Clinical course and interstage monitoring after the Norwood and hybrid procedures for hypoplastic left heart syndrome

Ability of Video Telemetry to Predict Unplanned Hospital Admissions for Single Ventricle Infants

Background

Our Cardiac High Acuity Monitoring Program (CHAMP) uses home video telemetry (HVT) as an adjunct to monitor infants with single ventricle during the interstage period. This study describes the development of an objective early warning score using HVT, for identification of infants with single ventricle at risk for clinical deterioration and unplanned hospital admissions (UHA).

Methods and Results

Six candidate scoring parameters were selected to develop a pragmatic score for routine evaluation of HVT during the interstage period. We evaluated the individual and combined ability of these parameters to predict UHA. All infants with single ventricle monitored at home by CHAMP between March 2014 and March 2018 were included. Videos obtained within 48 hours before UHA were compared with videos obtained at baseline. We used binary logistic regression models and receiver operating characteristic curves to evaluate the parameters' performance in discriminating the outcome of interest.

Thirty‐nine subjects with 64 UHA were included. We compared 64 pre‐admission videos to 64 paired baseline videos. Scoring was feasible for a mean of 91.6% (83.6%–98%) of all observations. Three different HVT score models were proposed, and a final model composed of respiratory rate, respiratory effort, color, and behavior exhibited an excellent discriminatory capability with an area under the receiver operating characteristic curve of 93% (89%–98%). HVT score of 5 was associated with specificity of 93.8% and sensitivity of 88.7% in predicting UHA.

Conclusions

We developed a feasible and reproducible HVT score that can serve as a tool to predict UHA in infants with single ventricle. Future directions involve prospective, multicenter validation of this tool.

Invasive Cardiac Procedures in Interstage Single Ventricle Patients in Emergent Hospitalizations

Single ventricle congenital heart disease (SV CHD) patients are at risk of morbidity and mortality between the first and second palliative surgical procedures (interstage). When these patients present acutely they often require invasive intervention. This study sought to compare the outcomes and costs of elective and emergent invasive cardiac procedures for interstage patients. Retrospective review of discharge data from The Vizient Clinical Data Base/Resource Manager™, a national health care analytics platform. The database was queried for admissions from 10/2014 to 12/2017 for children 1-6 months old with ICD-9 or ICD-10 codes for SV CHD who underwent invasive cardiac procedures. Demographics, length of stay (LOS), complication rate, in-hospital mortality and direct costs were compared between elective and emergent admissions using t test or χ², as appropriate. The three most frequently performed procedures were also compared. 871 admissions identified, with 141 (16%) emergent. Age of emergent admission was younger than elective (2.9 vs. 4 months p < 0.001). Emergent admissions including cardiac catheterization or superior cavo-pulmonary anastomosis had longer LOS (58.7 vs. 25.8 day, p < 0.001 and 54.8 vs .22.6 days, p < 0.001) and higher costs ($134,774 vs. $84,253, p = 0.013 and $158,679 vs. $81,899, p = 0.017). Emergent admissions for interstage SV CHD patients undergoing cardiac catheterization or superior cavo-pulmonary anastomosis are associated with longer LOS and higher direct costs, but with no differences in complications or mortality. These findings support aggressive interstage monitoring to minimize the need for emergent interventions for this fragile patient population.

New Aspects in the Diagnosis and Therapy of Fetal Hypoplastic Left Heart Syndrome

Fetal hypoplastic left heart syndrome (HLHS) is a severe congenital heart disease with a lethal prognosis without postnatal therapeutic intervention or surgery. The aim of this article is to give a brief overview of new findings in the field of prenatal diagnosis and the therapy of HLHS. As cardiac output in HLHS children depends on the right ventricle (RV), prenatal assessment of fetal RV function is of interest to predict poor functional RV status before the RV becomes the systemic ventricle. Prenatal cardiac interventions such as fetal aortic valvuloplasty and non-invasive procedures such as maternal hyperoxygenation seem to be promising treatment options but will need to be evaluated with regard to long-term outcomes. Novel approaches such as stem cell therapy or neuroprotection provide important clues about the complexity of the disease. New aspects in diagnostics and therapy of HLHS show the potential of a targeted prenatal treatment planning. This could be used to optimize parental counseling as well as pre- and postnatal management of affected children.

