Outcome of staged reconstructive surgery for hypoplastic left heart syndrome following antenatal diagnosis

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.

Current state of the art in hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a complex congenital heart condition in which a neonate is born with an underdeveloped left ventricle and associated structures. Without palliative interventions, HLHS is fatal. Treatment typically includes medical management at the time of birth to maintain patency of the ductus arteriosus, followed by three palliative procedures: most commonly the Norwood procedure, bidirectional cavopulmonary shunt, and Fontan procedures. With recent advances in surgical management of HLHS patients, high survival rates are now obtained at tertiary treatment centers, though adverse neurodevelopmental outcomes remain a clinical challenge. While surgical management remains the standard of care for HLHS patients, innovative treatment strategies continue to be developing. Important for the development of new strategies for HLHS patients is an understanding of the genetic basis of this condition. Another investigational strategy being developed for HLHS patients is the injection of stem cells within the myocardium of the right ventricle. Recent innovations in tissue engineering and regenerative medicine promise to provide important tools to both understand the underlying basis of HLHS as well as provide new therapeutic strategies. In this review article, we provide an overview of HLHS, starting with a historical description and progressing through a discussion of the genetics, surgical management, post-surgical outcomes, stem cell therapy, hemodynamics and tissue engineering approaches.

Prenatal grading of fetal congenital heart disease and its influence on decision making during pregnancy and postnatal period: a prospective study

BACKGROUND

Congenital heart defects(CHDs) are an important cause of neonatal mortality and morbidity. With advances in diagnosis and treatment, many defects are now amenable to correction. There is a need for individualized approach to prenatally detected lesions to predict the likely prognosis. Assigning them into risk category helps in prenatal counseling, decision making, referrals and formulation of management plan to improve the outcome.

OBJECTIVE

To grade the fetal CHDs according to severity and study its usefulness in decision making.

METHODS

A prospective study at a tertiary care institute between 2016 and 18, including pregnant women with antenatal diagnosis of fetal CHD. Detailed fetal echocardiography was followed by classification of lesions into four risk categories using modified grading system: (A) extremely high risk; (B) high risk (C) moderate risk (D) low risk. Appropriate counseling was provided to facilitate decision making and further management. The grading was reviewed and revised again postpartum/post-mortem for correlation.

RESULTS

Of the total 137 cases, almost half (45.53%) were Category B, while Category D, C and A had 24.1%, 20.4% and 10.2% of cases respectively. The mean gestation age at diagnosis was 26.5 weeks. Termination of pregnancy was done in 21 cases, mostly in Category B (71.4%) and of the 116 continued pregnancies, there were 16 intrauterine deaths. Prenatal and postnatal findings were available in 109 cases and kappa analysis for agreement between antenatal and postnatal grading showed good agreement (0.82).

CONCLUSION

Prenatal grading of congenital heart disease is a reliable, structured and simplified tool that can be used for providing counseling and facilitate decision making.

Hypoplastic left heart syndrome [HLHS]: treatment options in present era

Hypoplastic left heart syndrome (HLHS) is the most severe form of congenital heart defect (CHD). The first successful intervention for it was undertaken by Norwood in 1983. Since then, there have been much development in the pre, intra, and postoperative treatment option in staged palliative surgical procedures. Early diagnostic management, prenatal interventions, innovative diagnostic methods, constantly modified surgical techniques, and hybridization contribute to a significant progress in treatment options. This will allow for defining an optimal strategy of improving survival and quality of life in HLHS patients. The development of intervention cardiology makes possible the stepwise treatment of the defect with one operation only. The first and third stage may be done by hybrid or interventional methods, then only the second stage of treatment needs to be done surgically. The world experience and all the available literature says that the 1st-stage procedure could be done now safely either directly or with a bridge to Norwood followed by the stage 2 with a Glen or Hemi-Fontan and followed by a Fontan down the lane surgically.

Life After Surviving Fontan Surgery: A Meta-Analysis of the Incidence and Predictors of Late Death

AIM

We now know that 20-40% of patients with a single ventricle will develop heart failure after the second decade post-Fontan surgery. However, we remain unable to risk-stratify the cohort to identify patients at highest risk of late failure and death. We conducted a systematic review of all reported late outcomes for patients with a Fontan circulation to identify predictors of late death.

