Midgestation fetal pulmonary annulus size is predictive of outcome in tetralogy of fallot

Outcomes of Neonates Born with Symptomatic Tetralogy of Fallot and Absent Ductus Arteriosus

OBJECTIVE

To test the hypothesis that neonates with symptomatic tetralogy of Fallot (TOF) and absent ductus arteriosus (ADA) have worse clinical outcomes compared with those with a ductus arteriosus (DA), and that this difference is driven by those born with ADA and with critically deficient pulmonary blood flow (CDPBF).

STUDY DESIGN

We performed a retrospective, multicenter cohort study of neonates who underwent intervention for symptomatic TOF comparing death and reintervention between subjects with and without a DA identified on fetal echocardiogram or on echocardiogram performed in the first postnatal day. Exclusion criteria were as follows: inability to define DA status, collaterals supplying pulmonary blood flow, atrioventricular septal defect, and absent pulmonary valve. We defined CDPBF as undergoing a procedure to augment pulmonary blood flow on the date of birth or extracorporeal membrane oxygenation prior to such a procedure.

RESULTS

The study cohort included 519 patients, among whom 11% had ADA. Patients with ADA were more likely to have a genetic syndrome and had smaller branch pulmonary artery size. In analyses adjusting for center, interventional treatment strategy, genetic syndrome, and minimum branch pulmonary artery size, ADA was associated with higher mortality risk (adjusted hazard ratio of 2.37 (95% CI: 1.07,5.27; P = .034). Seven patients had CDPBF (1.3% of the entire cohort and 12% of patients with ADA).

CONCLUSIONS

A minority of symptomatic TOF neonates have ADA, which is associated with higher adjusted mortality risk compared with those with a DA. CDPBF appears to be a rare but important entity in this population.

Pulmonary Annulus Growth Pattern in Patients with Tetralogy of Fallot Prior to Surgical Repair

Objectives

The size of the pulmonary valve annulus often determines the feasibility of pulmonary valve preservation at the time of intracardiac repair of Tetralogy of Fallot. Currently, there is limited available data regarding the growth pattern and the determining factors that contribute towards pulmonary valve annulus growth.

Methods

This retrospective study included patients who underwent surgical repair of Tetralogy of Fallot with or without prior palliation. These patients had an echocardiogram at the time of initial diagnosis and a second echocardiogram prior to intracardiac repair. The sizes of the pulmonary annulus, the right and left pulmonary arteries with z-scores were recorded. Patients with improvement in the pulmonary annulus z-scores between the 2 echocardiographic examinations were allocated in Group I (n = 46) and Group II (n = 68) were those with no improvement.

Results

A total of 114 patients were included in the study. The right and left pulmonary arteries size and z scores improved significantly between the 2 echocardiograms. Although the median size of the pulmonary annulus increased between the 2 echocardiograms (6 and 7.9 mm; P<0.001), there was no significant change in the z-score (-2.2, -2.34; P = 0.185). Multivariate logistic regression analysis showed that gender, blood group, presence of collaterals, and palliation with Blalock-Taussig shunt had no impact on the improvement in pulmonary annulus z-score.

Conclusion

In Tetralogy of Fallot, the pulmonary valve annulus z-score may not change significantly prior to the intracardiac repair. Although in certain subgroups there may be an improvement, there was no specific factor that could be identified and had an influence on this improvement.

Fetal Echocardiographic Z Score Pilot Project: Study Design and Impact of Gestational Age and Variable Type on Reproducibility of Measurements Within and Across Investigators

BACKGROUND

Fetal echocardiography is widely available, but normative data are not robust. In this pilot study, the authors evaluated (1) the feasibility of prespecified measurements in a normal fetal echocardiogram to inform study design and (2) measurement variability to assign thresholds of clinical significance and guide analyses in larger fetal echocardiographic Z score initiatives.

METHODS

Images from predefined gestational age groups (16-20, >20-24, >24-28, and >28-32 weeks) were retrospectively analyzed. Fetal echocardiography expert raters attended online group training and then independently analyzed 73 fetal studies (18 per age group) in a fully crossed design of 53 variables; each observer repeated measures for 12 fetuses. Kruskal-Wallis tests were used to compare measurements across centers and age groups. Coefficients of variation (CoVs) were calculated at the subject level for each measurement as the ratio of SD to mean. Intraclass correlation coefficients were used to show inter- and intrarater reliabilities. Cohen's d > 0.8 was used to define clinically important differences. Measurements were plotted against gestational age, biparietal diameter, and femur length.

