Outcome after prenatal diagnosis of hypoplastic left-heart syndrome: a case series

Trends in survival of children with severe congenital heart defects by gestational age at birth: A population-based study using administrative hospital data for England

BACKGROUND

Children with congenital heart defects (CHD) are twice as likely as their peers to be born preterm (<37 weeks' gestation), yet descriptions of recent trends in long-term survival by gestational age at birth (GA) are lacking.

OBJECTIVES

To quantify changes in survival to age 5 years of children in England with severe CHD by GA.

METHODS

We estimated changes in survival to age five of children with severe CHD and all other children born in England between April 2004 and March 2016, overall and by GA-group using linked hospital and mortality records.

RESULTS

Of 5,953,598 livebirths, 5.7% (339,080 of 5,953,598) were born preterm, 0.35% (20,648 of 5,953,598) died before age five and 3.6 per 1000 (21,291 of 5,953,598) had severe CHD. Adjusting for GA, under-five mortality rates fell at a similar rate between 2004-2008 and 2012-2016 for children with severe CHD (adjusted hazard ratio [HR] 0.79, 95% CI 0.71, 0.88) and all other children (HR 0.78, 95% CI 0.76, 0.81). For children with severe CHD, overall survival to age five increased from 87.5% (95% CI 86.6, 88.4) in 2004-2008 to 89.6% (95% CI 88.9, 90.3) in 2012-2016. There was strong evidence for better survival in the ≥39-week group (90.2%, 95% CI 89.1, 91.2 to 93%, 95% CI 92.4, 93.9), weaker evidence at 24-31 and 37-38 weeks and no evidence at 32-36 weeks. We estimate that 51 deaths (95% CI 24, 77) per year in children with severe CHD were averted in 2012-2016 compared to what would have been the case had 2004-2008 mortality rates persisted.

CONCLUSIONS

Nine out of 10 children with severe CHD in 2012-2016 survived to age five. The small improvement in survival over the study period was driven by increased survival in term children. Most children with severe CHD are reaching school age and may require additional support by schools and healthcare services.

Medium-term Outcome of Prenatally Diagnosed Hypoplastic Left-Heart Syndrome and Impact of a Restrictive Atrial Septum Diagnosed in-utero

OBJECTIVE

Surgical outcome data differs from overall outcomes of prenatally diagnosed fetuses with hypoplastic left heart syndrome (HLHS). Our aim was to describe outcome of prenatally diagnosed fetuses with this anomaly.

METHODS

Retrospective review of prenatally diagnosed classical HLHS at a tertiary hospital over a 13-year period, estimated due dates 01/08/2006 to 31/12/2019. HLHS-variants and ventricular disproportion were excluded.

RESULTS

203 fetuses were identified with outcome information available for 201. There were extra-cardiac abnormalities in 8% (16/203), with genetic variants in 14% of those tested (17/122). There were 55 (27%) terminations of pregnancy, 5 (2%) intrauterine deaths and 10 (5%) babies had prenatally planned compassionate care. There was intention to treat (ITT) in the remaining 131/201(65%). Of these, there were 8 neonatal deaths before intervention, two patients had surgery in other centers. Of the other 121 patients, Norwood procedure performed in 113 (93%), initial hybrid in 7 (6%), and 1 had palliative coarctation stenting. Survival for the ITT group from birth at 6-months, 1-year and 5-years was 70%, 65%, 62% respectively. Altogether of the initial 201 prenatally diagnosed fetuses, 80 patients (40%) are currently alive. A restrictive atrial septum (RAS) is an important sub-category associated with death, HR 2.61, 95%CI 1.34-5.05, p = 0.005, with only 5/29 patients still alive.

CONCLUSION

Medium-term outcomes of prenatally diagnosed HLHS have improved however it should be noted that almost 40% do not get to surgical palliation, which is vital to those doing fetal counselling. There remains significant mortality particularly in fetuses with in-utero diagnosed RAS.

Being Born with a Single Cardiac Ventricle: What Do We Tell Prospective Parents

Being born with a single ventricle remains one of the most extreme congenital cardiac conditions. It encompasses a wide variety of lesions characterized by the existence of one small ventricular cavity. To allow survival, these patients must undergo a series of operations in the first years of life. It was long considered that the success of these interventions would be short-lived and that only a few of these patients would live beyond adulthood. The last decade has seen publication of multiple large outcomes researches on this population, and we now realize that its survival is longer than expected, but with a considerable burden of disease. As a consequence, the size of this single ventricle population is growing rapidly. As primary conveyer of the information on the future of these babies, obstetricians need to be aware of these changes in perspective. This article is protected by copyright. All rights reserved.

Fetal aortic valvuloplasty: first report of two cases from Saudi Arabia

Background

Fetal aortic stenosis may progress to hypoplastic left heart syndrome (HLHS), which carries a poor prognosis. We report two infants with fetal aortic stenosis successfully treated with fetal aortic valvuloplasty (FAV) using balloon dilatation.

Case presentation

Of five fetuses with aortic stenosis fulfilling the FAV criteria of severe aortic stenosis with a left ventricular length Z-score of ≥ − 2, retrograde flow in the transverse aortic arch, left-to-right flow across the foramen ovale, monophasic mitral inflow, and significant left ventricular dysfunction, we obtained permission for FAV in two fetuses. FAV was performed successfully under echocardiographic guidance using balloon dilatation. Both fetuses survived to birth. During FAV, mild pericardial effusion developed when introducing the stylet needle in the second fetus, and this resolved within 48 h. No intraprocedural complications occurred in the first patient, and no maternal complications occurred. The first infant underwent the Ross procedure after birth and is currently 7 years old and doing well. The second patient underwent aortic and mitral valve repair with endocardial fibroelastosis resection approximately 2 weeks after birth, which temporarily addressed the mitral valve stenosis; high doses of inotropes were subsequently required. The infant died of sepsis at 2 months of age.

Conclusion

FAV using balloon dilatation to treat fetal aortic stenosis was successful in our two patients, with subsequent neonatal biventricular repair resulting in long-term survival in one patient and death secondary to sepsis in the second patient.

