Echocardiographic predictors of aortopulmonary collaterals in infants with tetralogy of fallot and pulmonary atresia

Basic Concepts and Insights into Aortopulmonary Collateral Arteries in Congenital Heart Diseases

Aortopulmonary collateral arteries are persistent embryological vessels supplying lung parenchyma in various cardiopulmonary diseases with underlying pulmonary hypoperfusion. Their identification and mapping are important because of associated clinical implications and tendency to affect the surgical outcome. This article describes the embryological development and clinical relevance of aortopulmonary collaterals in various congenital cardiopulmonary conditions, along with the significance for treatment planning. Roles, strength, and shortcomings of the various imaging options and image-guided interventions are discussed, with a focus on presurgical planning and preparation, as well as postsurgical management.

Novel rare genetic variants of familial and sporadic pulmonary atresia identified by whole-exome sequencing

Pulmonary atresia (PA) is a severe cyanotic congenital heart disease. Although some genetic mutations have been described to be associated with PA, the knowledge of pathogenesis is insufficient. The aim of this research was to use whole-exome sequencing (WES) to determine novel rare genetic variants in PA patients. We performed WES in 33 patients (27 patient-parent trios and 6 single probands) and 300 healthy control individuals. By applying an enhanced analytical framework to incorporate de novo and case-control rare variation, we identified 176 risk genes (100 de novo variants and 87 rare variants). Protein‒protein interaction (PPI) analysis and Genotype-Tissue Expression analysis revealed that 35 putative candidate genes had PPIs with known PA genes with high expression in the human heart. Expression quantitative trait loci analysis revealed that 27 genes that were identified as novel PA genes that could be affected by the surrounding single nucleotide polymorphism were screened. Furthermore, we screened rare damaging variants with a threshold of minor allele frequency at 0.5% in the ExAC_EAS and GnomAD_exome_EAS databases, and the deleteriousness was predicted by bioinformatics tools. For the first time, 18 rare variants in 11 new candidate genes have been identified that may play a role in the pathogenesis of PA. Our research provides new insights into the pathogenesis of PA and helps to identify the critical genes for PA.

Prenatal Diagnosis and Postnatal Outcome of Fetuses with Pulmonary Atresia and Ventricular Septal Defect

PURPOSE

 To assess the intrauterine course, associated conditions and postnatal outcome of fetuses with pulmonary atresia with ventricular septal defect (PAVSD).

METHODS

 All cases of PAVSD diagnosed prenatally over a period of 10 years with a minimum follow-up of 6.5 years were retrospectively collected in 3 tertiary referral centers.

RESULTS

 50 cases of PAVSD were diagnosed prenatally. 44.0 % of fetuses had isolated PAVSD, 4.0 % had associated cardiac anomalies, 10.0 % had extra-cardiac anomalies, 38.0 % had chromosomal anomalies, 4.0 % had non-chromosomal syndromes. Among the 32 liveborn children, 56.3 % had reverse flow in the patent arterial duct, 25.0 % had major aortopulmonary collateral arteries (MAPCAs) with ductal agenesis and 18.7 % had a double supply. 17 pregnancies were terminated (34.0 %), there was 1 intrauterine fetal death (2.0 %), 1 neonatal death (2.0 %), and 6 deaths (12.0 %) in infancy. 25 of 30 (83.3 %) liveborn children with an intention to treat were alive at the latest follow-up. The mean follow-up among survivors was 10.0 years (range 6.5-15.1). 56.0 % of infants underwent staged repair, 44.0 % had one-stage complete repair. After exclusion of infants with additional chromosomal or syndromal anomalies, 88.9 % were healthy, and 11.1 % had mild limitations. The presence of MAPCAs did not differ significantly between survivors and non-survivors (p = 0.360), between one-stage or staged repair (p = 0.656) and healthy and impaired infants (p = 0.319).

CONCLUSION

 The prognosis in cases without chromosomal or syndromal anomalies is good. MAPCAs did not influence prognosis or postoperative health. The incidence of repeat interventions due to recurrent stenoses is significantly higher after staged compared with single-stage repair.

