Fetal tricuspid valve size and growth as predictors of outcome in pulmonary atresia with intact ventricular septum

Current Understanding of Indications, Technical Aspects and Outcomes of Fetal Cardiac Interventions

With the improvement in the detection of congenital heart disease in fetal life, fetal cardiac interventions are pushing the envelope in hopes of either altering the natural history of disease or improving survival in certain high-risk lesions. These interventions include fetal aortic valvuloplasty for evolving hypoplastic left heart syndrome, fetal atrial septoplasty with or without atrial septal stenting for hypoplastic left heart syndrome and variants with intact or severely restrictive atrial septum, and fetal pulmonary valvuloplasty for severe pulmonary stenosis or pulmonary atresia with intact ventricular septum. This review discusses their indications, technical aspects, and outcomes based on available literature.

Catheter-Based Fetal Cardiac Interventions

Fetal cardiac intervention (FCI) is an emerging and rapidly advancing group of interventions designed to improve outcomes for fetuses with cardiovascular disease. Currently, FCI is comprised of pharmacologic therapies (e.g., trans-placental antiarrhythmics for fetal arrhythmia), open surgical procedures (e.g., surgical resection of pericardial teratoma), and catheter-based procedures (e.g., fetal aortic valvuloplasty for aortic stenosis). This review focuses on the rationale, criteria for inclusion, technical details, and current outcomes of the three most frequently performed catheter-based FCI procedures: (1) aortic valvuloplasty for critical aortic stenosis (AS) associated with evolving hypoplastic left heart syndrome (HLHS), (2) atrial septal intervention for HLHS with severely restrictive or intact atrial septum (R/IAS), and (3) pulmonary valvuloplasty for pulmonary atresia with intact ventricular septum (PA/IVS).

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.

Prediction of postnatal circulation in pulmonary atresia/critical stenosis with intact ventricular septum: systematic review and external validation of models

OBJECTIVE

A favorable postnatal prognosis in cases of pulmonary atresia/critical stenosis with intact ventricular septum (PA/CS-IVS) is generally equated with the possibility of achieving biventricular (BV) repair. Identification of fetuses that will have postnatal univentricular (UV) circulation is key for prenatal counseling, optimization of perinatal care and decision-making regarding fetal therapy. We aimed to evaluate the accuracy of published models for predicting postnatal circulation in PA/CS-IVS using a large internationally derived validation cohort.

METHODS

This was a systematic review of published uni- and multiparametric models for the prediction of postnatal circulation based on echocardiographic findings at between 20 and 28 weeks of gestation. Models were externally validated using data from the International Fetal Cardiac Intervention Registry. Sensitivity, specificity, predictive values, area under the receiver-operating-characteristics curves (AUCs) and proportion of cases with true vs predicted outcome were calculated.

RESULTS

Eleven published studies that reported prognostic parameters of postnatal circulation were identified. Models varied widely in terms of the main outcome (UV (n = 3), non-BV (n = 3), BV (n = 3), right-ventricle-dependent coronary circulation (n = 1) or tricuspid valve size at birth (n = 1)) and in terms of the included predictors (single parameters only (n = 6), multiparametric score (n = 4) or both (n = 1)), and were developed on small sample sizes (range, 15-38). Nine models were validated externally given the availability of the required parameters in the validation cohort. Tricuspid valve diameter Z-score, tricuspid regurgitation, ratios between right and left cardiac structures and the presence of ventriculocoronary connections (VCC) were the most commonly evaluated parameters. Multiparametric models including up to four variables (ratios between right and left structures, right ventricular inflow duration, presence of VCC and tricuspid regurgitation) had the best performance (AUC, 0.80-0.89). Overall, the risk of UV outcome was underestimated and that of BV outcome was overestimated by most models.

CONCLUSIONS

Current prenatal models for the prediction of postnatal outcome in PA/CS-IVS are heterogeneous. Multiparametric models for predicting UV and non-BV circulation perform well in identifying BV patients but have low sensitivity, underestimating the rate of fetuses that will ultimately have UV circulation. Until better discrimination can be achieved, fetal interventions may need to be limited to only those cases in which non-BV postnatal circulation is certain. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Human phenotype ontology annotation and cluster analysis for pulmonary atresia to unravel clinical outcomes

Background

Pulmonary atresia (PA) is a heterogeneous congenital heart defect and ventricular septal defect (VSD) is the most vital factor for the conventional classification of PA patients. The simple dichotomy could not fully describe the cardiac morphologies and pathophysiology in such a complex disease. We utilized the Human Phenotype Ontology (HPO) database to explore the phenotypic patterns of PA and the phenotypic influence on prognosis.

Methods

We recruited 786 patients with diagnoses of PA between 2008 and 2016 at Fuwai Hospital. According to cardiovascular phenotypes of patients, we retrieved 52 HPO terms for further analyses. The patients were classified into three clusters based on unsupervised hierarchical clustering. We used Kaplan–Meier curves to estimate survival, the log-rank test to compare survival between clusters, and univariate and multivariate Cox proportional hazards regression modeling to investigate potential risk factors.

Results

According to HPO term distribution, we observed significant differences of morphological abnormalities in 3 clusters. We defined cluster 1 as being associated with Tetralogy of Fallot (TOF), VSD, right ventricular hypertrophy (RVH), and aortopulmonary collateral arteries (ACA). ACA was not included in the cluster classification because it was not an HPO term. Cluster 2 was associated with hypoplastic right heart (HRH), atrial septal defect (ASD) and tricuspid disease as the main morphological abnormalities. Cluster 3 presented higher frequency of single ventricle (SV), dextrocardia, and common atrium (CA). The mortality rate in cluster 1 was significantly lower than the rates in cluster 2 and 3 (p = 0.04). Multivariable analysis revealed that abnormal atrioventricular connection (AAC, p = 0.011) and persistent left superior vena cava (LSVC, p = 0.003) were associated with an increased risk of mortality.

Conclusions

Our study reported a large cohort with clinical phenotypic, surgical strategy and long time follow-up. In addition, we provided a precise classification and successfully risk stratification for patients with PA.

Natural history of pulmonary atresia with intact ventricular septum (PAIVS) and critical pulmonary stenosis (CPS) and prediction of outcome

Objectives

To analyse prenatal parameters predicting biventricular (BV) outcome in pulmonary atresia with intact ventricular septum/critical pulmonary stenosis (PAIVS/CPS).