Neonatal Palliative Care for Complicated Cardiac Anomalies: A 10-Year Experience of an Interdisciplinary Program at a Large Tertiary Cardiac Center

OBJECTIVES

To report the outcomes of a Neonatal Palliative Care (NPC) Program at a large tertiary cardiac center caring for a subset of fetuses and neonates with life-limiting cardiac diagnoses or cardiac diagnoses with medical comorbidities leading to adverse prognoses.

STUDY DESIGN

The Neonatal Comfort Care Program at New York-Presbyterian Morgan Stanley Children's Hospital/Columbia University Medical Center is an interdisciplinary team that offers the option of NPC to neonates prenatally diagnosed with life-limiting conditions, including single ventricle (SV) congenital heart disease (CHD) or less severe forms of CHD complicated by multiorgan dysfunction or genetic syndromes.

RESULTS

From 2008 to 2017, the Neonatal Comfort Care Program cared for 75 fetuses or neonates including 29 with isolated SV CHD, 36 with CHD and multiorgan dysfunction and/or severe genetic abnormalities, and 10 neonates with a prenatal diagnosis of isolated CHD and postnatal diagnoses of severe conditions who were initially in intensive care before transitioning to NPC because of a poor prognosis.

CONCLUSIONS

At New York-Presbyterian Morgan Stanley Children's Hospital/Columbia University Medical Center, a large tertiary cardiac center, 13.5% of parents of fetuses or neonates with isolated SV CHD opted for NPC. Twenty-six of 29 newborns with SV CHD treated with NPC died. Of the remaining, 2 neonates with mixing lesions are alive at 3 and 5 years of age, and 1 neonate was initially treated with NPC and then pursued surgical palliation. These results suggest that NPC is a reasonable choice for neonates with SV CHD.

Prenatal Sonographic Diagnosis of Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) represents a variety of cardiac malformations that may result from errors in the early stages of cardiac development. HLHS includes a wide spectrum of cardiac malformations including hypoplasia of the left ventricle, ascending aorta, hypoplasia, or atresia of the aortic and mitral valves. Over the recent years, the improved resolution of advanced equipment with awareness and increased performance of second-trimester ultrasound examinations for the assessment of fetal anomalies have helped in understanding the spectrum and have expanded our knowledge of HLHS. They are one of the causes which constitute for neonatal morbidity and mortality and hence the rapid need for prenatal evaluation with ultrasound to detect cardiac anomalies. Prenatal recognition of disease also allows families to prepare for a child with a life-threatening defect by consultation with the multidisciplinary team that will care for their newborn and discussing the short- and long-term prognosis.

Impact of introduction of 20-week ultrasound scan on prevalence and fetal and neonatal outcomes in cases of selected severe congenital heart defects in The Netherlands

OBJECTIVES

To evaluate in a population-based cohort the effect of the introduction of the 20-week ultrasound scan in 2007 on the time of diagnosis, pregnancy outcome and total prevalence and liveborn prevalence of cases with selected congenital heart defects (CHDs) in The Netherlands.

METHODS

We included children and fetuses diagnosed with selected severe CHD, born in the 11-year period from 2001 to 2011. Two groups of CHD were defined: those associated with an abnormal four-chamber view at ultrasound (Group 1), and those associated with a normal four-chamber view at ultrasound (Group 2). The time of diagnosis, pregnancy outcome and total liveborn prevalence were compared for both groups over two 5-year periods, before and after the introduction of the 20-week ultrasound scan. Trends in total and liveborn prevalence were examined over 2001 to 2011.

RESULTS

Information was collected on 269 children and fetuses. After the introduction of the 20-week ultrasound scan, the prenatal detection rate of CHDs increased in both groups (Group 1, 34.6% in 2001-2005 vs 84.8% in 2007-2011 (P < 0.001); Group 2, 14.3% in 2001-2005 vs 29.6% in 2007-2011 (P = 0.037)). The rate of termination of pregnancy (TOP) increased significantly only for Group 1 (15.4% vs 51.5% (P < 0.001)). The total prevalence of CHD in Group 1 increased over time from 2.9 per 10 000 births in 2001 to 6.4 per 10 000 births in 2011 (P = 0.016). The liveborn prevalence did not show a trend over time. For Group 2, no trends in total or liveborn prevalence could be detected over time.

CONCLUSIONS

Since the implementation of the routine 20-week ultrasound scan in The Netherlands, prenatal detection rate of selected severe CHDs increased significantly. Improved prenatal detection was accompanied by a more than three-fold increase in TOP, although only in those CHDs with an abnormal four-chamber view at prenatal ultrasound.

Resuscitation and perioperative management of the high-risk single ventricle patient: first-stage palliation

Infants born with hypoplastic left heart syndrome or other lesions resulting in a single right ventricle face the highest risk of mortality among all forms of congenital heart disease. Before the modern era of surgical palliation, these conditions were universally lethal; recent refinements in surgical technique and perioperative management have translated into dramatic improvements in survival. Nonetheless, these infants remain at a high risk of morbidity and mortality, and an appreciation of single ventricle physiology is fundamental to the care of these high-risk patients. Herein, resuscitation and perioperative management of infants with hypoplastic left heart syndrome are reviewed. Basic neonatal and pediatric life support recommendations are summarized, and perioperative first-stage clinical management strategies are reviewed.

Contemporary management of pulmonary and systemic circulations after the Norwood procedure

Hypoplastic left heart syndrome remains one of the most challenging pathologies in pediatric cardiac surgery. The surgical techniques, and anesthetic and intensive care management, have evolved over the last decades, which has resulted in improved outcomes. A central component in the postoperative management of hypoplastic left heart syndrome patients is to achieve an optimal balance between the pulmonary and systemic circulations. This article discusses the contemporary postoperative management of pulmonary and systemic circulations in detail.

