

Predictors of Neurologic Complications and Neurodevelopmental Outcome in Pediatric Cardiac Surgery With Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) has emerged as an important intervention for children both preceding and following cardiac surgery. There is a notable lack of comprehensive information regarding neurodevelopmental outcomes. The Norwood procedure and complex biventricular repairs exhibit the highest prevalence of ECMO usage. Examination of the data demonstrates that only 50% of ECMO survivors achieved normative cognitive outcomes, with 40% of those experiencing long-term neurological deficits. It is imperative to conduct robustly designed studies with extended follow-up periods to establish guidelines for neuromonitoring and neuroprotection during ECMO in the field of congenital cardiac surgery.

Placental-Heart Axis: An Evolutionary Perspective

To maintain its development, the growing fetus is directly dependent on the placenta, an organ that acts as both a modulator and mediator. As an essential component of pregnancy that is derived from both maternal and fetal tissues, the placenta facilitates the passage of all oxygen and nutrients from the expecting parent to their fetuses. Further, the placenta conveys multiple impacts of the maternal environment to the growing fetus. The timing of placental development parallels that of the fetal cardiovascular system, and placental anomalies are implicated as a potential cause of congenital heart disease. For example, congenital heart disease is more common in pregnancies complicated by maternal preeclampsia, a condition characterized by placental dysfunction. Given the placenta's intermediary links to the maternal environment and fetal health outcomes, it is an emerging focus of evolutionary medicine, which seeks to understand how interactions between humans and the environment affect our biology and give rise to disease. The present review provides an overview of the evolutionary and developmental courses of the placenta as well as their implications on infant health.

Safety and feasibility pilot study of continuous low-dose maternal supplemental oxygen in fetal single ventricle heart disease

OBJECTIVE

Fetuses with single ventricle physiology (SVP) exhibit reductions in fetal cerebral oxygenation, with associated delays in fetal brain growth and neurodevelopmental outcomes. Maternal supplemental oxygen (MSO) has been proposed to improve fetal brain growth, but current evidence on dosing, candidacy and outcomes is limited. In this pilot study, we evaluated the safety and feasibility of continuous low-dose MSO in the setting of SVP.

METHODS

This single-center, open-label, pilot phase-1 safety and feasibility clinical trial included 25 pregnant individuals with a diagnosis of fetal SVP. Participants self-administered continuous MSO using medical-grade oxygen concentrators for up to 24 h per day from the second half of gestation until delivery. The primary aim was the evaluation of the safety profile and feasibility of MSO. A secondary preliminary analysis was performed to assess the impact of MSO on the fetal circulation using echocardiography and late-gestation cardiovascular magnetic resonance imaging. Early outcomes were assessed, including perinatal growth and preoperative brain injury, and neurodevelopmental outcomes were assessed at 18 months using the Bayley Scales of Infant and Toddler Development 3rd edition, and compared with those of a contemporary fetal SVP cohort (n = 217) that received the normal standard of care (SOC).

RESULTS

Among the 25 participants, the median maternal age at conception was 35 years, and fetal SVP diagnoses included 16 with right ventricle dominant, eight with left ventricle dominant and one with indeterminate ventricular morphology. Participants started the trial at approximately 29 + 2 weeks' gestation and self-administered MSO for a median of 16.1 h per day for 63 days, accumulating a median of 1029 h of oxygen intake from enrolment until delivery. The only treatment-associated adverse events were nasal complications that were resolved typically by attaching a humidifier unit to the oxygen concentrator. No premature closure of the ductus arteriosus or unexpected fetal demise was observed. In the secondary analysis, MSO was not associated with any changes in fetal growth, middle cerebral artery pulsatility index, cerebroplacental ratio or head-circumference-to-abdominal-circumference ratio Z-scores over gestation compared with SOC. Although MSO was associated with changes in umbilical artery pulsatility index Z-score over the study period compared with SOC (P = 0.02), this was probably due to initial baseline differences in placental resistance. At late-gestation cardiovascular magnetic resonance imaging, MSO was not associated with an increase in fetal cerebral oxygen delivery. Similarly, no differences were observed in neonatal outcomes, including preoperative brain weight Z-score and brain injury, mortality by 18 months of age and neurodevelopmental outcomes at 18 months of age.

CONCLUSIONS

This pilot phase-1 clinical trial indicates that low-dose MSO therapy is safe and well tolerated in pregnancies diagnosed with fetal SVP. However, our protocol was not associated with an increase in fetal cerebral oxygen delivery or improvements in early neurological or neurodevelopmental outcomes. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Validation of a Paralimbic-Related Subcortical Brain Dysmaturation MRI Score in Infants with Congenital Heart Disease

