Altered contractility, Ca2+ transients, and cell morphology seen in a patient-specific iPSC-CM model of Ebstein's anomaly with left ventricular noncompaction.

Patients with two congenital heart diseases (CHDs), Ebstein's anomaly (EA) and left ventricular noncompaction (LVNC), suffer higher morbidity than either CHD alone. The genetic etiology and pathogenesis of combined EA/LVNC remain largely unknown. We investigated a familial EA/LVNC case associated with a variant (p.R237C) in the gene encoding Kelch-like protein 26 (KLHL26) by differentiating induced pluripotent stem cells (iPSCs) generated from affected and unaffected family members into cardiomyocytes (iPSC-CMs) and assessing iPSC-CM morphology, function, gene expression, and protein abundance. Compared with unaffected iPSC-CMs, CMs containing the KLHL26 (p.R237C) variant exhibited aberrant morphology including distended endo(sarco)plasmic reticulum (ER/SR) and dysmorphic mitochondria and aberrant function that included decreased contractions per minute, altered calcium transients, and increased proliferation. Pathway enrichment analyses based on RNASeq data indicated that the "structural constituent of muscle" pathway was suppressed, whereas the "ER lumen" pathway was activated. Taken together, these findings suggest that iPSC-CMs containing this KLHL26 (p.R237C) variant develop dysregulated ER/SR, calcium signaling, contractility, and proliferation.NEW & NOTEWORTHY We demonstrate here that iPSCs derived from patients with Ebstein's anomaly and left ventricular noncompaction, when differentiated into cardiomyocytes, display significant structural and functional changes that offer insight into disease pathogenesis, including altered ER/SR and mitochondrial morphology, contractility, and calcium signaling.

Association of Potentially Damaging De Novo Gene Variants With Neurologic Outcomes in Congenital Heart Disease.

Importance: Neurodevelopmental disabilities are commonly associated with congenital heart disease (CHD), but medical and sociodemographic factors explain only one-third of the variance in outcomes. Objective: To examine whether potentially damaging de novo variants (dDNVs) in genes not previously linked to neurodevelopmental disability are associated with neurologic outcomes in CHD and, post hoc, whether some dDNVs or rare putative loss-of-function variants (pLOFs) in specific gene categories are associated with outcomes. Design, Setting, and Participants: This cross-sectional study was conducted from September 2017 to June 2020 in 8 US centers. Inclusion criteria were CHD, age 8 years or older, and available exome sequencing data. Individuals with pathogenic gene variants in known CHD- or neurodevelopment-related genes were excluded. Cases and controls were frequency-matched for CHD class, age group, and sex. Exposures: Heterozygous for (cases) or lacking (controls) dDNVs in genes not previously associated with neurodevelopmental disability. Participants were separately stratified as heterozygous or not heterozygous for dDNVs and/or pLOFs in 4 gene categories: chromatin modifying, constrained, high level of brain expression, and neurodevelopmental risk. Main Outcomes and Measures: Main outcomes were neurodevelopmental assessments of academic achievement, intelligence, fine motor skills, executive function, attention, memory, social cognition, language, adaptive functioning, and anxiety and depression, as well as 7 structural, diffusion, and functional brain magnetic resonance imaging metrics. Results: The study cohort included 221 participants in the post hoc analysis and 219 in the case-control analysis (109 cases [49.8%] and 110 controls [50.2%]). Of those 219 participants (median age, 15.0 years [IQR, 10.0-21.2 years]), 120 (54.8%) were male. Cases and controls had similar primary outcomes (reading composite, spelling, and math computation on the Wide Range Achievement Test, Fourth Edition) and secondary outcomes. dDNVs and/or pLOFs in chromatin-modifying genes were associated with lower mean (SD) verbal comprehension index scores (91.4 [20.4] vs 103.4 [17.8]; P = .01), Social Responsiveness Scale, Second Edition, scores (57.3 [17.2] vs 49.4 [11.2]; P = .03), and Wechsler Adult Intelligence Scale, Fourth Edition, working memory scores (73.8 [16.4] vs 97.2 [15.7]; P = .03), as well as higher likelihood of autism spectrum disorder (28.6% vs 5.2%; P = .01). dDNVs and/or pLOFs in constrained genes were associated with lower mean (SD) scores on the Wide Range Assessment of Memory and Learning, Second Edition (immediate story memory: 9.7 [3.7] vs 10.7 [3.0]; P = .03; immediate picture memory: 7.8 [3.1] vs 9.0 [2.9]; P = .008). Adults with dDNVs and/or pLOFs in genes with a high level of brain expression had greater Conners adult attention-deficit hyperactivity disorder rating scale scores (mean [SD], 55.5 [15.4] vs 46.6 [12.3]; P = .007). Conclusions and Relevance: The study findings suggest neurodevelopmental outcomes are not associated with dDNVs as a group but may be worse in individuals with dDNVs and/or pLOFs in some gene sets, such as chromatin-modifying genes. Future studies should confirm the importance of specific gene variants to brain function and structure.