Prenatal diagnosis of hypoplastic left heart syndrome in current era

We sought to evaluate the relation of a prenatal diagnosis (preDx) with morbidity and mortality during the initial hospitalization in a contemporary cohort of patients with hypoplastic left heart syndrome (HLHS). A retrospective study of patients with HLHS presenting from 1999 to 2010 was performed. Patients with genetic disorders or a gestational age <34 weeks or who had intentionally received comfort care only were excluded. Of the 81 patients meeting the study criteria, 49 had a preDx and 32 were diagnosed postnatally (postDx). Birth weight (median 3.0 vs 3.4 kg; p = 0.007) and gestational age (median 38 vs 39 weeks; p <0.001) were lower in the preDx than in the postDx patients. Preoperatively, the postDx patients were intubated more frequently (97% vs 71%, p = 0.004) and ventilated longer (median 96 vs 24 hours, p = 0.005) than the preDx patients. They also had more preoperative acidosis, multiorgan failure, tricuspid valve regurgitation, and right ventricular dysfunction. Of the 73 patients undergoing surgery, no difference in survival was seen between the preDx and postDx groups (91% vs 89%). The median duration of postoperative ventilation was 7 days and the median length of stay was 36 days for the 66 survivors, with no difference between the 2 groups. Postoperative morbidities, including chylothorax and infection, were also similar in the preDx and postDx patients. No studied preoperative factor was associated with death, duration of postoperative ventilation, or length of stay. In conclusion, our recent experience has shown that preDx of HLHS was not associated with a survival advantage, fewer postoperative complications, or shorter length of stay. Improved preoperative status was observed in the preDx patients; however, they were born earlier with a lower birthweight. What effect these factors might have on longer term morbidity remains unknown.

Impact of mode of delivery on markers of perinatal hemodynamics in infants with hypoplastic left heart syndrome

OBJECTIVE

To determine whether the mode of delivery of infants prenatally diagnosed with hypoplastic left heart syndrome (HLHS) affects markers of perinatal hemodynamics.

STUDY DESIGN

A retrospective review of patients diagnosed prenatally with HLHS and delivered within our institution was undertaken. Arterial blood gases, echocardiographic data, and markers of end organ function were compared based on route of delivery.

RESULTS

A total of 79 infants with HLHS were enrolled between January 2002 and December 2008. The infants delivered by elective cesarian delivery (CD) had younger gestational age compared with those delivered by vaginal delivery (VD) or by urgent CD/operative VD. Those delivered by elective CD had lower pH and higher partial pressure of CO(2) on arterial cord blood gas analysis. There were no differences in partial pressure of O(2) and base deficit among the 3 study groups. One-minute and 5-minute Apgar scores, markers of end organ function, echocardiographic parameters, length of hospitalization, and survival to discharge were similar among the groups.

CONCLUSIONS

Overall, newborns with a prenatal diagnosis of HLHS transitioned well to extrauterine life without significant acidosis regardless of the mode of delivery. Delivery of newborns with HLHS by elective CD did not demonstrate any hemodynamic advantage over VD in our cohort of patients.

Perinatal and early surgical outcome for the fetus with hypoplastic left heart syndrome: a 5-year single institutional experience

OBJECTIVES

To review our experience with the prenatal diagnosis of hypoplastic left heart syndrome (HLHS). Our goal was to establish the benchmark for perinatal and early surgical outcome in the current era, from a center with an aggressive surgical approach and a cohort with a high level of intention-to-treat.

METHODS

Outcome was assessed in fetuses with HLHS following stratification into high-risk and standard-risk categories. High risk was defined as the presence of any of the following: extracardiac, genetic or chromosomal anomalies; prematurity of < 34 weeks' gestation; additional cardiac findings such as intact or highly restrictive atrial septum, severe degree of tricuspid regurgitation or severe ventricular dysfunction. Standard risk was defined as absence of these risk factors.

RESULTS

Of 240 fetuses evaluated over 5 years, 162 (67.5%) were in the standard-risk group and 78 (32.5%) were in the high-risk group. Of the 240 sets of parents, 38 (15.8%) chose termination or non-intervention at birth at initial prenatal counseling and 185 of the neonates (77.1%) underwent first-stage Norwood surgery with 155 surviving and 30 deaths, giving an overall Norwood operative survival of 83.8%. Breakdown by risk class reveals a significant Norwood operative survival advantage for the standard-risk group (92.8%) over the high-risk group (56.5%) (P < 0.001).

CONCLUSIONS

Following prenatal diagnosis of HLHS, families should be strongly encouraged to undertake comprehensive prenatal evaluation in order to obtain an accurate prognosis. One-third have additional risk factors that limit survival outcome, however two-thirds do not and have an excellent chance of early survival.

Evolution of treatment options and outcomes for hypoplastic left heart syndrome over an 18-year period

OBJECTIVES

We aimed to describe management strategies for neonates with hypoplastic left heart syndrome over the past 18 years in the United States and to identify determinants of institutional management decisions.

METHODS

Neonates with hypoplastic left heart syndrome were retrospectively identified by use of the Nationwide Inpatient Sample 1988-2005. Treatment was categorized as (1) transplantation, (2) Norwood operation (as defined by Risk Adjustment in Congenital Heart Surgery), (3) transfer to another facility, or (4) no surgical intervention (comfort care).

RESULTS

A total of 3286 neonates were identified, yielding a national estimate of 16,781 + or - 586 cases. Of these, 2% (348 + or - 47) underwent transplantation, 16% (2767 + or - 286) had Norwood operations, 25% (4143 + or - 156) were transferred to another facility, and 57% (9523 + or - 436) had comfort care. Changes in practice patterns occurred over time, with an increasing number of neonates undergoing Norwood, concomitant with decreasing numbers undergoing transplantation (P < .001). Bias toward the Norwood operation over time paralleled a significant, nearly linear decrease in the in-hospital mortality rate for the Norwood operation, from 86% in the earliest sextile to 24% in the most recent sextile (P < .001). Prevalence of transfer to definitive care hospitals remained constant over time, as did the number of infants (approximately half) who received no surgery (comfort care).

CONCLUSIONS

Despite improved surgical outcomes, the majority of infants continue to receive no surgical care. There has been an increase in the number of infants offered the Norwood operation for hypoplastic left heart syndrome over the past 2 decades, which seems to have come mostly owing to a decrease of transplants. The advent of prenatal diagnosis has not decreased the proportion of neonates born at institutions unequipped to provide definitive care.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome is a rare congenital heart defect in which the left side of the heart is underdeveloped. Surgical management of hypoplastic left heart syndrome has changed the prognosis of the condition that was previously regarded as fatal. We discuss surgical strategies based on staged procedures, with the right ventricle supporting both systemic and pulmonary circulation. We also discuss other management options, such as neonatal transplantation and the recent innovation of hybrid techniques. Surgical techniques and the understanding of the pathophysiology of this condition have been at the forefront of neonatal cardiac surgery and intensive care. The management of the syndrome remains a challenge because affected children grow into adolescence and adulthood posing various new problems and demands.