Methods

We evaluated 82 foetuses from 01/08 to 10/18 in 3 centres in intervals 1 (< 24 weeks), 2 (24–30 weeks) and 3 (> 30 weeks).

Results

61/82 (74.4%) were livebirths, 5 (8.2%) lost for follow-up, 3 (4.9%) had compassionate care leaving 53 (64.6% of the whole cohort and 86.9% of livebirths) with intention to treat. 9 died, 44/53 (83.0%) survived. 24/38 (63.2%) with information on postnatal outcome had BV outcome, 14 (36.8%) non-BV outcome (2 × 1.5 circulation). One with BV outcome had prenatal valvuloplasty. Best single parameter for BV outcome was tricuspid/mitral valve (TV/MV) ratio (AUC 0.93) in intervals 2 and 3 (AUC 0.92). Ventriculo-coronary-arterial communications (VCAC) were present in 11 (78.6%) in non-BV outcome group vs. 2 (8.3%) in BV outcome group (p < 0.001). Tricuspid insufficiency (TI)-Vmax > 2.5 m/s was present in BV outcome group in75.0% (18/24) vs. 14.3% (2/14) in non-BV outcome group. Including the most predictive markers (VCAC presence, TI- Vmax  < 2.5 m/s, TV/MV ratio < cutoff) to a score, non-BV outcome was correctly predicted when > 1 criterion was fulfilled in all cases. After recently published criteria for foetal intervention, only 4/9 (44.4%) and 5/14 (35.7%) in our interval 2 + 3 with predicted non-BV outcome would have been candidates for intervention. Two (1 × intrauterine intervention) in interval 2, two in interval 3 reached BV outcome and one 1.5 circulation without intervention.

Conclusion

TV/MV ratio as simple parameter has high predictive value. After our score, non-BV outcome was correctly predicted in all cases. Criteria for foetal intervention must further be evaluated.

Fetal Pulmonary Valvuloplasty in Fetuses with Right Ventricular Outflow Tract Obstructive Disease: Experience and Outcome of the First Five Cases in China

The current study was to report our initial experiences of fetal pulmonary valvuloplasty (FPV) for fetuses with pulmonary atresia with intact ventricular septum (PA/IVS) and critical pulmonary stenosis (CPS), including case selection, technical feasibility, and the effects of FPV on utero and postnatal outcome. Two fetuses with PA/IVS and three fetuses with CPS were enrolled between September 2016 and April 2018. All fetuses were with concomitant severe right ventricular dysplasia and growth arrest. Parameters of right cardiac development and hemodynamics, including tricuspid/mitral annulus ratio (TV/MV), right ventricle/left ventricle long-axis ratio (RV/LV), tricuspid valve inflow duration/cardiac cycle ratio (TVI/CC), degree of tricuspid regurgitation (TR), and blood flow direction of arterial duct and ductus venosus, were evaluated using echocardiogram. FPV was performed trans-abdominally under ultrasound guidance. Echocardiogram was performed post-FPV and every 2-4 weeks thereafter until delivery. The median gestational age at the time of FPV was 28 weeks. From technical perspective, pulmonary balloon valvuloplasty was successfully performed and the opening of pulmonary valve was improved in all fetuses in 2-4 weeks. However, progressive restenosis was observed in four fetuses with gestation advancing, and re-atresia occurred in two PA/IVS fetuses at 36th and 37th weeks' gestation, respectively. The growth trajectories of TV/MV, RV/LV, and TVI/CC were improved in the 1st week after FPV and then slowed down along with pulmonary valve restenosis. All fetuses were born alive and underwent postnatal interventions, including pulmonary balloon valvuloplasty in three fetuses and surgical procedures in two fetuses. During follow-up, three fetuses turned to be biventricular, one became one and a half ventricular at 1-year old, and one died of neonatal infection. Although pulmonary valve restenosis might occur as gestation advancing, FPV seems to be a safe and feasible procedure to improve the growth trajectories of right heart for fetuses with PA/IVS and CPS.

Prenatal cardiac care: Goals, priorities & gaps in knowledge in fetal cardiovascular disease: Perspectives of the Fetal Heart Society

Perinatal cardiovascular care has evolved considerably to become its own multidisciplinary field of care. Despite advancements, there remain significant gaps in providing optimal care for the fetus, child, mother, and family. Continued advancement in detection and diagnosis, perinatal care and delivery planning, and prediction and improvement of morbidity and mortality for fetuses affected by cardiac conditions such as heart defects or functional or rhythm disturbances requires collaboration between the multiple types of specialists and providers. The Fetal Heart Society was created to formalize and support collaboration between individuals, stakeholders, and institutions. This article summarizes the challenges faced to create the infrastructure for advancement of the field and the measures the FHS is undertaking to overcome the barriers to support progress in the field of perinatal cardiac care.

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Progress in perinatal cardiology is challenged by the rarity of fetal cardiac disease, care variation, and barriers to collaboration.

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The Fetal Heart Society was founded to formalize collaboration between the multiple disciplines in perinatal cardiac care.

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The FHS facilitates interdisciplinary multicenter research, education and advocacy to provide optimal perinatal cardiac care.

Fetal Cardiac Intervention for Pulmonary Atresia with Intact Ventricular Septum: International Fetal Cardiac Intervention Registry

INTRODUCTION

Invasive fetal cardiac intervention (FCI) for pulmonary atresia with intact ventricular septum (PAIVS) and critical pulmonary stenosis (PS) has been performed with small single-institution series reporting technical and physiological success. We present the first multicenter experience.

OBJECTIVES

Describe fetal and maternal characteristics of those being evaluated for FCI, including pregnancy/neonatal outcome data using the International Fetal Cardiac Intervention Registry (IFCIR).

METHODS

We queried the IFCIR for PAIVS/PS cases evaluated from January 2001 to April 2018 and reviewed maternal/fetal characteristics, procedural details, pregnancy and neonatal outcomes. Data were analyzed using standard descriptive statistics.

RESULTS

Of the 84 maternal/fetal dyads in the registry, 58 underwent pulmonary valvuloplasty at a median gestational age of 26.1 (21.9-31.0) weeks. Characteristics of fetuses undergoing FCI varied in terms of tricuspid valve (TV) size, TV regurgitation, and pulmonary valve patency. There were fetal complications in 55% of cases, including 7 deaths and 2 delayed fetal losses. Among those who underwent successful FCI, the absolute measurement of the TV increased by 0.32 (±0.17) mm/week from intervention to birth. Among 60 liveborn with known outcome, there was a higher percentage having a biventricular circulation following successful FCI (87 vs. 43%).