Background: Brain magnetic resonance imaging (MRI) of infants with congenital heart disease (CHD) shows brain immaturity assessed via a cortical-based semi-quantitative score. Our primary aim was to develop an infant paralimbic-related subcortical-based semi-quantitative dysmaturation score, termed brain dysplasia score (BDS), to detect abnormalities in CHD infants compared to healthy controls and secondarily to predict clinical outcomes. We also validated our BDS in a preclinical mouse model of hypoplastic left heart syndrome. Methods: A paralimbic-related subcortical BDS, derived from structural MRIs of infants with CHD, was compared to healthy controls and correlated with clinical risk factors, regional cerebral volumes, feeding, and 18-month neurodevelopmental outcomes. The BDS was validated in a known CHD mouse model named Ohia with two disease-causing genes, Sap130 and Pchda9. To relate clinical findings, RNA-Seq was completed on Ohia animals. Findings: BDS showed high incidence of paralimbic-related subcortical abnormalities (including olfactory, cerebellar, and hippocampal abnormalities) in CHD infants (n = 215) compared to healthy controls (n = 92). BDS correlated with reduced cortical maturation, developmental delay, poor language and feeding outcomes, and increased length of stay. Ohia animals (n = 63) showed similar BDS findings, and RNA-Seq analysis showed altered neurodevelopmental and feeding pathways. Sap130 mutants correlated with a more severe BDS, whereas Pcdha9 correlated with a milder phenotype. Conclusions: Our BDS is sensitive to dysmaturational differences between CHD and healthy controls and predictive of poor outcomes. A similar spectrum of paralimbic and subcortical abnormalities exists between human and Ohia mutants, suggesting a common genetic mechanistic etiology.

Atoh1 mediated disturbance of neuronal maturation by perinatal hypoxia induces cognitive deficits

Neurodevelopmental disorders are currently one of the major complications faced by patients with congenital heart disease (CHD). Chronic hypoxia in the prenatal and postnatal preoperative brain may be associated with neurological damage and impaired long-term cognitive function, but the exact mechanisms are unknown. In this study, we find that delayed neuronal migration and impaired synaptic development are attributed to altered Atoh1 under chronic hypoxia. This is due to the fact that excessive Atoh1 facilitates expression of Kif21b, which causes excess in free-state α-tubulin, leading to disrupted microtubule dynamic stability. Furthermore, the delay in neonatal brain maturation induces cognitive disabilities in adult mice. Then, by down-regulating Atoh1 we alleviate the impairment of cell migration and synaptic development, improving the cognitive behavior of mice to some extent. Taken together, our work unveil that Atoh1 may be one of the targets to ameliorate hypoxia-induced neurodevelopmental disabilities and cognitive impairment in CHD.

Effects of hemodynamic alterations and oxygen saturation on cerebral perfusion in congenital heart disease

BACKGROUND

Patients with severe congenital heart disease (CHD) are at risk for neurodevelopmental impairment. An abnormal cerebral blood supply caused by the altered cardiac physiology may limit optimal brain development. The aim of this study was to evaluate the effect of a systemic-to-pulmonary shunt, aortic arch obstruction and arterial oxygen saturation on cerebral perfusion in patients with severe CHD.

METHODS

Patients with severe CHD requiring cardiac surgery within the first six weeks of life, who underwent pre- and/or postoperative brain magnetic resonance imaging (MRI), and healthy controls with one postnatal scan were included. Cerebral perfusion in deep and cortical gray matter was assessed by pseudocontinuous arterial spin labeling MRI.

RESULTS

We included 59 CHD and 23 healthy control scans. The presence of a systemic-to-pulmonary shunt was associated with decreased perfusion in cortical (p = 0.003), but not in deep gray matter (p = 0.031). No evidence for an effect of aortic arch obstruction and arterial oxygen saturation on cerebral perfusion was found. After adjusting for hemodynamic and oxygen saturation parameters, deep (p = 0.018) and cortical (p = 0.012) gray matter perfusion was increased in patients with CHD compared to controls.

CONCLUSION

We detected regional differences in compensation to the cerebral steal effect in patients with severe CHD.

IMPACT

Patients with severe congenital heart disease (CHD) have altered postnatal brain hemodynamics. A systemic-to-pulmonary shunt was associated with decreased perfusion in cortical gray matter but preserved perfusion in deep gray matter, pointing towards regional differences in compensation to the cerebral steal effect. No effects of aortic arch obstruction and arterial oxygenation on cerebral perfusion were seen. Cerebral perfusion was increased in patients with CHD compared to healthy controls after adjusting for hemodynamic alterations and oxygen saturation. To improve neuroprotection and neurodevelopmental outcomes, it is important to increase our understanding of the factors influencing cerebral perfusion in neonates with severe CHD.

Fetal Brain MRI Abnormalities in Pyruvate Dehydrogenase Complex Deficiency

BACKGROUND AND OBJECTIVES

Pyruvate dehydrogenase complex deficiency (PDCD) is a disorder of mitochondrial metabolism that is caused by pathogenic variants in multiple genes, including PDHA1. Typical neonatal brain imaging findings have been described, with a focus on malformative and encephaloclastic features. Fetal brain MRI in PDCD has not been comprehensively described. The aims of this study were (1) to further characterize the fetal brain MRI findings in PDCD using comprehensive fetal imaging and genetic testing and (2) to determine whether markers of diagnosis of PDCD could be identified on prenatal imaging.

METHODS

Fetuses with a diagnosis of PDCD related to a genetic etiology that had undergone fetal MRI were included. Fetuses were identified retrospectively from local databases of 4 fetal diagnostic clinics within tertiary pediatric health care centers. Electronic medical records were reviewed retrospectively: demographics, maternal and pregnancy history, fetal outcomes, and neonatal outcomes (if available) were reviewed and recorded. Fetal and neonatal imaging reports were reviewed; source fetal and neonatal brain MRI scans were reviewed by a single pediatric neuroradiologist (J.W.S.) for consistency. Genetic testing strategies and results including variant type, zygosity, inheritance pattern, and pathogenicity were recorded. Deidentified data were combined and reported descriptively.