METHODS

We searched MEDLINE, Embase and PubMed with subject terms ("single ventricle", "Hypoplastic left heart syndrome", "congenital heart defects" or "Fontan procedure") AND ("heart failure", "post-operative complications", "death", "cause of death", "transplantation" or "follow-up studies") for relevant studies between January 1990 and December 2015. Variables identified as significant predictors of late death on multivariate analysis were collated for meta-analysis. Survival data was extrapolated from Kaplan-Meier survival curves to generate a distribution-free summary survival curve.

RESULTS

Thirty-four relevant publications were identified, with a total of 7536 patients included in the analysis. Mean follow-up duration was 114 months (range 24-269 months). There were 688 (11%) late deaths. Predominant causes of death were late Fontan failure (34%), sudden death (19%) and perioperative death (16%). Estimated mean survival at 5, 10 and 20 years post Fontan surgery were 95% (95%CI 93-96), 91% (95%CI 89-93) and 82% (95%CI 77-85). Significant predictors of late death include prolonged pleural effusions post Fontan surgery (HR1.18, 95%CI 1.09-1.29, p<0.001), protein losing enteropathy (HR2.19, 95%CI 1.69-2.84, p<0.001), increased ventricular end diastolic volume (HR1.03 per 10ml/BSA increase, 95%CI 1.02-1.05, p<0.001) and having a permanent pacemaker (HR12.63, 95%CI 6.17-25.86, p<0.001).

CONCLUSIONS

Over 80% of patients who survive Fontan surgery will be alive at 20 years. Developing late sequelae including protein losing enteropathy, ventricular dysfunction or requiring a pacemaker predict a higher risk of late death.

Screening for congenital heart disease during anatomical survey ultrasonography

Congenital heart disease (CHD) is among the most common congenital abnormalities. The prevalence of CHD ranges between 0.6% and 1.2% of live births. Despite its high prevalence, CHD is also among the most commonly missed abnormalities during prenatal ultrasound examination. A simple yet systematic approach to fetal heart examination, regular feedback, and implementation of training programs could improve detection rates and, in turn, neonatal outcome.

Assessment of right ventricular volumes in hypoplastic left heart syndrome by real-time three-dimensional echocardiography: comparison with cardiac magnetic resonance imaging

BACKGROUND

Accurate assessment of right ventricular (RV) volumes and function is important in patients with hypoplastic left heart syndrome (HLHS). We prospectively sought to determine the reproducibility of three-dimensional (3D) echocardiography and its agreement with cardiac magnetic resonance imaging (CMR) in HLHS.

METHODS AND RESULTS

Twenty-eight patients underwent CMR followed immediately by transthoracic 3D echocardiography under general anaesthesia. Semi-automated border detection software was used to determine echocardiographic RV volumes. Inter- and intra-observer variability, correlation and levels of agreement between techniques were determined. The median age was 0.37 years (0.18-9.28 years) and weight 6.24 kg (3.42-32.50 kg). Intra- and inter-observer variability was excellent for both techniques. Median (range) measurements for 3D echocardiography and CMR were; end-diastolic volume (EDV) 23.6 mL (6.5-63.2) and 30.6 mL (11.8-87.9), end-systolic volume (ESV) 12.6 mL (3.7-37.0) and 14.9 mL (5.8-33.9), stroke volume (SV) 11.2 mL (2.8-33.0) and 17.1 mL (6.0-54.1), ejection fraction (EF) 48.2% (31.2-64.9), and 56.5% (42.7-72.2). Correlation coefficients were r = 0.85, 0.84, 0.83, and 0.74, respectively (P < 0.01 for all). Volumetric data were expressed as a percentage of the echocardiographic volume to CMR volume. When compared with CMR, 3D echocardiography underestimated EDV, ESV and SV by 26.7% (SD ± 20.2), 10.6% (±28.1), and 37.5% (±20.1), respectively. The difference in volume appeared largest at low ventricular volumes. EF was 8.3% (±7.3) lower by 3D echocardiography compared with CMR.

CONCLUSION

Both 3D echocardiography and CMR volumes appear highly reproducible. Measurements obtained by 3D echocardiography are significantly lower than those obtained by CMR, with wide limits of agreement such that these two methods cannot be used interchangeably.

The Polish National Registry for Fetal Cardiac Pathology: organization, diagnoses, management, educational aspects and telemedicine endeavors

OBJECTIVE

We describe the National Registry for Fetal Cardiac Pathology, a program under the Polish Ministry of Health aimed at improving the prenatal diagnosis, care, and management of congenital heart disease (CHD).

METHODS

An online database was created to prospectively record diagnosis, prenatal care, delivery, follow-up, and still images and video for fetuses with CHD. A certification program in fetal cardiac ultrasound was also implemented. Optimal screening and referral centers were identified by number of fetuses entered in the Registry yearly by each center.