CONCLUSIONS

Our data suggest a possible benefit to fetal therapy for PAIVS/PS, though rates of technically unsuccessful procedures and procedure-related complications, including fetal loss were substantial. FCI criteria are extremely variable, making direct comparison to nonintervention patients challenging and potentially biased. More uniform FCI criteria for fetuses with PAIVS/PS are needed to avoid unnecessary procedures, expose only fetuses most likely to sustain a benefit, and to enable comparisons to be made with nonintervention patients.

Reference ranges and Z-scores for fetal cardiac measurements from two-dimensional echocardiography in Asian population

Currently available fetal echocardiographic reference values are derived mainly from North American and European population studies, and there is a lack of reference z-score for fetal echocardiographic measurement in Asian populations. The aim of this study was to establish normal ranges of echocardiographic measurements and z-scores in healthy Asian fetuses. A total of 575 healthy pregnant Taiwanese with an estimated gestational age from 14 to 38 weeks were enrolled voluntarily for this observational study. Standard two-dimensional echocardiography was performed to obtain measurements of the cardiac chambers and great arteries of the developing fetuses. In contrast to past studies, our sample was more evenly distributed for estimated gestational age (p<0.001). We present percentile graphs for 13 fetal echocardiographic measurements from the knowledge of estimated gestational age, biparietal distance, head circumference, abdominal circumference, and femur length. Most cardiac structures and developmental markers had linear models as the best-fitting, except for transverse aortic isthmus by estimated gestational age and transverse ductus arteriosus by femur length. Our findings indicate that estimated gestational age was generally the best model for fetal heart development, while head circumferences could be used as an optimal developmental marker to predict left atrium, right atrium, right ventricle, pulmonary annulus, and ductus arteriosus. Lastly, we developed nomograms for each of the 13 fetal heart measurements by each developmental markers. This is the first study providing echocardiographic reference ranges and nomograms for Asian fetuses. Computing z-scores from nomograms helps in standardizing comparisons and adds additional prognostic information to the diagnosis of congenital heart disease.

Low prenatal detection rate of valvar pulmonary stenosis: What are we missing?

OBJECTIVES

Critical pulmonary stenosis (PS) and pulmonary atresia with intact ventricular septum (PAIVS) require urgent neonatal intervention. Since PS may be more insidious than PAIVS during gestation, we hypothesized that neonates with PS would have lower rates of prenatal detection than PAIVS.

METHODS

We performed a retrospective chart review of all neonates who underwent diagnostic or interventional cardiac catheterization between 2000 and 2014 for critical PS or PAIVS. The rates of prenatal diagnosis were calculated for PS and PAIVS. Prenatal and postnatal echocardiographic data were reviewed.

RESULTS

178 patients met inclusion criteria: 91 with critical PS and 87 with PAIVS. The prenatal diagnosis rate for critical PS was lower than for PAIVS at 37% (34/91) vs 60% (52/87) (P = .003). At the time of diagnosis at a median gestational age of 25 weeks, the median TV z-score for patients with critical PS was larger than in PAIVS (-0.15 vs -3.0 P = .004).

CONCLUSION

Critical PS had a lower prenatal detection rate than PAIVS, likely due to a relatively normal 4-chamber view at the time of routine second trimester screening in patients with PS. Color flow Doppler of the outflow tracts may improve detection, since outflow tracts may appear normal by 2D imaging.

An Overview of Contemporary Outcomes in Fetal Cardiac Intervention: A Case for High-Volume Superspecialization?

Fetal cardiac interventions (FCI) offer the opportunity to rescue a fetus at risk of intrauterine death, or more ambitiously to alter disease progression. Most of these fetuses require multiple additional postnatal procedures, and it is difficult to disentangle the effect of the fetal procedure from that of the postnatal management sequence. The true clinical impact of FCI may only be discernible in large-volume institutions that can commit to a standardized postnatal approach and have sufficient case volume to overcome their FCI learning curve.

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.

Prenatal echocardiographic classification and prognostic evaluation strategy in fetal pulmonary atresia with intact ventricular septum

Fetal pulmonary atresia with intact ventricular septum (PA/IVS) is a rare congenital heart disease. The present study aimed to classify PA/IVS and determine the relationship between prenatal echocardiographic characteristics and postnatal biventricular or univentricular repair strategies.A total of 51 fetuses with PA/IVS were examined from 2012 to 2019. Data on prenatal echocardiography, associated anomaly, karyotype, and outcome were collected. Two-dimensional measurements included tricuspid valve (TV) z-score, mitral valve (MV) z-score, TV/MV ratio, and ratio of right to left ventricle (RV/LV) length, whereas color Doppler measurements included degree of tricuspid regurgitation (TR), ventriculo-coronary artery communication (VCAC), tricuspid inflow duration (TID), cardiac cycle duration (CCD), middle cerebral artery pulsatility index (MCA PI), and umbilical artery pulsatility index (UA PI). Diagnostic classification was based on the development of RV and the presence or absence of VCAC. Postnatal evaluation was divided according biventricular or univentricular repair.Of the 51 fetuses with PA/IVS, 20 were type I, 17 were type II, and 14 were type III. Only one fetus exhibited right aortic arch. The karyotype of all the fetuses was normal. Of the 28 patients who underwent postnatal surgery, 13 (46%) underwent biventricular repair and 15 (54%) underwent univentricular repair. TV z-score was significantly higher for the biventricular repair group compared with univentricular repair group (-1.20 ± 0.98 vs -4.33 ± 0.80, P = .000). TV/MV, RV/LV length, and TID/CCD were significantly higher for the biventricular repair group than the univentricular repair group (0.81 ± 0.14 vs 0.54 ± 0.09, 0.71 ± 0.11 vs 0.49 ± 0.09, 39.20 ± 3.84 vs 29.16 ± 4.58, P = .000). Moderate or severe TR and VCAC were significantly different between the 2 groups (P = .000). Gestational age, MCA PI, and UA PI did not differ between the 2 groups (P = .72, P = .36, P = .06). The cutoff values for the biventricular repair characteristic curves were TV z-score >-3.28, TV/MV ratio >0.71, RV/LV length >0.62, and TID/CCD >33.95%. The sensitivities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 100%, 77%, 85%, and 92%, respectively. The specificities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 94%, 100%, 100%, and 94%, respectively.Fetal echocardiography was able to classify PA/IVS according to variable degree of RV and VCAC. In fetal PA/IVS, TV z-score >-3.28, TV/MV >0.71, RV/LV length >0.62, TID/CCD >33.95%, moderate and severe TR, and the absence of VCAC were associated with postnatal biventricular repair strategy. These findings may have implications for prenatal counseling and prediction of fetal outcome.

