Single Ventricle Reconstruction Research Articles

Relationship of Aortopulmonary Collaterals and Pulmonary Artery Development During Staged Single Ventricle Reconstruction.

To evaluate the relationship of aortopulmonary collaterals and the development of central pulmonary arteries during staged palliation. A total of 287 patients, who underwent staged palliation with bidirectional cavopulmonary shunt and total cavopulmonary connection between 2008 and 2019, had available angiography. Pulmonary artery index was calculated using pulmonary angiography as described by Nakata and colleagues. Aortopulmonary collaterals were observed in 47 (16%) patients at stage II palliation, in 131 (46%) at total cavopulmonary connection, and afterwards in 49 (7%). The interventional closure of aortopulmonary collaterals was performed before stage II in 12 (4%) patients, before Fontan completion in 38 (13%), and afterwards in 39 (14%). Presence of aortopulmonary collaterals before stage II was not associated with the pulmonary artery index (129 vs. 150 mm2/m2, p = 0.176) at stage II. In contrast, aortopulmonary collaterals before the Fontan completion were associated with lower pulmonary artery index (154 vs. 172 mm2/m2, p = 0.005), and right pulmonary artery index (99 vs. 106 mm2/m2, p = 0.006). Patients who underwent interventional closure of aortopulmonary collaterals before total cavopulmonary connection had lower pulmonary artery index (141 vs. 169 mm2/m2, p < 0.001), lower right pulmonary artery index (93 vs. 106 mm2/m2, p = 0.007), and left pulmonary artery index (54 vs. 60 mm2/m2, p = 0.013) at Fontan completion. The presence of aortopulmonary collaterals did not influence pulmonary artery size by the time of stage II. However, presence of aortopulmonary collaterals was associated with under-developed pulmonary arteries at Fontan completion, especially in patients who needed interventional closure of aortopulmonary collaterals.

Precision in Norwood Shunt Sizing: Single Ventricle Reconstruction Trial Public Dataset Analysis

BackgroundMorbidity and mortality after the Norwood procedure remains high. Shunt size selection is not standardized and the impact of shunt size on outcomes is poorly understood. The Single Ventricle Reconstruction trial randomized infants to modified Blalock-Taussig-Thomas shunt (MBTTS) or right ventricle-to-pulmonary artery shunt at the Norwood procedure. We assessed shunt size distribution and its association with postoperative outcomes. MethodsWe included 544 patients, excluding 5 with ambiguous shunt crossover data. Normalized shunt diameter 1 and 2 were calculated as shunt diameter divided by patient’s weight and body surface area, respectively. The primary outcome was 30-day mortality after Norwood. Secondary outcomes were intensive care and total length of stay, and survival to Glenn procedure. Logistic and ordinal regression models evaluated the association of normalized shunt diameter with outcomes. ResultsThirty-day mortality after Norwood was 11.4% (n = 62), survival to Glenn procedure was 72.6% (n = 395), median length of stay was 14.0 (interquartile range, 9.0-27.7) days and 24.0 (interquartile range, 16.0-41.0) days in the intensive care and total, respectively. Normalized shunt diameters exhibited variation in both shunt types but were not associated with 30-day mortality. Right ventricle-to-pulmonary artery shunt size was not associated with secondary outcomes. However, a MBTTS diameter ≥1.5 mm/kg predicted longer Norwood (odds ratio, 4.89; 95% CI, 1.41-16.90) and intensive care (odds ratio, 4.11; 95% CI, 1.25-13.49]) duration. ConclusionsShunt size selection was variable. Right ventricle-to-pulmonary artery shunt had a wider size range seen with favorable outcomes compared with MBTTS. A MBTTS either too large or too small is associated with worse postoperative outcomes. Refining shunt sizing practices can improve surgical outcomes after the Norwood procedure.

Association between weight-for-length percentile and ICU length of stay in patients with a single ventricleundergoing bidirectional Glenn repair: A retrospective cohort study.