Early Outcomes of Hypoplastic Left Heart Syndrome Infants: Meta-Analysis of Studies Comparing the Hybrid and Norwood Procedures

The hybrid strategy is an alternative to the traditional Norwood procedure for initial palliation of infants with hypoplastic left heart syndrome (HLHS) who are deemed to be at high surgical risk. Numerous single-center studies have compared the two procedures, showing similar early outcomes, although the cohort sizes are likely insufficiently powered to detect significant differences. The current meta-analysis aims to explore the early morbidity and mortality associated with the hybrid compared to the Norwood procedure. MEDLINE, Cochrane Libraries, and Embase were systematically searched, and 14 studies were included for statistical synthesis, comprising 263 hybrid and 426 Norwood patients. Early mortality was significantly higher in the hybrid patients (relative risk [RR] = 1.54, P < .05, 95% confidence interval [CI]: 1.02-2.34), whereas interstage mortality was comparable between the two groups (RR = 0.88, P > .05, 95% CI: 0.46-1.70). Six-month (RR = 0.89, P < .05, 95% CI: 0.80-1.00) and one-year (RR = 0.88, P < .05, 95% CI: 0.78-1.00) transplant-free survival was also inferior among the hybrid patients. Furthermore, the hybrid patients required more reinterventions following initial surgical palliation (RR = 1.48, P < .05, 95% CI: 1.09-2.01), although the two groups had comparable length of hospital and intensive care unit stay postoperatively. In conclusion, our results suggest that the hybrid procedure is associated with worse early survival compared to the traditional Norwood when used for initial palliation of infants with HLHS. However, due to the hybrid being used preferentially for high-risk patients, definitive conclusions regarding the efficacy of the procedure cannot be drawn.

Interstage Home Monitoring After Newborn First-Stage Palliation for Hypoplastic Left Heart Syndrome: Family Education Strategies

Children born with hypoplastic left heart syndrome are at high risk for serious morbidity, growth failure, and mortality during the interstage period, which is the time from discharge home after first-stage hypoplastic left heart syndrome palliation until the second-stage surgical intervention. The single-ventricle circulatory physiology is complex, fragile, and potentially unstable. Multicenter initiatives have been successfully implemented to improve outcomes and optimize growth and survival during the interstage period. A crucial focus of care is the comprehensive family training in the use of home surveillance monitoring of oxygen saturation, enteral intake, weight, and the early recognition of "red flag" symptoms indicating potential cardiopulmonary or nutritional decompensation. Beginning with admission to the intensive care unit of the newborn with hypoplastic left heart syndrome, nurses provide critical care and education to prepare the family for interstage home care. This article presents detailed nursing guidelines for educating families on the home care of their medically fragile infant with single-ventricle circulation.

Psychosocial impact on families with an infant with a hypoplastic left heart syndrome during and after the interstage monitoring period - a prospective mixed-method study

AIMS AND OBJECTIVES

To investigate parents' experiences, coping ability and quality of life while monitoring their sick child with hypoplastic left heart syndrome at home.

BACKGROUND

Interstage home monitoring for children with hypoplastic left heart syndrome reduces interstage mortality between Norwood stages I and II. Little is known about the psychosocial impact of interstage home monitoring.

DESIGN

Prospective mixed-method study.

METHODS

This study assessed the psychosocial impact on parents during interstage home monitoring. This contains for quantitative assessment the Short Form Health Survey questionnaire and the Impact of Family Scale administered one and five weeks following discharge before and after stage II. For qualitative assessment, semi-structured interviews focussing on the postdischarge coping strategies were conducted twice, five weeks after hospital discharge before and after stage II.

RESULTS

Ten infants (eight males) with hypoplastic left heart syndrome (n = 7) or other types of univentricular heart malformations (n = 3), and their parents (nine mother/father two-parent households, one single mother) were included. There were no interstage deaths. Mental Health Composite Summary scores were low in both parents (mothers: 40·45 ± 9·07; fathers: 40·58 ± 9·69) and lowest for the item 'vitality' (mothers: 37·0 ± 19·46; fathers: 43·12 ± 25·9) before and after stage II. Impact of Family Scale values showed higher daily and social burdens for mothers. 'Becoming a family' was the most important task as coping strategy to equilibrate the fragile emotional balance. The parents judged interstage home monitoring as a protective intervention.