Separation of the PROX1 gene from upstream conserved elements in a complex inversion/translocation patient with hypoplastic left heart

Hypoplastic left heart (HLH) occurs in at least 1 in 10 000 live births but may be more common in utero. Its causes are poorly understood but a number of affected cases are associated with chromosomal abnormalities. We set out to localize the breakpoints in a patient with sporadic HLH and a de novo translocation. Initial studies showed that the apparently simple 1q41;3q27.1 translocation was actually combined with a 4-Mb inversion, also de novo, of material within 1q41. We therefore localized all four breakpoints and found that no known transcription units were disrupted. However we present a case, based on functional considerations, synteny and position of highly conserved non-coding sequence elements, and the heterozygous Prox1(+/-) mouse phenotype (ventricular hypoplasia), for the involvement of dysregulation of the PROX1 gene in the aetiology of HLH in this case. Accordingly, we show that the spatial expression pattern of PROX1 in the developing human heart is consistent with a role in cardiac development. We suggest that dysregulation of PROX1 gene expression due to separation from its conserved upstream elements is likely to have caused the heart defects observed in this patient, and that PROX1 should be considered as a potential candidate gene for other cases of HLH. The relevance of another breakpoint separating the cardiac gene ESRRG from a conserved downstream element is also discussed.

Hypoplastic left heart syndrome diagnosed in fetal life: associated findings, pregnancy outcome and results of palliative surgery

OBJECTIVES

To analyze the main prenatal characteristics of hypoplastic left heart syndrome (HLHS), its association with extracardiac anomalies including increased nuchal translucency (NT) and the outcome of affected patients.

METHODS

We searched our database for classical forms of HLHS (aortic atresia, mitral and aortic atresia and critical aortic stenosis evolved to a severely hypoplastic left ventricle) prenatally diagnosed between 1998 and 2006. Data on 101 fetuses were retrieved and analyzed.

RESULTS

The main reason for referral was suspected heart defect on a routine ultrasound scan (82%). The mean gestational age at diagnosis was 21 weeks. Most cases were detected at < or = 22 weeks (72%), the upper limit for termination of pregnancy (TOP) in our country (Spain). An intact atrial septum was diagnosed in 11 of the 58 fetuses (19%) in which pulmonary vein blood flow was assessed, and this diagnosis was proved to be correct in the six liveborn babies. Most fetuses (68%) had an isolated HLHS. Fourteen fetuses (14%) were chromosomally abnormal and all had associated extracardiac defects. NT was above the 95th centile in 21 of the 74 cases (28%) in which this measurement was available. 79% (58/73) of the cases in which HLHS was detected at < or = 22 weeks were terminated, and no differences in the rate of TOP were found through the study period. Among the 43 continuing pregnancies, seven fetuses died in utero and there were 36 live births; in 12 cases the parents opted for compassionate care and 24 chose to have the infant surgically treated. In the cohort of intention-to-treat cases, the overall survival rate was 36% (9/25). This rate improved from 18% (2/11) in the period 1998-2002 to 50% (7/14) in 2003-2006. There were no survivors in cases with intact atrial septum or when there were associated defects. At follow-up, 2/9 survivors suffered from significant neurological morbidity.

CONCLUSIONS

Fetal echocardiography allows an accurate diagnosis of HLHS, which is made in most instances in the first half of pregnancy. Despite the advantage offered by the prenatal detection of HLHS, which provides the opportunity to plan perinatal management, our up-to-date results show that the outlook for these fetuses is still poor, and highlight the importance of presenting these figures when counseling parents with affected fetuses.

Impact of antenatal diagnosis of hypoplastic left heart syndrome on the clinical presentation and surgical outcomes: the Australian experience

AIM

Antenatal diagnosis of severe congenital heart disease enables planning of perinatal care of affected infants. Congenital heart surgery is highly centralised in Australia, and surgery for hypoplastic left heart syndrome (HLHS) currently takes place at a single institution, in order to ensure case volume. The study aims to review the impact of antenatal diagnosis on the early clinical course of infants with HLHS in Australia.

METHODS

Retrospective review was performed on all neonates who were admitted for management of HLHS between 2001 and 2005 at the Paediatric Cardiac Surgical Unit, The Royal Children's Hospital, Melbourne, Australia.

RESULTS

Sixty neonates with HLHS were admitted, in whom an antenatal diagnosis was present in 46 (77%). Treatment was withdrawn in seven infants, of whom three had prenatal, and 4 had post-natal diagnoses. Antenatally diagnosed infants were commenced on prostaglandin earlier than post-natally diagnosed infants (age 1 h and 55 h respectively), and on paediatric intensive care unit admission had a higher pH (7.31 vs. 7.20), a lower lactate (3.0 vs. 6.7), a lower inspired oxygen fraction (0.21 vs. 0.96) and were less likely to be ventilated (10.8% vs. 92.9%). Infants with an antenatal diagnosis had lower peak creatinine (70 vs. 120) and alanine aminotransferase (29 vs. 242). The survival to intensive care discharge and stage 2 palliation was 74% and 68% respectively, and was not influenced by timing of diagnosis.

CONCLUSIONS

Antenatal diagnosis of HLHS was strongly associated with a superior pre-operative clinical status, but did not influence early survival after surgical palliation.

Changing spectrum and outcome of 705 fetal congenital heart disease cases: 12 years, experience in a third-level center

INTRODUCTION

Congenital heart diseases are the most common prenatal and postnatal malformations. Nowadays, fetal echocardiography is a widely practiced technique; however, the impact of prenatal diagnosis on prognosis of the newborns affected by congenital heart disease remains uncertain.

OBJECTIVE

To assess the outcome and the changes in the spectrum of prenatally detected congenital heart disease in our tertiary care centre in 12 years of activity (1995-2006).