Impact of Reintervention During Stage 1 Palliation Hospitalization: A National, Multicenter Study.

BACKGROUND: Stage 1 palliation (S1P) for hypoplastic left heart syndrome remains associated with high morbidity and mortality. Previous studies on burden of reinterventions did not include patients who remain hospitalized before stage 2 palliation (S2P). This study described the rate of reintervention during S1P hospitalization and sought to determine the impact of reintervention on outcomes. METHODS: All participants enrolled in phase II of the National Pediatric Cardiology Quality Improvement Collaborative after S1P were included in this study. The primary outcome was the rate of reintervention during hospitalization after S1P and before hospital discharge or S2P. Reintervention was defined as 1 or more unplanned interventional cardiac catheterizations or surgical reoperations. RESULTS: Between March 1, 2016 and October 1, 2019, 1367 participants underwent S1P and 339 (24.8%) had a reintervention; most commonly to address the source of pulmonary blood flow. Gestational age, weight at S1P, atrioventricular septal defect, heterotaxy, preoperative pulmonary artery bands, hybrid S1P, and an additional bypass run or early extracorporeal membrane oxygenation were significantly associated with reintervention. Participants in the reintervention group experienced higher rates of nearly all postoperative complications, were less likely to be discharged before S2P (57.1% vs 86%; P < .001), and more likely to experience in-hospital mortality (17% vs 5%; P < .001). CONCLUSIONS: Unplanned reintervention during hospitalization after S1P palliation occurred in 25% of participants in a large, registry-based national cohort. Participants who underwent reintervention were more likely to remain as inpatient and were less likely to survive to S2P. Reintervention was associated with a multitude of postoperative complications that affect survival and long-term outcome.

Intranasal dexmedetomidine for transthoracic echocardiography in infants with shunt-dependent single ventricle heart disease.

OBJECTIVES: We investigated the efficacy and complication profile of intranasal dexmedetomidine for transthoracic echocardiography sedation in patients with single ventricle physiology and shunt-dependent pulmonary blood flow during the high-risk interstage period. METHODS: A single-centre, retrospective review identified interstage infants who received dexmedetomidine for echocardiography sedation. Baseline and procedural vitals were reported. Significant adverse events related to sedation were defined as an escalation in care or need for any additional/increased inotropic support to maintain pre-procedural haemodynamics. Minor adverse events were defined as changes from baseline haemodynamics that resolved without intervention. To assess whether sedation was adequate, echocardiogram reports were reviewed for completeness. RESULTS: From September to December 2020, five interstage patients (age 29-69 days) were sedated with 3 mcg/kg intranasal dexmedetomidine. The median sedation onset time and duration time was 24 minutes (range 12-43 minutes) and 60 minutes (range 33-60 minutes), respectively. Sedation was deemed adequate in all patients as complete echocardiograms were accomplished without a rescue dose. When compared to baseline, three (60%) patients had a >10% reduction in heart rate, one (20%) patient had a >10% reduction in oxygen saturations, and one (20%) patient had a >30% decrease in blood pressure. Amongst all patients, no significant complications occurred and haemodynamic changes from baseline did not result in need for intervention or interruption of study. CONCLUSIONS: Intranasal dexmedetomidine may be a reasonable option for echocardiography sedation in infants with shunt-dependent single ventricle heart disease, and further investigation is warranted to ensure efficacy and safety in an outpatient setting.