RESULTS

From 2004 to 2009, 2910 fetuses with CHD were registered (2473 structural, 437 functional anomalies). The most common reasons for referral for fetal echocardiography were abnormal four-chamber view (56.0%) and extra-cardiac anomalies (8.2% ), while the most common diagnoses were atrioventricular septal defects (10.2%) and hypoplastic left heart syndrome (9.7%). Prenatal diagnosis increased yearly, from 10.0% of neonatal diagnoses in 2003 to 38.0% in 2008.

CONCLUSION

From inception of the registry up to 2009 there has been a fourfold increase in the number of neonates referred for cardiac surgery in whom the condition was prenatally diagnosed. Equally important achievements include the establishment of a certification program for fetal echocardiography and the organization of prenatal and neonatal management.

Hypoplastic left heart syndrome, cor triatriatum and partial anomalous pulmonary venous connection: Imaging of a very rare association

A newborn is presented with an association of hypoplastic left heart syndrome, cor triatriatum and partial anomalous pulmonary venous connection. The diagnosis was established with echocardiography and further confirmed with computed tomography. To our knowledge the images of such an association have never been reported before.

The process of family management when a baby is diagnosed with a lethal congenital condition

The Family Management Style Framework (FMSF) was used as a conceptual basis for secondary data analysis of 55 previously conducted interviews with mothers and fathers of children with a lethal congenital condition from two surgical treatment eras. The directed content analysis was guided by a coding structure developed from family management dimensions identified in prior research of family response to childhood chronic conditions. Results indicated that application of the FMSF was helpful in differentiating families and their processes of family management at the onset of their infant's illness through to surviving the first surgery and going home. The dimensions of Illness View and Child Identity were central to the parents' capacity to manage their baby's illness demands within their family context. Applying a robust family framework to a complex neonatal condition at illness onset provides compelling direction for clinical interventions and their rigorous evaluation.

Staged single-ventricle palliation in 2011: outcomes and expectations

Outcomes for staged palliation for single-ventricle heart disease have improved over the past two decades. As outcomes improve, parental expectations for survival and quality of life have risen accordingly. Nevertheless, the number of interventions and complications these patients must endure remain high. The final surgical destination of the single-ventricle patient, the total cavopulmonary connection (or Fontan operation) successfully separates systemic venous and pulmonary venous blood flow but does so at great cost. Fontan patients remain at significant risk of complications despite what are perceived to be "favorable" hemodynamics. The outcomes in this population are discussed in this review, with particular attention to the history behind our current strategies as well as to recent salient studies.

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.

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.

Risk factors for interstage death after stage 1 reconstruction of hypoplastic left heart syndrome and variants

OBJECTIVE

The risk of death during the interstage period remains high after stage 1 reconstruction for single ventricle lesions, despite improved surgical results. The purpose of this study is to identify risk factors for interstage death and to describe the events leading to interstage death.

METHODS

A nested case-control study was conducted of 368 patients who underwent stage 1 reconstruction at a single center between January 1998 and April 2005.

RESULTS

Among the 313 (85%) hospital survivors, there were 33 (10.5%) interstage deaths. Cases more frequently presented with intact or restrictive atrial septum (9 [27%] vs 4 [4%]; P < .001), were older at the time of surgery (5 [2-40] vs 3 [1-42] days; P = .005), had more postoperative arrhythmias (12 [36%] vs 15 [15%]; P = .01), and a higher incidence of airway or respiratory complications (12 [36%] vs 19 [19%]; P = .04). By multivariate analysis, only intact atrial septum (odds ratio 7.6; 95% confidence intervals 1.9-29.6; P = .003) and age at operation greater than 7 days (odds ratio 3.8; 95% confidence intervals 1.3-11.2; P = .017) were predictors of interstage death.

CONCLUSIONS

The presence of intact atrial septum and older age at the time of surgery are associated with a higher risk of interstage death. In addition, postoperative arrhythmia and airway complications are associated with a higher risk of interstage death in univariate analysis. The results of this study provide a focus for interstage monitoring and risk stratification of these high-risk infants, which may improve overall survival.

