The evolving genetic etiology of conotruncal anomalies

OBJECTIVE

To assess the diagnostic yield of genetic testing for antenatally detected conotruncal defects.

METHOD

This was a retrospective analysis of all antenatally detected cases of conotruncal anomalies over a 4-year period. Patients were offered antenatal and postnatal genetic testing including QF-PCR, microarray and exome sequencing (ES) antenatally or genome sequencing (GS) postnatally on a case-by-case basis.

RESULTS

There were 301 cases included. Overall, there were pathogenic genetic findings in 27.6% of the cases tested (53/192). The commonest finding was 22q11.21 deletion (20/192 cases, 10.4%), followed by trisomy 21 (6/192, 3.1%). There were 249 cases of isolated conotruncal anomalies, of which 59.8% (149/249) had genetic testing and 22.8% (34/149) had pathogenic findings. ES/GS was performed in five cases with no pathogenic findings. There were 52 cases of non-isolated contruncal anomalies, of which 82.7% (43/52) had genetic testing. ES/GS was performed in 11 cases in this group and increased the yield of clinically significant diagnoses from 32.6% (14/43) to 44.2% (19/43).

CONCLUSION

Genetic abnormalities are present in over one quarter of cases of antenatally detected conotruncal anomalies. The commonest abnormality is 22q11.21 deletion. Exome sequencing or genome sequencing leads to a significant increase in genetic diagnosis in non-isolated cases.

British Congenital Cardiac Association Fetal Cardiology Standards: impact of Patient and Public involvement exercise on the development of clinical standards

OBJECTIVE

To examine the impact of a Patient and Public Involvement exercise on the development of British Congenital Cardiac Association Fetal Cardiology Standards 2021.

DESIGN

Open-ended, semi-structured interviews were undertaken to inform the design of a study to improve the quality of parents' experiences during antenatal and perinatal care of their child with CHD. This Patient and Public Involvement exercise was used to inform the final version of the drafted 'Standards'.

SETTING

One-on-one interviews with parents who responded to a request on the closed Facebook page of the user group "Little Hearts Matter": "Would you be interested in helping us to design a study about parents' experience on learning that their child had CHD"?

PATIENTS

Parents of children with single ventricle CHD.

RESULTS

Twenty-one parents (18 mothers, 3 fathers) participated. Parents responses were reported to have variably reinforced, augmented, and added specificity in the later stages of drafting to six of the seven subsections of Section C Information and Support for Parents including: "At the time of the Scan"; "Counselling following the identification of an abnormality"; "Written information/resources"; "Parent support"; "Communication with other teams and ongoing care"; and "Bereavement support".

CONCLUSIONS

This Patient and Public Involvement exercise successfully informed the development of Standards after the initial drafting. It contributed to the establishment of face validity of the 'Standards', especially when consistent with what is reported in the literature. Further research is needed to explore approaches to involving and standardising Patient and Public Involvement in the development of clinical standards.

Prenatal diagnosis of hypoplastic left heart syndrome on ultrasound using artificial intelligence: How does performance compare to a current screening programme?

BACKGROUND

Artificial intelligence (AI) has the potential to improve prenatal detection of congenital heart disease. We analysed the performance of the current national screening programme in detecting hypoplastic left heart syndrome (HLHS) to compare with our own AI model.

METHODS

Current screening programme performance was calculated from local and national sources. AI models were trained using four-chamber ultrasound views of the fetal heart, using a ResNet classifier.

RESULTS

Estimated current fetal screening programme sensitivity and specificity for HLHS were 94.3% and 99.985%, respectively. Depending on calibration, AI models to detect HLHS were either highly sensitive (sensitivity 100%, specificity 94.0%) or highly specific (sensitivity 93.3%, specificity 100%). Our analysis suggests that our highly sensitive model would generate 45,134 screen positive results for a gain of 14 additional HLHS cases. Our highly specific model would be associated with two fewer detected HLHS cases, and 118 fewer false positives.

CONCLUSION

If used independently, our AI model performance is slightly worse than the performance level of the current screening programme in detecting HLHS, and this performance is likely to deteriorate further when used prospectively. This demonstrates that collaboration between humans and AI will be key for effective future clinical use.