RESULTS

Expert raters completed each set of measurements in a mean of 23 ± 9 min/fetus. Missingness ranged from 0% to 29%. CoVs were similar across age groups for all variables (P < .05) except ductus arteriosus mean velocity and left ventricular ejection time, which were both higher at older gestational age. CoVs were >15% for right ventricular systolic and diastolic widths despite fair to good repeatability (intraclass correlation coefficient > 0.5); ductal velocities and two-dimensional measures, left ventricular short-axis dimensions, and isovolumic times all had high CoVs and high interobserver variability despite good to excellent intraobserver agreement (intraclass correlation coefficient > 0.6). CoVs did not improve when ratios (e.g., tricuspid/mitral annulus) were used instead of linear measurements. Overall, 27 variables had acceptable inter- and intraobserver repeatability, while 14 had excessive variability between readers despite good intraobserver agreement.

CONCLUSIONS

There is considerable variability in fetal echocardiographic quantification in clinical practice that may affect the design of multicenter fetal echocardiographic Z score studies, and not all measurements may be feasible for standard normalization. As missingness was substantial, a prospective design will be needed. Data from this pilot study may aid in the calculation of sample sizes and inform thresholds for distinguishing clinically significant from statistically significant effects.

Predictive value of fetal echocardiographic parameters in surgical strategy for Tetralogy of Fallot

OBJECTIVES

This study aimed to evaluate whether fetal echocardiographic parameters were predictive of the postnatal surgical treatment required for fetuses with Tetralogy of Fallot (TOF).

METHODS

The fetal echocardiographic and postnatal clinical data of all cases of prenatal TOF at Xinhua Hospital from 2016 to 2020 were reviewed. Patients were categorized based on the operation type, and cardiac parameters were compared between groups.

RESULTS

Of the 37 fetuses assessed, the development of the pulmonary valve annulus (PVA) was significantly poorer in the transannular patch group. Patients with a prenatal PVA z-score (Schneider's method) ≥ -2.645, a PVA z-score (Lee's method) ≥ -2.805, a PVA/aortic valve annulus diameter ratio ≥ .697, and a pulmonary annulus index ≥ .823 were more likely to undergo pulmonary valve-sparing surgery. There was a strong correlation between prenatal and postnatal PVA z-scores. The PVA growth potential was greater in the pulmonary valve-sparing surgery group.

CONCLUSIONS

PVA-related parameters evaluated by fetal echocardiography can predict the type of surgical intervention required and are valuable in improving prenatal counseling in fetal cases of TOF.

Fetal cardiac parameters for predicting postnatal operation type of fetuses with tetralogy of Fallot

Background

To assess fetal cardiac parameters predictive of postnatal operation type in fetuses with tetralogy of Fallot (TOF).

Methods

Echocardiographic data obtained in the second and third trimesters were retrospectively reviewed for fetuses diagnosed with TOF between 2014 and 2018 at Asan Medical Center. The following fetal cardiac parameters were analyzed: 1) pulmonary valve annulus (PVA) z-score, 2) right pulmonary artery (RPA) z-score, 3) aortic valve annulus (AVA) z-score, 4) pulmonary valve peak systolic velocity (PV-PSV), 5) PVA/AVA ratio, and 6) RPA/descending aorta (DAo) ratio. These cardiac parameters were compared between a primary corrective surgery group and a palliative shunt operation followed by complete repair group.

Results

A total of 100 fetuses with TOF were included. Only one neonatal death occurred. Ninety patients underwent primary corrective surgery and 10 neonates underwent a multistage surgery. The PVA z-score, RPA z-score, and RPA/DAo ratio measured in the second trimester and the PVA z-score, RPA z-score, and PVA/AVA raio measured in the third trimester were significantly lower in the multistage surgery group, while the PV-PSV as measured in both trimesters were significantly higher in the multistage surgery group.

Conclusion

Fetal cardiac parameters are useful for predicting the operation type necessary for neonates with TOF.

Ventricular Myocardial Deformation in Fetuses With Tetralogy of Fallot: A Necessary Field of Investigation

Background: Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart defects (CHDs). The patterns of fetal myocardial deformations in TOF have not been well-studied. This study aimed to assess biventricular myocardial deformations in fetuses with TOF compared with normal fetuses.

