Prevalence and outcome of congenital heart disease in patients with neural tube defect

Systems analysis of de novo mutations in congenital heart diseases identified a protein network in the hypoplastic left heart syndrome

Despite a strong genetic component, only a few genes have been identified in congenital heart diseases (CHDs). We introduced systems analyses to uncover the hidden organization on biological networks of mutations in CHDs and leveraged network analysis to integrate the protein interactome, patient exomes, and single-cell transcriptomes of the developing heart. We identified a CHD network regulating heart development and observed that a sub-network also regulates fetal brain development, thereby providing mechanistic insights into the clinical comorbidities between CHDs and neurodevelopmental conditions. At a small scale, we experimentally verified uncharacterized cardiac functions of several proteins. At a global scale, our study revealed developmental dynamics of the network and observed its association with the hypoplastic left heart syndrome (HLHS), which was further supported by the dysregulation of the network in HLHS endothelial cells. Overall, our work identified previously uncharacterized CHD factors and provided a generalizable framework applicable to studying many other complex diseases. A record of this paper's Transparent Peer Review process is included in the supplemental information.

Congenital Heart Disease and Myelomeningocele in the Newborn: Prevalence and Mortality

Myelomeningocele (MMC) and congenital heart disease (CHD) are independent risk factors for increased morbidity and mortality in the newborn period and each can require significant operations shortly after birth. Few studies have examined the impact of these combined lesions. We sought to examine the incidence of CHD in patients with MMC, and to evaluate length of stay (LOS), hospital charges, and mortality. Using the Texas Inpatient Public Use Data File, ~ 6.9 million newborn records between 1/1999 and 12/2016 were examined. Hospitalizations were classified as MMC without CHD (n = 3054), CHD without MMC (n = 72,266), and MMC with CHD (n = 171). The birth prevalence of CHD with MMC was 0.3/10,000 live hospital births, with 5% of patients with MMC having CHD, and 0.2% of those with CHD having MMC. There was increased LOS in patients with both MMC and CHD (median 15 days, IQR 5-31), compared to CHD without MMC (median 6 days, IQR 2-20) and MMC without CHD (median 8 days, IQR 1-14) and higher total hospital charges (median $95,007, IQR $26,731-$222,660) compared to CHD without MMC (median $27,726, $6463-$118,370) and MMC without CHD (median $40,066, IQR $5744-$97,490). Mortality was significantly higher in patients with MMC and CHD (22.2% compared to 3.1% in MMC without CHD and 4.1% in CHD without MMC). Significance remained when limiting for patients without genetic conditions or additional major birth defects. MMC with CHD in the newborn compared to either CHD or MMC alone is associated with longer LOS, higher charges, and increased mortality.

Early Embryonic Expression of AP-2α Is Critical for Cardiovascular Development

Congenital cardiovascular malformation is a common birth defect incorporating abnormalities of the outflow tract and aortic arch arteries, and mice deficient in the transcription factor AP-2α (Tcfap2a) present with complex defects affecting these structures. AP-2α is expressed in the pharyngeal surface ectoderm and neural crest at mid-embryogenesis in the mouse, but the precise tissue compartment in which AP-2α is required for cardiovascular development has not been identified. In this study we describe the fully penetrant AP-2α deficient cardiovascular phenotype on a C57Bl/6J genetic background and show that this is associated with increased apoptosis in the pharyngeal ectoderm. Neural crest cell migration into the pharyngeal arches was not affected. Cre-expressing transgenic mice were used in conjunction with an AP-2α conditional allele to examine the effect of deleting AP-2α from the pharyngeal surface ectoderm and the neural crest, either individually or in combination, as well as the second heart field. This, surprisingly, was unable to fully recapitulate the global AP-2α deficient cardiovascular phenotype. The outflow tract and arch artery phenotype was, however, recapitulated through early embryonic Cre-mediated recombination. These findings indicate that AP-2α has a complex influence on cardiovascular development either being required very early in embryogenesis and/or having a redundant function in many tissue layers.

