Prenatal screening for major congenital heart disease: superiority of outflow tracts over the 4-chamber view

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.

A Simple Effective Protocol to Increase Prenatal Detection of Critical Congenital Heart Disease

Prenatal diagnosis of congenital heart disease (CHD) during routine obstetric sonography has been aptly named the sonographer’s Achilles heel. Although CHD occurs more commonly than any other major congenital abnormality, the detection rate remains low. The goal of this study was to improve the prenatal diagnosis of CHD during routine obstetric sonography through the development and implementation of a simple and effective screening protocol.

Prenatal diagnosis of nonsyndromic congenital heart defects

OBJECTIVES

Congenital heart defects (CHDs) occur in nearly 1% of live births. We sought to assess factors associated with prenatal CHD diagnosis in the National Birth Defects Prevention Study (NBDPS).

METHODS

We analyzed data from mothers with CHD-affected pregnancies from 1998 to 2005. Prenatal CHD diagnosis was defined as affirmative responses to questions about abnormal prenatal ultrasounds and fetal echocardiography obtained during a structured telephone interview.

RESULTS

Fifteen percent (1097/7299) of women with CHD-affected pregnancies (excluding recognized syndromes and single-gene disorders) reported receiving a prenatal CHD diagnosis. Prenatal CHD diagnosis was positively associated with advanced maternal age, family history of CHD, type 1 or type 2 diabetes, twin or higher-order gestation, CHD complexity, and presence of extracardiac defects. Prenatal CHD diagnosis was inversely associated with maternal Hispanic race/ethnicity, prepregnancy overweight or obesity, and preexisting hypertension. Prenatal CHD diagnosis varied by time to NBDPS interview and NBDPS study site.

CONCLUSIONS

Further work is warranted to identify reasons for the observed variability in maternal reports of prenatal CHD diagnosis and the extent to which differences in health literacy or health system factors such as access to specialized prenatal care and fetal echocardiography may account for such variability.

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart

OBJECTIVE

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology.

METHODS

We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum).

RESULTS

In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy.

CONCLUSIONS

The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify examination of the fetal heart and reduce operator dependency. The observation of abnormal echocardiography views in the diagnostic planes and/or VIS-Assistance® should raise the index of suspicion for congenital heart disease.

Performance of different scan protocols of fetal echocardiography in the diagnosis of fetal congenital heart disease: a systematic review and meta-analysis

OBJECTIVE

The rapid progress in fetal echocardiography has lead to early detection of congenital heart diseases. Increasing evidences have shown that prenatal diagnosis could be life saving in certain cases. However, there is no agreement on which protocol is most adaptive diagnostic one. Thus, we use meta-analysis to conduct a pooled performance test on 5 diagnostic protocols.

METHODS

We searched PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and WHO clinical trails registry center to identify relevant studies up to August, 2012. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 11.0 to estimate the publication bias and SPSS 17.0 to evaluate variance.

RESULTS

We use results from 81 studies in 63 articles to analyze the pooled accuracy. The overall performance of pooled sensitivities of spatiotemporal image correlation (STIC), extend cardiac echography examination (ECEE) and 4 chambers view + outflow tract view + 3 vessels and trachea view (4 CV+OTV+3 VTV) were around 0.90, which was significant higher than that of 4 chambers view + outflow tract view or 3 vessels and trachea view (4 CV+OTV/3 VTV) and 4 chambers view (4 CV). Unfortunately the pooled specificity of STIC was 0.92, which was significant lower than that of other 4 protocols which reached at 1.00. The area under the summary receiver operating characteristic curves value of STIC, ECEE, 4 CV+OTV+3 VTV, 4 CV+OTV/3 VTV and 4 CV were 0.9700, 0.9971, 0.9983, 0.9929 and 0.9928 respectively.

CONCLUSION

These results suggest a great diagnostic potential for fetal echocardiography detection as a reliable method of fetal congenital heart disease. But at least 3 sections view (4 CV, OTV and 3 VTV) should be included in scan protocol, while the STIC can be used to provide more information for local details of defects, and can not be used to make a definite diagnosis alone with its low specificity.

Two-dimensional sonographic cine imaging improves confidence in the initial evaluation of the fetal heart

OBJECTIVES

Initial screening sonography of the fetal heart with static images is often inadequate, resulting in repeated imaging or failure to detect abnormalities. We hypothesized that the addition of short cine clips would reduce the need for repeated imaging.

METHODS

Two-dimensional (2D) static sonograms and short 2D cine clips of the 4-chamber view and left and right ventricular outflow tracts were obtained from 342 patients with gestational ages of greater than 16 weeks. A diagnostic radiologist and a perinatologist retrospectively reviewed the static and cine images independently and graded them as normal, abnormal, or suboptimal.