Methods: A retrospective cohort study of fetuses with TOF and gestational age (GA)-matched controls was conducted at a single tertiary referral center from 2014 to 2020. All enrolled fetuses underwent detailed echocardiography, and four-chamber video-clips were recorded and analyzed offline for deformation assessment by using two-dimensional speckle tracking echocardiography (2D-STE). Comparisons for baseline characteristics, cardiac morphological measurements (ventricular, atrial, and great arterial diameters or ratios, global sphericity index), systolic function parameters [ejection fraction (EF), fractional area change (FAC)], and strain parameters [global longitudinal strain (GLS), global longitudinal strain rate in systole and diastole (GLSRs, GLSRd)] were performed between fetuses with TOF and GA-matched controls.

Results: Fifty-two fetuses with TOF and 52 GA-matched controls were enrolled in this study. Fetuses with TOF exhibited similar left ventricular (LV) EF (58.51 ± 5.11% vs. 57.59 ± 5.38%, P = 0.16) and right ventricular (RV) FAC (43.64 ± 2.89% vs. 44.27 ± 3.04%, P = 0.25), compared to normal fetuses. While, in deformational analysis, TOF fetuses demonstrated significantly lower LV and RV GLS values (−22.57 ± 2.91% vs. −27.39 ± 4.38%, P < 0.001 for LV GLS; −24.27 ± 3.18% vs. −28.71 ± 4.48%, P < 0.001 for RV GLS). Both LV GLS (r = −0.518, P < 0.001) and RV GLS (r = −0.534, P < 0.001) were found negatively correlated with the aortic valve-to-pulmonary valve diameter ratio (AV:PV ratio). Z-scores of PV annulus and main pulmonary artery (MPA) also had positive correlation with LV and RV GLS, respectively.

Conclusions: Decreased biventricular myocardial deformations can appear even in fetuses with TOF with normal systolic ventricular function. Both LV and RV GLS values are correlated with the severity of right ventricular outflow tract obstruction. It indicates 2D-STE may be a more sensitive tool to assess fetal cardiac function than the conventional echocardiographic methods.

Outcome and Associated Findings in Individuals with Pre- and Postnatal Diagnosis of Tetralogy of Fallot (TOF) and Prediction of Early Postnatal Intervention

PURPOSE

 The aim of our retrospective evaluation was to compare the outcome of patients with prenatal and postnatal diagnosis of Tetralogy of Fallot (TOF) and to analyze prenatal echocardiographic parameters predicting intervention within 30 days postnatal.

MATERIALS AND METHODS

 We evaluated 142 patients in our pediatric heart center and prenatal diagnosis center and prenatal practice Praenatal plus in Cologne between 01/08-06/16.

RESULTS

 Within the prenatal diagnosis group, 6/74 fetuses (8.1 %) had TOF with pulmonary atresia (TOF-PA), and 6 (8.1 %) had absent pulmonary valve syndrome (TOF-APVS). 14 (18.9 %) had an abnormal karyotype including 9/14 (64.3 %) with microdeletion 22q11.2. 25 (33.8 %) had extracardiac malformation. 4 (5.4 %) had agenesis of ductus arteriosus (DA), 22 (29.7 %) had right aortic arch (RAA) and 9 (12.2 %) had major aortopulmonary collateral arteries (MAPCAs). Within the postnatal diagnosis group, no patient had TOF-PA, 4/68 (5.9 %) had TOF-APVS. 12 (17.6 %) had extracardiac malformations, 9 (13.2 %) had an abnormal karyotype including 2/9 with microdeletion 22q11.2. 10 (14.7 %) had RAA, 9 (13.2 %) had MAPCAs. There were no cases with agenesis of DA. Increasing z-score values of the left/right pulmonary artery (LPA/RPA) prenatally were associated with a lower probability for early postnatal intervention (RPA: p = 0.017; LPA: p = 0.013). Within the prenatal diagnosis group, 12 of 41 (29.3 %) live-born patients with follow-up and intention to treat needed early intervention versus 7 (10.3 %) in the postnatal diagnosis group (p = 0.02). Within the postnatal diagnosis group, there were no deaths, while 2 (4.9 %) post-intervention deaths occurred in the prenatal diagnosis group.

CONCLUSION

 There are no significant differences concerning post-intervention survival in the prenatal diagnosis group versus the postnatal diagnosis group. Complex cases may be underrepresented in the postnatal diagnosis group. Smaller RPA/LPA values prenatally seem to be associated with early postnatal intervention.