Identification of rare variants in novel candidate genes in pulmonary atresia patients by next generation sequencing

Pulmonary atresia (PA) is a rare congenital heart defect (CHD) with complex manifestations and a high mortality rate. Since the genetic determinants in the pathogenesis of PA remain elusive, a thorough identification of the genetic factors through whole exome sequencing (WES) will provide novel insights into underlying mechanisms of PA. We performed WES data from PA/VSD (n = 60), PA/IVS (n = 20), TOF/PA (n = 20) and 100 healthy controls. Rare variants and novel genes were identified using variant-based association and gene-based burden analysis. Then we explored the expression pattern of our candidate genes in endothelium cell lines, pulmonary artery tissues, and embryonic hearts. 56 rare damage variants of 7 novel candidate genes (DNAH10, DST, FAT1, HMCN1, HNRNPC, TEP1, and TYK2) were certified to have function in PA pathogenesis for the first time. In our research, the genetic pattern among PA/VSD, PA/IVS and TOF/PA were different to some degree. Taken together, our findings contribute new insights into the molecular basis of this rare congenital birth defect.

Complete Preoperative Evaluation of Pulmonary Atresia with Ventricular Septal Defect with Multi-Detector Computed Tomography

Objective

To compare multi-detector computed tomography (MDCT) with cardiac catheterization and transthoracic echocardiography (TTE) in comprehensive evaluation of the global cardiovascular anatomy in patients with pulmonary atresia with ventricular septal defect (PA-VSD).

Methods

The clinical and imaging data of 116 patients with PA-VSD confirmed by surgery were reviewed. Using findings at surgery as the reference standard, data from MDCT, TTE and catheterization were reviewed for assessment of native pulmonary vasculature and intracardiac defects.

Results

MDCT was more accurate than catheterization and TTE in identification of native pulmonary arteries. MDCT is also the most accurate test for delineation of the major aortopulmonary collateral arteries. The inter-modality agreement for evaluation of overriding aorta and VSD were both excellent. In the subgroup with surgical correlation, excellent agreement was found between TTE and surgery, and substantial agreement was also found at MDCT.

Conclusion

MDCT can correctly delineate the native pulmonary vasculatures and intracardiac defects and may be a reliable method for noninvasive assessment of global cardiovascular abnormalities in patients with PA-VSD.

Prenatally diagnosed pulmonary atresia with ventricular septal defect: echocardiography, genetics, associated anomalies and outcome

OBJECTIVE

To assess the accuracy of prenatal diagnosis, the association with genetic and extracardiac anomalies, and outcome in fetuses with isolated pulmonary atresia with ventricular septal defect (PA-VSD).

DESIGN AND SETTING

Retrospective study in a tertiary centre for fetal cardiology.

PATIENTS AND OUTCOME MEASURES

Echocardiographic video recordings of 27 consecutive fetuses with PA-VSD were reviewed for: (1) intracardiac anatomy; (2) presence of confluence and size of the branch pulmonary arteries; (3) source of pulmonary blood supply; and (4) side of the aortic arch. Postmortem and postnatal data were added. Karyotyping was performed in 25 patients and, in 23 of these, fluorescent in situ hybridisation to identify 22q11.2 deletion.

RESULTS

PA-VSD was correctly diagnosed in 19 of 21 patients (90%) with postnatal or autopsy confirmation of diagnosis. Central pulmonary arteries were correctly identified in 79% (15/19), the source of pulmonary blood supply in 62% (13/21) and major aortopulmonary collateral arteries in 44% (4/9). Aneuploidy was detected in 4 of 25 patients (16%) and 22q11.2 deletion in 6 of 23 patients (26%). Five of 27 patients (19%) had extracardiac anomalies. Eleven pregnancies were interrupted. Eleven of 16 liveborn babies survived. Neonatal survival was 15 of 16 (94%, 95% confidence interval (CI) 70 to 100), one-year survival was 9 of 12 (75%, 95% CI 43 to 95) and two-year survival was 5 of 9 (56%, 95% CI 21 to 86).

CONCLUSION

PA-VSD can be diagnosed by fetal echocardiography with a high degree of accuracy. However, it can be difficult to determine the morphology of the central pulmonary arteries and to locate the source of pulmonary blood supply. In most liveborn infants, complete surgical repair can be achieved.