The Relationship Between Placental Pathology and Neurodevelopmental Outcomes in Complex Congenital Heart Disease.

Complex congenital heart disease (CCHD) is associated with impaired neurodevelopmental outcomes. Peri- and post-operative factors are known contributors while the impact of the prenatal environment is not yet delineated. Variations in fetal circulation, seen in transposition of the great arteries (TGA) and single ventricular physiology (SVP), are associated with placenta abnormalities. These abnormalities may be associated with placental insufficiency, a risk factor for poor neurodevelopmental outcomes. We hypothesized there is a correlation between placental pathology and impaired neurodevelopmental outcomes in patients with CCHD. We performed a single center retrospective cohort study with patients with TGA and SVP from 2010 to 2017 at Children's Wisconsin. Patient variables were obtained from the medical record. Bayley Scales of Infant Development Third Edition standard scores for cognitive, motor, and language performance were collected from neurodevelopmental visits. Placenta pathology reports were reviewed with tabulation of predetermined anatomical and pathological characteristics. We identified 79 patients in our cohort and 61 (77.2%) had abnormal placentas. There was no significant difference between the two groups in any demographic or clinical variables. For cognitive and motor performance, without adjusting for the covariates, infants with placental abnormalities had significantly lower scores compared to infants without (p = 0.026, p = 0.045 respectively). Conversely, there was no significant difference in language scores between the two groups (p = 0.12). Placenta abnormalities are common in patients with CCHD, and placenta abnormalities are associated with impaired neurodevelopmental outcomes. These results underscore the complex causal pathways of neurodevelopmental impairment in infants with CCHD and offer opportunities for targeted postnatal developmental interventions after discharge.

The pediatric heart network's study on long-term outcomes of children with HLHS and the impact of Norwood Shunt type in the single ventricle reconstruction trial cohort (SVRIII): Design and adaptations.

BACKGROUND: The Single Ventricle Reconstruction (SVR) Trial was the first randomized clinical trial of a surgical approach for treatment of congenital heart disease. Infants with hypoplastic left heart syndrome (HLHS) and other single right ventricle (RV) anomalies were randomized to a modified Blalock Taussig Thomas shunt (mBTTS) or a right-ventricular-to-pulmonary-artery shunt (RVPAS) at the time of the Norwood procedure. The aim of the Long-term Outcomes of Children with HLHS and the Impact of Norwood Shunt Type (SVR III) study is to compare early adolescent outcomes including measures of cardiac function, transplant-free survival, and neurodevelopment, between those who received a mBTTS and those who received an RVPAS. METHODS: Transplant-free survivors of the SVR cohort were enrolled at 10 to 15 years of age for multifaceted in-person evaluation of cardiac function (cardiac magnetic resonance [CMR], echocardiogram and exercise test) and neurodevelopmental evaluation. Right ventricular ejection fraction measured by CMR served as the primary outcome. Development of arrhythmias, protein losing enteropathy, and other comorbidities were assessed through annual medical history interview. Through the course of SVR III, protocol modifications to engage SVR trial participants were designed to enhance recruitment and retention. CONCLUSIONS: Evaluation of long-term outcomes will provide important data to inform decisions about the shunt type placed at the Norwood operation and will improve the understanding of cardiovascular and neurodevelopmental outcomes for early adolescents with HLHS.

A Systematic Review of Ebstein's Anomaly with Left Ventricular Noncompaction.

Traditional definitions of Ebstein's anomaly (EA) and left ventricular noncompaction (LVNC), two rare congenital heart defects (CHDs), confine disease to either the right or left heart, respectively. Around 15-29% of patients with EA, which has a prevalence of 1 in 20,000 live births, commonly manifest with LVNC. While individual EA or LVNC literature is extensive, relatively little discussion is devoted to the joint appearance of EA and LVNC (EA/LVNC), which poses a higher risk of poor clinical outcomes. We queried PubMed, Medline, and Web of Science for all peer-reviewed publications from inception to February 2022 that discuss EA/LVNC and found 58 unique articles written in English. Here, we summarize and extrapolate commonalities in clinical and genetic understanding of EA/LVNC to date. We additionally postulate involvement of shared developmental pathways that may lead to this combined disease. Anatomical variation in EA/LVNC encompasses characteristics of both CHDs, including tricuspid valve displacement, right heart dilatation, and left ventricular trabeculation, and dictates clinical presentation in both age and severity. Disease treatment is non-specific, ranging from symptomatic management to invasive surgery. Apart from a few variant associations, mainly in sarcomeric genes MYH7 and TPM1, the genetic etiology and pathogenesis of EA/LVNC remain largely unknown.