Severe Pulmonary Stenosis or Atresia with Intact Ventricular Septum in the Fetus: The Natural History

PURPOSE

To assess the intrauterine course, the outcome, and to establish a new prenatal echocardiographic scoring system to predict biventricular (BV) versus univentricular (UV) outcome of fetuses with severe pulmonary stenosis or atresia with intact ventricular septum (PSAIVS).

METHODS

All cases of PSAIVS diagnosed prenatally over a period of 14years were retrospectively collected in 2 tertiary referral centers.

RESULTS

Forty-nine fetuses with PSIVS (n = 11) or PAIVS (n = 38) were identified prenatally. Nineteen (38.8%) fetuses had additional ventriculocoronary connections (VCCs) and 21 (42.9%) fetuses had right ventricular hypoplasia. Four (8.2%) pregnancies were terminated, 2 (4.1%) ended in intrauterine fetal death, 4 (8.2%) in neonatal death, and 5 (10.2%) children died in infancy or childhood, including one case with compassionate care. Thirty-four of 44 (77.3%) fetuses with the intention-to-treat were alive at latest follow-up, 25 (73.5%) with BV, and 9 (26.5%) with UV circulation. Most significant predictive markers of UV circulation were Vmax of tricuspid regurgitation (TR) <2 m/s, right ventricle/left ventricle length ratio ≤0.6, and presence of VCC. A scoring system including these 3 markers had 100% sensitivity and 100% specificity predicting an UV outcome if more than one of these criteria was fulfilled. All 25 liveborn infants that were suitable for BV repair survived, whereas only 9 out of 14 candidates for UV repair survived. None of the 14 fetuses with predicted UV outcome would have met the inclusion criteria for fetal intervention, as 10 of them had VCC and the remaining 4 had absent TR or Vmax <2 m/s.

CONCLUSION

The prognosis of prenatally diagnosed PSAIVS is good if BV circulation can be achieved, while postnatal mortality in UV circulation is high within the first 4 months of life. Postnatal outcome can be predicted prenatally with high accuracy using a simple scoring system. This information is mandatory for parental counseling and may be useful in selecting fetuses for intrauterine valvuloplasty.

Myocardial strain abnormalities in fetuses with pulmonary atresia and intact ventricular septum

OBJECTIVES

Global and regional myocardial deformation have not been well described in fetuses with pulmonary atresia and intact ventricular septum (PA/IVS). Speckle-tracking echocardiography (STE), an angle-independent technique for assessing global and regional strain, may be a more sensitive way of determining ventricular systolic dysfunction compared with traditional 2D echocardiography. The aim of this study was to assess myocardial deformation in fetuses with PA/IVS compared with control fetuses and to determine if, in fetuses with PA/IVS, strain differs between those with and those without right ventricle-dependent coronary circulation (RVDCC).

METHODS

This was a retrospective analysis of fetuses with PA/IVS examined at two medical centers between June 2005 and October 2017. Left ventricular (LV) and right ventricular (RV) regional and global longitudinal strain (GLS) and strain rate were obtained using STE, and comparisons were made between fetuses with PA/IVS and gestational age (GA)-matched controls. Postnatal outcome was assessed, including the presence of RVDCC.

RESULTS

Fifty-seven fetuses with PA/IVS and 57 controls were analyzed at a mean GA of 26.5 ± 5 weeks. LV-GLS was significantly decreased in fetuses with PA/IVS compared with controls (-17.4 ± 1.7% vs -23.7 ± 2.0%, P < 0.001). LV strain rate was also significantly decreased (-1.01 ± 0.21/s vs -1.42 ± 0.20/s, P < 0.001). Fetuses with PA/IVS had decreased strain in all segments. Similarly, RV strain was significantly decreased in fetuses with PA/IVS (-11.6 ± 3.8% vs -24.6 ± 2.5%, P < 0.0001). Thirty-six patients had postnatal cardiac catheterization performed to define coronary anatomy; 10 fetuses had RVDCC. Fetuses with RVDCC had decreased LV strain compared with those without (-15.8 ± 1.2% vs -17.9 ± 1.7%, P = 0.009). RV strain was also decreased in fetuses with RVDCC vs those without (-7.0 ± 2.9% vs -12.1 ± 3.2%, P = 0.0004).

CONCLUSIONS

Fetuses with PA/IVS have decreased global and regional LV and RV strain compared with controls. The finding of decreased LV strain may be due to altered ventricular mechanics in the context of a hypertensive right ventricle and/or abnormal coronary perfusion. Moreover, fetuses that were found to have RVDCC postnatally had decreased LV and RV strain compared with those that did not. These results encourage further investigation to assess whether fetal ventricular strain could be a prenatal predictor of RVDCC. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetal cardiac intervention for right sided heart disease: Pulmonary atresia with intact ventricular septum

Congenital heart disease (CHD), the most common of birth defects, can be serious enough to require a lifetime of medical care including multiple surgeries or other interventions. Advances in ultrasound technology and a better understanding of the progression of CHDs have made it possible to intervene in utero. This early stage intervention allows the still plastic cardiovascular system to return to a more normal trajectory thus sparing the newborn from negative consequences to morbidity and mortality. Fetal cardiac intervention (FCI) has been successful for the alleviation of left ventricular dysfunction resulting in remarkably positive outcomes for many families. Promising results support that FCI may also be useful in alleviating right ventricular dysfunction. This bodes well for expanding the use of FCI to lead to better postnatal adaptation and improved long-term function for more children with CHD.

Fetal interventions for structural heart disease

Fetal cardiac intervention (FCI) offers the potential to alter in utero anatomy and physiology. For aortic stenosis with evolving hypoplastic left heart syndrome and pulmonary atresia with intact ventricular septum with evolving hypoplastic right heart syndrome, FCI may result in maintenance of a biventricular circulation, thus avoiding single-ventricle palliation and its attendant complications. In the case of hypoplastic left heart syndrome with intact atrial septum, FCI may ameliorate in utero pathophysiology and portend a more favorable postnatal prognosis. In all cases, a detailed fetal echocardiographic assessment to identify the appropriate FCI candidate is essential. This article reviews the three aforementioned lesions for which FCI can be considered. The pathophysiology and rationale for intervention, echocardiographic assessment, patient selection criteria, and outcomes for each lesion will be reviewed. A primary focus will be the echocardiographic evaluation of each lesion.