RESULTS

A total of 10 fetuses with a diagnosis of PDCD were included. 8 fetuses had corpus callosum dysgenesis, 6 had an abnormal gyration pattern, 10 had reduced brain volumes, and 9 had cystic lesions. 1 fetus had intraventricular hemorrhages. 1 fetus had a midbrain malformation with aqueductal stenosis and severe hydrocephalus. 6 fetuses imaged in the second trimester had cystic lesions involving the ganglionic eminences (GEs) while GE cysts were not present in the 4 fetuses imaged in the third trimester.

DISCUSSION

Fetuses with PDCD have similar brain MRI findings to neonates described in the literature, although some of these findings are subtle early in pregnancy. Additional features, such as cystic lesions of the GEs, are noted in the second trimester in fetuses with PDCD. These may represent an early diagnostic marker of PDCD, although more data are needed to validate this association. Early diagnosis of PDCD using fetal MRI may inform genetic counseling, pregnancy decision making, and neonatal care planning.

Identifying novel data-driven subgroups in congenital heart disease using multi-modal measures of brain structure

Individuals with congenital heart disease (CHD) have an increased risk of neurodevelopmental impairments. Given the hypothesized complexity linking genomics, atypical brain structure, cardiac diagnoses and their management, and neurodevelopmental outcomes, unsupervised methods may provide unique insight into neurodevelopmental variability in CHD. Using data from the Pediatric Cardiac Genomics Consortium Brain and Genes study, we identified data-driven subgroups of individuals with CHD from measures of brain structure. Using structural magnetic resonance imaging (MRI; N = 93; cortical thickness, cortical volume, and subcortical volume), we identified subgroups that differed primarily on cardiac anatomic lesion and language ability. In contrast, using diffusion MRI (N = 88; white matter connectivity strength), we identified subgroups that were characterized by differences in associations with rare genetic variants and visual-motor function. This work provides insight into the differential impacts of cardiac lesions and genomic variation on brain growth and architecture in patients with CHD, with potentially distinct effects on neurodevelopmental outcomes.

Anatomically constrained tractography of the fetal brain

Diffusion-weighted Magnetic Resonance Imaging (dMRI) is increasingly used to study the fetal brain in utero. An important computation enabled by dMRI is streamline tractography, which has unique applications such as tract-specific analysis of the brain white matter and structural connectivity assessment. However, due to the low fetal dMRI data quality and the challenging nature of tractography, existing methods tend to produce highly inaccurate results. They generate many false streamlines while failing to reconstruct the streamlines that constitute the major white matter tracts. In this paper, we advocate for anatomically constrained tractography based on an accurate segmentation of the fetal brain tissue directly in the dMRI space. We develop a deep learning method to compute the segmentation automatically. Experiments on independent test data show that this method can accurately segment the fetal brain tissue and drastically improve the tractography results. It enables the reconstruction of highly curved tracts such as optic radiations. Importantly, our method infers the tissue segmentation and streamline propagation direction from a diffusion tensor fit to the dMRI data, making it applicable to routine fetal dMRI scans. The proposed method can facilitate the study of fetal brain white matter tracts with dMRI.

Impact of postoperative necrotizing enterocolitis after neonatal cardiac surgery on neurodevelopmental outcome at 1 year of age

Objectives

We analyzed the impact of postoperative necrotizing enterocolitis (NEC) after cardiac surgery in neonatal age on neurodevelopmental (ND) outcome at 1 year of age.

Methods

Using data from the Swiss Neurodevelopmental Outcome Registry for Children with Congenital Heart Disease (ORCHID), we analyzed perioperative variables including postoperative NEC (Bell's stage ≥2) and 1-year ND outcome (Bayley III).

Results

The included patients (n = 101) had congenital heart disease (CHD), categorized as follows: 77 underwent biventricular repair for CHD with two functional chambers, 22 underwent staged palliation until the Fontan procedure for CHD with single ventricle physiology (n = 22), or 4 underwent single ventricle palliation or biventricular repair for borderline CHD (n = 4). Neonatal cardiopulmonary bypass (CBP) surgery was performed at a median age (IQR) of 8 (6) days. NEC occurred in 16 patients. Intensive care unit (ICU) length of stay (LOS) and the total duration of the hospitalization were longer in children with NEC than those in others (14 with vs. 8 days without NEC, p < 0.05; 49 with vs. 32 days without NEC, p < 0.05). The Bayley III scores of the analyzed patients determined at an age of 11.5 ± 1.5 months showed cognitive (CCS) (102.2 ± 15.0) and language scores (LCS) (93.8 ± 13.1) in the normal range and motor composite scores (MCS) (88.7 ± 15.9) in the low-normal range. After adjusting for socioeconomic status and CHD type, patients with NEC had lower CCS scores [β = -11.2 (SE 5.6), p = 0.049]. Using a cumulative risk score including NEC, we found a higher risk score to be associated with both lower CCS [β = -2.8 (SE 1.3), p = 0.030] and lower MCS [β = -3.20 (SE 1.3), p = 0.016].