NAFTNet retrospective report on the treatment of anti-Ro/SSA mediated fetal heart block with dexamethasone.

BACKGROUND: Complete atrioventricular block (CAVB) is a complication of maternal antibody positivity and treatment of fetal disease is controversial in terms of efficacy and safety. We hypothesized that dexamethasone treatment for fetal anti-Ro/SSA antibody-mediated cardiac disease leads to better pregnancy outcomes than expectant management. METHODS: A retrospective multi-center cohort study of anti-Ro/SSA antibody positive pregnancies with fetal conduction disease reported by participating North American Fetal Therapy Network (NAFTNet) centers between January 2010 and December 2018. The primary outcomes included: fetal death, oligohydramnios, growth restriction, preterm delivery, and new maternal comorbidities. Secondary outcomes included: pacemaker prior to 28 days, transplantation, and neonatal death in maternal/fetal dyads treated with dexamethasone versus not. RESULTS: In 127 anti-Ro/SSA positive pregnancies, 98 were treated with dexamethasone and 29 were not. Of those treated, 61/96 (63.5%) met the primary outcome including 45/91 (49.4%) premature deliveries; 20 mothers developed comorbidities during treatment (fetal death 5, 10 growth restriction, 14 oligohydramnios, two new/worsening gestational diabetes). In the untreated group, 15/25 (60%) met the primary outcome including 11/22 (50%) premature deliveries and four mothers developing comorbidities during their pregnancy (fetal death 3, one growth restriction, one new onset maternal hypertension). Regarding secondary outcomes, 37/96 (43%) treated fetuses required a pacemaker or died by 28 days, while untreated 13/25 (52%) required pacemaker placement, died prior to 28 days or required listing for transplantation. Excluding terminations, survival without transplant was 17 (68%) in untreated and 85 (89%) in treated patients (p<.01). CONCLUSIONS: While the use of dexamethasone in anti-Ro/SSA positive pregnancies is associated with a high rate of poor pregnancy outcomes, there was an unexpected similarly high rate in untreated positive pregnancies. This suggests that the maternal disease itself is influencing pregnancy complications independent of dexamethasone. Our data, which show that treatment decreases neonatal morbidity and overall mortality without increasing overall pregnancy complications, warrant further study.

Increases in oxygen saturation following discharge from Fontan palliation - an indicator of resolution of pulmonary arteriovenous malformations?

BACKGROUND: Pulmonary arteriovenous malformations in single ventricle congenital heart disease are poorly understood. Previous studies investigating pulmonary arteriovenous malformations predominantly focus on patients with heterotaxy syndrome and interrupted inferior caval vein. It is unknown if development and resolution of pulmonary arteriovenous malformations are similar for patients with and without heterotaxy syndrome. METHODS: In this retrospective single-institution study, we identified patients with a history of single ventricle congenital heart disease and Fontan palliation. We then matched patients with heterotaxy syndrome (intact and interrupted inferior caval vein) and non-heterotaxy hypoplastic left heart syndrome. To compare development of pulmonary arteriovenous malformations, we identified the frequency of positive diagnoses pre-Fontan. To compare resolution of pulmonary arteriovenous malformations, we recorded oxygen saturation changes for 12 months following Fontan. RESULTS: A total of 124 patients were included. Patients with heterotaxy and interrupted inferior caval vein were more likely to have a pre-Fontan contrast echocardiogram performed (p < 0.01) and more likely to be diagnosed with pulmonary arteriovenous malformations pre-Fontan (p < 0.01). There was no difference in oxygen saturation prior to Fontan, yet all patient groups had increased their oxygen saturations in the first year after Fontan discharge. CONCLUSIONS: Pulmonary arteriovenous malformations are variably diagnosed prior to Fontan palliation; however, all study groups had increased oxygen saturations after Fontan discharge, potentially indicating resolution of pulmonary arteriovenous malformations in all groups. The prevalence of pulmonary arteriovenous malformations pre-Fontan is likely underestimated. A quantitative, systematic approach to diagnosis and follow-up of pulmonary arteriovenous malformations is needed to better understand susceptibility and pathophysiology.