Fetal surgery

Fetal surgery has emerged from the realm of medical curiosity into an exciting, multidisciplinary specialty now capable of improving patient outcomes for a wide variety of diseases. Recent advances allow prenatal providers to both accurately diagnose and treat many fetal anomalies while maintaining maternal safety. As the initial postnatal health care providers to the majority of these newborns, neonatologists need to be familiar with some of the more recent state-of-the-art procedures currently being used. In this review, the authors discuss the prenatal evaluation process and various operative approaches (ie, open hysterotomy, fetoscopy, and percutaneous) to conduct fetal surgery. They then analyze the effectiveness of some of the more established and experimental prenatal therapies that are being performed for a number of fetal anomalies, including twin-twin transfusion syndrome, thoracic malformations, airway obstruction, congenital diaphragmatic hernia, myelomeningocele, and aortic valve stenosis.

Outcomes of surgical treatment of infants with hypoplastic left heart syndrome: an institutional experience 1983-2004

AIM

To determine outcomes of surgical treatment of infants with hypoplastic left heart syndrome (HLHS).

METHODS

Retrospective analysis of medical records of infants with HLHS.

RESULTS

129 of 206 (63%) infants with HLHS were managed surgically over the period 1983-2004. Survival from all stages of surgical repair was 52 (40%) patients with significantly different (P < 0.001) survival according to surgical techniques and post-operative intensive care management recognisable in three eras. During 1983-1995 a classical Norwood stage 1 operation with a systemic-pulmonary shunt was performed for 61 infants with 13 (21%) survivors. From 1996 to 2002, pulmonary vasoconstriction and systemic vasodilatation after stage 1 operation were used to optimise systemic blood flow yielding a survival of 22 of 46 (48%) infants. From 2002 to 2004 a ventricular-pulmonary conduit was used with survival of 17 of 22 (77%) infants. Survival at 1, 6, 12 months and at 5, 10 and 15 years was 65%, 53%, 48%, 38%, 38% and 25%, respectively. The mean +/- SD number of surgical procedures was 4.5 +/- 3.7; duration of hospitalisation 53 +/- 52 days (median 38); number of hospital admissions 3.0 +/- 3.5; duration in intensive care 18 +/- 20 days (median 11); hours of mechanical ventilation 278 +/- 398 (median 151).

CONCLUSION

Short-term survival of HLHS has improved substantially over recent years with a ventricular-pulmonary conduit while long-term survival has been mediocre after arterial systemic-pulmonary shunts. Irrespective of type of primary surgery, infants undergo many operations and spend long periods in hospital and intensive care.

Formation of thrombus in a native aortic sinus of Valsalva after palliation of hypoplastic left heart syndrome

An eight-month-old girl with hypoplastic left heart syndrome, who underwent a modified Norwood operation at the age of two days, and a Hemifontan operation at five months of age, had severely impaired ventricular function and new electrocardiographic changes. Coronary angiography demonstrated a small adherent thrombus in the non-coronary sinus of Valsalva of the native aortic root, which may be the cause of unexplained ventricular dysfunction.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome(HLHS) refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch). Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision relative to treatment, and long-term prognosis as information on long-term survival and quality of life for those born with the syndrome is limited.

Prenatal diagnosis of congenital heart defects - a population based study

AIM

The aim of this study was to describe the efficiency of routine prenatal ultrasound screening for the detection of cardiac defects in a Swedish region and to study the effect of prenatal diagnosis on the survival and outcome of the child.

METHODS

We identified all fetuses and infants with a diagnosed major cardiac defect born in 1999-2003 in a region of Sweden using a register of the regional paediatric cardiac clinic, various health-care registers and registers of prenatally detected malformations. The outcome of newborns with and without a prenatal diagnosis of a cardiac defect was compared.

RESULTS

During the study period, 77,241 infants were born in the area. Among 145 major cardiac defects, 21% were detected prenatally. For the two university departments the detection rate was 38%. Of the major cardiac defects diagnosed <23 gestational weeks, 30% were terminated. No significant difference in the outcome was found between children with and without a prenatal diagnosis of a major cardiac defect.

CONCLUSIONS

It could not be shown that survival and outcome for children with major cardiac defects was better when the defect was known prenatally than if it was detected postnatally. The size of the study prohibits conclusions on moderate differences.

Outcomes after the stage I reconstruction comparing the right ventricular to pulmonary artery conduit with the modified Blalock Taussig shunt

BACKGROUND

Recent reports advocate that a right ventricular to pulmonary artery (RV-PA) conduit improves outcome after the stage I reconstruction.

METHODS

We retrospectively compared the outcomes of all neonates who underwent a stage I reconstruction between January 1, 2002, and October 1, 2004, with use of the RV-PA conduit and modified Blalock-Taussig shunt (mBTS) interspersed over this time period.