Controversy About a High-Risk and Innovative Fetal Cardiac Intervention

A 20-week-old fetus was diagnosed with critical pulmonary valve stenosis. Given the ultrasound findings, the outcome was difficult to predict. The fetal cardiologists discussed the possibility of a pulmonary valvuloplasty (an experimental procedure) with the parents, wherein the fetal right ventricle would be punctured with a long 18G needle, and through it, a wire advanced across the pulmonary valve, allowing for balloon dilation of the valve. The experimental procedure had been performed at a handful of centers. There were some reports of success. The parents sought an opinion at one of the referral centers that had tried the procedure. The doctors there recommended against it. The doctors at the original center were unsure whether they should try the procedure. The parents wanted it. In this ethics rounds, doctors and the parents discuss the arguments for and against a high-risk, innovative in utero procedure.

Immediate effects and outcome of in-utero pulmonary valvuloplasty in fetuses with pulmonary atresia with intact ventricular septum or critical pulmonary stenosis

OBJECTIVE

To assess the immediate effects of fetal pulmonary valvuloplasty on right ventricular (RV) size and function as well as in-utero RV growth and postnatal outcome.

METHODS

Patients with pulmonary atresia with intact ventricular septum (PAIVS) or critical pulmonary stenosis (CPS) who underwent fetal pulmonary valvuloplasty at our center between October 2000 and July 2017 were included. Echocardiographic data obtained before and after the procedure were analyzed retrospectively (median interval after intervention, 1 (range, 1-3) days) for ventricular and valvular dimensions and ratios, RV filling time (duration of tricuspid valve (TV) inflow/cardiac cycle length), TV velocity time integral (TV-VTI) × heart rate (HR) and tricuspid regurgitation (TR) velocity. Longitudinal data were collected from only those fetuses followed up in our center. Outcome was assessed using the scoring system as described by Roman et al. for non-biventricular outcome.

RESULTS

Thirty-five pulmonary valvuloplasties were performed in our institution on 23 fetuses with PAIVS (n = 15) or CPS (n = 8). Median gestational age at intervention was 28 + 4 (range, 23 + 6 to 32 + 1) weeks. No fetal death occurred. Immediately after successful intervention, RV/left ventricular length (RV/LV) ratio (P ≤ 0.0001), TV/mitral valve annular diameter (TV/MV) ratio (P ≤ 0.001), RV filling time (P ≤ 0.00001) and TV-VTI × HR (P ≤ 0.001) increased significantly and TR velocity (P ≤ 0.001) decreased significantly. In fetuses followed longitudinally to delivery (n = 5), RV/LV and TV/MV ratios improved further or remained constant until birth. Fetuses with unsuccessful intervention (n = 2) became univentricular, all others had either a biventricular (n = 15), one-and-a-half ventricular (n = 3) or still undetermined (n = 3) outcome. Five of nine fetuses with a predicted non-biventricular outcome, in which the procedure was successful, became biventricular, while two of nine had an undetermined circulation.

CONCLUSION

In selected fetuses with PAIVS or CPS, in-utero pulmonary valvuloplasty led immediately to larger RV caused by reduced afterload and increased filling, thus improving the likelihood of biventricular outcome even in fetuses with a predicted non-biventricular circulation. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

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

BACKGROUND

Neonates with critical left heart obstruction and intact atrial septum (IAS) or restrictive atrial septum (RAS) are at risk for hypoxia within hours of birth and remain a group at high risk for mortality.

METHODS

Prenatally diagnosed fetuses with critical left heart obstruction and IAS or RAS with follow-up from January 1, 2005, to February 14, 2017, were included. Primary outcome was a composite measure of severe neonatal illness (pH < 7.15, venous pH < 7.10, bicarbonate < 16 mmol/L, lactic acid > 5 mmol/L, or median oxygen saturation < 60% within 2 hours of birth).

RESULTS

Of 68 live born fetuses, 52 (76.5%) had hypoplastic left heart syndrome, 14 (20.5%) had critical aortic stenosis, and two (3%) had complex anatomy with mitral stenosis/atresia. There were 27 (39.7%) fetuses with IAS and 41 (60.3%) with RAS. Severe neonatal illness was present in 36 (52.9%). The strongest discriminators for severe neonatal illness were a pulmonary vein A:R VTI ≤ 2.7 (P < 0.001, AUC 0.93) and larger pulmonary vein diameter (P = 0.025, AUC 0.77). A:R VTI ≤ 2.7 predicted death or transplant (log-rank P = 0.03).

CONCLUSIONS

In neonates with hypoplastic left heart syndrome and IAS or RAS, A:R VTI ≤ 2.7 is predictive of severe neonatal instability. This threshold can help guide resource planning, delivery management, and improve fetal intervention criteria.

Fetal pulmonary valve stenosis or atresia with intact ventricular septum: Predictors of need for neonatal intervention

OBJECTIVES

To compare the fetal echocardiographic measurements and neonatal outcome of fetuses with diagnosis of critical pulmonary stenosis (CPS/IVS) and pulmonary atresia with intact ventricular septum (PA/IVS) to identify the predictors of neonatal ductus dependence and the need for neonatal intervention.

METHODS

Forty-four fetuses with a diagnosis of membranous PA/IVS or CPS/IVS referred to Shanghai Xinhua Hospital Affiliated to Shanghai Jiaotong University between June 2009 and November 2014 were respectively analyzed. We analyzed their fetal and pediatric echocardiographic features and clinical features after birth.

RESULTS

Among the 29 infants in the final analysis, 19 were ductal dependent and were diagnosed as CPS/IVS or PA/IVS after birth. Ten patients with fetal CSP/IVS were ductal independent and were diagnosed as pulmonary stenosis after birth. In midtrimester, significance was only detected in pulmonary valve (PV) regurgitation between 2 groups (P = .009). The fetuses with PV regurgitation in midtrimester were more likely to be ductal independent (odds ratio = 6.67; P = .010) than those with absence of PV regurgitation in the midtrimester scan. In late trimester, the infants in ductus-independent group had better fetal right ventricular development than those in ductus dependent group. The right ventricle over left ventricle length ratio in last scan over 0.86 had the best capability in predicting ductus independence during neonatal period with help of receiver-operating characteristic curve and the logistic regression analysis.

