Prenatal and Postnatal Survival of Fetal Tetralogy of Fallot: A Meta-analysis of Perinatal Outcomes and Associated Genetic Disorders

Association of right aortic arch and agenesis of ductus arteriosus in prenatal tetralogy of Fallot spectrum and its clinical implications

OBJECTIVE

In our center, we observed an increased frequency of right aortic arch (RAA) with an agenesis of the ductus arteriosus (ADA) in prenatally diagnosed tetralogy of Fallot (ToF) and its variations. This study aimed to determine whether there is an association of RAA and ADA in fetuses with ToF. Distribution of genetic anomalies and impact on postnatal outcome were further evaluated.

METHOD

Single-center retrospective observational study including pregnancies with prenatal diagnosis of ToF from 2010 to 2023. All cases were subdivided into ToF with pulmonary stenosis (PS) and pulmonary atresia (PA). Clinical and echocardiographic databases were reviewed for pregnancy outcome, genetic anomalies, and postnatal course.

RESULTS

The cohort included 169 cases, 124 (73.4%) with ToF/PS and 45(26.6%) with ToF/PA. Agenesis of the ductus arteriosus was significantly associated with RAA in both subtypes of ToF (p = 0.001) compared to left aortic arch and found in 82.5% (33/40) versus 10.7% (9/84) of fetuses with ToF/PS and in 57.1% (8/14) versus 12.9% (4/31) of fetuses with ToF/PA. In both ToF/PS and ToF/PA, RAA/ADA versus RAA/patent DA revealed a significantly higher risk for the presence of genetic abnormalities, especially microdeletion 22q11.2, major aorto-pulmonary collateral arteries and a shorter time to complete surgical repair.

CONCLUSION

We demonstrated a significantly increased frequency of RAA/ADA in patients with prenatally diagnosed ToF. Although this association revealed no significant impact on overall survival, the prenatal detection of RAA/ADA has implications for counseling, genetic evaluation and postnatal management.

Prenatal screening and diagnosis of pulmonary artery anomalies

Congenital pulmonary artery anomalies are rare. Their antenatal diagnosis requires good knowledge of fetal cardiac anatomy because their clinical presentation varies depending on the type and severity of the underlying lesion. Screening of these vascular anomalies can be straightforward in some cases because of significant associated consequences that are detected easily on ultrasound, while other anomalies have considerably less obvious features. There may be an associated genetic syndrome. The aim of this review was to define anomalies of the main pulmonary artery and its branches and to propose, through the identification of suspicious findings during routine antenatal heart examination, an optimal screening method for the pulmonary artery pathway. We propose that pulmonary artery anomalies can be classified antenatally into four types of disorder. Herein we describe 14 cases subgrouped accordingly as: anomalies of the pulmonary valvular region, with stenosis or atresia of the valve (n = 4); conotruncal abnormalities (n = 4); anomalies associated with abnormal origin or course of the pulmonary artery (n = 4); and anomalies associated with abnormal growth of the pulmonary artery and its branches (n = 2). We highlight the need to differentiate the three-vessel view from the three-vessel-and-trachea view when assessing a fetus with a congenital pulmonary artery anomaly. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Evaluation of Fetal Cardiac Size and Shape: A New Screening Tool to Identify Fetuses at Risk for Tetralogy of Fallot

OBJECTIVE

Prenatal detection rates for tetralogy of Fallot (TOF) vary between 23 and 85.7%, in part because of the absence of significant structural abnormalities of the 4-chamber view (4CV), as well as the relative difficulty in detection of abnormalities during the screening examination of the outflow tracts. The purpose of this study was to evaluate whether the 4CV and ventricles in fetuses with TOF may be characterized by abnormalities of size and shape of these structures.

METHODS

This study retrospectively evaluated 44 fetuses with the postnatal diagnosis of TOF. Measurements were made from the 4CV (end-diastolic length, width, area, global sphericity index, and cardiac axis) and the right (RV) and left (LV) ventricles (area, length, 24-segment transverse widths, sphericity index, and RV/LV ratios). Logistic regression analysis was performed to identify variables that might separate fetuses with TOF from normal controls.

