Contemporary Results and Current Strategies in the Management of Hypoplastic Left Heart Syndrome

Inpatient Resource Utilization for Hypoplastic Left Heart Syndrome from Birth Through Fontan

Completing 3-stage palliation for hypoplastic left heart syndrome requires significant resources. An analysis of recent data has not been performed. We aimed to determine total charges necessary to complete all 3 stages of single-ventricle palliation, including interstage encounters. We also aimed to determine overall resource utilization, including hospital days, interstage admissions, and interstage procedures. We performed a retrospective cohort study using data from the Pediatric Health Information System database between 2016 and 2021, including all patients who completed 3-stage palliation for hypoplastic left heart syndrome. We identified 199 patients who underwent 3-stage palliation of hypoplastic left heart syndrome between 2016 and 2021. Median total adjusted charges (interquartile range, IQR) over the course of 3-stage palliation were $1,475,800 ($1,028,900-2,191,700). Median adjusted charges (IQR) for stage 1, 2, and 3 hospitalizations were $604,300 ($419,000-891,400), $234,000 ($164,300-370,800), and $256,260 ($178,300-345,900), respectively. Median hospital length of stay (IQR) for stages 1, 2, and 3 was 36 (26,53), 9 (6,17), and 10 (7,14) days, respectively. Pulmonary artery stenosis was the most common admitting diagnosis for interstage hospitalizations (3.4% of hospitalizations). Cardiac catheterization (24.1% of procedures) and feeding tube placement (10.0% of procedures) were the most common principal procedures during interstage hospitalizations. Total inpatient charges incurred throughout 3-stage palliation of hypoplastic left heart syndrome are substantial and have risen since prior studies. Gastrointestinal comorbidities and feeding optimization contribute considerably to this resource utilization.

Attrition between the superior cavopulmonary connection and the Fontan procedure in hypoplastic left heart syndrome

OBJECTIVE

We investigated the incidence and predictors of failure to undergo the Fontan in children with hypoplastic left heart syndrome who survived superior cavopulmonary connection.

METHODS

The cohort consists of all patients with hypoplastic left heart syndrome who survived to hospital discharge after superior cavopulmonary connection between 1988 and 2017. The primary outcome was attrition, which was defined as death, nonsuitability for the Fontan, or cardiac transplantation before the Fontan. Subjects were excluded if they were awaiting the Fontan, were lost to follow-up, or underwent biventricular repair. The study period was divided into 4 eras based on changes in operative or medical management. Attrition was estimated with 95% confidence intervals, and predictors were identified using adjusted, logistic regression models.

RESULTS

Of the 856 hospital survivors after superior cavopulmonary connection, 52 died, 7 were deemed unsuitable for Fontan, and 12 underwent or were awaiting heart transplant. Overall attrition was 8.3% (71/856). Attrition rate did not change significantly across eras. A best-fitting multiple logistic regression model was used, adjusting for superior cavopulmonary connection year and other influential covariates: right ventricle to pulmonary artery shunt at Norwood (P < .01), total support time at superior cavopulmonary connection (P < .01), atrioventricular valve reconstruction at superior cavopulmonary connection (P = .02), performance of other procedures at superior cavopulmonary connection (P = .01), and length of stay after superior cavopulmonary connection (P < .01).

CONCLUSIONS

In this study spanning more than 3 decades, 8.3% of children with hypoplastic left heart syndrome failed to undergo the Fontan after superior cavopulmonary connection. This attrition rate has not decreased over 30 years. Use of a right ventricle to pulmonary artery shunt at the Norwood procedure was associated with increased attrition.

Reduced Right Ventricular Fractional Area Change, Strain, and Strain Rate before Bidirectional Cavopulmonary Anastomosis is Associated with Medium-Term Mortality for Children with Hypoplastic Left Heart Syndrome

BACKGROUND

Ventricular dysfunction is associated with increased morbidity and mortality in children with hypoplastic left heart syndrome. The aim of this study was to assess the diagnostic performance of conventional and speckle-tracking echocardiographic measures of right ventricular (RV) function before bidirectional cavopulmonary anastomosis palliation in predicting death or need for heart transplantation (HTx).