Poor weight gain has been identified as an independent risk factor for increased surgical morbidity and mortality for patients with single-ventricle physiology undergoing staged surgical palliation. Conversely, excessive weight gain has also emerged as an independent risk factor predicting increased morbidity and mortality in a single-center study. Given this novel single-center concept, we investigated the impact of excessive weight on patients with single-ventricle physiology undergoing bidirectional Glenn palliation in a multicenter study model. Patients from the Pediatric Heart Network Single Ventricle Reconstruction Trial (n = 387) were analyzed in a retrospective cohort study examining the independent effect of weight percentile on intensive care unit (ICU) length of stay (LOS) and ventilator days. Locally estimated scatterplot smoothing (LOESS) regression was used to plot weight-for-length (WFL) percentiles by ICU LOS and ventilator days. Unadjusted and adjusted ordinal regression was used to model ICU LOS and ventilator days. Scatterplots and LOESS regression curves demonstrated increasing ICU LOS and ventilator days for increasing WFL percentiles. Unadjusted ordinal regression analysis of ICU LOS demonstrated a trend of increasing ICU LOS for increasing WFL percentiles that was not statistically significant (P = 0.11). A similar trend was demonstrated in adjusted ordinal regression that was not statistically significant (P = 0.48). Unadjusted and adjusted ordinal regression analysis of ventilator days did not reach statistical significance (P = 0.07). Excessive weight gain has a clinically relevant but not statistically significant association with increased ICU LOS and ventilator days for those patients in the >90th WFL percentile for age.

Using machine learning to predict five-year transplant-free survival among infants with hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a congenital malformation commonly treated with palliative surgery and is associated with significant morbidity and mortality. Risk stratification models have often relied upon traditional survival analyses or outcomes data failing to extend beyond infancy. Individualized prediction of transplant-free survival (TFS) employing machine learning (ML) based analyses of outcomes beyond infancy may provide further valuable insight for families and healthcare providers along the course of a staged palliation. Data from both the Pediatric Heart Network (PHN) Single Ventricle Reconstruction (SVR) trial and Extension study (SVR II), which extended cohort follow up for five years was used to develop ML-driven models predicting TFS. Models incrementally incorporated features corresponding to successive phases of care, from pre-Stage 1 palliation (S1P) through the stage 2 palliation (S2P) hospitalization. Models trained with features from Pre-S1P, S1P operation, and S1P hospitalization all demonstrated time-dependent area under the curves (td-AUC) beyond 0.70 through 5 years following S1P, with a model incorporating features through S1P hospitalization demonstrating particularly robust performance (td-AUC 0.838 (95% CI 0.836–0.840)). Machine learning may offer a clinically useful alternative means of providing individualized survival probability predictions, years following the staged surgical palliation of hypoplastic left heart syndrome.

Abstract 13952: Neurodevelopmental Outcomes in Early Adolescence: The Pediatric Heart Network’s Single Ventricle Reconstruction Trial

