Prenatal sonography of the foramen ovale predicts urgent balloon atrial septostomy in neonates with complete transposition of the great arteries

Intubation and Lower Saturation in the Delivery Room are Associated with Balloon Atrial Septostomy in Neonates with Transposition of the Great Arteries

OBJECTIVE

To identify delivery room (DR) characteristics of patients with transposition of the great arteries (TGA) who underwent preoperative balloon atrial septostomy (BAS).

STUDY DESIGN

Retrospective cohort study of all patients with prenatally diagnosed TGA delivered at our center between 2013 and 2023 who underwent arterial switch operation during the newborn admission.

RESULTS

A total of 168 patients were included (median gestational age 39.5 weeks, 64% male, 33% with ventricular septal defect [VSD], 8% with aortic arch hypoplasia). BAS was performed in 84 patients (50%). Patients who underwent BAS had higher proportion of intubation in the DR (87% vs. 33%, p<0.001), lower maximum oxygen saturation in the first 10 minutes (64% vs. 74%, p<0.001) and 20 minutes (71% vs. 81%, p<0.001) of life, and lower maximum oxygen saturation at any point in the DR (79% vs. 87%, p<0.001). Adjusting for confounders (VSD, aortic arch anomaly, 5-minute Apgar, birth weight), intubation in the DR (adjusted odds ratio [aOR] 9.5, 95% CI 3.9, 25.0) and lower maximum oxygen saturation in the DR (aOR 0.9, 95% CI 0.8, 0.9) were independently associated with BAS. By receiver operating characteristic analysis, a maximum oxygen saturation of less than 86% at any timepoint in the DR discriminated for BAS with a specificity of 0.88, sensitivity of 0.70, and area under the curve of 0.82.

CONCLUSIONS

Intubation and lower oxygen saturation in the DR are independently associated with BAS in patients with TGA born at our center. A maximum DR saturation of less than 86% best discriminates patients who undergo BAS in our population.

How reliably does prenatal echocardiography predict urgent balloon atrial septostomy in fetuses with d-TGA?

OBJECTIVE

To analyze the prenatal and postnatal outcomes of fetuses with d-TGA and to determine whether prenatal echocardiography may predict postnatal urgent BAS.

STUDY DESIGN

A retrospective study of fetuses with d-TGA, for which fetal echocardiography was performed at our tertiary hospital from January 2018 to May 2023. We assessed the appearance of the septum primum and the FO flap in the four-chamber view as to whether the FO had a restrictive appearance during measurement of the diameter of the FO at its maximal angle to the attachment point. Color Doppler was used to detect VSDs and measure its diameter both in the four-chamber view and when visualizing the outlets of the great arteries in the sagittal section of the heart.

RESULTS

During the study period, 64 fetuses were diagnosed with d-TGA, which was also confirmed postnatally. Of these, 16 fetuses were excluded due to additional cardiac anomalies or the inability to reach the mother. In total, 48 cases were included in this series. In our study, the FO diameter was significantly decreased in the urgent BAS group, compared with the fetuses without urgent BAS (5.1 mm vs 6.3 mm). A cut off of 6 mm for the FO diameter (sensitivity, 73.3 %; specificity, 72.2 %; area under the curve [AUC], 0.764) and 3.2 mm for the VSD diameter (sensitivity, 75 %; specificity, 75 %; AUC, 0.728) suggested urgent BAS.

CONCLUSION

Prenatal echocardiography performed after 37 weeks of gestation in fetuses with d-TGA provides valuable information to estimate the need for postnatal urgent BAS that would prevent immediate life-threatening complications.

D-Transposition of the great arteries with restrictive foramen ovale in the fetus: the dilemma of predicting the need for postnatal urgent balloon atrial septostomy

OBJECTIVE

Restrictive foramen ovale (FO) in dextro-transposition of the great arteries (d-TGA) with intact ventricular septum may lead to severe life-threatening hypoxia within the first hours of life, making urgent balloon atrial septostomy (BAS) inevitable. Reliable prenatal prediction of restrictive FO is crucial in these cases. However, current prenatal echocardiographic markers show low predictive value, and prenatal prediction often fails with fatal consequences for a subset of newborns. In this study, we described our experience and aimed to identify reliable predictive markers for BAS.