METHODS

RV fractional area change (RVFAC) and longitudinal and circumferential strain and strain rate (SR) were measured in 64 prospectively recruited patients with hypoplastic left heart syndrome from echocardiograms obtained before bidirectional cavopulmonary anastomosis surgery. The composite end point of death or HTx was examined. Receiver operating characteristic analysis was performed, and cutoff values optimizing sensitivity and specificity were derived.

RESULTS

At a median follow-up of 5.0 years (interquartile range, 2.8-6.4 years), 13 patients meeting the composite end point had lower longitudinal strain and SR, circumferential SR, and RVFAC compared with survivors (n = 51). The conventional cutoff of RVFAC < 35% was specific for death or HTx (86%) but had poor sensitivity (46%), with an area under the curve of 0.73. Speckle-tracking echocardiographic variables showed similar areas under the curve (range, 0.69-0.79), with negative predictive values >90%. Addition of speckle-tracking echocardiographic variables to RVFAC < 35% showed no added benefit. However, in a subpopulation of patients with RVFAC ≥ 35% (n = 44), those meeting the composite end point (n = 7) had lower longitudinal SR (median, -1.0 1/sec [interquartile range, -0.8 to -1.1 1/sec] vs -1.21/sec [interquartile range, -1.0 to -1.3 1/sec], P = .03). Interobserver reproducibility was superior for longitudinal strain and SR (intraclass correlation coefficient > 0.92) compared with RVFAC (intraclass correlation coefficient = 0.75).

CONCLUSIONS

Children with hypoplastic left heart syndrome with normal RVFAC and ventricular deformation before bidirectional cavopulmonary anastomosis have a low likelihood of death or HTx in the medium term. In the presence of reduced RVFAC, speckle-tracking echocardiography does not provide additional prognostic value. However, in patients with "normal" RVFAC, it may have a role in improving outcome prediction and warrants further investigation.

Norwood Procedure for Palliation of Hypoplastic Left Heart Syndrome: Right Ventricle to Pulmonary Artery Conduit vs Modified Blalock-Taussig Shunt

Patients with hypoplastic left heart syndrome undergo a series of operations to separate the pulmonary and systemic circulations. The first of at least 3 operations occurs in the newborn period, with a stage I palliation. The goal of stage I palliation is to provide pulmonary blood flow and create an unobstructed systemic outflow tract. Advances in surgical techniques and intraoperative and postoperative care have helped decrease morbidity and mortality for patients with hypoplastic left heart syndrome who have the stage I Norwood operation, but the patients continue to be at increased risk for hemodynamic collapse and adverse outcomes. This article discusses risk factors, surgical approach, postoperative nursing and medical management strategies, differences between and outcomes for the Norwood operation with the right ventricle to pulmonary artery conduit and the Norwood operation with a modified Blalock-Taussig shunt.

Physical and neurodevelopmental outcomes in children with single-ventricle circulation

OBJECTIVE

To investigate longer-term physical and neurodevelopmental outcomes of patients with hypoplastic left heart syndrome (HLHS) compared with other patients with functionally single-ventricle circulation surviving beyond the age of 10 years.

DESIGN

A retrospective, observational study from a UK tertiary centre for paediatric cardiology.

RESULTS

58 patients with HLHS and 44 non-HLHS patients with single-ventricle physiology were included. Subjective reduction in exercise tolerance was reported in 72% (95% CI 61% to 84%) of patients with HLHS and 45% (31% to 60%) non-HLHS patients. Compared with non-HLHS patients, educational concerns were reported more frequently in patients with HLHS, 41% (29% to 54%) vs 23% (10% to 35%), as was a diagnosis of a behaviour disorder (autism or attention deficit hyperactivity disorder) 12% (4% to 21%) vs 0%, and referral to other specialist services 67% (55% to 79%) vs 48% (33% to 63%).

CONCLUSIONS

Within a group of young people with complex congenital heart disease, those with HLHS are likely to have worse physical, psychological and educational outcomes.

Is routine rapid-staged bilateral pulmonary artery banding before stage 1 Norwood a viable strategy?

OBJECTIVE

We adopted a policy of rapid-staged bilateral pulmonary artery banding (bPAB) before the Norwood (NW) procedure for all patients with hypoplastic left heart syndrome. We hypothesized that this strategy might mitigate some of the traditional risk factors and that postponing a major bypass procedure beyond the newborn period could have both short- and long-term benefits. The purpose of the present study was to evaluate the efficacy of this strategy with respect to the short-term outcomes.