METHODS AND RESULTS

We detected 705 congenital heart diseases: 32% (223) were associated with extracardiac or chromosomal anomalies or both, and 68% (482) were isolated. Termination of pregnancy was chosen in 81% for associated anomalies and 37% for isolated anomalies (P<0.001). Of these, more than one-third occurred in hypoplasic left heart cases. The general survival rate was 72%; it was significantly lower in the group with associated heart diseases (46 vs. 80%, P<0.001). Over 12 years we noticed a reduction in the number of multimalformed fetuses and of the hypoplasic left heart cases, and a higher number of aortic arch anomalies detected. During the past 6 years of activity the survival rate obtained has significantly increased (55 to 84%, P<0.05), the termination rate has significantly decreased (35 to 14%, P<0.001) and the number of neonatal deaths has significantly decreased (39 to 10%, P<0.001).

CONCLUSION

The survival and the voluntary termination of fetuses with prenatally detected congenital heart diseases are strongly influenced by disease severity and by associated extracardiac or chromosomal anomalies, or both. Over 12 years, the spectrum of fetal congenital heart disease has changed and their outcome has significantly improved.

Decreasing number of deaths of infants with hypoplastic left heart syndrome

OBJECTIVE

To assess mortality rates and demographic characteristics for infants with hypoplastic left heart syndrome (HLHS) in California.

STUDY DESIGN

We used California death registry files from 1990 to 2004 to compare overall mortality and demographic characteristics between infants with HLHS (n = 856) who received surgical intervention and those who received comfort care. The California discharge database was used to calculate the annual incidence of disease and survival rates for infants with HLHS undergoing surgery between 1995 and 1999.

RESULTS

The annual number of deaths for infant with HLHS decreased by nearly 50% over the study period, even though the incidence of the disease remained constant during this period. For all deaths, the proportion of infants receiving comfort care decreased significantly over time compared with those infants who underwent surgery. Although the total number of deaths in infants with HLHS who underwent surgical intervention increased, the mortality rate for this cohort decreased. Interstage unexpected mortality and the median age at death both increased in the infants who underwent surgery.

CONCLUSIONS

Over the study period of 1990 to 2004 in California, fewer families chose comfort care for infants diagnosed with HLHS, and the number of deaths for those infants who underwent surgical intervention increased. These changes likely reflect improved treatment outcomes and an increased number of families desiring surgical intervention in higher-risk infants.

Outcomes of management decisions by parents for their infants with hypoplastic left heart syndrome born with and without a prenatal diagnosis

AIM

To study the influence of a prenatal diagnosis on parental choice of treatment for infants born with hypoplastic left heart syndrome (HLHS).

METHODS

Retrospective review of medical records of infants admitted to a paediatric tertiary hospital 1983-2004 with a diagnosis of HLHS.

RESULTS

A total of 201 infants had HLHS diagnosed by echocardiography after birth with 129 subsequently undergoing surgery and 72 non-surgical management (compassionate/comfort care). When the diagnosis of HLHS was made prenatally, 68 of 71 (96%) infants underwent surgery whereas when the diagnosis was made post-natally 61 of 130 (47%) infants underwent surgery. Prenatal diagnosis was significantly associated with a parental choice of surgery (P < 0.001). Among 72 infants managed non-surgically, compassionate care was chosen by parents for 49 (68%) despite being fit for surgery, 20 (28%) were deemed unfit for surgery and in three (4%) the reasons for non-surgical management were unknown. Of the total 178 infants considered fit for surgery, 68 (38%) had had a prenatal diagnosis and 110 (62%) did not. Of 20 considered unfit for surgery, none had had a prenatal diagnosis. A prenatal diagnosis was significantly associated with fitness for surgery (P < 0.001).

CONCLUSIONS

Approximately half of parents chose non-surgical management (compassionate care) of their infant if the diagnosis was post-natal. Although most parents of infants born with a prenatal diagnosis of HLHS chose surgical management of their infant, this is the likely influence of termination of pregnancy for this condition. Lack of prenatal diagnosis compromised fitness for surgery.

In vitro hemodynamic investigation of the embryonic aortic arch at late gestation

This study focuses on the dynamic flow through the fetal aortic arch driven by the concurrent action of right and left ventricles. We created a parametric pulsatile computational fluid dynamics (CFD) model of the fetal aortic junction with physiologic vessel geometries. To gain a better biophysical understanding, an in vitro experimental fetal flow loop for flow visualization was constructed for identical CFD conditions. CFD and in vitro experimental results were comparable. Swirling flow during the acceleration phase of the cardiac cycle and unidirectional flow following mid-deceleration phase were observed in pulmonary arteries (PA), head-neck vessels, and descending aorta. Right-to-left (oxygenated) blood flowed through the ductus arteriosus (DA) posterior relative to the antegrade left ventricular outflow tract (LVOT) stream and resembled jet flow. LVOT and right ventricular outflow tract flow mixing had not completed until approximately 3.5 descending aorta diameters downstream of the DA insertion into the aortic arch. Normal arch model flow patterns were then compared to flow patterns of four common congenital heart malformations that include aortic arch anomalies. Weak oscillatory reversing flow through the DA junction was observed only for the Tetralogy of Fallot configuration. PA and hypoplastic left heart syndrome configurations demonstrated complex, abnormal flow patterns in the PAs and head-neck vessels. Aortic coarctation resulted in large-scale recirculating flow in the aortic arch proximal to the DA. Intravascular flow patterns spatially correlated with abnormal vascular structures consistent with the paradigm that abnormal intravascular flow patterns associated with congenital heart disease influence vascular growth and function.

The chick embryo as a model for intrauterine ultrasound-guided heart intervention

OBJECTIVES

Prenatal minimally invasive therapy represents a challenging option for reducing long-term complications of pathological fetal heart development. Here, the potential of the chick embryo as a model for ultrasound-guided intrauterine cardiac intervention is explored.

METHODS

Chick embryos were incubated for 18 days in fenestrated eggs and their hearts were punctured in ovo under ultrasound guidance. Indian ink and Nile blue sulfate were applied to mark the injection channel. After cardiac intervention, embryos were further incubated and subsequently sacrificed for macroscopic and histological evaluation of the heart.

