Clinical implication of isolated right dominant heart in the fetus

Diagnostic accuracy of prenatal ultrasound in coarctation of aorta: systematic review and individual participant data meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA).

METHODS

An individual participant data meta-analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally. MEDLINE, EMBASE and CINAHL were searched for studies published between January 2000 and November 2021. Inclusion criteria were fetuses with suspected isolated CoA, defined as ventricular and/or great vessel disproportion with right dominance on ultrasound assessment. Individual participant-level data were obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for extracting data, and the QUADAS-2 tool was used for assessing quality and applicability. The reference standard was CoA, defined as narrowing of the aortic arch, diagnosed after birth. The most commonly evaluated parameters on ultrasound, both in B-mode and on Doppler, constituted the index test. Summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and likelihood ratios were computed using the hierarchical summary receiver-operating-characteristics model.

RESULTS

The initial search yielded 72 studies, of which 25 met the inclusion criteria. Seventeen studies (640 fetuses) were included. On random-effects logistic regression analysis, tricuspid valve/mitral valve diameter ratio > 1.4 and > 1.6, aortic isthmus/arterial duct diameter ratio < 0.7, hypoplastic aortic arch (all P < 0.001), aortic isthmus diameter Z-score of < -2 in the sagittal (P = 0.003) and three-vessel-and-trachea (P < 0.001) views, pulmonary artery/ascending aorta diameter ratio > 1.4 (P = 0.048) and bidirectional flow at the foramen ovale (P = 0.012) were independently associated with CoA. Redundant foramen ovale was inversely associated with CoA (P = 0.037). Regarding diagnostic accuracy, tricuspid valve/mitral valve diameter ratio > 1.4 had a sensitivity of 72.6% (95% CI, 48.2-88.3%), specificity of 65.4% (95% CI, 46.9-80.2%) and DOR of 5.02 (95% CI, 1.82-13.9). The sensitivity and specificity values were, respectively, 75.0% (95% CI, 61.1-86.0%) and 39.7% (95% CI, 27.0-53.4%) for pulmonary artery/ascending aorta diameter ratio > 1.4, 47.8% (95% CI, 14.6-83.0%) and 87.6% (95% CI, 27.3-99.3%) for aortic isthmus diameter Z-score of < -2 in the sagittal view and 74.1% (95% CI, 58.0-85.6%) and 62.0% (95% CI, 41.6-78.9%) for aortic isthmus diameter Z-score of < -2 in the three-vessel-and-trachea view. Hypoplastic aortic arch had a sensitivity of 70.0% (95% CI, 42.0-88.6%), specificity of 91.3% (95% CI, 78.6-96.8%) and DOR of 24.9 (95% CI, 6.18-100). The diagnostic yield of prenatal ultrasound in detecting CoA did not change significantly when considering multiple categorical parameters. Five of the 11 evaluated continuous parameters were independently associated with CoA (all P < 0.001) but all had low-to-moderate diagnostic yield.

CONCLUSIONS

Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. However, diagnostic accuracy is only moderate, even when combinations of parameters are considered. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Coarctation of the aorta: Prenatal assessment, postnatal management and neonatal outcomes

Coarctation of the aorta (Coa) is a potentially life threatening diagnosis. It occurs in 0.3 per 1000 live births and accounts for 6-8% of all infants with congenital heart defects. Neonates with severe Coa may be completely asymptomatic at birth, as the ductus arteriosus can provide flow to the lower body. Those who are not diagnosed prenatally may be diagnosed only after constriction of the ductus arteriosus, when they present in cardiogenic shock. This group has a higher risk for mortality and morbidity relative to those diagnosed prenatally. Despite the increasing practice of universal pulse oximetry screening, many cases with significant coarctation of the aorta still go undiagnosed in the newborn period. In this article, we present the pathophysiology, diagnosis, presentation, treatment and outcomes of Coa.