COVID-19 in congenital heart disease (COaCHeD) study

BACKGROUND

COVID-19 has caused significant worldwide morbidity and mortality. Congenital heart disease (CHD) is likely to increase vulnerability and understanding the predictors of adverse outcomes is key to optimising care.

OBJECTIVE

Ascertain the impact of COVID-19 on people with CHD and define risk factors for adverse outcomes.

METHODS

Multicentre UK study undertaken 1 March 2020-30 June 2021 during the COVID-19 pandemic. Data were collected on CHD diagnoses, clinical presentation and outcomes. Multivariable logistic regression with multiple imputation was performed to explore predictors of death and hospitalisation.

RESULTS

There were 405 reported cases (127 paediatric/278 adult). In children (age <16 years), there were 5 (3.9%) deaths. Adjusted ORs (AORs) for hospitalisation in children were significantly lower with each ascending year of age (OR 0.85, 95% CI 0.75 to 0.96 (p<0.01)). In adults, there were 24 (8.6%) deaths (19 with comorbidities) and 74 (26.6%) hospital admissions. AORs for death in adults were significantly increased with each year of age (OR 1.05, 95% CI 1.01 to 1.10 (p<0.01)) and with pulmonary arterial hypertension (PAH; OR 5.99, 95% CI 1.34 to 26.91 (p=0.02)). AORs for hospitalisation in adults were significantly higher with each additional year of age (OR 1.03, 95% CI 1.00 to 1.05 (p=0.04)), additional comorbidities (OR 3.23, 95% CI 1.31 to 7.97 (p=0.01)) and genetic disease (OR 2.87, 95% CI 1.04 to 7.94 (p=0.04)).

CONCLUSIONS

Children were at low risk of death and hospitalisation secondary to COVID-19 even with severe CHD, but hospital admission rates were higher in younger children, independent of comorbidity. In adults, higher likelihood of death was associated with increasing age and PAH, and of hospitalisation with age, comorbidities and genetic disease. An individualised approach, based on age and comorbidities, should be taken to COVID-19 management in patients with CHD.

Double aortic arch: implications of antenatal diagnosis, differential growth of arches during pregnancy, associated abnormalities and postnatal outcome

OBJECTIVES

To evaluate the prenatal characteristics of double aortic arch (DAA), assess the relative size of the arches and their growth during pregnancy, describe associated cardiac, extracardiac and chromosomal/genetic abnormalities and review postnatal presentation and clinical outcome.

METHODS

This was a retrospective cohort study of all fetuses with a confirmed diagnosis of DAA seen in five specialized referral centers in London, UK, between October 2012 and November 2019. Cases were identified from the hospitals' fetal databases. Fetal echocardiographic findings, intracardiac and extracardiac abnormalities, genetic defects, computed tomography (CT) findings and postnatal clinical presentation and outcome were evaluated.

RESULTS

A total of 79 fetuses with DAA were included. Of those assessed postnatally, 48.6% had an atretic left aortic arch (LAA), while 5.1% had an atretic LAA at the first fetal scan and were misdiagnosed antenatally with right aortic arch (RAA). The LAA was atretic in 55.8% of those who underwent CT. DAA was an isolated abnormality in 91.1% of cases; 8.9% of patients had an additional intracardiac abnormality and 2.5% had both intra- and extracardiac abnormalities. Among the 52 cases that underwent genetic testing, 11.5% had genetic abnormalities and, specifically, the 22q11 microdeletion was identified in 3.8% of patients. At a median follow-up of 993.5 days, 42.5% of patients had developed symptoms of tracheoesophageal compression (5.5% during the first month after birth) and 56.2% had undergone intervention. Statistical analysis using the χ-square test showed no significant relationship between morphology of DAA (patency of both aortic arches vs atretic LAA) and the need for intervention (P = 0.134), development of vascular ring symptoms (P = 0.350) or evidence of airway compression on CT (P = 0.193).