RESULTS

The mean gestational age at the time of the last examination prior to delivery was 28 weeks 5 days (SD 4 weeks, 4 days). The mean z-scores were significantly lower in fetuses with TOF for the 4CV and RV and LV measurements of size and shape. Logistic regression analysis identified simple linear measurements of the 4CV, RV, and LV that had a sensitivity of 90.9 and specificity of 98.5% that outperformed the 4CV cardiac axis (sensitivity of 22.7%) as a screening tool for TOF.

CONCLUSIONS

Measurements of the 4CV, RV, and LV can be used as an adjunct to the outflow tract screening examination to identify fetuses with TOF.

Long-term outcomes in children with absent pulmonary valve syndrome: it is not just fixing the heart

OBJECTIVE

Absent pulmonary valve syndrome (APV) is a rare condition usually associated with tetralogy of Fallot (TOF). Some infants develop respiratory failure from bronchial compression and the long-term neurodevelopmental outcome is unknown. We aimed to investigate the outcomes of APV and the need for long-term ventilation (LTV).

DESIGN, PATIENTS AND SETTING

Retrospective single-centre review of patients diagnosed with APV between 2007 and 2017.

OUTCOME MEASURES

Survival, neurological disability and postoperative LTV (≥3 months of non-invasive or invasive respiratory support).

RESULTS

Thirty patients were identified, 22 (73%) of whom were prenatally diagnosed. Pregnancy was discontinued in one patient, while in utero death occurred in three. One was lost to follow-up. Of the remaining 25 liveborn, 21 had the classic TOF/APV. One baby died immediately after birth, while two patients had palliative care due to severe airway compression and inability to wean ventilation support. Surgical repair was performed in 21 of the 25 (84%) liveborn, with one awaiting surgery. Of those undergoing surgery, two patients died: one during surgery and the other due to severe airway malacia 5 months postsurgery. In the surgical group survival from birth at 1 and 5 years was 89% (95% CI 75% to 100%). Six (30%) patients required LTV postoperatively; all had surgery within the first 6 months of life. Learning and/or other physical difficulties were evident in 63%.

CONCLUSIONS

Majority of patients with APV are diagnosed antenatally. A third of those operated required LTV and over half had learning and/or other physical difficulties. Prospective studies are needed to identify prenatal factors that predict postnatal outcomes so parents can be counselled appropriately.

A 'holistic' sonographic view on congenital heart disease - How automatic reconstruction using fetal intelligent navigation echocardiography (FINE) eases the unveiling of abnormal cardiac anatomy part I: Right heart anomalies

Attempting a comprehensive examination of the fetal heart remains challenging for unexperienced operators as it emphasizes the acquisition and documentation of sequential cross-sectional and sagittal views and inevitably results in diminished detection rates of fetuses affected by congenital heart disease. The introduction of four-dimensional spatio-temporal image correlation (4D STIC) technology facilitated a volumetric approach for thorough cardiac anatomic evaluation by the acquisition of cardiac 4D datasets. By analyzing and re-arranging of numerous frames according to their temporal event within the heart cycle, STIC allows visualization of cardiac structures as an endless cine loop sequence of a complete single cardiac cycle in motion. However, post-analysis with manipulation and repeated slicing of the volume usually requires experience and in-depth anatomic knowledge, which limits the widespread application of this advanced technique in clinical care and unfortunately leads to the underestimation of its diagnostic value to date. Fetal intelligent navigation echocardiography (FINE), a novel method that automatically generates and displays nine standard fetal echocardiographic views in normal hearts, has shown to be able to overcome these limitations. Very recent data on the detection of congenital heart defects (CHDs) using the FINE method revealed a high sensitivity and specificity of 98% and 93%, respectively. In this two-part manuscript, we focused on the performance of FINE in delineating abnormal anatomy of typical right and left heart lesions and thereby emphasized the educational potential of this technology for more than just teaching purposes. We further discussed recent findings in a pathophysiological and/or functional context.

The Fetal 3-Vessel Views: An Illustrative Case-Based Tutorial

In 2018, the American Institute of Ultrasound in Medicine revised its obstetric Practice Parameter for the second-trimester fetal anatomic survey. The 2018 Practice Parameter recommends incorporation of the 3-vessel view and 3-vessel and trachea view "if technically feasible." Sonographers and other medical providers may require additional training and education to develop greater proficiency in obtaining and interpreting these views. This pictorial essay, including ultrasound images alongside their respective schematic diagrams, provides an up-to-date, practical, and clinically oriented review of the 3-vessel view and 3-vessel and trachea view and their most common presentations in the context of congenital heart disease.