METHODS

From 2008 to 2010, 14 patients underwent bPAB and maintenance of ductal patency with prostaglandin E1 infusion before stage 1 NW. For reference, we also reviewed the data from patients who had undergone the primary NW procedure in the 2 years immediately before the study period.

RESULTS

The bPAB was performed at a median age of 6 days (range, 2-39), gestational age of 38.5 weeks (range, 36-41), and weight of 2.75 kg (range, 2.3-3.6). The subsequent NW was performed at a gestational age of 43.5 weeks (range, 41-51) and weight of 3.2 kg (range, 2.2-4.9). When the NW procedure was eventually performed on the pBAB group, the maximum blood lactate levels within the first 24 hours after the NW were lower than those in the earlier primary NW group (2.8±0.9 vs 10.1±6.5 mmol/dL, P=.0002) and the urine output in the first 24 hours after the NW was greater in the pPAB group (4.1±2.1 vs 2.2±1.5 mL/kg/h; P=.0051).

CONCLUSIONS

These data suggest that rapid-staged bPAB before NW can reduce the challenge of postoperative management in the early postoperative period after the NW procedure and have potential to improve the outcomes.

Current outcomes of hypoplastic left heart syndrome with restrictive atrial septum: a single-center experience

Advances in the management of hypoplastic left heart syndrome (HLHS) have resulted in improved survival. However, short and long-term mortality in patients with a restrictive atrial septum remains high. All neonates diagnosed with HLHS from 2003 to 2010 at our institution were evaluated. Patients who underwent atrial septostomy within the first 72 h conformed the restrictive atrial septum group (HLHS-RS). Patients with a non-restrictive communication (HLHS-NRS) formed the control group. Outcomes and survival status were determined from review of medical records. Of the 141 newborns diagnosed with HLHS, 20 (14 %) required intervention for a restrictive atrial septum. Procedural success was achieved in 17/20 (85 %) patients. Complications occurred in ten procedures, two of which were life threatening. No procedural deaths occurred. Overall median follow up was 35.5 months (0.4-104). Initial hospitalization survival was 16/20 (80 %) for the HLHS-RS group and 114/121(94 %) for the HLHS-NRS (p = 0.028). Twenty (14 %) patients were lost to follow up and 9 (6 %) underwent heart transplant. Overall survival was 10/16 (62 %) for HLHSRS patients and 77/95 (81 %) for HLHS-NRS (p = 0.1). Survival after initial discharge was 10/12 (83 %) for the HLHS-RS group and 77/88 (87 %) for the HLHS-NRS (p = 0.67). No predictors for HLHS-RS outcome were identified. Mortality at first-stage palliation in HLHS neonates with a restrictive atrial septum remains higher than in those with an unrestrictive communication. However, survival after initial hospital discharge is similar.

Energy loss and coronary flow simulation following hybrid stage I palliation: a hypoplastic left heart computational fluid dynamic model

OBJECTIVES

The theoretical differences in energy losses as well as coronary flow with different band sizes for branch pulmonary arteries (PA) in hypoplastic left heart syndrome (HLHS) remain unknown. Our objective was to develop a computational fluid dynamic model (CFD) to determine the energy losses and pulmonary-to-systemic flow rates. This study was done for three different PA band sizes.

METHODS

Three-dimensional computer models of the hybrid procedure were constructed using the standard commercial CFD softwares Fluent and Gambit. The computer models were controlled for bilateral PA reduction to 25% (restrictive), 50% (intermediate) and 75% (loose) of the native branch pulmonary artery diameter. Velocity and pressure data were calculated throughout the heart geometry using the finite volume numerical method. Coronary flow was measured simultaneously with each model. Wall shear stress and the ratio of pulmonary-to-systemic volume flow rates were calculated. Computer simulations were compared at fixed points utilizing echocardiographic and catheter-based metric dimensions.