Prenatal Diagnosis of Aortic Coarctation: Prediction Algorithm according to Gestational Age

OBJECTIVES

The aim of the study was first to quantify the diagnostic accuracy of predictive anatomical factors of aortic coarctation (CoA) and second to design a postnatal CoA probability algorithm according to gestational age (GA) in prenatal period.

METHODS

Global and according to GA diagnostic performance of cardiac anatomical variables using the ROC curve were evaluated in a retrospective cohort of fetuses with suspicion of CoA (2004-2020). A serial testing strategy to predict postnatal CoA by fetal echocardiography was designed.

RESULTS

114 fetuses were included. Isthmus-to-ductal (I/D) ratio provided the best discrimination between healthy fetuses and those with CoA (AUC 0.91, 95% CI: 0.86-0.96, I/D < 0.74 sensitivity 96.3%, I/D < 0.6, specificity 92.5%) with good classification capacity in both the second and third trimesters of gestation. Isthmus z-score and pulmonary/aortic valve ratio increased accuracy in fetuses >28 and tricuspid/mitral valve ratio (TV/MV) in fetuses ≤28 weeks. Study of I/D plus TV/MV ratio in fetuses ≤28 and I/D ratio plus isthmus z-scores in fetuses >28 weeks allowed to correctly classify 91.8% of fetuses as high or low probability of postnatal CoA.

CONCLUSIONS

Diagnostic discrimination of anatomic predictive factors for CoA varies according to GA. Specific algorithms according to GA increase accuracy in CoA's prenatal prediction.

A Fetal Risk Stratification Pathway for Neonatal Aortic Coarctation Reduces Medical Exposure

OBJECTIVE

To test the hypothesis that a fetal stratification pathway will effectively discriminate between infants at different levels of risk for surgical coarctation and reduce unnecessary medicalization.

STUDY DESIGN

We performed a pre-post nonrandomized study in which we prospectively assigned fetuses with prenatal concern for coarctation to 1 of 3 risk categories and implemented a clinical pathway for postnatal management. Postnatal clinical outcomes were compared with those in a historical control group that were not triaged based on the pathway.

RESULTS

The study cohort comprised 109 fetuses, including 57 treated along the fetal coarctation pathway and 52 historical controls. Among mild-risk fetuses, 3% underwent surgical coarctation repair (0% of those without additional heart defects), compared with 27% of moderate-risk and 63% of high-risk fetuses. The combined fetal aortic, mitral, and isthmus z-score best discriminated which infants underwent surgery (area under the curve = 0.78; 95% CI, 0.66-0.91). Compared with historical controls, infants triaged according to the fetal coarctation pathway had fewer delivery location changes (76% vs 55%; P = .025) and less umbilical venous catheter placement (74% vs 51%; P = .046). Trends toward shorter intensive care unit stay, hospital stay, and time to enteral feeding did not reach statistical significance.

CONCLUSIONS

A stratified risk-assignment pathway effectively identifies a group of fetuses with a low rate of surgical coarctation and reduces unnecessary medicalization in infants who do not undergo aortic surgery. Incorporation of novel measurements or imaging techniques may improve the specificity of high-risk criteria.

Application of a Global Multiparameter Scoring System for the Prenatal Prediction of Coarctation of the Aorta

To assess prospectively the capability of our previously reported global multiparameter scoring system to predict coarctation of the aorta (CoAo) in fetuses with cardiac asymmetry, we applied and analyzed the performance of our scoring system in predicting postnatal CoAo in fetuses undergoing prenatal echocardiographic assessment because of cardiac asymmetry between 2011 and 2021, and we determined the cut-off points of the score with the best balance between specificity and sensitivity, and of maximum sensitivity and specificity. CoAo was confirmed in 39/179 newborns (21.8%). We found a significantly higher probability of CoAo in fetuses with CoAo than in cases without CoAo (84.2 ± 18.2% vs. 26.0 ± 28.6%, p < 0.001). The AUC of the ROC of the score was 0.93 (95% CI 0.89–0.97). The cut-off value with the best balance between specificity and sensitivity was a predicted risk of ≥53% (sensitivity 92.3% and specificity 80.0%). The cut-off point of maximum sensitivity was ≥35% (sensitivity 100% and specificity 72.9%), and that of maximum specificity was ≥96% (sensitivity 43.6% and specificity 96.4%). In none of the fetuses with a probability of CoAo < 35% was this condition confirmed after birth. This occurred in 102 fetuses in the whole study population (57%) and in 84 of the 111 in whom CoAo was suspected beyond 28 weeks (75.7%). This multiparameter score allows an adequate discrimination between fetuses without CoAo and those with CoAo, reducing the false positive diagnoses in cardiac asymmetry.