RESULTS

In all, 149 infants underwent a stage I reconstruction (95 mBTS, 54 RV-PA) for hypoplastic left heart syndrome (HLHS) or variants. There was a preference for the RV-PA conduit in patients with aortic atresia (mBTS 30% versus RV-PA 67%, p < 0.01). There was no difference in surgical mortality (mBTS 14% versus RV-PA 17%, p = 0.67), time to extubation (mBTS 4.5 +/- 4.8 days versus RV-PA 3.9 +/- 3.5 days, p = 0.47), or length of hospital stay (mBTS 25 +/- 29 days versus RV-PA 21 +/- 23 days, p = 0.52). There was an increased incidence of shunt reinterventions in the patients with the RV-PA conduit (mBTS 17% versus RV-PA 32%, p = 0.04). Patients with RV-PA conduit returned earlier for stage II reconstruction (mBTS 6.5 +/- 2.5 months versus RV-PA 5.6 +/- 1.7 months, p = 0.05). There was no difference in overall mortality (mBTS 32% versus RV-PA 30%, p = 0.45) with a median duration of follow-up of 18 +/- 8 months.

CONCLUSIONS

Comparing shunt strategies (mBTS versus RV-PA) over the same time period, we found no difference in outcome. These data support the need for a larger prospective, randomized trial.

Factors affecting technical success of fetal aortic valve dilation

OBJECTIVE

We have reported previously that valve dilation enhances growth of cardiac structures and may prevent hypoplastic left heart syndrome (HLHS) in fetuses with critical aortic stenosis. We aimed to investigate maternal/fetal factors which may affect the technical success of fetal valvuloplasty, and to describe perinatal complications of the procedure.

METHODS

This was a descriptive series of 22 fetuses diagnosed with critical aortic stenosis developing into HLHS which underwent intervention by valvuloplasty. Initially this was attempted using a percutaneous approach; reassessment after our first five attempts, only one of which was successful, led to the introduction of the option of laparotomy. Technical success was defined as balloon inflation across the aortic annulus and a broader jet through the aortic valve as assessed by Doppler. Data collected included body mass index, demographic variables, ultrasound findings and postprocedure interventions.

RESULTS

Technical success increased significantly if maternal laparotomy was an option (83.3% vs. 20.0%, P = 0.017). Laparotomy was performed in 66.6% (12/18) of cases. There was a learning curve that showed an increase in success rate and decrease in need for laparotomy over the 3-year study period. Neither the need for laparotomy nor the chances of technical success were predictable by gestational age, body mass index or placental location. Tocolysis was limited to perioperative prophylaxis; one woman experienced wound infection and fluid overload. Postoperatively, three fetuses died and two delivered prematurely, 2 and 7 weeks after intervention.

CONCLUSION

Fetal aortic valvuloplasty can be performed with technical success, with low fetal loss rate and few maternal complications. While the need for laparotomy cannot be predicted, having it available as an option improves the technical success rate.

Extracorporeal membrane oxygenation after stage I reconstruction for hypoplastic left heart syndrome

OBJECTIVE

Although extracorporeal membrane oxygenation (ECMO) is an acceptable strategy for children with refractory cardiac dysfunction after cardiac surgery, its role after stage I reconstruction for hypoplastic left heart syndrome and its variants is controversial. Our objective is to describe the outcome of "nonelective" ECMO after stage I reconstruction.

DESIGN

Retrospective case series.

SETTING

Pediatric cardiac intensive care unit.

PATIENTS

Infants placed on ECMO after stage I reconstruction from January 1998 to May 2005.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 382 infants who underwent stage I reconstruction during the study period, 36 (9.4%) required ECMO in the postoperative period. There were 22 infants with hypoplastic left heart syndrome. Indications for ECMO included inability to separate from cardiopulmonary bypass in 14 and cardiac arrest in 22. Fourteen infants (38.8%) survived to hospital discharge. Nonsurvivors had longer cardiopulmonary bypass time (150.1 +/- 70.0 mins vs. 103.9 +/- 30.0 mins, p =. 01). 9/14 infants (64%) supported with ECMO> than 24 hrs after stage I reconstruction survived while only 5/22 infants (22%) requiring ECMO< 24 hrs of stage I reconstruction survived (p =. 02). Of note, all five infants diagnosed with an acute shunt thrombosis were early survivors. Mean duration of ECMO was 50.1 +/- 12.5 hrs for survivors and 125.2 +/- 25.0 for nonsurvivors (p =. 01). 7/14 early survivors are alive at a median follow-up of 20 months (2-78 months).