RESULTS

Restricting the PA band to a 25% diameter demonstrated the greatest energy loss. The 25% banding model produced an energy loss of 16.76% systolic and 24.91% diastolic vs loose banding at 7.36% systolic and 17.90% diastolic. Also, restrictive PA bands had greater coronary flow compared with loose PA bands (50.2 vs 41.9 ml/min). Shear stress ranged from 3.75 Pascals with restrictive PA banding to 2.84 Pascals with loose banding. Intermediate PA banding at 50% diameter achieved a Qp/Qs (closest to 1) at 1.46 systolic and 0.66 diastolic compared with loose or restrictive banding without excess energy loss.

CONCLUSIONS

CFD provides a unique platform to simulate pressure, shear stress as well as energy losses of the hybrid procedure. PA banding at 50% provided a balanced pulmonary and systemic circulation with adequate coronary flow but without extra energy losses incurred.

Variation in perioperative care across centers for infants undergoing the Norwood procedure

OBJECTIVES

In the Single Ventricle Reconstruction trial, infants undergoing the Norwood procedure were randomly allocated to undergo a right ventricle-to-pulmonary artery shunt or a modified Blalock-Taussig shunt. Apart from shunt type, subjects received the local standard of care. We evaluated variation in perioperative care during the Norwood hospitalization across 14 trial sites.

METHODS

Data on preoperative, operative, and postoperative variables for 546 enrolled subjects who underwent the Norwood procedure were collected prospectively on standardized case report forms, and variation across the centers was described.

RESULTS

Gestational age, birth weight, and proportion with hypoplastic left heart syndrome were similar across sites. In contrast, all recorded variables related to preoperative care varied across centers, including fetal diagnosis (range, 55%-85%), preoperative intubation (range, 29%-91%), and enteral feeding. Perioperative and operative factors were also variable across sites, including median total support time (range, 74-189 minutes) and other perfusion variables, arch reconstruction technique, intraoperative medication use, and use of modified ultrafiltration (range, 48%-100%). Additional variation across centers was seen in variables related to postoperative care, including proportion with an open sternum (range, 35%-100%), median intensive care unit stay (range, 9-44 days), type of feeding at discharge, and enrollment in a home monitoring program (range, 1%-100%; 5 sites did not have a program). Overall, in-hospital death or transplant occurred in 18% (range across sites, 7%-39%).

CONCLUSIONS

Perioperative care during the Norwood hospitalization varies across centers. Further analysis evaluating the underlying causes and relationship of this variation to outcome is needed to inform future studies and quality improvement efforts.

Acute ST changes during anesthesia induction 10 months after Norwood procedure

After the Norwood procedure for palliation of hypoplastic left heart syndrome, there is still significant interstage and late mortality with often unclear etiology. An important, but possibly under-recognized complication of the Norwood operation is the potential for coronary insufficiency from pre-coronary stenosis due to kinking or scarring at the anastomosis between the native and neo-aorta. We report a case of a clinically thriving 10-month old infant status post bidirectional Glenn who had acute ischemic changes on electrocardiogram (ECG) during induction of anesthesia for elective bilateral herniorrhaphy. A discrete narrowing in the native aorta to neo-aorta anastomosis was identified. A stent was placed emergently to restore adequate coronary blood flow after failure of simple angioplasty to adequately improve the stenosis.

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.

Inpatient costs and charges for surgical treatment of hypoplastic left heart syndrome

OBJECTIVE

Hypoplastic left heart syndrome (HLHS) is one of the most serious congenital cardiac anomalies. Typically, it is managed with a series of 3 palliative operations or cardiac transplantation. Our goal was to quantify the inpatient resource burden of HLHS across multiple academic medical centers.

METHODS

The University HealthSystem Consortium is an alliance of 101 academic medical centers and 178 affiliated hospitals that share diagnostic, procedural, and financial data on all discharges. We examined inpatient resource use by patients with HLHS who underwent a staged palliative procedure or cardiac transplantation between 1998 and 2007.

RESULTS

Among 1941 neonates, stage 1 palliation (Norwood or Sano procedure) had a median length of stay (LOS) of 25 days and charges of $214,680. Stage 2 and stage 3 palliation (Glenn and Fontan procedures, respectively) had median LOS and charges of 8 days and $82,174 and 11 days and $79,549, respectively. Primary neonatal transplantation had an LOS of 87 days and charges of $582,920, and rescue transplantation required 36 days and $411,121. The median inpatient wait time for primary and rescue transplants was 42 and 6 days, respectively. Between 1998 and 2007, the LOS for stage 1 palliation increased from 16 to 28 days and inflation-adjusted charges increased from $122,309 to $280,909, largely because of increasing survival rates (57% in 1998 and 83% in 2007).