Redundancy of foramen ovale flap may mimic fetal aortic coarctation

OBJECTIVES

To assess the relationship between presence of a redundant foramen ovale flap (RFOF), in the absence of a clearly restrictive foramen ovale, and ventricular disproportion, in three groups of fetuses: (1) those with a final diagnosis of aortic coarctation (CoA); (2) those referred for suspicion of ventricular disproportion and/or CoA which did not develop CoA postnatally; and (3) normal fetuses.

METHODS

This was a retrospective study including 73 fetuses: 12 with a final diagnosis of isolated CoA; 30 referred for suspicion of ventricular disproportion and/or CoA, which did not develop CoA postnatally; and 31 normal fetuses. Four-dimensional volume datasets and clips were assessed offline. Maximum diameters of the FOF (FOFD), left atrium (LAD), right atrium, left and right ventricles and, when available, aortic isthmus, were measured, as were areas of the FOF (FOFA), left atrium (LAA) and right atrium. The left/right ratios for all segments of the heart, as well as the FOFD/LAD ratio and FOFA/LAA ratio, were calculated. Regression analysis was performed to assess the relationship between RFOF and ventricular disproportion and means were compared by ANOVA.

RESULTS

Repeatability was fair, with all variables having an intraclass correlation coefficient ≥ 83%. In the pooled group of fetuses with no CoA found at birth (normal fetuses plus those with ventricular disproportion (n = 61)), there was a significant linear correlation between redundancy of the FOF and degree of ventricular disproportion (P < 0.01 and P < 0.05 for diameter and area ratios, respectively). Categorizing the FOF redundancy, FOFD/LAD ratio ≥ 0.65 was significantly associated with ventricular disproportion (P = 0.006). Based on the degree of FOF prominence, we described four categories of redundancy, ranging from no redundancy/ventricular disproportion (Stage 0) to severe redundancy/ventricular disproportion with transient obstruction of the foramen ovale or mitral orifice (Stage III). Comparing cases without neonatal evidence of coarctation but FOFD/LAD ratio ≥ 0.65 vs those with neonatal evidence of coarctation, there was no statistically significant difference in the degree of ventricular disproportion or in the Z-score of the aortic isthmus maximum diameter.

CONCLUSIONS

This study demonstrates that: (1) there is an association between RFOF and ventricular disproportion, independent of the association with a restrictive foramen ovale, and (2) the presence of a RFOF may mimic CoA. In fact, it causes both ventricular disproportion and a significant reduction in the diameter of the aortic isthmus, associated in some cases also with reversed isthmic flow. Future prospective studies are needed to evaluate whether focusing the sonologist's attention on the appearance of the foramen ovale may reduce the rate of false-positive diagnosis of CoA. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Neonatal outcome of cases with isolated prenatal ventricular disproportion with a dominant right ventricle

OBJECTIVES

Isolated prenatal ventricular disproportion with a dominant right ventricle represents a challenge in decision-making for both physicians and pregnant women. In the current study, we sought to delineate the postnatal outcomes of these cases.

METHODS

This retrospective analysis included consecutive cases of isolated ventricular disproportion identified using complete fetal echocardiography at the Fetal Heart Center of Xinhua Hospital from January 2014 to October 2017. Postnatal cardiac outcome was examined using transthoracic echocardiography within the first 6 months after birth.

