Echocardiographic predictors of neonatal illness severity in fetuses with critical left heart obstruction with intact or restrictive atrial septum

Utilizing Fetal Echocardiography to Risk Stratify and Predict Neonatal Outcomes in Fetuses Diagnosed with Congenital Heart Disease

OBJECTIVE

 Risk stratification of fetuses diagnosed with congenital heart disease (CHD) helps provide a delivery plan and prepare families and medical teams on expected course in the delivery room. Our aim was to assess the accuracy of echocardiographically determined risk-stratification assignments in predicting postnatal cardiac outcomes beyond the delivery room.

STUDY DESIGN

 This was a retrospective study at a single center evaluating all fetuses with CHD who were risk-stratified by echocardiographically determined level of care (LOC) assignment, ranging from 1a (lowest risk) to 4 (highest risk). All data were collected from January 1, 2017, to November 1, 2021. Outcomes included any unexpected cardiac interventions and neonatal clinical outcomes including in-hospital mortality, the need for prostaglandins or inotropes, and defined critical illness. These outcomes were assessed for each LOC assignment by Fisher's exact test.

RESULTS

 Out of 817 patients assigned a LOC, a total of 747 fetuses were included in our final cohort with a separate subanalysis of 70 fetuses diagnosed with coarctation of the aorta. The sensitivity and specificity were high for all LOC levels in predicting delivery room needs (93-100%). Higher LOC levels (3-4) had a lower positive predictive value (66-67%) indicating a high false-positive rate. Subjects with higher LOC assignments had a greater frequency of critical illness, hospital mortality, need for inotropes, need for neonatal surgical or catheterization interventions, and need for prostaglandins (p < 0.001 for all outcomes). A post-hoc analysis reviewing LOC assignments revealed a greater tendency to over-assign LOC at higher assignments (19% for LOC 3 and 4) compared to lower assignments (4% for LOC 1 and 2).

CONCLUSION

 Risk stratification based on fetal echocardiography can predict neonatal clinical outcomes and acuity of postnatal management needs. However, there is greater variability in expected clinical events and an expected degree of false positives for those with higher LOC assignments.

KEY POINTS

· Risk stratification utilizing fetal echocardiography can be used to predict neonatal needs.. · Complex heart disease has lower positive predictive value in predicting postnatal clinical needs.. · There is a tendency to over-assign risk of acute hemodynamic instability for complex heart disease.. · False positives are expected when planning high-risk deliveries to avoid compromising situations..

Anatomical and physiological diagnostic discrepancies in fetuses with single-ventricle congenital heart disease in a contemporary cohort

OBJECTIVE

Image quality of fetal echocardiography (FE) has improved in the recent era, but few recent studies have reported the accuracy of FE, specifically in single ventricle (SV) congenital heart disease (CHD). This study aimed to assess the ability of FE to correctly predict SV-CHD postnatal anatomy and physiology in a contemporary cohort.

METHODS

The contemporary clinical reports of patients with SV-CHD, in which FE was performed between July 2017 and July 2021, were compared with postnatal echocardiograms from a formal quality assurance program. SV fetuses were grouped by anatomical subtype. Diagnostic errors were designated as major if the error would have caused significant alteration in parental counseling or postnatal management. The remaining errors were classified as minor. Physiological discrepancies, including prostaglandin-E (PGE) dependency, atrioventricular valve regurgitation (AVVR), pulmonary venous obstruction and restrictive atrial septum (RAS), were assessed by chart review of the postnatal course.

RESULTS

A total of 119 subjects were analyzed. SV subtypes in the cohort included hypoplastic left heart syndrome (HLHS) (n = 68), tricuspid atresia (n = 16), double-inlet left ventricle (n = 12), unbalanced atrioventricular canal (UAVC) (n = 11), heterotaxy (n = 9) and other (n = 3). The rate of major anatomical and physiological errors was low (n = 6 (5.0%)). A higher proportion of minor errors was noted in HLHS and tricuspid atresia, but the differences were not statistically significant. Physiological discrepancies were uncommon, with three major discrepancies, including underestimation of the degree of venous obstruction in one non-HLHS fetus with total anomalous pulmonary venous return, overestimation of RAS in one HLHS fetus and incorrect prediction of PGE dependency in one case false-negative for pulmonary blood flow. No discrepancy in degree of AVVR or RAS affected postnatal care. Minor physiological discrepancies included two false-positive predictions of PGE dependency with one false-positive for ductal-dependent systemic flow and one false-positive for pulmonary blood flow.