RESULTS

Stereomicroscopic analysis revealed that the catheter had successfully penetrated the cardiac ventricular wall in 26/38 embryos. The myocardium was not severely injured. Histological evaluation showed that the myocardium had almost reoccluded after the intervention and that the injection channel was clogged with fibrin. In one case, the embryo was not sacrificed, but was removed from the egg 24 h after the intervention, with no signs of cardiac dysfunction, and was followed up for 6 months.

CONCLUSIONS

Intrauterine ultrasound-guided heart intervention in the human fetus can be simulated in the chick embryo. Fenestrated eggs have to be used because the egg shell and shell membrane are impermeable to ultrasound.

Waiting before birth: outcomes after fetal listing for heart transplantation

Following fetal diagnosis of a profound heart defect, transplantation (HTx) is an alternative to pregnancy termination or neonatal surgical palliation. Retrospective review of the cardiac and transplant databases of fetal listings for HTx between 1990 and July 2006 was undertaken to describe outcomes after listing. We identified 26 fetal listings (of 269 total listings). Diagnoses included congenital heart disease (n = 24) and cardiomyopathy (n = 2). Seven patients were delisted after birth: in five cases parents opted for surgical palliation, two clinically improved. One patient died wait-listed (stillborn). Time wait-listed as a fetus ranged from 1-41 days (median 19 days). Eighteen patients underwent HTx (median weight 2.8 kg, range 2.1-10.9 kg); median days wait-listed after birth was 22 (4 h-123 days). Two fetuses were surgically delivered at 36 weeks gestation when a donor organ became available; 11 were transplanted as neonates (<30 days). The median age at HTx was 1 month (4 h-2.6 months). Fetal listing for HTx increases the potential window of opportunity for a donor organ to become available; patients had low wait-list mortality and a fair intermediate-term outcome. Well-defined criteria for eligibility for fetal listing and priority allocation to infants over fetuses seem rational approaches for centers that offer fetal listing.

Effect of shunt type on echocardiographic indices after initial palliations for hypoplastic left heart syndrome: Blalock-Taussig shunt versus right ventricle-pulmonary artery conduit

OBJECTIVES

The study objective was to compare echocardiographic indices in infants with hypoplastic left heart syndrome (HLHS) randomized to different surgical pathways.

BACKGROUND

Initial surgical palliation for HLHS has evolved to two strategies that vary by source of pulmonary blood flow: a modified Blalock-Taussig (BT) shunt or a right ventricle to pulmonary artery (RV-PA) conduit.

METHODS

Seventeen patients were randomized to either a BT shunt or RV-PA as their first-stage palliation, and 15 survived through bidirectional Glenn (BDG) (seven BT shunts/eight RV-PAs). Echocardiography was performed pre-stage 1 palliation (S1P), early post-S1P, pre-BDG, and post-BDG. Echocardiographic measurements included indices of right ventricle function and shape, right ventricle myocardial performance index, neoaortic Doppler flow patterns and cardiac output, Doppler inflow and tissue imaging, and conduit/neoaortic regurgitant fraction.

RESULTS

There were no significant differences in right ventricle size, shape, or estimates of systolic and diastolic function between groups. Patterns of changes in neoaortic Doppler flow in the RV-PA conduit group showed a decrease in all indices of systemic flow early after initial palliation, but these measures consistently increase later post-S1P and post-BDG. In contrast, the BT shunt group increases these same indices post-S1P and pre-BDG with a decrease after shunt removal.

CONCLUSIONS

Right ventricle size and function do not appear significantly affected by surgical type of initial palliation for HLHS, and this correlates with early outcome. Echocardiographic Doppler findings correlate well with the expected physiologies of the different shunts as these infants progress through initial palliative strategies.

Revisiting animal models of aortic stenosis in the early gestation fetus

BACKGROUND

Mechanisms leading to left ventricular hypoplasia and endocardial fibroelastosis in the fetus remain unknown. Prevailing theory is that obstruction to blood flow through the left ventricle leads to elevated end-diastolic pressures, compromised myocardial perfusion, and endocardial ischemia. Fetal interventions are now being performed, based on the presumption that they would prevent such pathogenic mechanisms.

METHODS

Forty first-trimester fetal sheep (mean gestational age, 53 days) were studied. Severe fetal left ventricular outflow obstruction was created by banding the ascending aorta in 25 fetuses; 15 control fetuses underwent "sham" surgery with thoracotomy. Serial fetal echocardiography was used to assess left ventricular growth and fetal hemodynamics. Findings were correlated to morphologic and histopathologic changes, and intracardiac pressure measurements obtained from fetal cardiac catheterization.

RESULTS

Surviving banded fetuses (n = 13) had one of two phenotypes: compensatory left ventricular hypertrophy (n = 7) or noncompensatory left ventricular dilatation (n = 6) with hydrops and severe left ventricular dysfunction. All fetuses had elevated left ventricular end-diastolic pressures (mean, 21 mm Hg; range, 14 to 28 mm Hg), which correlated to the gradient across the ascending aorta (mean, 41 mm Hg; range, 28 to 73 mm Hg). In vivo echocardiography findings were incongruous with those at autopsy, and demonstrated preservation of left ventricular growth indices in all fetuses. Endocardial fibroelastosis and myocardial fibrosis were not observed in any banded fetus.

CONCLUSIONS

While early gestational obstruction to flow can compromise left ventricular function in the fetus, it does not retard normal growth. Similarly, an elevated left ventricular end-diastolic pressure is not sufficient to cause myocardial fibrosis or endocardial fibroelastosis in the fetus.

The genetics of cardiac birth defects

Congenital heart disease likely results from a complex mixture of environmental and genetic factors. Recent work has elucidated rare single gene mutations that cause a variety of cardiac defects, but the etiologies of more common disease remains unknown. Here, we review the known genetic causes of cardiac malformations and discuss future approaches for addressing sporadic congenital heart disease as a complex trait.