RESULTS

A total of 90 fetuses were included in the final analysis. The median gestational age (GA) at diagnosis was 29 weeks (range 24 to 36). At postnatal examination, cardiac malformations were detected in 39 cases (43.3%), including 25 (27.8%) cases of congenital cardiac septal defects, eight (8.9%) of persistent left superior vena cava, four (4.4%) of left-sided obstructive diseases, and one (1.1%) case of coronary fistula. Nineteen cases (21.1%) with fetal cardiac malformations had significant lower GA at diagnosis (P = .01) and greater right to left ventricle ratio (1.38 vs 1.30, P = .02). Neonatal surgical intervention was not required in any of the cases.

CONCLUSIONS

Isolated prenatal ventricular disproportion with a dominant right ventricle comprises minor postnatal cardiac malformations and doesn't require neonatal intervention.

How often an isolated cardiac disproportion predicts a coarctation of the aorta? Single center experience and systematic review of the literature

BACKGROUND

Cardiac disproportion is considered as an indirect sign of coarctation of the aorta (CoA). In this review, we have reassessed the positive predictive value (PPV) of such finding for a postnatal confirmation of CoA.

DATA SOURCES

All cases of isolated cardiac disproportion diagnosed in the four-chamber and/or three-vessel/three-vessel and trachea views (right/left sections >1.5) were included. Postnatal cardiac findings were recorded. Additionally, a systematic literature search (PubMed, EMBASE, Cochrane library, and the reference lists of identified articles) regarding the association between antenatally detected cardiac disproportion and postnatal confirmation of CoA was performed. Data from our center were pooled with those derived from the literature.

RESULTS

Ten fetuses with isolated cardiac disproportion were selected from our center and 259 from the literature review. CoA was postnatally confirmed in 101/269 (PPV 38%). PPV of antenatal cardiac findings was significantly higher in earlier gestation (23/27, 85% <26⁺⁰weeks versus 11/39, 28%≥26⁺⁰weeks, p < .001). No significant difference was noticed comparing ventricular disproportion with combined ventricular and great vessels disproportion (86/230 versus 15/39, p  .89).

DISCUSSION

Isolated cardiac disproportion has an overall chance of one in three of heralding a CoA in the neonate. The specificity of these findings is significantly higher in the second trimester.

Prenatal Diagnosis of Right Dominant Heart in Fetuses: A Tertiary Center Experience over a 7-year Period

Background:

Right dominant heart (RDH) in fetuses can occur with a number of cardiac as well as noncardiac anomalies. Analysis of the enlargement of the right cardiac chamber in the fetus remains a major challenge for sonographers and echocardiographers. The aim of this study was to report the experience with prenatal diagnosis of RDH in the fetuses over a 7-year period.

Methods:

Fetuses with prenatal diagnosis of RDH from July 2009 to July 2016 were evaluated in two different categories: according to the gestational age, Group I (n = 154, second trimester) and Group II (n = 298, third trimester); and according to the fetal echocardiography diagnosis, Group A (n = 452, abnormal cardiac structure) and Group B (n = 90, normal cardiac structure). Differences in categorical variables were assessed by Chi-square exact test and continuous variables were evaluated by independent Student's t-test or Mann–Whitney U-test depending on parametric or nonparametric nature of the data.

Results:

Over a 7-year period, 452 fetuses were referred for the assessment of suspected RDH. Left-sided obstructive lesions were observed most frequently in the fetuses with RDH. When comparing Group I with Group II and Group A with Group B, the latter groups exhibited significant differences in the right/left ventricle (RV/LV) ratio (1.435 vs. 1.236, P = 0.002; 1.309 vs. 1.168, P = 0.047), RV width Z-score (1.626 vs. 1.104, P < 0.001; 1.553 vs. 0.814, P = 0.014), and above +2 cutoff percentages (14.3% vs. 22.5%; P = 0.038; 21.5% vs. 12.2%, P = 0.046). Multivariable logistic regression revealed no variables associated with perinatal survival.