CONCLUSIONS

Most cases of DAA can be diagnosed easily at midgestation, as typically both arches are patent with a dominant RAA at this stage. However, we found that the LAA had become atretic in approximately half of the cases postnatally, supporting the theory of differential growth of the arches during pregnancy. DAA is usually an isolated abnormality; however, thorough assessment is required to exclude associated intra- and extracardiac anomalies and to determine the need for invasive prenatal genetic testing. Postnatally, early clinical assessment is needed and CT scan should be considered, irrespective of the presence of symptoms. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Discordant Post-natal Patterns in Fetuses With Heterotaxy Syndrome: A Retrospective Single-Centre Series on Outcome After Fetal Diagnosis

OBJECTIVE

Cardiac and extra-cardiac anomalies in 46 pre-natally diagnosed cases of heterotaxy were compared to post-natal anatomical patterns in order to reveal discordant findings. Second, the outcome of these fetuses was evaluated.

METHODS

Fetuses with heterotaxy, diagnosed in a tertiary referral centre, were analysed retrospectively. Based on the foetal abdominal situs view, right atrial isomerism (RAI) and left atrial isomerism (LAI) were defined as foetal sub-types. Post-natally, discordant anatomical patterns for broncho-pulmonary branching, atrial appendage morphology, and splenic status were further clarified with CT scans. In summary, the spectrum of pre-natally and post-natally detected cardiac and extra-cardiac anomalies is systematically reviewed. Necessary surgical interventions and mid-long-term outcomes were compared between the two sub-types in surviving infants.

RESULTS

A total of 46 fetuses with heterotaxy were included; LAI was diagnosed in 29 (63%) fetuses and RAI was diagnosed in 17 (37%) fetuses. Extra-cardiac anomalies were noted in 35% of fetuses. Seven out of the 29 fetuses (24%) with LAI had atrio-ventricular block (AVB) and four of these cases presented with hydrops. Twenty nine out of the 46 participating fetuses (63%) were live births, with 62% in the LAI group and 65% in the RAI group. Five fetuses were lost to follow-up. At the age of 1 year, the overall survival of live births [estimate (95% CI)] was 67% (48; 92%) in patients with LAI and 55% (32; 94%) in patients with RAI. At the age of 5 years, the estimates were 67% (48; 92%) in the LAI group and 46% (24-87%) in the RAI group. The median survival (first quartile; third quartile) was 11.1 (0.1; 14) years for patients with LAI and 1.3 (0.09; NA) years for patients with RAI. Of 17 children who had undergone cardiac surgery, five (29%) children achieved a bi-ventricular repair and 12 (70%) children achieved a uni-ventricular palliation. Three were primarily palliated, but converted to bi-ventricular thereafter. Foetal subtype definition of heterotaxy based on the abdominal situs and post-natal thoracic imaging studies showed a discordant pattern of broncho-pulmonary branching and atrial appendage anatomy in 40% of our live-born children.

CONCLUSION

Heterotaxy is a rare and complex condition with significant morbidity and mortality related to severe cardiac and extra-cardiac associations. Accurate pre-natal diagnosis can help identify the fetuses at risk and allow for timely intervention in a multi-disciplinary setting. Further studies are warranted to shed light on the exact sub-type definition in fetuses with heterotaxy and the presence of discordant post-natal patterns.

Low-bandwidth teleconsultations for patients with complex congenital heart diseases

We have reviewed our experience with a low-bandwidth paediatric telecardiology link (using ISDN at 128 kbit/s) between a tertiary centre in Belgrade and a tertiary centre in London. Over a two-year period, 12 videoconferences were held, during which 40 case histories of 38 patients were presented from Belgrade. The patients were aged 7 days to 20 years, and most of them had complex congenital heart defects. Changes in diagnosis and/or therapy occurred in 21 cases. Clinically relevant changes in diagnosis occurred in 2/40 cases (5%). In 12 cases, there were slight differences in opinion which resulted in minor changes in therapy for 9 of the patients. In another 9 patients, major changes in therapy occurred. There were no major problems with the quality of image and sound in any of the videoconferences. Our experience suggests that when there are experienced paediatric cardiologists at both ends of the connection, transmission via a single ISDN line is safe and accurate.