Pediatric Heart Network Echocardiographic Z Scores: Comparison with Other Published Models.

BACKGROUND: Different methods have resulted in variable Z scores for echocardiographic measurements. Using the measurements from 3,215 healthy North American children in the Pediatric Heart Network (PHN) echocardiographic Z score database, the authors compared the PHN model with previously published Z score models. METHODS: Z scores were derived for cardiovascular measurements using four models (PHN, Boston, Italy, and Detroit). Model comparisons were performed by evaluating (1) overlaid graphs of measurement versus body surface area with curves at Z = -2, 0, and +2; (2) scatterplots of PHN versus other Z scores with correlation coefficients; (3) Bland-Altman plots of PHN versus other Z scores; and (4) comparison of median Z scores for each model. RESULTS: For most measurements, PHN Z score curves were similar to Boston and Italian curves but diverged from Detroit curves at high body surface areas. Correlation coefficients were high when comparing the PHN model with the others, highest with Boston (mean, 0.99) and lowest with Detroit (mean, 0.90). Scatterplots suggested systematic differences despite high correlations. Bland-Altman plots also revealed poor agreement at both extremes of size and a systematic bias for most when comparing PHN against Italian and Detroit Z scores. There were statistically significant differences when comparing median Z scores between the PHN and other models. CONCLUSIONS: Z scores from the multicenter PHN model correlated well with previous single-center models, especially the Boston model, which also had a large sample size and similar methodology. The Detroit Z scores diverged from the PHN Z scores at high body surface area, possibly because there were more subjects in this category in the PHN database. Despite excellent correlation, significant differences in Z scores between the PHN model and others were seen for many measurements. This is important when comparing publications using different models and for clinical care, particularly when Z score thresholds are used to guide diagnosis and management.

Fetal Cardiac Intervention for Pulmonary Atresia with Intact Ventricular Septum: International Fetal Cardiac Intervention Registry.

INTRODUCTION: Invasive fetal cardiac intervention (FCI) for pulmonary atresia with intact ventricular septum (PAIVS) and critical pulmonary stenosis (PS) has been performed with small single-institution series reporting technical and physiological success. We present the first multicenter experience. OBJECTIVES: Describe fetal and maternal characteristics of those being evaluated for FCI, including pregnancy/neonatal outcome data using the International Fetal Cardiac Intervention Registry (IFCIR). METHODS: We queried the IFCIR for PAIVS/PS cases evaluated from January 2001 to April 2018 and reviewed maternal/fetal characteristics, procedural details, pregnancy and neonatal outcomes. Data were analyzed using standard descriptive statistics. RESULTS: Of the 84 maternal/fetal dyads in the registry, 58 underwent pulmonary valvuloplasty at a median gestational age of 26.1 (21.9-31.0) weeks. Characteristics of fetuses undergoing FCI varied in terms of tricuspid valve (TV) size, TV regurgitation, and pulmonary valve patency. There were fetal complications in 55% of cases, including 7 deaths and 2 delayed fetal losses. Among those who underwent successful FCI, the absolute measurement of the TV increased by 0.32 (±0.17) mm/week from intervention to birth. Among 60 liveborn with known outcome, there was a higher percentage having a biventricular circulation following successful FCI (87 vs. 43%). CONCLUSIONS: Our data suggest a possible benefit to fetal therapy for PAIVS/PS, though rates of technically unsuccessful procedures and procedure-related complications, including fetal loss were substantial. FCI criteria are extremely variable, making direct comparison to nonintervention patients challenging and potentially biased. More uniform FCI criteria for fetuses with PAIVS/PS are needed to avoid unnecessary procedures, expose only fetuses most likely to sustain a benefit, and to enable comparisons to be made with nonintervention patients.

Echocardiographic Identification of Pulmonary Artery Flow Reversal: An Indicator of Adverse Outcomes in Single Ventricle Physiology.