CONCLUSIONS

Patients with HLHS demand considerable inpatient resources, whether treated with the Norwood-Glenn-Fontan procedure pathway or cardiac transplantation. Improved survival rates have led to increased hospital stays and costs.

Anesthetic management of the hybrid stage 1 procedure for hypoplastic left heart syndrome (HLHS)

INTRODUCTION

Despite advances in the surgical and perioperative management of patients with hypoplastic left heart syndrome (HLHS), outcomes for this high-risk group of patients remains suboptimal. The hybrid approach [bilateral pulmonary artery (PA) banding, ductal stenting, balloon atrial septostomy], is an emerging alternative therapy for the management of HLHS, which defers the risks of a major surgical repair until the infants are older. This article will describe our experience providing the anesthetic management of patients undergoing the hybrid procedure.

METHODS

After Institutional Review Board approval, we retrospectively reviewed the records of 77 patients who underwent the hybrid procedure as neonates between July 2002 and August 2008. We reviewed both the anesthetic and intensive care records.

RESULTS

The hybrid procedure was performed in 77 patients (31 female and 46 male). The average age of the patients was 11.8 days with an average weight of 2.98 kg. Fentanyl was used for analgesia at an average dose of 5.7 mcg x kg(-1). The average increase in the systolic blood pressure after placement of the right and left PA bands was 11.3 mmHg. The average drop in the systemic saturation after placement of the bands was 7%, with an average postband and stent SaO(2) of 82%. Twenty-one patients received blood transfusion (27.3%) at an average dose of 43.5 ml (14.5 ml x kg(-1)). Forty patients received albumin during the case (51.9%) at an average dose of 23.2 ml (7.7 ml x kg(-1)). Seventeen patients arrived at the hybrid suite already intubated, and no attempt was made to extubate these patients at the end of the case. Thirty-six patients were extubated at the end of the procedure, and a total of 64.9% of patients were extubated within the first 24 h postoperatively. Patients had notably stable hemodynamics throughout the first 24 h in the intensive care unit.

DISCUSSION

Patients undergoing the hybrid procedure have relatively stable intraoperative and early postoperative hemodynamics. The procedure is performed without cardiopulmonary bypass (CPB) and with minimal narcotic and anesthetic exposure. Patients typically do not require blood transfusions or inotropic support and are extubated at either the end of the procedure or within 24 h of ICU admission. In our experience, the anesthetic management of patients undergoing the hybrid procedure is straightforward and requires relatively few interventions when compared to traditional neonatal surgical repairs. Deferring the risks of anesthesia, CPB, hypothermic circulatory arrest, and prolonged postoperative sedation may yield developmental advantages to patients born with HLHS.

[Update on pediatric cardiology and congenital heart disease]

The fields of pediatric cardiology and congenital heart disease have experienced considerable progress in the last few years, with advances in new diagnostic and therapeutic techniques that can be applied at all stages of life from the fetus to the adult. This article reviews scientific publications in a number of areas that appeared between August 2007 and September 2008. In developed countries, congenital heart disease is becoming increasingly prevalent in nonpediatric patients, including pregnant women. Actions aimed at preventing coronary heart disease must be started early in infancy and should involve the promotion of a healthy diet and lifestyle. Recent developments in echocardiography include the introduction of three-dimensional echocardiography and of new techniques such as two-dimensional speckle tracking imaging, which can be used for both anatomical and functional investigations in patients with complex heart disease, including a univentricular heart. Progress has also occurred in fetal cardiology, with new data on prognosis and prognostic factors and developments in intrauterine interventions, though indications for these interventions have still to be established. Heart transplantation has become a routine procedure, supplemented in some cases by circulatory support devices. In catheter interventions, new devices have become available for the closure of atrial or ventricular septal defects and patent ductus arteriosus as well as for percutaneous pulmonary valve implantation. Surgery is also advancing, in some cases with hybrid techniques, particularly for the treatment of hypoplastic left heart syndrome. The article ends with a review of publications on cardiomyopathy, myocarditis and the treatment of bacterial endocarditis.

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.