CONCLUSIONS

In our experience, ECMO after stage I reconstruction can be life saving in about a third of infants with otherwise fatal conditions. It is particularly useful in potentially reversible conditions such as acute shunt thrombosis and transient depression of ventricular function.

Delayed diagnosis of congenital heart disease worsens preoperative condition and outcome of surgery in neonates

OBJECTIVES

To assess whether the route by which neonatal congenital heart disease (CHD) is first recognised influences outcome after surgery.

METHODS

Surgical neonates admitted to a tertiary cardiac unit between March 1999 and February 2002 were retrospectively reviewed with analysis of risk factors for outcome. Three routes to initial recognition of CHD were compared: antenatal diagnosis, detection on the postnatal ward, and presentation after discharge to home. Outcome measures were mortality and duration of perioperative ventilation.

RESULTS

286 neonates had cardiac surgery with a median duration of ventilation of 101 h and in-hospital mortality of 12%. Recognition of CHD was antenatal in 20%, on the postnatal ward in 55% and after discharge to home in 25%. Multiple regression analyses, including the cardiac diagnosis, associated problems and other risk factors, indicated that severe cardiovascular compromise on admission to the cardiac unit was significantly related to mortality and prolonged ventilation. Considered in isolation, the route to recognition of heart disease did not influence mortality or ventilation time. Route to initial recognition did, however, influence the patient's condition on admission to the cardiac unit. Cardiovascular compromise and end organ dysfunction were least likely when recognition was antenatal and most common when presentation followed discharge to home.

CONCLUSION

The setting in which neonatal CHD is first recognised has an impact on preoperative condition, which in turn influences postoperative progress and survival after surgery. Optimal screening procedures and access to specialist care will improve outcome for neonates undergoing cardiac surgery.

Hypoplastic left heart syndrome: knowledge discovery with a data mining approach

Hypoplastic left heart syndrome (HLHS) affects infants and is uniformly fatal without surgical palliation. Post-surgery mortality rates are highly variable and dependent on postoperative management. A data acquisition system was developed for collection of 73 physiologic, laboratory, and nurse-assessed parameters. The acquisition system was designed for the collection on numerous patients. Data records were created at 30s intervals. An expert-validated wellness score was computed for each data record. To efficiently analyze the data, a new metric for assessment of data utility, the combined classification quality measure, was developed. This measure assesses the impact of a feature on classification accuracy without performing computationally expensive cross-validation. The proposed measure can be also used to derive new features that enhance classification accuracy. The knowledge discovery approach allows for instantaneous prediction of interventions for the patient in an intensive care unit. The discovered knowledge can improve care of complex to manage infants by the development of an intelligent bedside advisory system.

A risk assessment scoring system predicts survival following the Norwood procedure

No one set of characteristics has been consistently predictive of perioperative mortality and morbidity associated with the Norwood procedure. The purpose of the current study is to further validate a scoring system shown to be predictive of mortality following the Norwood procedure. We performed a retrospective review of all infants with the diagnosis of hypoplastic left heart syndrome (HLHS) who underwent the Norwood procedure at St. Louis Children's Hospital from July 1, 1994, to December 31, 2002. A weighted score for each of six factors comprised the scoring system. The factors included ventricular function, tricuspid regurgitation, ascending aortic diameter, atrial septal defect blood flow characteristics, blood type, and age. A score of > or = 7 points indicated lower reconstructive mortality risk, and a total score of < 7 points indicated a higher mortality risk. A total of 57 patients were analyzed. Twenty-five infants (44%) had a low risk score. These infants had a significantly greater survival at 48 hours compared to infants with a score of < 7 (92 vs 75%, p < 0.05). Infants with a high risk score had a significantly greater relative risk of mortality at 48 hours [OR = 2.04; confidence interval (CI) 1.04-4.00; p = 0.036]. The area under the receiver operating characteristic (ROC) curve is 0.8534 (95% CI, 0.78-0.922). This suggests that the scoring system has a very good degree of discriminatory power in selecting children who did not survive. Based on the results of the ROC, a cutoff score of >7 gives the best sensitivity and specificity for survival. When applied retrospectively, the survival outcomes predicted by our scoring system significantly correlated with actual outcomes. This supports the conclusion that a specific population of HLHS patients may have a higher mortality risk independent of surgical technique and postoperative care based on factors that can be assessed preoperatively.