Individuals with single ventricle congenital heart disease (CHD) undergo multiple staged surgical palliations. Staged single ventricle palliation with a superior cavopulmonary connection (SCPC) in infancy followed by a Fontan in early childhood relies on passive, unobstructed pulmonary blood flow and normal pulmonary vasculature. We hypothesized that patients with echocardiographic identification of retrograde flow in a branch pulmonary artery (PA) after SCPC or Fontan are at increased risk for adverse outcomes. We conducted a retrospective chart review of patients seen at Children's Wisconsin from 1999 to 2019. Inclusion criteria included a history of single ventricle congenital heart disease and surgical palliation with a superior cavopulmonary connection (SCPC). We created two cohorts based on transthoracic echocardiographic identification of branch PA flow patterns: those with color Doppler-defined pulmonary artery flow reversal (PA reversal cohort) and those with normal anterograde flow (Non-reversal cohort). We identified 21 patients in the PA reversal cohort and 539 patients in the Non-reversal cohort. The PA reversal cohort had increased hospital length of stay after SCPC palliation (p < 0.001) and decreased transplant-free survival (p = 0.032), but there was no difference in overall survival (p = 0.099). There was no difference in hospital length of stay after Fontan (p = 0.17); however, the PA reversal cohort was significantly less likely to progress to Fontan palliation during early childhood (p = 0.005). Echocardiographic color Doppler identification of branch PA flow reversal in patients with single ventricle physiology is a high-risk indicator for adverse short- and long-term outcomes.

Challenges and lessons learned from the Pediatric Heart Network Normal Echocardiogram Database study.

BACKGROUND: The Pediatric Heart Network Normal Echocardiogram Database Study had unanticipated challenges. We sought to describe these challenges and lessons learned to improve the design of future studies. METHODS: Challenges were divided into three categories: enrolment, echocardiographic imaging, and protocol violations. Memoranda, Core Lab reports, and adjudication logs were reviewed. A centre-level questionnaire provided information regarding local processes for data collection. Descriptive statistics were used, and chi-square tests determined differences in imaging quality. RESULTS: For the 19 participating centres, challenges with enrolment included variations in Institutional Review Board definitions of "retrospective" eligibility, overestimation of non-White participants, centre categorisation of Hispanic participants that differed from National Institutes of Health definitions, and exclusion of potential participants due to missing demographic data. Institutional Review Board amendments resolved many of these challenges. There was an unanticipated burden imposed on centres due to high numbers of echocardiograms that were reviewed but failed to meet submission criteria. Additionally, image transfer software malfunctions delayed Core Lab image review and feedback. Between the early and late study periods, the proportion of unacceptable echocardiograms submitted to the Core Lab decreased (14 versus 7%, p < 0.01). Most protocol violations were from eligibility violations and inadvertent protected health information disclosure (overall 2.5%). Adjudication committee reviews led to protocol changes. CONCLUSIONS: Numerous challenges encountered during the Normal Echocardiogram Database Study prolonged study enrolment. The retrospective design and flaws in image transfer software were key impediments to study completion and should be considered when designing future studies collecting echocardiographic images as a primary outcome.

Novel KLHL26 variant associated with a familial case of Ebstein's anomaly and left ventricular noncompaction.

BACKGROUND: Ebstein's anomaly (EA) is a rare congenital heart disease of the tricuspid valve and right ventricle. Patients with EA often manifest with left ventricular noncompaction (LVNC), a cardiomyopathy. Despite implication of cardiac sarcomere genes in some cases, very little is understood regarding the genetic etiology of EA/LVNC. Our study describes a multigenerational family with at least 10 of 17 members affected by EA/LVNC. METHODS: We performed echocardiography on all family members and conducted exome sequencing of six individuals. After identifying candidate variants using two different bioinformatic strategies, we confirmed segregation with phenotype using Sanger sequencing. We investigated structural implications of candidate variants using protein prediction models. RESULTS: Exome sequencing analysis of four affected and two unaffected members identified a novel, rare, and damaging coding variant in the Kelch-like family member 26 (KLHL26) gene located on chromosome 19 at position 237 of the protein (GRCh37). This variant region was confirmed by Sanger sequencing in the remaining family members. KLHL26 (c.709C > T p.R237C) segregates only with EA/LVNC-affected individuals (FBAT p < .05). Investigating structural implications of the candidate variant using protein prediction models suggested that the KLHL26 variant disrupts electrostatic interactions when binding to part of the ubiquitin proteasome, specifically Cullin3 (CUL3), a component of E3 ubiquitin ligase. CONCLUSION: In this familial case of EA/LVNC, we have identified a candidate gene variant, KLHL26 (p.R237C), which may have an important role in ubiquitin-mediated protein degradation during cardiac development.