CONCLUSIONS

In this contemporary review of FE at our center, there was high accuracy in describing anatomical and physiological findings in SV-CHD. Major physiological discrepancies were uncommon but included important cases of false-negative prediction of PGE dependency and underestimation of obstruction of total anomalous pulmonary venous return. These data can inform more accurate counseling of families with SV-CHD fetuses and guide diagnostic improvement efforts. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal cardiac intervention in hypoplastic left heart syndrome with intact or restrictive atrial septum, systematic review, and meta-analysis

To investigate outcomes of fetuses with hypoplastic left heart syndrome (HLHS) with an intact or restrictive atrial septum (I/RAS) managed expectantly or with fetal atrial septal intervention (FASI PubMed, Scopus, and Web of Science were searched systematically from inception until April 2023. Outcomes were classified by those who had FASI and those who had expectant management (EM). To estimate the overall proportion of each endpoint, a meta-analysis of proportions was employed using a random-effects model. Heterogeneity was assessed using the I2 value. Thirty-two studies reporting on 746 fetuses with HLHS and I/RAS met our inclusion criteria. Eleven studies (123 fetuses) were in the FASI group and 21 studies (623 fetuses) were in the EM group. Among the 123 FASI cases, 107 (87%) were reported to be technically successful. The mean gestational age (GA) at diagnosis was comparable between the groups (26.2 weeks FASI vs. 24.4 weeks EM group). The mean GA at FASI was 30.4 weeks (95% CI 28.5, 32.5). The mean GA at delivery was also comparable (37.7 weeks FASI vs. 38.1 weeks EM group). Neonatal outcomes, including live birth, neonatal death, and survival to hospital discharge pooled proportions, were also comparable between groups (live birth: 92% (95% CI 64, 99) FASI versus 93% (95% CI 79, 98) in EM, neonatal death: 32% (95% CI 11, 65) FASI versus 30% (95% CI 21, 41) EM, survival to hospital discharge: 37% (95% CI 25, 52) FASI versus 52% (95% CI 42, 61) EM). Age at neonatal death was higher in the FASI group (mean: 17 days FASI vs. 7.2 days EM group). There was a lower rate of postnatal atrial restrictive septum in the FASI group 38% (95% CI 17, 63) compared to the EM group 88% (95% CI 57, 98). Our review shows variations across centers in the selection criteria and techniques used for FASI. Although survival including livebirth, neonatal death, and survival to hospital discharge did not differ between groups, the procedure may translate into a less restrictive septum at birth. Future multicenter studies are needed to better identify the subset of cases that might have improved outcomes, use standardized definitions, unified techniques, utilize core outcome set, and assess long-term benefits.

Prenatal Diagnosis of Congenital Heart Disease: The Crucial Role of Perinatal and Delivery Planning

Although most congenital heart defects (CHDs) are asymptomatic at birth, certain CHD lesions are at significant risk of severe hemodynamic instability and death if emergent cardiac interventions are not performed in a timely fashion. Therefore, accurate identification of at-risk fetuses and appropriate delivery resource planning according to the degree of anticipated hemodynamic instability is crucial. Fetal echocardiography has increased prenatal CHD detection in recent years due to advancements in ultrasound techniques and improved obstetrical cardiac screening protocols, enabling the prediction of newborns' hemodynamic status. This assessment can guide multidisciplinary resource planning for postnatal care, including selection of delivery site, delivery room management, and transport to a cardiac center based on CHD risk severity. This review will discuss fetal cardiovascular physiology and the circulatory changes that occur at the time of and immediately following birth, outline fetal echocardiographic findings used to risk-stratify newborns with CHDs, and outline principles for neonatal resuscitation and initial transitional care in neonates with these complex CHD lesions.