Conclusions

Postoperative NEC is associated with longer ICU and hospital LOS and contributes together with other complications to impaired ND outcome at 1 year of age. In the future, national and international patient registries may provide the opportunity to analyze large cohorts and better identify the impact of modifiable perioperative risk factors on ND outcome.

Clinical Trial Registration

ClinicalTrials.gov identifier: NCT05996211.

Total and Regional Brain Volumes in Fetuses With Congenital Heart Disease

BACKGROUND

Congenital heart disease (CHD) is common and is associated with impaired early brain development and neurodevelopmental outcomes, yet the exact mechanisms underlying these associations are unclear.

PURPOSE

To utilize MRI data from a cohort of fetuses with CHD as well as typically developing fetuses to test the hypothesis that expected cerebral substrate delivery is associated with total and regional fetal brain volumes.

STUDY TYPE

Retrospective case-control study.

POPULATION

Three hundred eighty fetuses (188 male), comprising 45 healthy controls and 335 with isolated CHD, scanned between 29 and 37 weeks gestation. Fetuses with CHD were assigned into one of four groups based on expected cerebral substrate delivery.

FIELD STRENGTH/SEQUENCE

T2-weighted single-shot fast-spin-echo sequences and a balanced steady-state free precession gradient echo sequence were obtained on a 1.5 T scanner.

ASSESSMENT

Images were motion-corrected and reconstructed using an automated slice-to-volume registration reconstruction technique, before undergoing segmentation using an automated pipeline and convolutional neural network that had undergone semi-supervised training. Differences in total, regional brain (cortical gray matter, white matter, deep gray matter, cerebellum, and brainstem) and brain:body volumes were compared between groups.

STATISTICAL TESTS

ANOVA was used to test for differences in brain volumes between groups, after accounting for sex and gestational age at scan. PFDR-values <0.05 were considered statistically significant.

RESULTS

Total and regional brain volumes were smaller in fetuses where cerebral substrate delivery is reduced. No significant differences were observed in total or regional brain volumes between control fetuses and fetuses with CHD but normal cerebral substrate delivery (all PFDR > 0.12). Severely reduced cerebral substrate delivery is associated with lower brain:body volume ratios.

DATA CONCLUSION

Total and regional brain volumes are smaller in fetuses with CHD where there is a reduction in cerebral substrate delivery, but not in those where cerebral substrate delivery is expected to be normal.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Fetal circulatory physiology and brain development in complex congenital heart disease: A multi-modal imaging study

OBJECTIVE

Fetuses with complex congenital heart disease have altered physiology, contributing to abnormal neurodevelopment. The effects of altered physiology on brain development have not been well studied. We used multi-modal imaging to study fetal circulatory physiology and brain development in hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (TGA).

METHODS

This prospective, cross-sectional study investigated individuals with fetal congenital heart disease and controls undergoing fetal echocardiography and fetal brain MRI. MRI measured total brain volume and cerebral oxygenation by the MRI quantification method T2*. Indexed cardiac outputs (CCOi) and vascular impedances were calculated by fetal echocardiography. Descriptive statistics assessed MRI and echocardiogram measurement relationships by physiology.

RESULTS

Sixty-six participants enrolled (control = 20; HLHS = 25; TGA = 21), mean gestational age 33.8 weeks (95% CI: 33.3-34.2). Total brain volume and T2* were significantly lower in fetuses with cardiac disease. CCOi was lower in HLHS, correlating with total brain volume - for every 10% CCOi increase, volume increased 8 mm3 (95% CI: 1.78-14.1; p = 0.012). Echocardiography parameters and cerebral oxygenation showed no correlation. TGA showed no CCOi or aortic output correlation with MRI measures.

CONCLUSIONS

In HLHS, lower cardiac output is deleterious to brain development. Our findings provide insight into the role of fetal cardiovascular physiology in brain health.

Advanced magnetic resonance imaging detects altered placental development in pregnancies affected by congenital heart disease

Congenital heart disease (CHD) is the most common congenital malformation and is associated with adverse neurodevelopmental outcomes. The placenta is crucial for healthy fetal development and placental development is altered in pregnancy when the fetus has CHD. This study utilized advanced combined diffusion-relaxation MRI and a data-driven analysis technique to test the hypothesis that placental microstructure and perfusion are altered in CHD-affected pregnancies. 48 participants (36 controls, 12 CHD) underwent 67 MRI scans (50 control, 17 CHD). Significant differences in the weighting of two independent placental and uterine-wall tissue components were identified between the CHD and control groups (both pFDR < 0.001), with changes most evident after 30 weeks gestation. A significant trend over gestation in weighting for a third independent tissue component was also observed in the CHD cohort (R = 0.50, pFDR = 0.04), but not in controls. These findings add to existing evidence that placental development is altered in CHD. The results may reflect alterations in placental perfusion or the changes in fetal-placental flow, villous structure and maturation that occur in CHD. Further research is needed to validate and better understand these findings and to understand the relationship between placental development, CHD, and its neurodevelopmental implications.

