Search

Neurodevelopmental impairments are the most common extracardiac morbidities among patients with complex congenital heart disease (CHD) across the lifespan. Robust clinical research in this area has revealed several cardiac, medical, and social factors that can contribute to neurodevelopmental outcome in the context of CHD. Studies using brain magnetic resonance imaging (MRI) have been instrumental in identifying quantitative and qualitative difference in brain structure and maturation in this patient population. Full-term newborns with complex CHD are known to have abnormal microstructural and metabolic brain development with patterns similar to those seen in premature infants at approximately 34 to 36 weeks' gestation. With the advent of fetal brain MRI, these brain abnormalities are now documented as they begin in utero, as early as the third trimester. Importantly, disturbed brain development in utero is now known to be independently associated with neurodevelopmental outcome in early childhood, making the prenatal period an important timeframe for potential interventions. Advances in fetal brain MRI provide a robust imaging tool to use in future neuroprotective clinical trials. The causes of abnormal fetal brain development are multifactorial and include cardiovascular physiology, genetic abnormalities, placental impairment, and other environmental and social factors. This review provides an overview of current knowledge of brain development in the context of CHD, common prenatal imaging tools to evaluate the developing fetal brain in CHD, and known risk factors contributing to brain immaturity.

ObjectiveTo test the hypothesis that delayed brain development in fetuses with d-transposition of the great arteries or hypoplastic left heart syndrome heightens their postnatal susceptibility to acquired white matter injury.MethodsThis is a cohort study across 3 sites. Subjects underwent fetal (third trimester) and neonatal preoperative magnetic resonance imaging of the brain to measure total brain volume as a measure of brain maturity and the presence of acquired white matter injury after birth. White matter injury was categorized as no-mild or moderate-severe based on validated grading criteria. Comparisons were made between the injury groups.ResultsA total of 63 subjects were enrolled (d-transposition of the great arteries: 37; hypoplastic left heart syndrome: 26). White matter injury was present in 32.4% (n=12) of d-transposition of the great arteries and 34.6% (n=8) of those with hypoplastic left heart syndrome. Overall total brain volume (taking into account fetal and neonatal scan) was significantly lower in those with postnatal moderate-severe white matter injury compared with no-mild white matter injury after adjusting for age at scan and site in d-transposition of the great arteries (coefficient: 14.8mL, 95% confidence interval, -28.8 to -0.73, P=.04). The rate of change in total brain volume from fetal to postnatal life did not differ by injury group. In hypoplastic left heart syndrome, no association was noted between overall total brain volume and change in total brain volume with postnatal white matter injury.ConclusionsLower total brain volume beginning in late gestation is associated with increased risk of postnatal moderate-severe white matter injury in d-transposition of the great arteries but not hypoplastic left heart syndrome. Rate of brain growth was not a risk factor for white matter injury. The underlying fetal and perinatal physiology has different implications for postnatal risk of white matter injury.

Background Tetralogy of Fallot with absent pulmonary valve is associated with high mortality, but it remains difficult to predict outcomes prenatally. We aimed to identify risk factors for mortality in a large multicenter cohort. Methods and Results Fetal echocardiograms and clinical data from 19 centers over a 10‐year period were collected. Primary outcome measures included fetal demise and overall mortality. Of 100 fetuses, pregnancy termination/postnatal nonintervention was elected in 22. Of 78 with intention to treat, 7 (9%) died in utero and 21 (27%) died postnatally. With median follow‐up of 32.9 months, no deaths occurred after 13 months. Of 80 fetuses with genetic testing, 46% had chromosomal abnormalities, with 22q11.2 deletion in 35%. On last fetal echocardiogram, at a median of 34.6 weeks, left ventricular dysfunction independently predicted fetal demise (odds ratio [OR], 7.4; 95% CI 1.3, 43.0; P =0.026). Right ventricular dysfunction independently predicted overall mortality in multivariate analysis (OR, 7.9; 95% CI 2.1–30.0; P =0.002). Earlier gestational age at delivery, mediastinal shift, left ventricular/right ventricular dilation, left ventricular dysfunction, tricuspid regurgitation, and Doppler abnormalities were associated with fetal and postnatal mortality, although few tended to progress throughout gestation on serial evaluation. Pulmonary artery diameters did not correlate with outcomes. Conclusions Perinatal mortality in tetralogy of Fallot with absent pulmonary valve remains high, with overall survival of 64% in fetuses with intention to treat. Right ventricular dysfunction independently predicts overall mortality. Left ventricular dysfunction predicts fetal mortality and may influence prenatal management and delivery planning. Mediastinal shift may reflect secondary effects of airway obstruction and abnormal lung development and is associated with increased mortality.