Imaging for Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome is a complex congenital heart defect with clinical presentation in the neonatal period. Echocardiography is the main diagnostic tool and allows detailed examination of the underlying anatomy and physiology and both pre and postnatally. In the following pages, key information regarding the evaluation of the interatrial septum, cardiac valves, right ventricular function, and ductal and aortic arches will be discussed in a systematic fashion allowing decision regarding the possible therapeutic strategies.

Hypoplastic left heart syndrome with prenatally diagnosed foramen ovale restriction: diagnosis, management and outcome

OBJECTIVE

Despite advances in prenatal diagnosis and postnatal intervention/surgery methods, patients with Hypoplastic Left Heart Syndrome (HLHS) and coexisting foramen oval restriction still achieve high mortality rates. Our objective was to determine survival predictors and to find answers to, why restriction develops in some, but not others.

METHODS

We performed a retrospective analysis of prenatal history and postnatal sequel of 22 patients with HLHS and foramen ovale restriction between 2008 and 2017.

RESULTS

There were 11 survivors and 11 nonsurvivors. The most significant difference between the two groups pertained to the average time of foramen ovale restriction diagnosis which was 33 weeks for survivors and 28 weeks for nonsurvivors (p = .0416) and the duration of in-utero restriction (9 versus 5 weeks, p = .0213). Twenty patients (20/22) exhibited possible signs of infection.

CONCLUSIONS

(1) Earlier development and longer presence of foramen ovale restriction in the setting of HLHS is associated with higher short-term mortality regardless of the degree of restriction. (2) Ratio of forward pulmonary vein flow to reverse flow (f/r) expressed as a velocity-time integral (VTI) is a good emergent intervention predictor, but it does not correlate with foramen ovale size and maximal velocity, nor does it influence survival rates. (3) Ultrasonographic signs of possible infection of the fetus is a potential risk factor of foramen ovale restriction development in patients with HLHS.

Maternal Hyperoxygenation Testing in Fetuses with Hypoplastic Left-Heart Syndrome: Association with Postnatal Atrial Septal Restriction

INTRODUCTION

In fetuses with hypoplastic left-heart syndrome (HLHS), maternal hyperoxygenation (MHO) may aid risk stratification. We hypothesized that pulmonary vein (Pvein) velocity time integral (VTI) change with MHO would more reliably identify neonates who undergo emergent atrial septoplasty (EAS) than changes in pulmonary arterial pulsatility index (PA PI).

METHODS

Fetuses with HLHS who underwent MHO testing at our institution between 2014 and 2019 were identified. Data were reviewed in a blinded, retrospective manner. Pvein VTI ratio (prograde:retrograde) was calculated. The primary outcome was neonatal EAS.

RESULTS

Twenty-seven HLHS fetuses underwent MHO, and 5 (19%) underwent EAS. Without MHO, a Pvein VTI ratio <3 conferred 60% sensitivity and 100% specificity for EAS. With MHO, a Pvein VTI ratio <6.5 conferred 100% sensitivity and specificity. For an intermediate group of fetuses with a baseline Pvein VTI ratio 3-7, the ratio decrease with MHO conferred 100% sensitivity and specificity. Compared to the Pvein VTI ratio, PA PI was less accurate in identifying EAS neonates.

DISCUSSION/CONCLUSION

Addition of MHO appears to improve the diagnostic ability of the Pvein VTI ratio to identify HLHS fetuses who undergo EAS. The Pvein VTI ratio change may more accurately identify fetuses who undergo EAS than change in PA PI and has less interobserver variability.

Fetal cardiac interventions: Where do we stand?

Fetal cardiac intervention (FCI) is a novel and evolving technique that allows for in utero treatment of a subset of congenital heart disease. This review describes the rationale, selection criteria, technical features, and current outcomes for the three most commonly performed FCI: fetal aortic stenosis with evolving hypoplastic left heart syndrome (HLHS); HLHS with intact or restrictive atrial septum; and pulmonary atresia with intact ventricular septum, with concern for worsening right ventricular (RV) hypoplasia.