Clinical Risk Assessment and Prediction in Congenital Heart Disease Across the Lifespan: JACC Scientific Statement

Congenital heart disease (CHD) comprises a range of structural anomalies, each with a unique natural history, evolving treatment strategies, and distinct long-term consequences. Current prediction models are challenged by generalizability, limited validation, and questionable application to extended follow-up periods. In this JACC Scientific Statement, we tackle the difficulty of risk measurement across the lifespan. We appraise current and future risk measurement frameworks and describe domains of risk specific to CHD. Risk of adverse outcomes varies with age, sex, genetics, era, socioeconomic status, behavior, and comorbidities as they evolve through the lifespan and across care settings. Emerging technologies and approaches promise to improve risk assessment, but there is also need for large, longitudinal, representative, prospective CHD cohorts with multidimensional data and consensus-driven methodologies to provide insight into time-varying risk. Communication of risk, particularly with patients and their families, poses a separate and equally important challenge, and best practices are reviewed.

Postnatal Brain Trajectories and Maternal Intelligence Predict Childhood Outcomes in Complex CHD

Objective: To determine whether early structural brain trajectories predict early childhood neurodevelopmental deficits in complex CHD patients and to assess relative cumulative risk profiles of clinical, genetic, and demographic risk factors across early development. Study Design: Term neonates with complex CHDs were recruited at Texas Children's Hospital from 2005-2011. Ninety-five participants underwent three structural MRI scans and three neurodevelopmental assessments. Brain region volumes and white matter tract fractional anisotropy and radial diffusivity were used to calculate trajectories: perioperative, postsurgical, and overall. Gross cognitive, language, and visuo-motor outcomes were assessed with the Bayley Scales of Infant and Toddler Development and with the Wechsler Preschool and Primary Scale of Intelligence and Beery-Buktenica Developmental Test of Visual-Motor Integration. Multi-variable models incorporated risk factors. Results: Reduced overall period volumetric trajectories predicted poor language outcomes: brainstem ((β, 95% CI) 0.0977, 0.0382-0.1571; p = 0.0022) and white matter (0.0023, 0.0001-0.0046; p = 0.0397) at 5 years; brainstem (0.0711, 0.0157-0.1265; p = 0.0134) and deep grey matter (0.0085, 0.0011-0.0160; p = 0.0258) at 3 years. Maternal IQ was the strongest contributor to language variance, increasing from 37% at 1 year, 62% at 3 years, and 81% at 5 years. Genetic abnormality's contribution to variance decreased from 41% at 1 year to 25% at 3 years and was insignificant at 5 years. Conclusion: Reduced postnatal subcortical-cerebral white matter trajectories predicted poor early childhood neurodevelopmental outcomes, despite high contribution of maternal IQ. Maternal IQ was cumulative over time, exceeding the influence of known cardiac and genetic factors in complex CHD, underscoring the importance of heritable and parent-based environmental factors.

Exploring the prospects, advancements, and challenges of in vitro modeling of the heart-brain axis

Research on bidirectional communication between the heart and brain has often relied on studies involving nonhuman animals. Dependance on animal models offer limited applicability to humans and a lack of high-throughput screening. Recently, the field of 3D cell biology, specifically organoid technology, has rapidly emerged as a valuable tool for studying interactions across organ systems, i.e., gut-brain axis. The initial success of organoid models indicates the usefulness of 3D cultures for elucidating the intricate interactivity of the autonomic nervous system and overall health. This perspective aims to explore the potential of advancing in vitro modeling of the heart-brain axis by discussing the benefits, applications, and adaptability of organoid technologies. We closely examine the current state of brain organoids in conjunction with the advancements of cardiac organoids. Moreover, we explore the use of combined organoid systems to investigate pathophysiology and provide a platform for treatment discovery. Finally, we address the challenges that accompany the use of 3D models for studying the heart-brain axis with an emphasis on generating tailored engineering strategies for further refinement of dynamic organ system modeling in vitro.

Language brain responses and neurodevelopmental outcome in preschoolers with congenital heart disease: A fNIRS study

Neurodevelopmental disabilities affect up to 50% of survivors of congenital heart disease (CHD). Language difficulties are frequently identified during preschool period and can lead to academic, social, behavioral, and emotional difficulties. Structural brain alterations are associated with poorer neurodevelopmental outcomes in patients with CHD during infancy, childhood, and adolescence. However, evidence is lacking about the functional brain activity in children with CHD and its relationship with neurodevelopment. This study therefore aimed to characterize brain responses during a passive story-listening task in 3-year-old children with CHD, and to investigate the relationship between functional brain patterns of language processing and neurodevelopmental outcomes. To do so, we assessed hemodynamic concentration changes, using functional near-infrared spectroscopy (fNIRS), and neurodevelopmental outcomes, using the Wechsler Preschool and Primary Scale of Intelligence - 4th Edition (WPPSI-IV), in children with CHD (n = 19) and healthy controls (n = 23). Compared to their healthy peers, children with CHD had significantly lower scores on the Verbal comprehension index (VCI), the Vocabulary acquisition index (VAI), the General ability index (GAI), and the Information and the Picture Naming subtests of the WPPSI-IV. During the passive story-listening task, healthy controls showed significant hemodynamic brain responses in the temporal and the temporal posterior regions, with stronger activation in the temporal posterior than in the temporal regions. In contrast, children with CHD showed reduced activation in the temporal posterior regions compared to controls, with no difference of activation between regions. Reduced brain responses in the temporal posterior regions were also correlated with lower neurodevelopmental outcomes in both groups. This is the first study that reveals reduced brain functional responses in preschoolers with CHD during a receptive language task. It also suggests that the temporal posterior activation could be a potential brain marker of cognitive development. These findings provide support for the feasibility of identifying brain correlates of neurodevelopmental vulnerabilities in children with CHD.