Selective Use of Inpatient Interstage Management After Norwood Procedure.

BACKGROUND: We report our intermediate-term results after Norwood procedure, including use of an interstage inpatient management strategy for high-risk patients, and seek to create a predictive model for probability of discharge. METHODS: A single-site retrospective review was conducted for all patients undergoing Norwood procedure from 2006 to 2016 (N = 177). We compared those discharged home with those who either remained hospitalized until Glenn procedure or died before Norwood procedure discharge. Multivariable logistic regression was used to develop a predictive model for discharge. RESULTS: During the study period, 120 (68%) patients were discharged home, 45 (25%) remained hospitalized, and 12 (7%) died before Glenn procedure (median age: 71 days). Interstage survival for those discharged after Norwood procedure was 100%. Longitudinal survival for the cohort was 86%, 81%, and 77% at 1, 5, and 10 years, resepectively. Ten-year survival was significantly greater for the discharged group compared with the interstage inpatients (86% vs 56%, P < .001). A reduced predictive model of discharge included lower gestational age (odds ratio [OR]: 0.95), lower median income for ZIP code (OR: 0.4), lower birth-weight-for-age z-score (OR: 0.56), longer cardiopulmonary bypass time (OR: 0.45), and Blalock-Taussig shunt (OR: 0.32). CONCLUSIONS: Survival up to 10 years after Norwood procedure is good using a strategy of inpatient care for a subset of high-risk patients to mitigate home interstage mortality. A probabilistic model used after Norwood procedure was able to predict interstage discharge with good accuracy, but will require external validation to ensure generalizability. Further work is also needed to determine optimal palliative pathways for the high-risk patients because of the notable attrition beyond successful bidirectional Glenn procedure.

Survival After Norwood Procedure in High-Risk Patients.

BACKGROUND: Multiple single-ventricle populations are noted to be at increased risk for mortality after the Norwood procedure. Preoperative risk factors include low birth weight, restrictive/intact atrial septum, obstructed pulmonary veins, ventricular dysfunction, and atrioventricular valve regurgitation. We report outcomes of the Norwood procedure in standard- and high-risk patients in the recent era. METHODS: All patients born with hypoplastic left heart syndrome between 2006 and 2016 who underwent a Norwood procedure at our institution were included. Patient data were retrospectively reviewed, and Kaplan-Meier analysis was used to evaluate survival between groups. RESULTS: The cohort included 177 patients. Fifty patients were determined high-risk preoperatively: low birth weight (n = 18), ventricular dysfunction/atrioventricular valve regurgitation (n = 13), intact or restrictive atrial septum/obstructed anomalous pulmonary venous return (n = 14), and multiple factors (n = 5). There were 2 (1.6%) deaths before Glenn in the standard-risk group, with a total of 10 (20%) from the high-risk groups (P < .0001). Survival at 1 year differed greatly between groups, with highest being standard risk at 89% and lowest in the intact septum/obstructed veins group at 54%. The difference between groups in long-term survival was significant (P < .001). CONCLUSIONS: Outcomes after the Norwood procedure have improved for standard-risk patients. Those with preoperative risk factors account for most of the early deaths after the Norwood procedure. This high-risk status does not resolve after Glenn, because longer-term survival continues to diverge from the standard-risk group.

Ventricular Fibrillation and Myocardial Depression Following Pulmonary Valve Replacement in Tetralogy of Fallot With an Intramural Coronary Artery and Coronary Artery Compression by Chest Tube.

We describe the case of a 10-year-old male with a history of repaired Tetralogy of Fallot and known intramural right coronary artery (RCA) who presented for bioprosthetic pulmonary valve replacement. The operation was complicated by postoperative ventricular fibrillation arrest. Selective coronary angiography revealed external compression of the mid-RCA by a mediastinal chest tube that improved immediately upon removal of the tube. Ultimately, the patient required additional unroofing of the intramural coronary for full recovery. This case highlights the need to thoroughly investigate malignant ventricular dysrhythmias following pediatric cardiac surgery and to rule out coronary insufficiency, which may be due to both extrinsic and/or intrinsic lesions.