CONCLUSION

Among fetuses with pulmonary valve stenosis and right ventricle dysplasia at the time of first fetal echo in midtrimester, use of pulmonary valve regurgitation can identify who will be ductal dependent at births. In late trimester, right ventricle over left ventricle length ratio less than 0.86 had the best capability of predicting neonatal ductal dependence. Fetuses with reversed ductus arteriosus flow direction in late trimester were more likely to be ductus dependent after birth.

Pulmonary Atresia With an Intact Ventricular Septum: Preoperative Physiology, Imaging, and Management

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare complex cyanotic congenital heart disease with heterogeneous morphological variation. Prenatal diagnosis allows for developing a safe plan for delivery and postnatal management. While transthoracic echocardiography allows for detailed delineation of the cardiac anatomy, additional imaging modalities such as computed tomography, magnetic resonance imaging, and catheterization may be necessary to further outline features of the cardiac anatomy, specifically coronary artery anatomy. The size of the tricuspid valve and right ventricular cavity as well as the presence of right ventricle–dependent coronary circulation help to dichotomize between biventricular repair versus univentricular palliation or heart transplantation, as well as predicting the expected survival. The delineation and understanding of these features help to dictate both medical and surgical management.

A potentially curative fetal intervention for hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) encapsulates a spectrum of complex congenital cardiovascular malformations involving varying degrees of underdevelopment of the left-sided heart structures. However, despite improved survival rates since the introduction of staged surgical reconstruction, treatment options for HLHS remain palliative rather than curative. A major limiting factor in the development of definitive curative therapy for HLHS is an incomplete understanding of its pathogenesis. Currently, the aetiology HLHS is best conceptualised by the 'flow theory' of cardiogenesis, which states that normal cardiac development is reliant on the interrelationship of normal flow patterns of blood through the developing heart, and appropriate growth of the cardiac valves and myocardium. Thus, congenital cardiac malformations, such as HLHS, are thought to arise when these two processes are incorrectly coupled in utero. The rationale for the hypothesis proposed herein rests upon the flow theory of cardiogenesis. Morphological studies of HLHS indicate that, although underdeveloped, all left-sided cardiac structures are present and anatomically correct. Further, of the various structural abnormalities that can occur within the spectrum of HLHS, the presence of a ventricular septal defect (VSD) is rare. The rarity of a VSD within the morphological spectrum of HLHS suggests the syndrome may not develop in the presence of a functionally significant VSD. Presumably, the presence of a functional VSD establishes a communication between the two ventricles during cardiac development, and preserves the normal pressure-flow-dependent growth of the left ventricular (LV) myocardium, despite inflow/outflow valve defects. It is proposed that surgical creation of a VSD in utero will 'rescue' the LV of hearts with left-sided valvular deformities that render them susceptible to the development of HLHS later in gestation. In evaluating this hypothesis, potential techniques for surgical creation of a VSD in utero are offered. These techniques are based on already established catheter-based in utero interventions, and conventional postnatal percutaneous procedures for VSD creation. Further discussion is also offered on techniques to avoid, and manage, potential complications (i.e. conduction system damage) of the proposed technique(s). Finally, if VSD creation in utero is indeed practically feasible, and successfully establishes the hypothesised hemodynamic and myocardial growth normalisation within the abnormally developing LV, the clinical implications are profound. This procedure may hold a potential cure for almost every sub-type of HLHS.

The boundaries of fetal cardiac intervention: Expand or tighten?

Fetal cardiac intervention (FCI) is a relatively new and continually evolving field, and, for select cardiac defects, offers the potential to alter the progression of the disease and improve outcomes. It is a procedure that requires a collaborative effort between maternal-fetal medicine, interventional cardiology and fetal echo/ultrasound specialists, as well as fetal and maternal anesthesiologists, nursing specialists, and social workers. This article reviews the most recently reported data and advances in FCI. Currently, FCI is most frequently performed in fetuses with severe aortic stenosis (AS) with evolving hypoplastic left heart syndrome (eHLHS), established HLHS with intact or highly restrictive atrial septum (IAS), and pulmonary atresia with intact ventricular septum (PA-IVS) with evolving hypoplastic right heart syndrome (eHRHS). The goal of FCI for eHLHS and eHRHS is to promote a postnatal biventricular circulation with, theoretically, the potential for better long-term outcomes. In HLHS with IAS the aim is to improve survival. Contemporary data for FCI demonstrate limited maternal risks and improving technical success. With experience, FCI in severe AS with eHLHS has shown improved rates of biventricular outcome and early survival. Limited data for PA-IVS show promise for improving postnatal biventricular outcomes; however, for HLHS with IAS, FCI has yet to clearly demonstrate improved survival. FCI has an evolving role in the management of congenital heart defects. Ongoing analysis of disease progression, patient selection and postnatal outcomes, in conjuncture with technologic innovations and a multicenter collaborative approach, is essential as the field expands.

Prenatal Echocardiographic Predictors of Postnatal Management Strategy in the Fetus with Right Ventricle Hypoplasia and Pulmonary Atresia or Stenosis

Fetuses with pulmonary atresia or pulmonary stenosis with intact ventricular septum manifest variable degrees of right ventricle hypoplasia and inadequacy. We studied the relationship between prenatal echocardiographic parameters and their progression through gestation as potential predictors of postnatal single-ventricle or two-ventricle care strategy. Serial fetal echocardiograms of pulmonary atresia (n = 28) or severe pulmonary stenosis (n = 8) and intact ventricular septum were reviewed. Measurements included tricuspid valve and mitral valve diameter and Z scores, degree of tricuspid regurgitation, presence of subaortic stenosis, presence of coronary artery fistulae, and Doppler pulsatility indices in middle cerebral and umbilical artery. Data were compared between first and last fetal studies. Subjects were divided based on postnatal course of single- or two-ventricle repair. Tricuspid valve size of those destined for single ventricle is smaller than of those destined for a two-ventricle repair at first study (26w, Z score -4.22 v -1.83, p < 0.001) and at final study (35w, -4.94 v -1.42, p < 0.001). Tricuspid valve and right ventricle grow in those destined for two ventricle, but not single-ventricle palliation. Tricuspid valve Z score = -3 at first or last study discriminated between single- or two-ventricle repair, except in two unusual cases with significant subaortic stenosis. Tricuspid valve Doppler-derived parameters of middle cerebral artery and umbilical artery did not distinguish between groups. In the fetus with pulmonary atresia or stenosis and intact ventricular septum, tricuspid valve Z score ≥-3, presence of important tricuspid regurgitation, absence of coronary fistulae, and absence of subaortic stenosis are associated with a two-ventricle postnatal strategy.