Characteristic Fetal Brain MRI Abnormalities in Pyruvate Dehydrogenase Complex Deficiency

Pyruvate dehydrogenase complex deficiency (PDCD) is a disorder of mitochondrial metabolism that is caused by pathogenic variants in multiple genes, including PDHA1. Typical neonatal brain imaging findings in PDCD have been described, with a focus on malformative features and chronic encephaloclastic changes. However, fetal brain MRI imaging in confirmed PDCD has not been comprehensively described. We sought to demonstrate the prenatal neurological and systemic manifestations of PDCD determined by comprehensive fetal imaging and genomic sequencing. All fetuses with a diagnosis of genetic PDCD who had undergone fetal MRI were included in the study. Medical records, imaging data, and genetic testing results were reviewed and reported descriptively. Ten patients with diagnosis of PDCD were included. Most patients had corpus callosum dysgenesis, abnormal gyration pattern, reduced brain volumes, and periventricular cystic lesions. One patient had associated intraventricular hemorrhages. One patient had a midbrain malformation with aqueductal stenosis and severe hydrocephalus. Fetuses imaged in the second trimester were found to have enlargement of the ganglionic eminences with cystic cavitations, while those imaged in the third trimester had germinolytic cysts. Fetuses with PDCD have similar brain MRI findings to neonates described in the literature, although some of these findings may be subtle early in pregnancy. Additional features, such as cystic cavitations of the ganglionic eminences, are noted in the second trimester in fetuses with PDCD, and these may represent a novel early diagnostic marker for PDCD. Using fetal MRI to identify these radiological hallmarks to inform prenatal diagnosis of PDCD may guide genetic counseling, pregnancy decision-making, and neonatal care planning.

Neurological injury in pediatric heart disease: A review of developmental and acquired risk factors and management considerations

Medical and surgical advancements have improved survival in children with acquired and congenital heart disease (CHD), but the burden of neurological morbidity is high. Brain disorders associated with CHD include white matter injury, stroke, seizure, and neurodevelopmental delays. While genetics and disease-specific factors play a substantial role in early brain injury, therapeutic management of the heart disease intensifies the risk. There is a growing interest in understanding how to reduce brain injury and improve neurodevelopmental outcomes in cardiac diseases. Pediatric neurologists serve a vital role in care teams managing these complex patients, providing interpretation of neuromonitoring and imaging, managing neurologic emergencies, assisting with neuro prognostication, and identifying future research aims.

The multifaceted role of neuropsychology in pediatric solid organ transplant: preliminary guidelines and strategies for clinical practice

The incidence of pediatric solid organ transplantation (SOT) has increased in recent decades due to medical and surgical advances as well as improvements in organ procurement. Survival rates for pediatric kidney, liver, and heart transplantation are above 85% but patients continue to experience complex healthcare needs over their lifetime. Long-term developmental and neuropsychological sequelae are becoming increasingly recognized in this population, although preliminary work is limited and deserves further attention. Neuropsychological weaknesses are often present prior to transplantation and may be related to underlying congenital conditions as well as downstream impact of the indicating organ dysfunction on the central nervous system. Neuropsychological difficulties pose risk for functional complications, including disruption to adaptive skill development, social-emotional functioning, quality of life, and transition to adulthood. The impact of cognitive dysfunction on health management activities (e.g., medication adherence, medical decision-making) is also an important consideration given these patients' lifelong medical needs. The primary aim of this paper is to provide preliminary guidelines and clinical strategies for assessment of neuropsychological outcomes across SOT populations for pediatric neuropsychologists and the multidisciplinary medical team, including detailing unique and shared etiologies and risk factors for impairment across organ types, and functional implications. Recommendations for clinical neuropsychological monitoring as well as multidisciplinary collaboration within pediatric SOT teams are also provided.

Neurodevelopmental Outcomes for Individuals With Congenital Heart Disease: Updates in Neuroprotection, Risk-Stratification, Evaluation, and Management: A Scientific Statement From the American Heart Association

Over the past decade, new research has advanced scientific knowledge of neurodevelopmental trajectories, factors that increase neurodevelopmental risk, and neuroprotective strategies for individuals with congenital heart disease. In addition, best practices for evaluation and management of developmental delays and disorders in this high-risk patient population have been formulated based on literature review and expert consensus. This American Heart Association scientific statement serves as an update to the 2012 statement on the evaluation and management of neurodevelopmental outcomes in children with congenital heart disease. It includes revised risk categories for developmental delay or disorder and an updated list of factors that increase neurodevelopmental risk in individuals with congenital heart disease according to current evidence, including genetic predisposition, fetal and perinatal factors, surgical and perioperative factors, socioeconomic disadvantage, and parental psychological distress. It also includes an updated algorithm for referral, evaluation, and management of individuals at high risk. Risk stratification of individuals with congenital heart disease with the updated categories and risk factors will identify a large and growing population of survivors at high risk for developmental delay or disorder and associated impacts across the life span. Critical next steps must include efforts to prevent and mitigate developmental delays and disorders. The goal of this scientific statement is to inform health care professionals caring for patients with congenital heart disease and other key stakeholders about the current state of knowledge of neurodevelopmental outcomes for individuals with congenital heart disease and best practices for neuroprotection, risk stratification, evaluation, and management.