Descriptive epidemiology of hemivertebrae, Hawaii, 1986-2002

The intent of this study was to report on the epidemiology of hemivertebrae. Cases were derived from a population-based birth defects registry in Hawaii and comprised all infants and fetuses with hemivertebrae delivered during 1986-2002. Hemivertebrae rates per 10 000 births were determined for selected factors and comparisons made by calculating the rate ratio (RR) and 95% confidence interval (CI). Forty-two cases of hemivertebrae were identified, for a total rate of 1.33. Forty-one of the cases were live births, of which 26.83% expired within one year after delivery. Other major structural birth defects were found in 95.24% of the cases. The most frequent associated defect was scoliosis, affecting 54.76% of the cases. The rate among females was significantly lower than among males (RR 0.48, 95% CI 0.23-0.94). The rate was lower with maternal age > or =35 years (RR 0.50, 95% CI 0.10-1.57) and higher with birth weight < 2500 g (RR 5.96, 95% CI 2.84-11.90) and gestational age < 38 weeks (RR 3.94, 95% CI 2.01-7.64). The majority of hemivertebrae cases had other major structural birth defects. Hemivertebrae occurred predominantly among males and risk was lower with increased maternal age. Rates for hemivertebrae were higher with lower birth weight and gestational age. Further population-based research involving larger study populations are recommended to confirm these observations.

The impact of fetal echocardiography on the prevalence of liveborn congenital heart disease

Fetal echocardiography allows for early detection of congenital heart disease, and pregnancy termination may be an option in cases of complex defects. In the current study, the most important factors contributing to the diagnosis and termination of affected pregnancies are reviewed and their combined effect on the future prevalence of liveborn congenital heart disease is evaluated. The relative reduction of the prevalence of the most severe forms of congenital heart disease is estimated as the product of the probability that (1) a fetal cardiac screening is performed (p (evaluation)), (2) an affected pregnancy is detected (P (detection)), (3) pregnancy termination is decided following antenatal diagnosis (P (decision)). In areas where termination of pregnancy is a realistic and supported option, a universal sonographic screening of all pregnancies (P (evaluation) = 1), with an average reported sensitivity of 35% and a termination rate of 43% following antenatal diagnosis, would result in a 15% overall reduction of the prevalence of the most severe forms of congenital heart disease. However, wide variability exists regarding the defect-specific estimates (2-50% prevalence relative reduction) due to considerable differences in the reported diagnostic sensitivity and termination rates associated with each heart defect. If an earlier diagnosis could be achieved, which is reported to be associated with an average 1.4-fold increased probability of termination, the overall reduction of the prevalence of congenital heart disease could approach 21%. As the skills of obstetric and pediatric cardiology sonographers improve, fetal echocardiography is expected to have a substantial impact on the future epidemiology of liveborn congenital heart disease.

Progression of fetal heart disease and rationale for fetal intracardiac interventions

The outcome of cardiac disease diagnosed before birth is paradoxically worse than that diagnosed postnatally. In part, this is because fetal screening detects cases that are already showing failure of cardiac growth which are usually progressive with secondary damage to the myocardium, lungs and brain. Fetal valvuloplasty has been proposed for cases of critical aortic and pulmonary stenosis or atresia, and atrial septostomy for a restrictive oval foramen associated with aortic stenosis, hypoplastic left heart syndrome and transposition of the great arteries. The rationale for fetal therapy is to restore forward flow and reduce intraventricular pressure, thus improving coronary perfusion and minimizing ischaemic damage. Successful valvuloplasty has reduced systemic venous pressures and reversed fetal hydrops, thus prolonging pregnancy. It has resulted in improved ventricular growth in some cases and spontaneous opening of a closed oval foramen with normalization of pulmonary venous waveforms. These signs suggest better fetal cardiopulmonary development and improved surgical outcomes.

Pregnancy outcome of fetuses with a diagnosis of hypoplastic left ventricle on prenatal sonography

OBJECTIVE

The goal of our study was to assess the pregnancy outcome of fetuses with a diagnosis of hypoplastic left heart syndrome (HLHS) on prenatal sonography to determine the frequency of intrauterine fetal demise (IUFD) and any factors associated with IUFD.

METHODS

We reviewed all cases with the diagnosis of HLHS on prenatal sonography at our institution from 1992 through 2003. Data collected included gestational age at diagnosis, sonographic findings, karyotype testing, and pregnancy outcome.

RESULTS

Our study included 176 fetuses with HLHS. One hundred thirty-four fetuses were liveborn; 32 pregnancies were terminated; 3 IUFDs occurred; and outcome was unknown in 7. Of the 134 liveborn fetuses, 2 had abnormal karyotypes and 30 had other anomalies. Two of the 3 fetuses with IUFD had abnormal karyotypes, 1 with trisomy 13 and 1 with trisomy 18, and both had other anomalies on sonography. The third fetus with IUFD had no other anomalies but was 1 of triplets, and the karyotype was unknown.

CONCLUSIONS

Fetuses with HLHS diagnosed prenatally who have normal chromosomes are unlikely to die in utero.

Preliminary Investigations into a New Method of Functional Assessment of the Fetal Heart Using a Novel Application of ‘Real-Time’ Cardiac Magnetic Resonance Imaging

OBJECTIVES

Because of quantitative echocardiographic limitations of fetal ventricular volumes as well as poor windows, we sought to determine if real-time magnetic resonance imaging (MRI) could be used.

METHODS

Real-time, functional, true fast imaging with steady-state precession, cardiac MRI was performed on 2 fetuses (one with hypoplastic left heart syndrome and one with ductal constriction). Fetal echocardiography was performed and cardiac index by Doppler was used to validate volume measures by MRI.

RESULTS

This technique was able to visualize the beating heart and assess ventricular volumes. Cardiac index and assessment of right ventricular hypertrophy and dilation by echocardiography were consistent with the ventricular volumes and right ventricular hypertrophy obtained by cardiac MRI.

CONCLUSION

Real-time, functional fetal cardiac MRI is possible and can be used to quantitatively assess ventricular volumes and cardiac index in utero.

The influence of prenatal diagnosis on postnatal outcome in patients with structural congenital heart disease

Examination of the fetal heart has become an established part of mid-trimester anomaly scanning. Along side this has emerged the ability to diagnose congenital heart disease in the fetus with accuracy. Despite this, the development of screening programmes to look for fetal cardiac disease has only been partially successful. Furthermore, when detected, there seems to be little survival advantage associated with prenatal diagnosis. Demonstrating such an advantage is complicated by the nature of fetal cardiac disease, which tends to be severe and is often associated with extra-cardiac abnormalities. More selective studies, mostly involving small numbers of cases, are now beginning to demonstrate both improved survival and reduced morbidity in prenatally diagnosed infants presenting to cardiac intensive care units compared to those with a postnatal diagnosis.