Introduction: Neurodevelopmental (ND) and functional impairments for survivors of palliated hypoplastic left heart syndrome (HLHS) are among the most consequential morbidities, resulting in an increased risk of poor school performance and lower reported quality of life. Longitudinal follow-up of those enrolled in the Single Ventricle Reconstruction (SVR) III study provides opportunity to measure important outcomes such as ND, and understand associated risk factors. Goals/Aims: Describe and identify predictors of ND outcomes at 10-12 years of age in participants enrolled in SVR. Methods: Transplant-free survivors from the SVR III trial were invited to complete in-person ND assessments, including the Wechsler Intelligence Scale for Children-V, Wechsler Individual Achievement Test-III, and the Behavior Rating Inventory of Executive Function (BRIEF). Descriptive and regression analyses were performed. Results: Of the 237 enrolled in SVR III, 200 (84%) received a ND assessment. Participants who did vs did not undergo assessment were more likely to be male (63% vs 51%), white (87% vs 76%) and have a higher Child Opportunity Index (61 ±26 vs 46 ±39). Mean Full Scale IQ for the cohort was almost 1 standard deviation (SD) below the normative mean (88 ±18), with 39% &gt;1 and 15% &gt;2 SD below the normative mean. Similar patterns were seen for Reading (38% &gt;1 SD and 16% &gt; 2SD) and Math Composites (38% &gt;1 SD, 19% &gt; 2SD). Executive functions measured with the BRIEF were similarly affected, with 25% to 45% of individuals showing clinically significant (T score &gt;65) Plan/Organization problems on parent and teacher forms, respectively. Measures of socioeconomic status, number of complications, and requirement for a gastrostomy-tube were all independent predictors for multiple ND outcomes. Conclusions: In early adolescence, transplant-free survivors of surgical palliation for HLHS show clinically significant ND concerns across multiple domains of functioning. The distribution of outcomes is broad. Our findings support the American Heart Association recommendations for screening and evaluation in middle school to inform interventions that promote academic success and quality of life.

Abstract 17067: Long-Term Transplant-Free Survival is Improved in Hypoplastic Left Heart Syndrome With Cell-Based Therapy

Hypoplastic left heart syndrome (HLHS) is a univentricular congenital heart defect that has high morbidity and mortality and requires three-stage surgical reconstruction so that the right ventricle (RV) delivers systemic circulation. Poor outcomes result from RV failure in the systemic position. Accordingly, we conducted a phase I clinical trial (called ELPIS) of Lomecel-B™, an allogeneic bone-marrow derived cell-based therapy designed to improve cardiovascular performance, delivered as a one-time treatment during the Stage II (Glenn) surgery at approximately 4 months after birth. This trial met its primary endpoint (safety through 1-year post-treatment). To assess whether Lomecel-B™ has survival benefits, all ELPIS patients ( n=10, 7 males, and 3 females) were enrolled in a multi-year follow-on study and compared to a retrospective control group which was identified by a relevant clinical HLHS database. Patients in both studies were assessed for up to 5 years (range 3.5 - 5.0 years post-treatment for ELPIS) for mortality, heart transplants, and stage III (Fontan) surgery. Outcomes were compared with long-term historical data from patients in the Single Ventricle Reconstruction (SVR) Trial receiving the same shunt type at Stage I (Norwood) operation. 5-year Kaplan-Meier survival was 100% in ELPIS patients with none requiring heart transplant. This compared to 81.6% (95% CI= [76.5, 87.0]) transplant-free survival in the SVR trial through 5 years post-Glenn surgery, and a 5.2% (95% CI= [2.0, 8.3]) heart transplantation rate (Figure 1). No stem cell related safety issues were reported. These findings support Lomecel-B™ as a potential adjunct to HLHS reconstruction surgery to improve clinical benefits and reduce the need for subsequent heart transplantation. Further long-term follow-up and controlled trials are both warranted and underway.

School age and adolescent heart failure following the Norwood procedure

Heart failure results in significant morbidity and mortality for young children with hypoplastic left heart syndrome (HLHS) following the Norwood procedure. The trajectory in later childhood is not well described. We studied the outcome into adolescence of participants enrolled in the Single Ventricle Reconstruction (SVR) trial who underwent the Fontan procedure or survived to 6 years without having undergone Fontan procedure. The primary outcome was heart failure events, defined as heart transplant listing or death attributable to heart failure. Symptomatic heart failure for participants surviving 10 or more years was also assessed utilizing the PedsQL. Of the 345 participants who underwent a Fontan operation or survived to 6 years without Fontan, 25 (7.2%) had a heart failure event before age 12 years. Among these, 21 were listed for heart transplant and 4 died from heart failure. Nineteen participants underwent heart transplant, all of whom survived to age 12 years. Factors associated with a heart failure event included longer Norwood hospital length of stay, aortic atresia and no Fontan operation by age 6 years. Assessment of heart failure symptoms at 12 years of age revealed that 24 (12.2%) of 196 PedsQL respondents "often" or "almost always" had difficulty walking more than one block. Heart failure events occur in over 5% of children with palliated HLHS between preschool age and adolescence. Outcomes for children listed for transplant are excellent. However, a substantial portion of palliated HLHS children have significant symptoms of heart failure at 12 years of age.