OBJECTIVE Fetal cerebrovascular resistance is influenced by several factors in the setting of intact autoregulation to allow for normal cerebral blood flow and oxygenation. Maternal hyperoxygenation (MH) allows for acute alterations in fetal physiology and can be a tool to test cerebrovascular reactivity in late-gestation fetuses. In this study, we utilized MH to evaluate cerebrovascular reactivity in fetuses with specific congenital heart disease (CHD). METHODS This was a cross-sectional study of fetuses with complex CHD compared to controls without CHD. CHD cases were grouped according to physiology into: left-sided obstructive lesion (LSOL), right-sided obstructive lesion (RSOL) or dextro-transposition of the great arteries (d-TGA). Subjects underwent MH testing during the third-trimester fetal echocardiogram. The pulsatility index (PI) was calculated for the fetal middle cerebral artery (MCA), umbilical artery (UA) and branch pulmonary artery (PA). The change in PI from baseline to during MH was compared between each CHD group and controls. RESULTS Sixty pregnant women were enrolled (CHD, n = 43; control, n = 17). In the CHD group, there were 27 fetuses with LSOL, seven with RSOL and nine with d-TGA. Mean gestational age was 33.9 (95% CI, 33.6-34.2) weeks. At baseline, MCA-PI Z-score was lowest in the LSOL group (-1.8 (95% CI, -2.4 to -1.2)) compared with the control group (-0.8 (95% CI, -1.3 to -0.3)) (P = 0.01). In response to MH, MCA-PI Z-score increased significantly in the control and d-TGA groups but did not change significantly in the LSOL and RSOL groups. The change in MCA-PI Z-score was significantly higher in the control group than in the LSOL group (0.9 (95% CI, 0.42-1.4) vs 0.12 (95% CI, -0.21 to 0.45); P = 0.03). This difference was more pronounced in the LSOL subgroup with retrograde aortic arch flow. Branch PA-PI decreased significantly in response to MH in all groups, with no difference in the change from baseline to MH between the groups, while UA-PI was unchanged during MH compared with at baseline. CONCLUSIONS The fetal cerebrovascular response to MH varies based on the underlying CHD diagnosis, suggesting that cardiovascular physiology may influence the autoregulatory capacity of the fetal brain. Further studies are needed to determine the clinical implications of these findings on long-term neurodevelopment in these at-risk children. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Background: Prenatal detection (PND) has benefits for infants with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), but associations between sociodemographic and geographic factors with PND have not been sufficiently explored. This study evaluated whether socioeconomic quartile (SEQ), public insurance, race and ethnicity, rural residence, and distance of residence (distance and driving time from a cardiac surgical center) are associated with the PND or timing of PND, with a secondary aim to analyze differences between the United States and Canada. Methods: In this retrospective cohort study, fetuses and infants z score using the neighborhood summary score or Canadian Chan index and separated into quartiles. Insurance type and self-reported race and ethnicity were obtained from medical charts. We evaluated associations among SEQ, insurance type, race and ethnicity, rural residence, and distance of residence with PND of HLHS and TGA (aggregate and individually) using bivariate analysis with adjusted associations for confounding variables and cluster analysis for centers. Results: Data on 1862 subjects (HLHS: n=1171, 92% PND; TGA: n=691, 58% PND) were submitted by 21 centers (19 in the United States). In the United States, lower SEQ was associated with lower PND in HLHS and TGA, with the strongest association in the lower SEQ of pregnancies with fetal TGA (quartile 1, 0.78 [95% CI, 0.64–0.85], quartile 2, 0.77 [95% CI, 0.64–0.93], quartile 3, 0.83 [95% CI, 0.69–1.00], quartile 4, reference). Hispanic ethnicity (relative risk, 0.85 [95% CI, 0.72–0.99]) and rural residence (relative risk, 0.78 [95% CI, 0.64–0.95]) were also associated with lower PND in TGA. Lower SEQ was associated with later PND overall; in the United States, rural residence and public insurance were also associated with later PND. Conclusions: We demonstrate that lower SEQ, Hispanic ethnicity, and rural residence are associated with decreased PND for TGA, with lower SEQ also being associated with decreased PND for HLHS. Future work to increase PND should be considered in these specific populations.

Background Impairments in fetal oxygen delivery have been implicated in brain dysmaturation seen in congenital heart disease (CHD), suggesting a role for in utero transplacental oxygen therapy. We applied a novel imaging tool to quantify fetal cerebral oxygenation by measuring T2* decay. We compared T2* in fetuses with CHD with controls with a focus on cardiovascular physiologies (transposition or left‐sided obstruction) and described the effect of brief administration of maternal hyperoxia on T2* decay. Methods and Results This is a prospective study performed on pregnant mothers with a prenatal diagnosis of CHD compared with controls in the third trimester. Participants underwent a fetal brain magnetic resonance imaging scan including a T2* sequence before and after maternal hyperoxia. Comparisons were made between control and CHD fetuses including subgroup analyses by cardiac physiology. Forty‐four mothers (CHD=24, control=20) participated. Fetuses with CHD had lower total brain volume (238.2 mm 3 , 95% CI, 224.6–251.9) compared with controls (262.4 mm 3 , 95% CI, 245.0–279.8, P =0.04). T2* decay time was faster in CHD compared with controls (beta=−14.4, 95% CI, −23.3 to −5.6, P =0.002). The magnitude of change in T2* with maternal hyperoxia was higher in fetuses with transposition compared with controls (increase of 8.4 ms, 95% CI, 0.5–14.3, P =0.01), though between‐subject variability was noted. Conclusions Cerebral tissue oxygenation is lower in fetuses with complex CHD. There was variability in the response to maternal hyperoxia by CHD subgroup that can be tested in future larger studies. Cardiovascular physiology is critical when designing neuroprotective clinical trials in the fetus with CHD.