Fetal interventions for congenital heart disease

PURPOSE OF REVIEW

This article discusses the rationale, patient selection, technical aspects, and outcomes of percutaneous, ultrasound-guided fetal cardiac intervention (FCI) for structural congenital heart disease.

RECENT FINDINGS

FCI is most commonly performed for three forms of congenital heart disease: severe aortic stenosis with evolving hypoplastic left heart syndrome (HLHS), pulmonary atresia with intact ventricular septum and evolving hypoplastic right heart syndrome, and HLHS with intact or highly restrictive atrial septum. For severe aortic stenosis and pulmonary atresia with intact ventricular septum, the goal of intervention is to alter the natural history such that a biventricular circulation may be achieved postnatally. A growing number of patients have achieved a biventricular circulation; however, patient selection and postnatal management strategy are essential for success. HLHS with intact or highly restrictive atrial septum is one of the most lethal forms of congenital heart disease, and the goal of FCI is to improve survival. Although the creation of an atrial communication in utero is technically feasible and may permit greater stability in the immediate postnatal period, significant improvements in survival have not yet been reported.

SUMMARY

FCI is an evolving form of treatment for congenital heart disease that holds promise for select patients. Critical evaluation of both short and long-term outcomes is warranted.

International Fetal Cardiac Intervention Registry: A Worldwide Collaborative Description and Preliminary Outcomes

BACKGROUND

Invasive fetal cardiac intervention (FCI) has been reported in single-institution series, promoting technical and physiologic success.

OBJECTIVES

This study describes the creation of an international registry of cases presenting for FCI, intended to compile technical and outcome data from a multicenter cohort.

METHODS

For this initial analysis, the entire database of the International Fetal Cardiac Intervention Registry (IFCIR) was queried for details of diagnoses, procedures, and outcomes. Maternal-fetal dyads from January 2001 through June 2014 were included.

RESULTS

Eighteen institutions submitted data by data harvest. Of 370 cases entered, 245 underwent FCI: 100 aortic valvuloplasties from a previous single-center report (excluded from additional reporting here), an additional 86 aortic and 16 pulmonary valvuloplasties, 37 atrial septal cases, and 6 unclassified cases. FCI did not appear to affect overall survival to hospital discharge. Among live-born infants with a fetal diagnosis of aortic stenosis/evolving hypoplastic left heart syndrome, more than twice as many were discharged with biventricular circulation after successful FCI versus those meeting institutional criteria but without any or successful FCI (42.8% vs. 19.4%, respectively). When fetal deaths were counted as treatment failures, the percentages were similar: biventricular circulation at discharge was 31.3% versus 18.5% for those discharged with univentricular palliation. Survival to discharge for live-born fetuses with atrial restriction was similar to that of those undergoing technically successful versus unsuccessful FCI (63.6% vs. 46.7%, respectively), although criteria for diagnosis were nonuniform.

CONCLUSIONS

We describe the contents of the IFCIR and present post-natal data to suggest potential benefit to fetal therapy among pregnancies considered for possible intervention and support proposals for additional work.

Echocardiographic factors discriminating biventricular versus univentricular approach in the foetus with borderline left ventricle

BACKGROUND

The term "borderline left ventricle" describes a small left heart that may be inadequate to provide systemic cardiac output and implies the potential need for a single-ventricle palliation. The aim of this study was to identify foetal echocardiographic features that help discriminate which infants will undergo single-ventricle palliation versus biventricular repair to aid in prenatal counselling.

METHODS

The foetal database at our institution was searched to identify all foetuses with borderline left ventricle, as determined subjectively by a foetal cardiologist, from 2000 to 2011. The foetal images were retrospectively analysed for morphologic and physiologic features to determine which best predicted the postnatal surgical choice.

RESULTS

Of 39 foetuses identified with borderline left ventricle, 15 were planned for a univentricular approach, and 24 were planned for a biventricular approach. There were significant differences between the two outcome groups in the Z-scores of the mitral valve annulus, left ventricular end-diastolic dimension, aortic valve annulus, and ascending aorta diameter (p<0.05). With respect to discriminating univentricular outcomes, cut-offs of mitral valve Z-score ⩽-1.9 and tricuspid:mitral valve ratio ⩾1.5 were extremely sensitive (100%), whereas a right:left ventricular end-diastolic dimension ratio ⩾2.1 provided the highest specificity (95.8%).

CONCLUSION

In foetuses with borderline left ventricle, a mitral valve Z-score ⩾-1.9 or a tricuspid:mitral valve ratio ⩽1.5 suggests a high probability of biventricular repair, whereas a right:left ventricular end-diastolic dimension ratio ⩾2.1 confers a likelihood of single-ventricle palliation.

Fetal cardiac interventions: an update of therapeutic options

Objective

This article aims to present updated therapeutic options for fetal congenital heart diseases.

Methods

Data source for the present study was based on comprehensive literature retrieval on fetal cardiac interventions in terms of indications, technical approaches and clinical outcomes.

Results

About 5% of fetal congenital heart diseases are critical and timely intrauterine intervention may alleviate heart function. Candidates for fetal cardiac interventions are limited. These candidates may include critical aortic valve stenosis with evolving hypoplastic left heart syndrome, pulmonary atresia with an intact ventricular septum and evolving hypoplastic right heart syndrome, and hypoplastic left heart syndrome with an intact or highly restrictive atrial septum as well as fetal heart block. The advocated option are prenatal aortic valvuloplasty, pulmonary valvuloplasty, creation of atrial communication and fetal cardiac pacing.

Conclusion

Fetal cardiac interventions are feasible at midgestation with gradually improved technical success and fetal/postnatal survival due mainly to a well-trained multidisciplinary team, sophisticated equipment and better postnatal care.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease.

METHODS AND RESULTS

A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease.

CONCLUSIONS

Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

Left ventricle after palliation of hypoplastic left heart syndrome: friend, fiend, or innocent bystander?

Hypoplasia of the left side of the heart is the most common cause of death from congenital heart disease in the first weeks of life. Once considered a surgically fatal disease, hypoplasia has been successfully palliated for more than 30 years. Although the palliative route is staged by an early differential bypass of the systemic outflow and the venous inflow to the right ventricle, the left ventricle remains anatomically and biologically influential throughout. Given the variation of the left ventricle, contemporary outcomes for different hypoplastic left heart subsets can vary both early after palliation and long term. This review critically examines the contemporary understanding of the structure and function of the hypoplastic ventricle in this syndrome. It also provides insight into future research directions relevant to clinicians and surgeons.