Informed consent and hypoplastic left heart syndrome

We present an ethical analysis from the perspective of shared decision-making and informed consent of a change in clinical management of infants born with hypoplastic left heart syndrome (HLHS). We reported a change in treatment of HLHS at the University of Alberta away from comfort care to life-saving surgery (LST) between 1987 and 1998. In a second review (1996-2001), 49/62 infants received LST, with 81% survival from the NICU and 58% at 35 mo. Eleven infants died preoperatively of non-cardiac conditions and two received elective comfort care. Sixteen infants had 18-mo Bayley Mental Development Index, mean score 84+/-19, but five scored <70. Although we continue to present the comfort care option to parents, since 2001 LST use for HLHS at our center is almost universal despite serious complications.

CONCLUSION

We conclude that these findings are inconsistent with an open, shared decision-making model of informed consent and we suggest that comfort care should remain an ethically valid choice until the rate of serious long-term complications of LST decreases.

Improved Interstage Mortality With the Modified Norwood Procedure: A Meta-Analysis

BACKGROUND

Modification of the Norwood procedure has been reported to improve immediate postoperative mortality compared with the classic Norwood. Interstage mortality has not been shown to be improved with the modified Norwood probably because of the small number of patients from each institution. The goal of this study was to determine if meta-analysis would provide sufficient data to prove statistical difference in interstage mortality for the modified Norwood procedure.

METHODS

PubMed was searched using six different terms individually for articles from January 2003 to October 2004. Manuscripts that compared the classic to modified Norwood were reviewed. Mantel-Haenszel analysis was used to evaluate the relationship between treatment method and mortality stratified across hospitals. The Breslow-Day procedure tested homogeneity of odds ratio across hospitals. Separate analyses were performed for inpatient and interstage periods.

RESULTS

A total of 4,545 citations was screened. Five manuscripts met the criteria. Seventy-two patients undergoing classic Norwood and 84 patients undergoing modified Norwood survived to initial hospital discharge. The Breslow-Day statistic supported homogeneity of odds ratios for survival across hospitals (chi2 = 2.09, df = 4, p = 0.72). Odds of interstage death was 11.6 times greater (2.2 to 62.1, 95% CI) for the classic Norwood compared with the modified Norwood procedure. This difference was statistically significant by the Mantel-Haenszel chi2 (11.0, p = 0.001). The Breslow-Day statistic supported homogeneity of the odds ratios across hospitals (chi2 = 3.1, df = 4, p = 0.53).

CONCLUSIONS

The modified Norwood procedure has a significantly lower interstage mortality compared with the classic Norwood procedure. A large randomized study is needed to determine whether these results remain consistent.

What's Happening in Paediatric Cardiology?

Recent decades have witnessed dramatic advances in the care of adults with heart disease. However, equally significant advances have occurred in the care of children. In this review we describe some of the advances, which have been made in the care of children with heart disease, focusing not only on technological advances, but also on developments in team-based care, which together have resulted in significant improvements in outcomes.

Clinical outcomes and secondary diagnoses for infants born with hypoplastic left heart syndrome

OBJECTIVE

To explore clinical outcomes and secondary diagnoses present at discharge for infants born with hypoplastic left heart syndrome (HLHS), from a national perspective.

METHODS

We examined hospitalizations for infants < or =30 days of age who were born with HLHS, using hospital discharge data from the 1997 Kids Inpatient Database. To explore treatment choices, clinical outcomes, and resource use, we used International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedure codes to classify discharges according to type of surgical intervention versus no surgical intervention. To investigate outcomes in more detail, we identified secondary diagnoses noted at discharge, using International Classification of Diseases, 9th Revision, Clinical Modification codes, and stratified results according to type of surgical intervention.

RESULTS

Of a total of 550 patients with HLHS, 234 underwent the Norwood procedure, 17 underwent orthotopic heart transplantation, and 106 died in the hospital with no reported surgical intervention. Although we found no demographic variables to be significantly associated with the type of treatment received, discharged patients who died without surgical intervention were significantly more likely to have received care in hospitals identified as small (odds ratio [OR]: 1.5; 95% confidence interval [CI]: 1.03-3.1) or not children's hospitals (OR: 2.02; 95% CI: 1.13-3.6). Secondary diagnoses of cardiac arrest (OR: 2.0; 95% CI: 1.1-3.4) and seizures (OR: 2.6; 95% CI: 1.2-5.5) occurred more frequently in orthotopic heart transplantation cases than in Norwood procedure cases.

CONCLUSIONS

These data from a national perspective reflect outcomes of infants with HLHS during a time when rates of initial survival after surgical intervention were considered to be improved. These findings may be useful to clinicians when they are considering and recommending initial medical and surgical strategies currently being proposed for the treatment of HLHS.