Is routine preoperative transthoracic echocardiography necessary in newborns with myelomeningocele?

OBJECTIVE

Congenital heart disease (CHD) is common in newborns with myelomeningocele. Echocardiography before neonatal back closure has been recommended. Its utility in the era of prenatal diagnosis is unclear.

STUDY DESIGN

We reviewed all newborns with myelomeningocele evaluated by preoperative echocardiography at our institution over 11 years.

RESULT

Seventy-six successive newborns were identified. Ninety-one percent were prenatally diagnosed with myelomeningocele. In all, 1% had critical, 12% critical or non-critical and 22% critical, non-critical or possible CHD. The single case of critical CHD was both prenatally diagnosed and clinically identifiable.

CONCLUSION

The prevalence of CHD in newborns with myelomeningocele is increased compared with the general population; however, critical disease is uncommon. We propose preoperative echocardiography is unnecessary when the myelomeningocele is prenatally diagnosed, antenatal cardiac screening is complete and normal, and the newborn is clinically well.

Scrib:Rac1 interactions are required for the morphogenesis of the ventricular myocardium

Aims

The organization and maturation of ventricular cardiomyocytes from the embryonic to the adult form is crucial for normal cardiac function. We have shown that a polarity protein, Scrib, may be involved in regulating the early stages of this process. Our goal was to establish whether Scrib plays a cell autonomous role in the ventricular myocardium, and whether this involves well-known polarity pathways.

Methods and results

Deletion of Scrib in cardiac precursors utilizing Scrib^flox mice together with the Nkx2.5-Cre driver resulted in disruption of the cytoarchitecture of the forming trabeculae and ventricular septal defects. Although the majority of mice lacking Scrib in the myocardium survived to adulthood, they developed marked cardiac fibrosis. Scrib did not physically interact with the planar cell polarity (PCP) protein, Vangl2, in early cardiomyocytes as it does in other tissues, suggesting that the anomalies did not result from disruption of PCP signalling. However, Scrib interacted with Rac1 physically in embryonic cardiomyocytes and genetically to result in ventricular abnormalities, suggesting that this interaction is crucial for the development of the early myocardium.

Conclusions

The Scrib–Rac1 interaction plays a crucial role in the organization of developing cardiomyocytes and formation of the ventricular myocardium. Thus, we have identified a novel signalling pathway in the early, functioning, heart muscle. These data also show that the foetus can recover from relatively severe abnormalities in prenatal ventricular development, although cardiac fibrosis can be a long-term consequence.

Anesthetic concerns and perioperative complications in repair of myelomeningocele: a retrospective review of 135 cases

Myelomeningocele (MMC) a complex congenital spinal anomaly, results from neural tube defect during first 4 weeks of gestation. Medical records of 135 children who underwent excision and repair of MMC from January 2003 to December 2006 were analyzed, retrospectively. Data on associated illnesses, anesthetic management, perioperative complications, and outcome were recorded. The patient population consisted of older infants with unrepaired MMC. The average age of presentation was 1 year and 8 months. The commonest site of presentation was lumbar (39.3%). Leaking MMC was present in 19.3% of cases, most had associated electrolyte imbalance. Hydrocephalus was the commonest association (67.4%) followed by Chiari-II malformation (58.4%). Renal abnormality was present in 9% of cases and 24.4% of children had scoliosis. Two infants (1.5%) presented with inspiratory stridor. Intraoperative cardiac and respiratory problems were observed in 15.6% and 11.1%, of cases, respectively. Two children (1.5%) suffered cardiac arrest; both had associated Chiari-II malformation and hydrocephalus. Postoperative ventilation was required in 8.9% of children, primarily due to inadequate reversal from neuromuscular blockade. Infection, cerebrospinal fluid leak, and pseudomeningocele were common surgical complications. Improvement of motor, sensory, and sphincteric function was observed in 30.5%, 22.9%, and 14.1%, respectively. To conclude, surgical repair of MMC may at times pose life-threatening complications mostly because of associated anomalies. Children with associated Chiari malformation and/or hydrocephalus need special attention during perioperative period.