METHODS

We included 45 fetuses with isolated d-TGA that were diagnosed and delivered between 2010 and 2022 in two large German tertiary referral centers. Inclusion criteria were the availability of former prenatal ultrasound reports, of stored echocardiographic videos and still images, which had to be obtained within the last 14 days prior to delivery and that were of sufficient quality for retrospective re-analysis. Cardiac parameters were retrospectively assessed and their predictive value was evaluated.

RESULTS

Among the 45 included fetuses with d-TGA, 22 neonates had restrictive FO postnatally and required urgent BAS within the first 24 h of life. In contrast, 23 neonates had normal FO anatomy, but 4 of them unexpectedly showed inadequate interatrial mixing despite their normal FO anatomy, rapidly developed hypoxia and also required urgent BAS ('bad mixer'). Overall, 26 (58%) neonates required urgent BAS, whereas 19 (42%) achieved good O2 saturation and did not undergo urgent BAS. In the former prenatal ultrasound reports, restrictive FO with subsequent urgent BAS was correctly predicted in 11 of 22 cases (50% sensitivity), whereas a normal FO anatomy was correctly predicted in 19 of 23 cases (83% specificity). After current re-analysis of the stored videos and images, we identified three highly significant markers for restrictive FO: a FO diameter < 7 mm (p < 0.01), a fixed (p = 0.035) and a hypermobile (p = 0.014) FO flap. The maximum systolic flow velocities in the pulmonary veins were also significantly increased in restrictive FO (p = 0.021), but no cut-off value to reliably predict restrictive FO could be identified. If the above markers are applied, all 22 cases with restrictive FO and all 23 cases with normal FO anatomy could correctly be predicted (100% positive predictive value). Correct prediction of urgent BAS also succeeded in all 22 cases with restrictive FO (100% PPV), but naturally failed in 4 of the 23 cases with correctly predicted normal FO ('bad mixer') (82.6% negative predictive value).

CONCLUSION

Precise assessment of FO size and FO flap motility allows a reliable prenatal prediction of both restrictive and normal FO anatomy postnatally. Prediction of likelihood of urgent BAS also succeeds reliably in all fetuses with restrictive FO, but identification of the small subset of fetuses that also requires urgent BAS despite their normal FO anatomy fails, because the ability of sufficient postnatal interatrial mixing cannot be predicted prenatally. Therefore, all fetuses with prenatally diagnosed d-TGA should always be delivered in a tertiary center with cardiac catheter stand-by, allowing BAS within the first 24 h after birth, regardless of their predicted FO anatomy.

Out-of-hours versus in-hours delivery of antenatally diagnosed transposition of the great arteries: outcomes from a United Kingdom Tertiary Centre

OBJECTIVE

To study the impact of out-of-hours delivery on outcome for neonates with antenatally diagnosed transposition of the great arteries.

SETTING

Tertiary paediatric cardiology centre (Yorkshire, United Kingdom), with co-located tertiary neonatal unit.

PATIENTS

Neonates with antenatally diagnosed simple transposition of the great arteries delivered out-of-hours (Monday to Friday 17:00-08:00 and weekends) versus in-hours between 2015 and 2020.

OUTCOME

The primary outcome was survival to hospital discharge. Secondary outcomes included neurological morbidity, length of stay, and time to balloon atrial septostomy.

RESULTS

Of 51 neonates, 38 (75%) were delivered out-of-hours. All neonates born in the tertiary centre survived to discharge. Time to balloon atrial septostomy was slightly longer for out-of-hours deliveries compared to in-hours (median 130 versus 93 mins, p = 0.33). Neurological morbidity occurred for nine (24%) patients in the out-of-hours group and one (8%) in-hours (OR 3.72, 95% CI: 0.42-32.71, p = 0.24). Length of stay was also similar (18.5 versus 17.3 days, p = 0.59). Antenatal diagnosis of a restrictive atrial septum was associated with a lower initial pH (7.03 versus 7.13; CI: 0.03-0.17, p = 0.01), longer length of stay (22.6 versus 17.3 days; CI: 0.37-10.17, p = 0.04), and increased neurological morbidity (44% versus 14%; OR 4.80, CI 1.00-23.15, p = 0.05). A further three neonates were delivered in surrounding hospitals, with a mortality of 67% (versus 0 in tertiary centre; OR 172, CI 5-5371, p = 0.003).