Comparison of echocardiographic measurements to invasive measurements of diastolic function in infants with single ventricle physiology: a report from the Pediatric Heart Network Infant Single Ventricle Trial.

BACKGROUND: While echocardiographic parameters are used to quantify ventricular function in infants with single ventricle physiology, there are few data comparing these to invasive measurements. This study correlates echocardiographic measures of diastolic function with ventricular end-diastolic pressure in infants with single ventricle physiology prior to superior cavopulmonary anastomosis. METHODS: Data from 173 patients enrolled in the Pediatric Heart Network Infant Single Ventricle enalapril trial were analysed. Those with mixed ventricular types (n = 17) and one outlier (end-diastolic pressure = 32 mmHg) were excluded from the analysis, leaving a total sample size of 155 patients. Echocardiographic measurements were correlated to end-diastolic pressure using Spearman's test. RESULTS: Median age at echocardiogram was 4.6 (range 2.5-7.4) months. Median ventricular end-diastolic pressure was 7 (range 3-19) mmHg. Median time difference between the echocardiogram and catheterisation was 0 days (range -35 to 59 days). Examining the entire cohort of 155 patients, no echocardiographic diastolic function variable correlated with ventricular end-diastolic pressure. When the analysis was limited to the 86 patients who had similar sedation for both studies, the systolic:diastolic duration ratio had a significant but weak negative correlation with end-diastolic pressure (r = -0.3, p = 0.004). The remaining echocardiographic variables did not correlate with ventricular end-diastolic pressure. CONCLUSION: In this cohort of infants with single ventricle physiology prior to superior cavopulmonary anastomosis, most conventional echocardiographic measures of diastolic function did not correlate with ventricular end-diastolic pressure at cardiac catheterisation. These limitations should be factored into the interpretation of quantitative echo data in this patient population.

Challenges With Left Ventricular Functional Parameters: The Pediatric Heart Network Normal Echocardiogram Database.

BACKGROUND: The reliability of left ventricular (LV) systolic functional indices calculated from blinded echocardiographic measurements of LV size has not been tested in a large cohort of healthy children. The objective of this study was to estimate interobserver variability in standard measurements of LV size and systolic function in children with normal cardiac anatomy and qualitatively normal function. METHODS: The Pediatric Heart Network Normal Echocardiogram Database collected normal echocardiograms from healthy children ≤18 years old distributed equally by age, gender, and race. A core lab used two-dimensional echocardiograms to measure LV dimensions from which a separate data coordinating center calculated LV volumes and systolic functional indices. To evaluate interobserver variability, two independent expert pediatric echocardiographic observers remeasured LV dimensions on a subset of studies, while blinded to calculated volumes and functional indices. RESULTS: Of 3,215 subjects with measurable images, 552 (17%) had a calculated LV shortening fraction (SF) < 25% and/or LV ejection fraction (EF) < 50%; the subjects were significantly younger and smaller than those with normal values. When the core lab and independent observer measurements were compared, individual LV size parameter intraclass correlation coefficients were high (0.81-0.99), indicating high reproducibility. The intraclass correlation coefficients were lower for SF (0.24) and EF (0.56). Comparing reviewers, 40/56 (71%) of those with an abnormal SF and 36/104 (35%) of those with a normal SF based on core lab measurements were calculated as abnormal from at least one independent observer. In contrast, an abnormal EF was less commonly calculated from the independent observers' repeat measures; only 9/47 (19%) of those with an abnormal EF and 8/113 (7%) of those with a normal EF based on core lab measurements were calculated as abnormal by at least one independent observer. CONCLUSIONS: Although blinded measurements of LV size show good reproducibility in healthy children, subsequently calculated LV functional indices reveal significant variability despite qualitatively normal systolic function. This suggests that, in clinical practice, abnormal SF/EF values may result in repeat measures of LV size to match the subjective assessment of function. Abnormal LV functional indices were more prevalent in younger, smaller children.