Excess birth prevalence of Hypoplastic Left Heart syndrome in eastern Wisconsin for birth cohorts 1997-1999

BACKGROUND

Hypoplastic Left Heart syndrome (HLHS) is a group of cardiac malformations involving underdevelopment of the left heart with an inability to maintain systemic circulation. Because of a clinical impression of excess HLHS prevalence, we completed a medical record review of cases born from 1997 through 1999 who were Wisconsin residents and seen at the Children's Hospital of Wisconsin (CHW).

METHODS

Cases were identified either in the CHW medical records database or the Division of Pediatric Cardiology database and confirmed by echocardiogram, catheterization, surgery, or autopsy. U.S. and international surveillance systems were used to estimate population risk. Rates per 10,000 births were computed for eastern Wisconsin and four regions within this portion of the state, and compared to the estimated population risk. The same methods were used to evaluate whether rates for tetralogy of Fallot and transposition of the great arteries were elevated.

RESULTS

A total of 61 cases were ascertained yielding a birth prevalence of 3.7 per 10,000 births, which was greater than the estimated population risk of 2.79. The rate for the southeast region also exceeded the expected rate. The most urban and industrialized areas had the highest rates. Rates for the other two diagnoses evaluated were not different from estimated population risks.

CONCLUSIONS

Eastern Wisconsin, particularly the urban southeast region, had elevated rates of HLHS. Because of the geographic clustering of high rates, environmental factors may be associated with this finding.

Postmortem findings and clinicopathological correlation in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a severe life-threatening disease, with an incidence of 3 per 10,000 births, that can occur as an isolated defect or in combination with other congenital anomalies. We reviewed the clinical and autopsy reports of 39 subjects with CDH that were autopsied between 1988 and 2001 to determine whether autopsy had an additional value in the detection of malformations in patients with CDH. We compared the clinical data (including echographic results in some patients) concerning congenital anomalies with the autopsy results. Before autopsy, 6 structural cardiac defects, 3 anomalies of the urogenital system, and 3 anomalies of the digestive tract were observed in 10 patients (clinical and echographic results). However, with postmortem examination, only 4 structural cardiac defects were confirmed, 2 cases showed another cardiac anomaly, and 7 new cardiac defects were found. In the urogenital system, 1 anomaly was confirmed, 1 was not confirmed, and 1 showed another malformation. In addition, in 7 patients new urogenital malformations were found after autopsy. In the digestive tract, all 3 malformations were confirmed, but we found 3 new malformations after postmortem examination. All clinically established dysmorphic features and anomalies of the skeletal system and central nervous system were confirmed by autopsy, and no additional malformations were found. We concluded that postmortem examination has an important additional role in the detection of structural cardiac defects and malformations of the urogenital system and digestive tract in children with CDH.

Antenatal diagnosis of fetal heart disease

Antenatal diagnosis of congenital heart disease is most commonly made at the routine 20-week anomaly scan. Not all abnormalities can be detected by prenatal ultrasound but detection can be improved by obtaining outlet views and by the use of colour Doppler. This article provides an overview of the uses and limitations of fetal echocardiography.

Outcome following, and impact of, prenatal identification of the candidates for the Norwood procedure

OBJECTIVES

Our study evaluates hospital survival following prenatal identification of candidates for the Norwood procedure, and the impact of prenatal diagnosis on survival, preoperative stability, and postoperative morbidity.

METHODS

We reviewed records of all patients who were identified prenatally as candidates for the Norwood procedure, and compared them to all postnatally diagnosed patients who underwent the Norwood procedure between August 1995 and May 2002.

RESULTS

Of the 98 patients studied, 45 (46%) were diagnosed prenatally. Of these, 35 underwent the Norwood procedure, 29 (83%) of who survived. Thus, 29 of 45 (64%) patients survived from prenatal diagnosis to discharge following the Norwood procedure. Of the 53 postnatally diagnosed patients who underwent the Norwood procedure, 42 (79%) survived. Prenatal diagnosis was not associated with improvement in survival, preoperative stability, or postoperative morbidity. By multivariate analysis, ascending aortic diameter equal to or greater than 2 mm (p = 0.01), and gestational age 36 weeks or greater (p = 0.01) independently predicted survival. Based on this, patients were stratified into groups at low risk, consisting of 69 patients, and at high risk, consisting of 19 patients. Prenatal diagnosis was unassociated with improved survival in either group. Results were unchanged when the analysis was restricted to patients with hypoplasia of the left heart.

CONCLUSION

From the time of prenatal diagnosis, 64% of patients survived to discharge following the Norwood procedure. Prenatal diagnosis did not affect preoperative stability, survival or postoperative morbidity. This remained the case after stratifying patients by risk, or restricting analysis to patients with hypoplasia of the left heart. Ascending aortic diameter and gestational age independently predicted survival.

A European perspective on the management of hypoplastic left heart syndrome

Recently, the well-known American political commentator, Robert Kagan, reapplied an existing populist statement in describing Americans as being from Mars, and Europeans from Venus.1He said “they agree on little and understand one another less and less”. In general, it would be churlish to say that this applied to the medical fraternity, but it has great resonance with intercontinental differences in the management of hypoplastic left heart syndrome. In this review, I offer a personal view of those differences, potential explanations for them, and consider how the situation may change in coming years.

Neonatal hemodynamics in patients with hypoplastic left heart syndrome

The neonate with hypoplastic left heart syndrome presents a challenge for clinical diagnosis and management. Three diagnostic goals must be met. First, it is necessary to make an etiologic cardiac diagnosis so as to rule out any genetic abnormality. Second, the anatomic cardiac diagnosis is made by segmental echocardiographic analysis, including details of the atrial arrangement, venous return, the patency of the arterial duct, atrial anatomy, and the arrangement of the aortic arch. Finally, the physiologic cardiac diagnosis is made by Doppler evaluation. In some patients, the diagnosis of hypoplastic left heart syndrome is not synonymous with functionally univentricular physiology, and a bi-ventricular repair can be achieved.1