Fetal pulmonary atresia with ventricular septal defect: Features, associations, and outcome in fetuses with different pulmonary circulation supply types

OBJECTIVES

To assess features and outcome in fetuses with pulmonary atresia with ventricular septal defect (PA-VSD).

METHODS

Fetuses with PA-VSD were prospectively enrolled and grouped on the basis of the pulmonary blood supply, including type A (only arterial duct [DA]), type B (both DA and major aortopulmonary collateral arteries [MAPCAs] present), and type C (MAPCAs only). The echocardiography features, associated chromosomal/genetic malformations, and postnatal outcome were compared among the three groups.

RESULTS

Fifty-five fetuses with PA-VSD were enrolled. The presence of confluent PAs varied, with the highest displaying rate in type A and lowest rate in type C (100% vs 41.1%). The intrapericardial pulmonary arteries in all groups were hypoplastic but smaller in types B and C than in type A (P < .05). Deletion of 22q11.2 and right aortic arch were more frequently observed in types B and C than in type A. At the end of the study, overall survival rates in type C were lower than those in type A (22.1% vs 77.3%).

CONCLUSION

There are great differences in the size of pulmonary arteries, associated genetic malformations, and perinatal outcomes among fetuses with PA-VSD. These results could be used for family counseling and surgical planning.

Genetic anomalies in fetuses with tetralogy of Fallot by using high-definition chromosomal microarray analysis

Background

The etiology of TOF is complex and the genesis of TOF has been associated with environmental factors and genetic disorders, including chromosomal anomalies, aneuploidies, 22q11.2 deletion and single-gene disease. Previous literatures have shown that a chromosome alteration in about 30% patients with TOF and recently published articles reported that 22q11.2 deletion syndrome accounts for 16% cases with TOF diagnosed postnatally. CMA now is considered as gold standard for detecting genetic anomalies in fetuses with congenital malformations. CMA could detect a 6.6–25% incremental yield of CNVs in CHDs. The aim of this study was to assess the genetic anomalies in fetal tetralogy of Fallot (TOF) by using high-definition CMA.

Methods

This retrospective study reviewed all the fetuses diagnosed with TOF between 2013 and 2018. Prenatal ultrasongraphic findings, including cardiac angle, and the findings of CMA using Affymetrix CytoScan HD array were collected.

Results

Ninety-six fetuses with TOF and known genetic results were enrolled. Right aortic arch was the most common associated anomalies (22.9%). One fetus with trisomy 18, one with 46, XX, t (7;10)(q36;q22), one with 47, XYY and five with trisomy 21 were identified. Clinically significant CNVs occurred in 6.8% and uncertain significant CNVs in 3.4% fetal TOF with normal karyotype. A total of four cases with 22q11.2 microdeletion and two fetuses with Yq11.223q11.23 microduplication have been identified. Genetic anomalies, including chromosomal aberrations and pathogenic CNVs, were significantly higher in the TOF with extracardiac anomaly group than in the TOF without extracardiac anomaly group (P = 0.005). Abnormal cardiac angle was noticed in 24.0% fetal TOF. Genetic anomalies were more common in the TOF with abnormal cardiac angle than with normal cardiac angle (P = 0.001). On the other hand, abnormal cardiac angle was noticed in 64.3% fetal TOF with genetic anomalies while abnormal cardiac angle occurred in 17.1% fetal TOF with normal genetic results (P = 0.001).

Conclusions

Genetic testing should be offered, specially using microarray analysis, for the fetal TOF with abnormal cardiac angle or extracardiac defects.

Tetralogy of Fallot in Spain: a nationwide registry-based mortality study across 36 years

BACKGROUND

Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart defect. TOF mortality has fallen remarkably in recent years due to therapeutic advances. Accordingly, the aim of this study was to assess temporal and spatial variability in TOF-related mortality in Spain across the period 1981-2016, using data drawn from the nationwide population-based registry.

METHODS

Annual deaths due to TOF were sourced from the Spanish National Institute of Statistics database by reference to International Classification of Diseases (ICD), 9th and 10th Revision codes, namely, ICD-9 code 745.2 (period 1981-1998) and ICD-10 code Q21.3 (period 1999-2016). Age-specific and age-adjusted mortality rates were calculated, as were standardised mortality ratios (SMRs) by province, district and municipality for the period 1999-2016.