Placental Pathology Contributes to Impaired Volumetric Brain Development in Neonates With Congenital Heart Disease

BACKGROUND

Neonates with congenital heart disease are at risk for impaired brain development in utero, predisposing children to postnatal brain injury and adverse long-term neurodevelopmental outcomes. Given the vital role of the placenta in fetal growth, we assessed the incidence of placental pathology in fetal congenital heart disease and explored its association with total and regional brain volumes, gyrification, and brain injury after birth.

METHODS AND RESULTS

Placentas from 96 term singleton pregnancies with severe fetal congenital heart disease were prospectively analyzed for macroscopic and microscopic pathology. We applied a placental pathology severity score to relate placental abnormalities to neurological outcome. Postnatal, presurgical magnetic resonance imaging was used to analyze brain volumes, gyrification, and brain injuries. Placental analyses revealed the following abnormalities: maternal vascular malperfusion lesions in 46%, nucleated red blood cells in 37%, chronic inflammatory lesions in 35%, delayed maturation in 30%, and placental weight below the 10th percentile in 28%. Severity of placental pathology was negatively correlated with cortical gray matter, deep gray matter, brainstem, cerebellar, and total brain volumes (r=-0.25 to -0.31, all P<0.05). When correcting for postmenstrual age at magnetic resonance imaging in linear regression, this association remained significant for cortical gray matter, cerebellar, and total brain volume (adjusted R2=0.25-0.47, all P<0.05).

CONCLUSIONS

Placental pathology occurs frequently in neonates with severe congenital heart disease and may contribute to impaired brain development, indicated by the association between placental pathology severity and reductions in postnatal cortical, cerebellar, and total brain volumes.

The role of point-of-care ultrasound in the management of neonates with congenital diaphragmatic hernia

In the last few years, current evidence has supported the use of point-of-care ultrasound (POCUS) for a number of diagnostic and procedural applications. Considering the valuable information that POCUS can give, we propose a standardized protocol for the management of neonates with a congenital diaphragmatic hernia (CDH-POCUS protocol) in the neonatal intensive care unit. Indeed, POCUS could be a valid tool for the neonatologist through the evaluation of 1) cardiac function and pulmonary hypertension; 2) lung volumes, postoperative pleural effusion or pneumothorax; 3) splanchnic and renal perfusion, malrotations, and/or signs of necrotizing enterocolitis; 4) cerebral perfusion and eventual brain lesions that could contribute to neurodevelopmental impairment. In this article, we discuss the state-of-the-art in neonatal POCUS for which concerns congenital diaphragmatic hernia (CDH), and we provide suggestions to improve its use. IMPACT: This review shows how point-of-care ultrasound (POCUS) could be a valid tool for managing neonates with congenital diaphragmatic hernia (CDH) after birth. Our manuscript underscores the importance of standardized protocols in neonates with CDH. Beyond the well-known role of echocardiography, ultrasound of lungs, splanchnic organs, and brain can be useful. The use of POCUS should be encouraged to improve ventilation strategies, systemic perfusion, and enteral feeding, and to intercept any early signs related to future neurodevelopmental impairment.

Mitotic Block and Epigenetic Repression Underlie Neurodevelopmental Defects and Neurobehavioral Deficits in Congenital Heart Disease

Poor neurodevelopment is often observed with congenital heart disease (CHD), especially with mutations in chromatin modifiers. Here analysis of mice with hypoplastic left heart syndrome (HLHS) arising from mutations in Sin3A associated chromatin modifier Sap130 , and adhesion protein Pcdha9, revealed neurodevelopmental and neurobehavioral deficits reminiscent of those in HLHS patients. Microcephaly was associated with impaired cortical neurogenesis, mitotic block, and increased apoptosis. Transcriptional profiling indicated dysregulated neurogenesis by REST, altered CREB signaling regulating memory and synaptic plasticity, and impaired neurovascular coupling modulating cerebral blood flow. Many neurodevelopmental/neurobehavioral disease pathways were recovered, including autism and cognitive impairment. These same pathways emerged from genome-wide DNA methylation and Sap130 chromatin immunoprecipitation sequencing analyses, suggesting epigenetic perturbation. Mice with Pcdha9 mutation or forebrain-specific Sap130 deletion without CHD showed learning/memory deficits and autism-like behavior. These novel findings provide mechanistic insights indicating the adverse neurodevelopment in HLHS may involve cell autonomous/nonautonomous defects and epigenetic dysregulation and suggest new avenues for therapy.