Conclusions:

The study demonstrates that RDH warrants careful attention to the possible presence of a structural cardiac anomaly, especially left-sided obstructive lesions. A diagnosis of RDH is best supported by a combination of the RV Z-score and RV/LV ratio. Most of the fetuses with RDH and structurally normal hearts had favorable outcomes.

Prenatal Sonographic Predictors of Neonatal Coarctation of the Aorta

OBJECTIVES

To identify practical prenatal sonographic markers for the postnatal diagnosis of coarctation of the aorta.

METHODS

We reviewed the fetal echocardiograms and postnatal outcomes of fetal cases of suspected coarctation of the aorta seen at a single institution between 2010 and 2014. True- and false-positive cases were compared. Logistic regression analysis was used to determine echocardiographic predictors of coarctation of the aorta. Optimal cutoffs for these markers and a multivariable threshold scoring system were derived to discriminate fetuses with coarctation of the aorta from those without coarctation of the aorta.

RESULTS

Among 35 patients with prenatal suspicion of coarctation of the aorta, the diagnosis was confirmed postnatally in 9 neonates (25.7% true-positive rate). Significant predictors identified from multivariate analysis were as follows: Z score for the ascending aorta diameter of -2 or less (P = < .001), Z score for the mitral valve annulus of -2 or less (P= .033), Zscore for the transverse aortic arch diameter of -2 or less (P= .028), and abnormal aortic valve morphologic features (P= .026). Among all variables studied, the ascending aortic Z score had the highest sensitivity (78%) and specificity (92%) for detection of coarctation of the aorta. A multivariable threshold scoring system identified fetuses with coarctation of the aorta with still greater sensitivity (89%) and only mildly decreased specificity (88%).

CONCLUSIONS

The finding of a diminutive ascending aorta represents a powerful and practical prenatal predictor of neonatal coarctation of the aorta. A multivariable scoring system, including dimensions of the ascending and transverse aortas, mitral valve annulus, and morphologic features of the aortic valve, provides excellent sensitivity and specificity. The use of these practical sonographic markers may improve prenatal detection of coarctation of the aorta.

Gestational age-specific scoring systems for the prediction of coarctation of the aorta

OBJECTIVES

To determine which combination of cardiac parameters provides the best prenatal prediction of coarctation of aorta (CoAo).

METHODS

We selected all cases of simple cardiac asymmetry prenatally diagnosed in 2003-2013. Logistic regression was used to select the best predictors of CoAo.

RESULTS

The study population included 115 fetuses. CoAo was confirmed in 52 neonates (45%). The sample was divided in two groups according to the gestational age (GA) at diagnosis: early group (EG) ≤28 weeks (n = 57), and late group (LG) >28 weeks (n = 58). CoAo was confirmed in 75% and 16% of cases, respectively. GA-specific scoring systems with maximum two parameters were made, and the pairwise combination with the best diagnostic performance for each group was selected. In EG, the z-score of ascending aorta (AAo) and aortic isthmus (three vessels and trachea view) showed the best diagnostic accuracy [area under receiver-operating curve (AUC) 0.98, 95% confidence interval (CI) 0.94-1.00]. In the LG, the best results were provided by the tricuspid valve/mitral valve ratio with the main pulmonary artery/AAo ratio (AUC 0.84, 95% CI 0.67-1.00).

CONCLUSIONS

Gestational age-specific scoring systems combining size-based cardiac parameters may improve the accuracy of fetal echocardiography to stratify the risk of CoAo. The objectivity and simplicity of its components may facilitate its implementation in fetal cardiology units.

Prenatal diagnosis of prevalence of the right heart: associated anomalies and outcome predictors

OBJECTIVES

To analyze the characteristics, associations, and outcomes of prevalence of the right heart and to evaluate the use of sonography to predict the risk of a poor prognosis in fetuses with this condition.