Third trimester predictors of interventional timing and accuracy of fetal anticipatory guidance in tetralogy of Fallot: A multi-center study

OBJECTIVE

The objective was to evaluate and improve accuracy of anticipatory counseling regarding neonatal intervention for prenatally diagnosed tetralogy of Fallot (TOF) by assessing new and previously published predictors of neonatal intervention.

METHODS

This is a multi-center, retrospective study from three centers of 112 fetal TOF patients undergoing third trimester fetal echocardiograms from 2004 to 2017. Additional cardiac defects requiring neonatal intervention were excluded. Fetal echocardiographic, clinical, and consultation data were compared between neonatal and late intervention. Optimal echocardiographic values were determined.

RESULTS

Twenty-six infants (23%) required neonatal intervention. Those infants had significantly different pulmonary valve (PV) z-scores, PV:aortic valve (AoV) ratios, PV:AoV z-score differences (absolute difference between z-scores), and increased likelihood of abnormal ductal flow. Counseling during fetal echocardiogram regarding interventional timing was accurate for 50% needing neonatal intervention and 86% undergoing late intervention (P = .002). The best neonatal intervention predictors were PV:AoV ratio of <0.6 and counseling for neonatal intervention. PV:AoV z-score difference ≥5 provided 89% negative predictive value for excluding patients from neonatal repair.

CONCLUSIONS

Third trimester fetal echocardiograms can predict interventional timing. The best predictors of neonatal intervention are PV:AoV ratio <0.6, PV:AoV z-score difference ≥5, and cardiologist counseling that neonatal intervention was likely.

Cerebrovascular blood flow in patients with tetralogy of fallot: prediction for early surgical intervention

OBJECTIVES

Children with tetralogy of Fallot (TOF) require initial intervention at varying times reflecting a spectrum of obstruction to pulmonary blood flow. In utero, fetal patients with right sided obstructive lesions demonstrate increased middle cerebral artery (MCA) pulsatility index (PI). We sought to determine whether MCA flow patterns are associated with the degree of pulmonary obstruction and the consequential need for early surgical intervention (ESI).

METHODS

We performed a multi-center retrospective study evaluating patients with a prenatal diagnosis of TOF. All echocardiographic fetal studies performed from 16 weeks' gestational age through delivery were reviewed between 2001 and 2015 with subsequent postnatal medical chart review.

RESULTS

82 patients met inclusion criteria. Patients who ultimately required ESI (n=30) demonstrated an increased MCA PI z-score (-0.68 vs -1.32, p=0.02) compared to those who did not (n=52). An elevated MCA PI in patients with TOF was associated with ESI after 24 weeks' gestational age (-0.36 vs -1.22, p=0.02).

CONCLUSIONS

Fetal patients with TOF demonstrate altered MCA flow that correlates with need for ESI. This effect is blunted earlier in gestation which may reflect cerebral autoregulation. MCA PI may be a beneficial tool in helping determine perinatal management and counseling for patients with TOF.

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.

The Effects of Hemodynamic Alterations on Lung Volumes in Fetuses with Tetralogy of Fallot: An MRI Study

This study assessed whether the presence of tetralogy of Fallot (TOF) affects fetal lung development and whether these fetuses are at risk of pulmonary hypoplasia (PH). Furthermore, we investigated whether the degree of the concomitant pulmonary valve (PV) stenosis or a stenosis in the branch pulmonary arteries correlates with the fetal lung volume. Lung volumetry was performed in 16 fetuses with TOF who underwent MRI between gestational weeks 21 and 35 and in 22 controls. Fetal biometric data and the diameters of the PVs were evaluated by ultrasound. PV and branch pulmonary artery diameters were standardized (z-scores), and fetal lung volume/fetal body weight (FLV/FBW) ratios (ml/g) were calculated. The mean FLV/FBW ratio (0.031 ± 0.009 ml/g) in the TOF group was statistically significantly lower than in the control group (0.041 ± 0.009 ml/g; P = 0.003). None of the fetuses with TOF met the criterion for PH. FLV did not correlate with the degree of PV stenosis, but rather with the presence of a significant stenosis in at least one branch pulmonary artery. The presence of TOF moderately affects fetal lung growth, which is apparently not dependent on the degree of the PV stenosis. However, only an additional stenosis in at least one branch pulmonary artery was associated with a small FLV, but not with PH. Thus, reduced pulmonary blood flow may be offset by additional factors, such as the ability to establish a sufficient collateral system and to alter structural vascular size and, thus, pulmonary vascular resistance.