Acute myocardial infarction as a cause of death in palliated hypoplastic left heart syndrome

A 20 month old child with hypoplastic left heart syndrome died suddenly from a massive myocardial infarction 15 months after a hemi-Fontan operation. This was confirmed at postmortem examination and histological examinations. The sites of surgical reconstruction were all in good condition, there were no gross anatomical coronary abnormalities, and the coronary ostia were unobstructed. On microscopy the internal coronary arteries had notable intimal and medial thickening with narrowing of the lumen, although no thrombotic occlusion was seen. To the authors' knowledge, this is the first published report of arteriosclerosis of the coronary arteries in hypoplastic left heart syndrome. It raises the question as to whether there may be a primary histological abnormality in some children with this condition or whether some mechanism of accelerated arteriosclerosis is at work.

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.

Effect of a selection and postoperative care protocol on survival of infants with hypoplastic left heart syndrome

BACKGROUND

We report the development and implementation of a program designed to assign patients preoperatively to either transplant or Norwood procedure based on a score derived from known risk factors and to enhance postoperative care of infants undergoing the Norwood procedure.

METHODS

A weighted score for each of six variables comprised the scoring system: ventricular function, tricuspid regurgitation, ascending aortic diameter, atrial septal defect blood flow characteristics, blood type, and age. The scoring system was used to prospectively assign mortality risk and lead to recommendation of either Norwood procedure or transplantation.

RESULTS

Survival following the Norwood procedure significantly improved after the management program was implemented (88% versus 40% at 48 hours, 57% versus 10% at 30 days, and 50% versus 10% at 1 year, p < 0.0001 at each time point). The survival of the group that received a score of 7 or less (high risk) who underwent the Norwood procedure was 78% at 48 hours, 44% at 30 days, and 33% at 1 year; survival rates among patients considered lower risk (greater than 7) were 100% at 48 hours and 80% at 30 days and 1 year. Transplant outcomes remained unchanged.

CONCLUSIONS

We report improved survival following the Norwood procedure after the implementation of an institutional management approach aimed at improving the outcome of infants with hypoplastic left heart syndrome and may help neutralize historical biases toward Norwood procedure or transplantation.

Outcomes from an interprovincial program of newborn open heart surgery

OBJECTIVES

To determine 18-month neurodevelopmental outcome of survivors of complex open heart surgery at </=6 weeks of age through an interprovincial program and to explore preoperative, operative, and postoperative outcome predictors. Study design Of 85 children from this inception cohort (21% mortality), 67 18-month-old survivors received multidisciplinary assessment including the Bayley Scales of Infant Development-II. Cumulative risk for adverse outcome was determined through univariate and multivariate analyses.

RESULTS

Survival of the 85 children included 23 of 23 after arterial switch, 16 of 26 after Norwood, six of six after total anomalous pulmonary venous drainage repair, and 22 of 30 after miscellaneous repair. Outcomes were as follows: in-hospital death, 14 (16%); postdischarge death, four (5%); motor/sensory disability, three (4%); motor/mental delay (<70), 21 (25%); and intact survivors, 43 (50%). Cohort mental (84+/-17) and motor (80+/-22) scores were lower for those with chromosomal abnormalities, 67+/-16 and 61+/-17, respectively. Fifty-five percent of the outcome variance was explained by duration of preoperative ventilation, 18%; genetic anomaly, 5%; intraoperative variables, 18%; and postoperative variables, 14%.

CONCLUSIONS

Risk for adverse outcome is cumulative, with preoperative determinants contributing significantly to total variance. Potentially modifiable variables should be sought in an attempt to improve outcome.

Concordance for hypoplastic left heart syndrome in a monochorionic twin pregnancy

The risk of structural heart disease is significantly higher in twin pregnancies than in singleton pregnancies, but the concordance rate has been found to be relatively low, even in monochorionic pregnancies. This is the first report of a monochorionic twin pregnancy concordant for hypoplastic left heart syndrome (HLHS), the diagnosis having been made by fetal echocardiography at 15 weeks' gestation. The findings were confirmed at necropsy at 17 weeks' gestation, following termination of pregnancy. Both twins had mitral and aortic atresia, with severely hypoplastic aortic arches. This report adds weight to there being a genetic component to the cause of HLHS in some cases and illustrates how the findings from early fetal echocardiography with postmortem follow up can help to extend the understanding of the aetiology of this condition.