METHODS

We conducted a retrospective cohort study of 182 fetuses with prevalence of the right heart. At the initial evaluation, the left ventricle (LV) and right ventricle (RV) sizes, left atrium and right atrium sizes, great artery diameters, appearance of the aortic arch and ductus arteriosus arch, and flow direction across the foramen ovale and aortic arch were documented. Malformations were documented in fetuses with intracardiac anomalies, who were divided into groups with and without coexisting extracardiac defects. The RV-LV diameter ratio and main pulmonary artery-to-aortic root diameter ratio were calculated and compared. The following variables were analyzed: coexisting intracardiac anomalies, associated extracardiac anomalies, diagnosis before 24 gestational weeks, fetal growth restriction, reversed flow across the foramen ovale, reversed flow in the aortic arch, and RV-LV ratio greater than 2.0. Relationships between these sonographic findings and the prognosis were evaluated by multivariable logistic regression.

RESULTS

Of the 182 fetuses, 1 (0.5%) had intrauterine death, and 25 (13.7%) had neonatal death; 1 (0.5%) had selective reduction, and 106 (58.2%) underwent termination of pregnancy; 49 (26.9%) survived at this writing. The mean RV-LV ratio was 1.67. Multivariable logistic regression revealed that only 2 sonographic parameters, coexisting intracardiac anomalies (odds ratio, 17.75; 95% confidence interval, 4.18-75.26) and diagnosis before 24 weeks (odds ratio, 17.26; 95% confidence interval, 1.80-165.39) were significantly associated with a poor prognosis.

CONCLUSIONS

The sonographic parameters of coexisting intracardiac anomalies and diagnosis before 24 gestational weeks are significant independent predictors of a poor prognosis in fetuses with prevalence of the right heart. Combinations of these risk factors may be useful in prenatal consultation.

Technique of fetal echocardiography

Congenital heart disease is the most common abnormality in the human fetus. Fetal echocardiography has been used to detect the majority of cardiac defects, and it is now part of the routine screening method for fetal evaluation. In this article, we present standard ultrasonographic views of the normal fetal heart obtained during the second trimester, first-trimester fetal echocardiography findings, and a modified myocardial performance index.

Prediction of coarctation of the aorta in the second half of pregnancy

OBJECTIVE

To determine which combination of cardiac parameters provides the best prediction of postnatal coarctation of the aorta (CoAo) in fetuses with cardiac asymmetry.

METHODS

We selected all cases of disproportion of the ventricles and great vessels prenatally diagnosed between 2003 and 2010 at the Hospital Universitario '12 de Octubre', Madrid, Spain. Only appropriate-for-gestational age liveborn fetuses with isolated cardiac asymmetry and with complete postnatal follow-up were included in the study. Eighty-five cases were retrieved and analyzed. Logistic regression analysis was used to select the best predictors of CoAo. Optimal cut-offs for these parameters were identified and the corresponding likelihood ratios used to calculate the post-test probability of CoAo in each fetus.

RESULTS

CoAo was confirmed in 41/85 neonates (48%). The parameters selected by logistic regression and their cut-off values were: gestational age at diagnosis ≤ 28 weeks, Z-score of diameter of the ascending aorta ≤ -1.5, pulmonary valve/aortic valve diameters ratio ≥ 1.6 and Z-score of the aortic isthmus diameter in the three vessels and trachea view ≤ -2. We divided the study group into two subgroups: Group A, in whom the diagnosis was made at ≤ 28 weeks' gestation (80% CoAo (32/40)); and Group B, in whom the diagnosis was made at > 28 weeks (20% CoAo (9/45)). The mean post-test probabilities of CoAo were higher in fetuses with CoAo than in normal fetuses in both subgroups (Group A, 82 vs 55%; P = 0.002 and Group B, 51 vs 20%; P < 0.001). In addition, a rate of growth of the aortic valve of ≤ 0.24 mm/week provided 80% sensitivity and 100% specificity for predicting CoAo in Group A.

CONCLUSIONS

We have derived a multiparametric scoring system, combining size-based cardiac parameters and gestational age at diagnosis, which may improve the accuracy of fetal echocardiography for the stratification of the risk of CoAo. The objectivity and simplicity of its components may allow its implementation in fetal cardiology units.