RESULTS

A statistically significant increase in the number of structures called normal was seen when 2D cine clips were added to static imaging for both observers (P < .05); the radiologist called 86.5% normal with combined static and cine images versus 61.9% with static images alone, whereas the perinatologist recorded 68.1% as normal versus 58.8%, respectively. The radiologist called 77.8% of structures normal with cine images only versus 61.9% with static images only (P < .001), whereas the perinatologist called fewer structures normal with cine images alone (38.9%) versus static images alone (58.8%). The use of cine loops alone resulted in no significant increase in the ability to clear the heart as normal. The maternal body mass index was inversely associated with the ability to clear structures when 2D cine images were added to static images (P < .05).

CONCLUSIONS

The addition of 2D cine clips to standard 2D static imaging of the fetal heart significantly improves the number of structures cleared as normal. Two-dimensional cine clips are easily obtained, add little time to a study, and require minimal archival space.

Effectiveness of prenatal screening for congenital heart disease: assessment in a jurisdiction with universal access to health care

BACKGROUND

Neonates with certain forms of severe congenital heart disease (CHD) diagnosed prenatally might have better outcomes in comparison with those diagnosed after birth. The proportion of prenatally detected neonates with severe CHD and the effect of prenatal diagnosis on clinical outcomes have not been previously investigated in Canada.

METHODS

We retrospectively studied infants in Alberta, Canada, who required surgical or catheter intervention for CHD at younger than 1 year of age, between January 2007 and December 2010, and pregnancy terminations affected by CHD.

RESULTS

Of the 374 subjects identified (327 infants, 47 pregnancies with termination), 188 (50%) were detected prenatally. Failure of prenatal diagnosis was associated with anomalies not involving the 4-chamber view on ultrasound (odds ratio, 1.86; 95% confidence interval, 1.48-2.35; P < 0.001) and region of residence (P = 0.04). Prenatal detection was associated with fewer days to hospital admission (P < 0.001), fewer days to surgery (P = 0.003), and greater use of prostaglandins (P = 0.001). Infants diagnosed prenatally who underwent surgery within 15 days of age had higher preductal O2 saturations (P = 0.04), fewer days to admission (P = 0.03), and less frequently required preoperative intubation (P = 0.004), and inotropes (P = 0.001). Pregnancy termination occurred among 49% of fetuses detected before 24 weeks' gestation.

CONCLUSIONS

Only 50% of fetuses and/or neonates with severe CHD managed in Alberta have a prenatal diagnosis. The likelihood of prenatal detection is influenced by the status of the 4-chamber view on ultrasound and the region of maternal residence indicating heterogeneous access to fetal echocardiography within Alberta. Prenatal detection might improve clinical outcomes for neonates with severe CHD.

Improved prenatal detection of congenital heart disease in an integrated health care system

The reported prenatal detection rates (PDRs) for significant congenital heart disease (sCHD) have been suboptimal, even in the current era. Changes in prenatal ultrasound policy and training may lead to improved prenatal detection of sCHD. This study analyzed the results of a policy to assess fetal cardiac outflow tracts shown by screening prenatal ultrasound using the electronic medical record (EMR). During a 6-year period, fetuses and patients younger than 1 year with sCHD were identified. The EMR was used to gather detection and outcome data. As an internal control within the same health care system, the PDR of only the surgical cases was compared with that of a similar group in which documentation of the fetal cardiac outflow tracts was not standard policy. Among 25,666 births, sCHD was identified in 93 fetuses or patients, yielding an incidence of 3.6 per 1,000 births. The PDR was 74.1%. Detection after birth but before discharge was 20.4%, and detection after discharge was 5.4%. A significant improvement in the PDR of sCHD was found when a concerted effort was made to obtain fetal cardiac outflow tract views during pregnancy screening (59.3 vs. 28%). Within an integrated health care system and with the use of an EMR, a PDR of 74% can be obtained, and 94% of sCHD can be detected before discharge. A concerted program that includes documentation of fetal cardiac outflow tracts in the pregnancy screening can result in improved PDR of sCHD.

Population-based review of tetralogy of Fallot with absent pulmonary valve: is prenatal diagnosis really associated with a poor prognosis?

OBJECTIVES

Tetralogy of Fallot with absent pulmonary valve syndrome (TETAPV) is reported in obstetric literature to have an extremely poor prognosis. We sought to determine the clinical outcome associated with TETAPV and whether prenatal diagnosis confers a poor prognosis.

METHODS

All cases of TETAPV diagnosed in British Columbia between 1980 and 2009 were reviewed and grouped according to time of diagnosis, either prenatal or postnatal. The groups were compared with respect to mortality, respiratory problems, number of interventions and functional capacity at last follow-up.