CONCLUSIONS

Although psychosocial burden before and after stage II remains high, becoming a family is an essential experience for parents and confirms their parenthood.

RELEVANCE TO CLINICAL PRACTICE

Healthcare professionals must be aware of parents' needs during this vulnerable interstage period and to provide psychosocial and nursing support.

Understanding the Hybrid Stage I Approach for Hypoplastic Left Heart Syndrome

Hybrid stage I palliation combines cardiothoracic surgery and interventional transcatheter procedures for treatment of hypoplastic left heart syndrome. The approach is an alternative to the Norwood procedure, the traditional first stage of surgical palliation. Hybrid stage I palliation involves placing bilateral branch pulmonary artery bands and a patent ductus arteriosus stent through a median sternotomy, performed without cardiopulmonary bypass. The purpose of the bands is to control blood flow to the lungs and protect the pulmonary bed while the stent sustains systemic cardiac output. A balloon atrial septostomy is performed to create an atrial septal defect for unobstructed blood flow from the left atrium to the right atrium. The second stage of palliative surgery is the comprehensive stage II, which incorporates removal of the stent and pulmonary artery bands, atrial septectomy, anastomosis of the diminutive ascending aorta to the main pulmonary artery, aortic arch augmentation, and bidirectional cavopulmonary anastomosis. The traditional Fontan procedure completes the series of palliation.

Rbfox2 function in RNA metabolism is impaired in hypoplastic left heart syndrome patient hearts

Hypoplastic left heart syndrome (HLHS) is a fatal congenital heart disease in which the left side of the heart is underdeveloped, impairing the systemic circulation. Underdeveloped left ventricle exerts biomechanical stress on the right ventricle that can progress into heart failure. Genome-wide transcriptome changes have been identified at early stages in the right ventricle (RV) of infants with HLHS, although the molecular mechanisms remain unknown. Here, we demonstrate that the RNA binding protein Rbfox2, which is mutated in HLHS patients, is a contributor to transcriptome changes in HLHS patient RVs. Our results indicate that majority of transcripts differentially expressed in HLHS patient hearts have validated Rbfox2 binding sites. We show that Rbfox2 regulates mRNA levels of targets with 3’UTR binding sites contributing to aberrant gene expression in HLHS patients. Strikingly, the Rbfox2 nonsense mutation identified in HLHS patients truncates the protein, impairs its subcellular distribution and adversely affects its function in RNA metabolism. Overall, our findings uncover a novel role for Rbfox2 in controlling transcriptome in HLHS.

The role of home monitoring in interstage management of infants following the Norwood procedure

Although outcomes for infants with complex single ventricle heart defects have steadily improved in recent decades, there is still a significant risk for mortality and morbidity during the interstage period between stage 1 Norwood hospitalization discharge and stage 2 palliation. Home monitoring programs, which involve parental surveillance of daily weight and oxygen saturations during the interstage period, have been shown to significantly improve survival rates. This article describes the potential risk factors or causes of interstage mortality and reviews the role of home monitoring in early detection and potential prevention of adverse outcomes.

Stents in paediatric and adult congenital interventional cardiac catheterization

A 'stent' is a tubular meshed endoprosthesis that has contributed to the development of interventional catheterization over the past 30 years. In congenital heart diseases, stents have offered new solutions to the treatment of congenital vessel stenosis or postsurgical lesions, to maintain or close shunt patency, and to allow transcatheter valve replacement. First, stents were made of bare metal. Then, stent frameworks evolved to achieve a better compromise between radial strength and flexibility. However, almost all stents used currently in children have not been approved for vascular lesions in children and are therefore used 'off-label'. Furthermore, the inability of stents to follow natural vessel growth still limits their use in low-weight children and infants. Recently, bioresorbable stents have been manufactured and may overcome this issue; they are made from materials that may dissolve or be absorbed in the body. In this review, we aim to describe the history of stent development, the technical characteristics of stents used currently, the clinical applications and results, and the latest technological developments and perspectives in paediatric and adult congenital cardiac catheterization.