Background: Neonates with congenital heart disease are more likely to be small for gestational age. Few studies have investigated the effect of birth weight Z-score on outcomes after congenital heart surgery. Methods: Patients from the Society of Thoracic Surgeons Congenital Heart Surgery Database (2010 to 2016) undergoing cardiac surgery at a corrected gestational age ≤ 44 weeks were included, and classified as severely (birth weight Z-score -4 to -2), moderately (Z-score between -2 and -1) and mildly growth restricted (Z-score -1.0 to -0.5) and compared to a reference (Z-score 0 to 0.5). Multivariable logistic regression clustering on center was used to evaluate the association of birth weight Z-score with operative mortality, postoperative complications and length of stay, adjusting for other patient characteristics. Interaction between Z-score for birth weight and gestational age was assessed. Results: In 25,244 patients, operative mortality was 8.6% and major complications occurred in 19.4%. Compared to the reference group with no growth restriction, the adjusted odds (AOR) of mortality was increased in infants with severe (AOR 2.4, CI 2.0-3.0), moderate (AOR 1.7, CI 1.4-2.0) and mild growth restriction (AOR 1.4, CI 1.2-1.6). The AOR for major postoperative complications was increased for infants with severe (AOR 1.4, CI 1.2-1.7) and moderate growth restriction (AOR 1.2, CI 1.1-1.4), but not in mildly growth restricted infants (AOR 1.0, CI 0.9-1.2). Length of stay was prolonged for all growth restricted cohorts (adjusted Hazard Ratio38 weeks) and then preterm infants ( Conclusions: Even birth weight Z-scores that are slightly below average are independent risk factors for mortality and morbidity in neonates undergoing cardiac surgery. The strongest association between poor fetal growth and operative mortality exists in early-term neonates. These novel findings may account for some of the previously unexplained variation in cardiac surgical outcomes.

ObjectiveTo assess the trajectory of perioperative brain growth in relationship to cardiac diagnosis and acquired brain injuries.MethodsThis was a cohort study of term neonates with hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (d-TGA). Subjects underwent magnetic resonance imaging of the brain pre- and postoperatively to determine the severity of brain injury and total and regional brain volumes by the use of automated morphometry. Comparisons were made by cardiac lesion and injury status.ResultsA total of 79 subjects were included (49, d-TGA; 30, HLHS). Subjects with HLHS had more postoperative brain injury (55.6% vs 30.4%, P=.03) and more severe brain injury (moderate-to-severe white matter [WM] injury, P=.01). Total and regional perioperative brain growth was not different by brain injury status (either pre- or postoperative). However, subjects with moderate-to-severe WM injury had a slower rate of brain growth in WM and gray matter compared with those with no injury. Subjects with HLHS had a slower rate of growth globallyand in WM and deep gray matter as compared with d-TGA (total brain volume: 12cm3/wk vs 7cm3; WM: 2.1cm3/wk vs 0.6cm3; deep gray matter: 1.5cm3/wk vs 0.7cm3; P&nbsp

BackgroundA growing body of evidence indicates that right ventricular dysfunction in patients with palliated hypoplastic left heart syndrome (HLHS) originates in fetal life. In this study, the systolic-to-diastolic time index (SDI) was used to study the presence of ventricular dysfunction in single right ventricles in fetuses with HLHS or evolving HLHS and to assess whether this dysfunction is related to increase preload, myocardial performance, or interventricular interaction.MethodsEchocardiograms from 78 fetuses with HLHS and 10 with evolving HLHS were retrospectively compared with those of 78 normal control fetuses. Fetuses with HLHS were further grouped according to morphology of the left ventricle (LV): not visible (n=35) or visible (n=43). Spectral Doppler signals obtained from right ventricular inflow (blood pool) and tissue Doppler from the tricuspid lateral annulus were analyzed. The SDI was calculated as the ratio of the ejection time plus isovolumic contraction and relaxation times to the diastolic filling time. E/A and E/e' ratios, cardiac output, preload index, and Tei index were also calculated.ResultsFetuses with HLHS demonstrated significantly elevated right ventricular SDI values by both blood pool Doppler and Doppler tissue imaging compared with control subjects (1.89±0.33 vs 1.58±0.29 [P&nbsp