CONCLUSION

Neonates with antenatally diagnosed transposition of the great arteries have similar outcomes when delivered out-of-hours versus in-hours. Antenatal diagnosis of restrictive atrial septum is a significant predictor of worse outcomes. In our region, delivery outside the tertiary cardiac centre had a significantly higher risk of mortality.

Fetal heart foramen ovale area by three-dimensional ultrasound using stic in the rendering mode: reference range and applicability in congenital heart diseases

To determine reference values for the foramen ovale (FO) area of fetal hearts by three-dimensional (3D) ultrasound using spatio-temporal image correlation (STIC) method in the rendering mode, as well as applicability in fetuses with congenital heart disease (CHD). A retrospective and prospective study was performed of 242 normal fetuses and 36 fetuses with CHD between 20 and 33 + 6 weeks of gestation. The FO area was determined in the four-chamber view with manual delineation. To determine the reference curve of the FO area as a function of gestational age (GA), a linear regression model was utilized with an adjusted coefficient of determination (R²). For intra- and interobserver reproducibility calculations, the concordance correlation coefficient (CCC) was used. The mean ± standard deviation (SD) of the FO measurement area was 21.2 ± 1.8 and 48.1 ± 1.9 mm² at 20 and 33 weeks' gestation, respectively. A linear correlation was observed between the FO area and GA (1.924*GA - 17.95; R² = 0.91). Good intra- (CCC = 0.97) and interobserver (CCC = 0.94) agreement was observed for the FO area measurement. The mean difference in FO area between normal and CHD fetuses was - 14.4 mm² (p < 0.001). Reference values for the FO area of fetal hearts were determined by 3D ultrasound using STIC in the rendering mode. This method showed good intra- and interobserver reproducibility and could be used to assess different CHD types.

Echocardiographic features and outcome of restrictive foramen ovale in fetuses with and without cardiac malformations: Literature review

Foramen ovale is a small communication between the left and the right atrium and its restriction is a rare congenital heart anomaly. There is no consensus on diagnosis and management of fetal restrictive foramen ovale (RFO). In our paper we included 11 studies about fetuses affected by isolated RFO, RFO with D-Transposition of the Great Arteries (dTGA) and RFO with hypoplastic left heart syndrome (HLHS). While fetuses affected from HLHS and dTGA with RFO have a poor prognosis, premature RFO in an otherwise structurally normal heart, if found in later gestation, have an overall good outcome.

Longitudinal functional assessment of atrial M-mode in dextro- transposition of the great arteries fetus may help to predict the necessity for urgent neonatal Rashkind procedure

Six fetal echocardiographic examinations were analyzed and presented with special emphasis on atrial M-mode in one case of fetal isolated dextro- transposition of the great arteries. The only significant changes were seen based on analysis of the new index of foramen ovale (FO) flap movement. Emergency Rashkind procedure on the first day of postnatal life was predicted based on fetal atrial M-mode.

Functional assessment of atrial M-mode in 3rd trimester in the context of postnatal balloon atrial septostomy in fetuses with simple dextro-transposition of the great arteries

OBJECTIVE

This study aimed to identify new functional echocardiographic features of fetal foramen ovale (FO) to predict the need of urgent balloon atrial septostomy (BAS) in neonates with simple dextro-transposition of the great arteries (d-TGA).

METHOD

Single-center prospective study of fetuses, who had prenatal echocardiographic examination <30 days before delivery and fetal diagnosis of simple d-TGA. The subjects were divided according to the need of BAS within the first 24 h after neonatal birth and before arterial switch operation. We analyzed following parameters: FO diameter, pulmonary venous maximal velocity, new FO flap tracings index analyzed by M-mode echocardiography.

RESULTS

Out of 130 fetuses, 12 patients were included. Cutoff value of FO index provided maximum sensitivity (100%) and negative predictive value (100%) and cutoff value of FO index multiplied by FO diameter provided maximum specificity (100%) and positive predictive value (100%) in fetuses with fetal d-TGA in predicting need of urgent BAS.

CONCLUSION

FO index could potentially be used to predict postnatal haemodynamic stability in fetuses with simple d-TGA. FO index multiplied by FO diameter could potentially be used to predict prenatally the need of urgent BAS following the birth.