Model-Informed Vancomycin Dosing Optimization to Address Delayed Renal Maturation in Infants and Young Children with Critical Congenital Heart Disease

Ensuring safe and effective drug therapy in infants and young children often requires accounting for growth and organ development; however, data on organ function maturation are scarce for special populations, such as infants with congenital diseases. Children with critical congenital heart disease (CCHD) often require multiple staged surgeries depending on their age and disease severity. Vancomycin (VCM) is used to treat postoperative infections; however, the standard pediatric dose (60-80 mg/kg/day) frequently results in overexposure in children with CCHD. In this study, we characterized the maturation of VCM clearance in pediatric patients with CCHD and determined the appropriate dosing regimen using population pharmacokinetic (PK) modeling and simulations. We analyzed 1,254 VCM serum concentrations from 152 postoperative patients (3 days-13 years old) for population PK analysis. The PK model was developed using a two-compartment model with allometrically scaled body weight, estimated glomerular filtration rate (eGFR), and postmenstrual age as covariates. The observed clearance in patients aged ≤ 1 year and 1-2 years was 33% and 40% lower compared with that of non-CCHD patients, respectively, indicating delayed renal maturation in patients with CCHD. Simulation analyses suggested VCM doses of 25 mg/kg/day (age ≤ 3 months, eGFR 40 mL/min/1.73 m2 ) and 35 mg/kg/day (3 months < age ≤ 3 years, eGFR 60 mL/min/1.73 m2 ). In conclusion, this study revealed delayed renal maturation in children with CCHD, could be due to cyanosis and low cardiac output. Model-informed simulations identified the lower VCM doses for children with CCHD compared with standard pediatric guidelines.

Preoperative serum cortisone levels are associated with cognition in preschool-aged children with tetralogy of Fallot after corrective surgery: new evidence from human populations and mice

BACKGROUND

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Children with TOF would be confronted with neurological impairment across their lifetime. Our study aimed to identify the risk factors for cerebral morphology changes and cognition in postoperative preschool-aged children with TOF.

METHODS

We used mass spectrometry (MS) technology to assess the levels of serum metabolites, Wechsler preschool and primary scale of intelligence-Fourth edition (WPPSI-IV) index scores to evaluate neurodevelopmental levels and multimodal magnetic resonance imaging (MRI) to detect cortical morphological changes.

RESULTS

Multiple linear regression showed that preoperative levels of serum cortisone were positively correlated with the gyrification index of the left inferior parietal gyrus in children with TOF and negatively related to their lower visual spaces index and nonverbal index. Meanwhile, preoperative SpO2 was negatively correlated with levels of serum cortisone after adjusting for all covariates. Furthermore, after intervening levels of cortisone in chronic hypoxic model mice, total brain volumes were reduced at both postnatal (P) 11.5 and P30 days.

CONCLUSIONS

Our results suggest that preoperative serum cortisone levels could be used as a biomarker of neurodevelopmental impairment in children with TOF. Our study findings emphasized that preoperative levels of cortisone could influence cerebral development and cognition abilities in children with TOF.

Advanced magnetic resonance imaging detects altered placental development in pregnancies affected by congenital heart disease

Congenital heart disease (CHD) is the most common congenital malformation and is associated with adverse neurodevelopmental outcomes. The placenta is crucial for healthy fetal development and placental development is altered in pregnancy when the fetus has CHD. This study utilized advanced combined diffusion-relaxation MRI and a data-driven analysis technique to test the hypothesis that placental microstructure and perfusion are altered in CHD-affected pregnancies. 48 participants (36 controls, 12 CHD) underwent 67 MRI scans (50 control, 17 CHD). Significant differences in the weighting of two independent placental and uterine-wall tissue components were identified between the CHD and control groups (both pFDR<0.001), with changes most evident after 30 weeks gestation. A Significant trend over gestation in weighting for a third independent tissue component was also observed in the CHD cohort (R = 0.50, pFDR=0.04), but not in controls. These findings add to existing evidence that placental development is altered in CHD. The results may reflect alterations in placental perfusion or the changes in fetal-placental flow, villous structure and maturation that occur in CHD. Further research is needed to validate and better understand these findings and to understand the relationship between placental development, CHD, and its neurodevelopmental implications.

Evaluation of Neurological and Auditory Development in Children with Congenital Heart Disease using Essence Q Questionnaire and Auditory Brainstem Response (ABR) Test

Objectives

The progress of cardiac surgery in children and the increase in the survival of children with Congenital Heart Disease (CHD) has led to consider another issue called a neurodevelopmental disorder. In this study, 53 children with CHD were evaluated in terms of development with the Essence Q questionnaire, Otoacoustic Emission (OAE), and Auditory Brainstem Response (ABR) regarding these patients' hearing and risk factors. The Essence Q scores were also examined.

Materials & Methods

In this prospective, cross-sectional study, the researchers included 53 children diagnosed with CHD. Initially, each child underwent ABR and OAE tests. Subsequently, data on potential risk factors associated with neurodevelopmental delay were collected. A trained project associate administered the Essence Q questionnaire, using parents' information as a guide. Following data collection, this study proceeded with an in-depth analysis of the information.

Results

Thirty-six boys (67.92%) and 17 girls (32.08%) with CHD were included in the study. The mean age of children was 26.98± 10.64 months. The mean Essence Q score for boys was 7.48± 2.57. Moreover, the average score for girls was 2.23 ± 8.11. According to this questionnaire, 39 patients (73.58%) had hyperactivity disorder, 46 patients (86.79%) had behavioral disorders, and ten patients (16.98%) had a motor delay. Unlike previous studies, all patients had normal OAE and ABR hearing.

Conclusion

This study demonstrated that factors such as developmental delay in the first year, a known genetic disease, and a history of seizures significantly impacted the Essence Q score. However, elements like prematurity, the use of ventilation, abnormalities on the dorsum, and the number of days post-surgery did not significantly affect the Essence Q score. Essence Q can be a reliable tool in screening for neurodevelopment in children with CHD.