Diaphragmatic hernia: a postnatal complication of anomalous drainage of the umbilical vein

The ductus venosus (DV) connects the portal venous system to the inferior vena cava. Rarely, the umbilical venous drainage is anomalous, either connecting to the portal sinus within the liver or having an extrahepatic connection, bypassing the liver and draining to one of a variety of sites, including to the heart directly. Prenatally, there is a recognized association of anomalous umbilical venous drainage with aneuploidy and other structural malformations. The fetus may also develop right heart failure because of unregulated volume loading. We report the postnatal development of diaphragmatic hernia in three fetuses with absent DV and umbilical venous drainage to the right atrium directly in two cases and to the coronary sinus in the third. In all fetuses, the abnormality was well-tolerated in pregnancy, with only a modest degree of right heart dilatation. All three neonates underwent repair of the diaphragmatic hernia and made a good recovery.

Sonographic predictors of surgery in fetal coarctation of the aorta

OBJECTIVES

Isolated fetal coarctation of the aorta (CoA) has high false-positive diagnostic rates by cardiologists in tertiary centers. Isthmal diameter Z-scores (I), ratio of isthmus to duct diameters (I:D), and visualization of CoA shelf (Shelf) and isthmal flow disturbance (Flow) distinguish hypoplastic from normal aortic arches in retrospective studies, but their ability to predict a need for perinatal surgery is unknown. The aim of this study was to determine whether these four sonographic features could differentiate prenatally cases which would require neonatal surgery in a prospective cohort diagnosed with CoA by a cardiologist.

METHODS

From 83 referrals with cardiac disproportion (January 2006 to August 2010), we identified 37 consecutive fetuses diagnosed with CoA. Measurements of I and I:D were made and the presence of Shelf or Flow recorded. Sensitivity, specificity and areas under receiver-operating characteristics curves, using previously reported limits of I < - 2 and I:D < 0.74, as well as Shelf and Flow were compared at first and final scan. Associations between surgery and predictors were compared using multivariable logistic regression and changes in measurements using ANCOVA.

RESULTS

Among the 37 fetuses, 30 (81.1%) required surgery and two with an initial diagnosis of CoA were revised to normal following isthmal growth, giving an 86% diagnostic accuracy at term. The median age at first scan was 22.4 (range. 16.6-7.0) weeks and the median number of scans per fetus was three (range, one to five). I < - 2 at final scan was the most powerful predictor (odds ratio, 3.6 (95% CI, 0.47-27.3)). Shelf was identified in 66% and Flow in 50% of fetuses with CoA.

CONCLUSION

Incorporation of these four sonographic parameters in the assessment of fetuses with suspected CoA at a tertiary center resulted in better diagnostic precision regarding which cases would require neonatal surgery than has been reported previously.

Timing of removal of pacing wires following paediatric cardiac surgery

BACKGROUND

Temporary percutaneous epicardial pacing wires are routinely placed in children following cardiac surgery. There is uncertainty in clinical practice about the optimum timing for their removal, and practice varies widely both within and between different institutions.

AIM

The aim of our study was to describe the use of temporary pacing in children undergoing cardiac surgery.

METHODS

We performed a prospective audit of 140 children following cardiac surgery in two institutions. Information on diagnosis, surgical procedure, occurrence of arrhythmias, use of pacing wires, timing of removal of the wire, and complications related to removal was recorded on a daily basis from clinical records.

RESULTS

We studied 140 patients undergoing a total of 141 operations. Of these, 39 (28%) required pacing postoperatively. In 38, pacing was required within the first 24 hours. One patient, who was in nodal rhythm for the first 24 hours, required pacing on the second postoperative day, while 29 patients required pacing beyond the first 24 hours. No patient in sinus rhythm on the first postoperative day required new pacing after this time. The median time to removal of the pacing wires was 4.5 days, with an inter-quartile range from 2 to 9 days. Complications included malfunction of atrial wires in 2 patients.

CONCLUSIONS

Our study shows that no patient who was in sinus rhythm for the first 24 hours post-operatively required pacing before their discharge from hospital. This suggests that, in those patients in a stable state of sinus rhythm, and who have not required pacing within the first 24 hours, it may be safe to remove pacing wires after 24 hours. This could be timed to coincide with the removal of chest drains, thus avoiding the need for multiple distressing procedures.