Fetal intervention in right outflow tract obstructive disease: selection of candidates and results

Objectives. To describe the process of selection of candidates for fetal cardiac intervention (FCI) in fetuses diagnosed with pulmonary atresia-critical stenosis with intact ventricular septum (PA/CS-IVS) and report our own experience with FCI for such disease. Methods. We searched our database for cases of PA/CS-IVS prenatally diagnosed in 2003–2012. Data of 38 fetuses were retrieved and analyzed. FCI were offered to 6 patients (2 refused). In the remaining it was not offered due to the presence of either favourable prognostic echocardiographic markers (n = 20) or poor prognostic indicators (n = 12). Results. The outcome of fetuses with PA/CS-IVS was accurately predicted with multiparametric scoring systems. Pulmonary valvuloplasty was technically successful in all 4 fetuses. The growth of the fetal right heart and hemodynamic parameters showed a Gaussian-like behaviour with an improvement in the first weeks and slow worsening as pregnancy advanced, probably indicating a restenosis. Conclusions. The most likely type of circulation after birth may be predicted in the second trimester of pregnancy by means of combining cardiac dimensions and functional parameters. Fetal pulmonary valvuloplasty in midgestation is technically feasible and in well-selected cases may improve right heart growth, fetal hemodynamics, and postnatal outcome.

Fetal cardiac interventions: myths and facts

An early, primary, in utero cardiac abnormality may prevent normal heart development and cause irreversible secondary structural changes. The idea of foetal cardiac intervention stems from this understanding and focuses on antenatal intervention targeting the primary abnormality to allow normal flow and haemodynamics and thus normal heart development. Crucial aspects of foetal vascular access, varying foetal lie and structural complexity make it very hard to set procedural standards. The procedures are complex and are associated with significant maternal and foetal morbidity and mortality. The high risk-benefit ratio clearly explains the investigational nature of such therapies. With the development of minimally invasive techniques and continued animal experiments, foetal interventional therapy may see a low rate of morbidity and mortality, improving the prognosis of newborns with congenital heart disease previously considered incurable.

Starnes procedure in a neonate with pulmonary atresia and intact ventricular septum

We describe the case of 7-day-old neonate with pulmonary atresia, intact ventricular septum, and severe tricuspid valve (TV) dysplasia who underwent a Starnes right ventricular exclusion procedure (RVEP). The patient had severe tricuspid stenosis and regurgitation and right ventricular dysfunction after perforation and balloon dilation of the pulmonary valve.

Rationale for and current status of prenatal cardiac intervention

The idea of prenatal intervention in congenital heart defects was put forward over 20 years ago, arising from the observation that some forms of cardiac malformation progressed in severity as pregnancy advanced. The simultaneous development of minimally invasive catheter techniques in children, led to the concept of treating the foetal heart directly, in an attempt to prevent the changes which had been observed. Early efforts at prenatal valvuloplasty were largely set aside after poor results and the coincidental development of alternative, increasingly successful, postnatal surgical strategies. However, in the last 10 years or so, some centres have revived and extended the interventional techniques, with some success. The application of these techniques is limited to very few conditions, and suitable cases are relatively uncommon. Exploration of these procedures, therefore, should be limited to very few centres and the results should be closely scrutinised before this becomes an accepted management option.

Comparison of cardiac Z-score with cardiac asymmetry for prenatal screening of congenital heart disease

OBJECTIVE

To determine the best screening tests for discriminating early indicators of cardiac hypoplasia in congenital heart disease (CHD) from normal variations in fetal cardiac growth.

METHODS

We retrospectively examined fetal echocardiograms from 90 infants with confirmed CHD: Group 1 (n = 35) with right-sided obstructive lesions and Group 2 (n = 55) with left-sided obstructive lesions. Our control group comprised 2735 normal fetuses, from which we determined fetal cardiac Z-scores of right ventricle (RV), left ventricle (LV), aorta (Ao) and pulmonary artery (PA) diameters and ratios of right to left ventricle (RV:LV) and pulmonary artery to aorta (PA:Ao) size. We compared our control group to Groups 1 and 2 using ANOVA and area under receiver-operating characteristics curve (AUC) analysis.

RESULTS

For Group 1, RV:LV ratio, RV-Z-score and PA:Ao ratio were the best screening tests, with highest AUCs (0.879, 0.868 and 0.832, respectively). For Group 2, the Ao-Z-score, PA:Ao and RV:LV ratios were the best screening tests, with AUCs of 0.770, 0.723 and 0.716, respectively.

CONCLUSION

None of the screening tests was found to be a perfect early discriminator for the cardiac lesions tested. Although ratios of PA:Ao and RV:LV are useful, they should be combined with fetal cardiac Z-scores to maximize screening sensitivity.

Impact of prenatal diagnosis on outcome of pulmonary atresia and intact ventricular septum

OBJECTIVES

To determine the impact of fetal echocardiography on the management of pregnancy and of newborns affected by pulmonary atresia and intact ventricular septum (PAIVS) and to evaluate the outcome of infants with and without prenatal diagnosis of PAIVS.

METHODS

We searched our database for cases of PAIVS prenatally and postnatally diagnosed during the period January 1993-December 2009. Postnatal follow-up was available in all cases included in the study. Karyotyping and fluorescent in situ hybridization analysis for the DiGeorge critical region (22q11.2) were performed in all but one case.

RESULTS

The study comprised 60 cases of PAIVS: 36 with (Group A) and 24 without (Group B) prenatal diagnosis. In Group A, there were two intrauterine deaths, six postnatal deaths (five early after birth) and one termination of pregnancy. In this group, radiofrequency (RF) perforation was successfully performed in 25 cases; 20/25 infants had a biventricular (BV) repair, without further operation in 13 of them. No patient of Group B died. In this group, RF perforation was successfully performed in 22 cases; 20/22 had a BV repair without further procedure in 15 of them.

CONCLUSIONS

Prenatal diagnosis of PAIVS allows a reliable prognosis of severity and planning of proper surgical repair strategies. Fetuses that are prenatally diagnosed present a more severe spectrum of the disease; for the cases capable of getting through the neonatal period, the mortality rate and the need for further intervention were not significantly different when compared with babies with only postnatal diagnosis.