RESULTS

A total of 1035 deaths were attributed to TOF (57.78% of them were men and 42.22% were women). The age-adjusted mortality rate ranged from 0.75 per 1,000,000 inhabitants (95% confidence interval [CI]: 0-1.36) in 1981 to 0.03 per 1,000,000 (95% CI: 0.01-0.06) in 2016 for both sexes. In 2011, there was a change in the mortality trend, with a significant decrease of 49.22% per year (p < 0.001). In terms of geographical analysis, some areas with a significantly higher risk of TOF mortality were identified in the south of Spain, though no specific spatial pattern was in evidence.

CONCLUSION

The decrease in TOF mortality may be related to improvements in diagnostic and treatment techniques. More studies are needed to analyse regions with a higher mortality risk, in order to improve medical planning and resource allocation, and identify risk factors and preventive measures.

Fetal cardiac axis in tetralogy of Fallot: associations with prenatal findings, genetic anomalies and postnatal outcome

OBJECTIVE

To compare prenatal findings, associated genetic anomalies and postnatal outcome in fetuses with tetralogy of Fallot (TOF) with normal cardiac axis (CAx) and those with abnormal CAx.

METHODS

In this retrospective cohort study, 85 cases diagnosed with TOF by prenatal ultrasound at our clinic between 2005 and 2015 were reviewed. Follow-up ultrasound and postnatal outcome were available for 68 cases. One case complicated with absent pulmonary valve syndrome and a further seven cases diagnosed postnatally with anomalies other than TOF were excluded from the study. The remaining 60 cases of postnatally confirmed TOF were divided according to CAx into two groups: those with normal CAx (n = 33) and those with abnormal CAx (n = 27). CAx was defined as the angle between the interventricular septum and midline of the fetal thorax at the level of the four-chamber view. CAx > 65° or < 25° was considered abnormal. Prenatal sonographic findings, associated genetic anomalies and postnatal outcome were compared between the two groups.

RESULTS

Fetuses with TOF and abnormal CAx were more likely to have pulmonary atresia (40.7% vs 15.2%; P = 0.026) and right-sided aortic arch (48.1% vs 21.2%; P = 0.028) than those with normal CAx. Postnatal death occurred in 30.4% of infants with abnormal CAx vs 6.5% with normal CAx (P = 0.028). Incidence of tested genetic anomalies was similar between the two groups.

CONCLUSION

In fetuses with TOF, abnormal CAx is associated with the presence of pulmonary atresia, right-sided aortic arch and a higher risk of postnatal death. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Effect of Concomitant Birth Defects and Genetic Anomalies on Infant Mortality in Tetralogy of Fallot

BACKGROUND

A substantial proportion of infants born with tetralogy of Fallot (TOF) die in infancy. A better understanding of the heterogeneity associated with TOF, including extracardiac malformations and chromosomal anomalies is vital to stratifying risk and optimizing outcomes during infancy.

METHODS

Using the North Carolina Birth Defects Monitoring Program, infants diagnosed with TOF and born between 2003 and 2012 were included. Kaplan-Meier survival curves were used to estimate cumulative 1-year mortality, stratified by the presence of concomitant birth defects (BDs) and chromosomal anomalies. Multivariable logistic regression was used to estimate the direct effect of each concomitant BD, after adjusting for all others.

RESULTS

A total of 496 infants with TOF were included, and 15% (n = 76) died. The number of concomitant BD systems was significantly associated with the risk of death at 1-year, p < 0.0001. Specifically, the risk of mortality was 8% among infants with TOF with or without additional cardiac defects, 16% among infants with TOF and 1 extracardiac BD system, 19% among infants with 2 extracardiac BD systems, and 39% among infants with ≥ 3 extracardiac BD systems. After adjustment, concomitant eye and gastrointestinal defects were significantly associated increased with 1-year mortality, odds ratio 2.83 (95% confidence interval, 1.08-7.32) and odds ratio 4.43 (95% confidence interval, 1.57, 12.45), respectively. Infants with trisomy 13 or trisomy 18 were also significantly more likely to die, p < 0.0001.

CONCLUSION

Both concomitant BDs and genetic anomalies increase the risk of mortality among infants with TOF. Future studies are needed to identify the underlying genetic and socioeconomic risk factors for high-risk TOF infants. Birth Defects Research 109:1154-1165, 2017. © 2017 Wiley Periodicals, Inc.