RESULTS

Eight and 11 patients were included in the prenatally and postnatally diagnosed groups, with overall long-term survival of 71% and 82%, respectively. There was no significant difference in mortality, frequency of preoperative intubation, number of interventions or functional capacity between groups.

CONCLUSION

From a population-based retrospective analysis of TETAPV cases identified over three decades it is concluded that the prognosis for TETAPV is better than that previously reported in the obstetric literature. This information should be used to guide prenatal counseling.

The changing occurrences of tetralogy of Fallot and simple transposition of the great arteries in Southern Nevada

We analysed the occurrence of tetralogy of Fallot and simple transposition in the Hispanic and non-Hispanic populations of Clark County, Nevada, in the United States of America over a 30-year period from 1980 to 2009. We found a downward trend in the incidence of simple transposition of the great arteries in the non-Hispanic population but an upward trend in the incidence in the Hispanic population. For tetralogy of Fallot, we found an upward trend in the incidence in both populations; the trend, however, was more dramatic in the Hispanic population. We also noted differences in the male to female ratios in the different groups. Even though we make no definitive conclusions regarding the causes of these incidence curves or the differences in occurrence between males or females, the data suggest an interplay of genetics and the environment.

Simple targeted arterial rendering (STAR) technique: a novel and simple method to visualize the fetal cardiac outflow tracts

OBJECTIVE

To describe a novel and simple technique—simple targeted arterial rendering (STAR)—to visualize the fetal cardiac outflow tracts from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView).

METHODS

We developed a technique to image the outflow tracts by drawing three dissecting lines through the four-chamber view of the heart contained in a STIC volume dataset. Each line generated the following plane: (a) Line 1: ventricular septum en face with both great vessels (pulmonary artery anterior to the aorta); (b) Line 2: pulmonary artery with continuation into the longitudinal view of the ductal arch; and (c) Line 3: long-axis view of the aorta arising from the left ventricle. The pattern formed by all three lines intersecting approximately through the crux of the heart resembles a star. The technique was then tested in 50 normal fetal hearts at 15.3–40.4 weeks' gestation. To determine whether the technique could identify planes that departed from the normal images, we tested the technique in four cases with proven congenital heart defects (ventricular septal defect (VSD), transposition of great vessels, tetralogy of Fallot and pulmonary atresia with intact ventricular septum).

RESULTS

The STAR technique was able to generate the intended planes in all 50 normal cases. In the abnormal cases, the STAR technique allowed identification of the VSD, demonstrated great vessel anomalies and displayed views that deviated from what was expected from the examination of normal hearts.

CONCLUSIONS

This novel and simple technique can be used to visualize the outflow tracts and ventricular septum en face in normal fetal hearts. Inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease involving the great vessels and/or the ventricular septum. The STAR technique may simplify examination of the fetal heart and could reduce operator dependency.

Three-dimensional fast acquisition with sonographically based volume computer-aided analysis for imaging of the fetal heart at 18 to 22 weeks' gestation

OBJECTIVE

The purpose of this study was to determine how frequently cardiac images derived from 3-dimensional (3D) volume sets, acquired by fast acquisition and evaluated with sonographically based volume computer-aided analysis (sonoVCAD), were satisfactory for prenatal screening at 18 to 22 weeks' gestation.

METHODS

A prospective study of 100 women with singleton pregnancies was undertaken. Three fast acquisition 3D volume sets were obtained from each patient. Four reviewers independently evaluated the 4-chamber and 5 extracted VCAD views. Factors contributing to unsatisfactory screening were also evaluated.

RESULTS

The frequency with which adequate views for cardiac screening could be obtained varied widely; some single views, such as that of the stomach, were well seen frequently, whereas others, such as the ductal arch, were well seen significantly less frequently (P < .05). A satisfactory screening examination, defined as a visualized 4-chamber, left ventricular outflow tract, right ventricular outflow tract, and axial stomach view, was obtained for 43% to 65% of patients (dependent on reviewer). Logistic regression revealed that obesity (odds ratio, 3.0; 95% confidence interval, 1.7-5.0) and a fetus with the spine toward the maternal abdomen (odds ratio, 1.7; 95% confidence interval, 1.1-2.5) were independently associated with an unsatisfactory screening examination

CONCLUSIONS

Three-dimensional fast acquisition volumes evaluated with sonoVCAD did not allow a satisfactory fetal cardiac screening examination to be obtained a high percentage of the time in a general obstetric population during the second trimester. Certain patient factors, such as body habitus and fetal position, are associated with unsatisfactory 3D imaging.