Longitudinal Follow-Up of Children With HLHS and Association Between Norwood Shunt Type and Long-Term Outcomes: The SVR III Study.

In the SVR trial (Single Ventricle Reconstruction), newborns with hypoplastic left heart syndrome were randomly assigned to receive a modified Blalock-Taussig-Thomas shunt (mBTTS) or a right ventricle-to-pulmonary artery shunt (RVPAS) at Norwood operation. Transplant-free survival was superior in the RVPAS group at 1 year, but no longer differed by treatment group at 6 years; both treatment groups had accumulated important morbidities. In the third follow-up of this cohort (SVRIII [Long-Term Outcomes of Children With Hypoplastic Left Heart Syndrome and the Impact of Norwood Shunt Type]), we measured longitudinal outcomes and their risk factors through 12 years of age. Annual medical history was collected through record review and telephone interviews. Cardiac magnetic resonance imaging (CMR), echocardiogram, and cycle ergometry cardiopulmonary exercise tests were performed at 10 through 14 years of age among participants with Fontan physiology. Differences in transplant-free survival and complication rates (eg, arrhythmias or protein-losing enteropathy) were identified through 12 years of age. The primary study outcome was right ventricular ejection fraction (RVEF) by CMR, and primary analyses were according to shunt type received. Multivariable linear and Cox regression models were created for RVEF by CMR and post-Fontan transplant-free survival. Among 549 participants enrolled in SVR, 237 of 313 (76%; 60.7% male) transplant-free survivors (mBTTS, 105 of 147; RVPAS, 129 of 161; both, 3 of 5) participated in SVRIII. RVEF by CMR was similar in the shunt groups (RVPAS, 51±9.6 [n=90], and mBTTS, 52±7.4 [n=75]; P=0.43). The RVPAS and mBTTS groups did not differ in transplant-free survival by 12 years of age (163 of 277 [59%] versus 144 of 267 [54%], respectively; P=0.11), percentage predicted peak Vo2 for age and sex (74±18% [n=91] versus 72±18% [n=84]; P=0.71), or percentage predicted work rate for size and sex (65±20% versus 64±19%; P=0.65). The RVPAS versus mBTTS group had a higher cumulative incidence of protein-losing enteropathy (5% versus 2%; P=0.04) and of catheter interventions (14 versus 10 per 100 patient-years; P=0.01), but had similar rates of other complications. By 12 years after the Norwood operation, shunt type has minimal association with RVEF, peak Vo2, complication rates, and transplant-free survival. RVEF is preserved among the subgroup of survivors who underwent CMR assessment. Low transplant-free survival, poor exercise performance, and accruing morbidities highlight the need for innovative strategies to improve long-term outcomes in patients with hypoplastic left heart syndrome. URL: https://www. gov; Unique identifier: NCT0245531.

Cardiac Magnetic Resonance Imaging to Determine Single Ventricle Function in a Pediatric Population is Feasible in a Large Trial Setting: Experience from the Single Ventricle Reconstruction Trial Longitudinal Follow up

The Single Ventricle Reconstruction (SVR) Trial was a randomized prospective trial designed to determine survival advantage of the modified Blalock-Taussig-Thomas shunt (BTTS) vs the right ventricle to pulmonary artery conduit (RVPAS) for patients with hypoplastic left heart syndrome. The primary aim of the long-term follow-up (SVRIII) was to determine the impact of shunt type on RV function. In this work, we describe the use of CMR in a large cohort follow up from the SVR Trial as a focused study of single ventricle function. The SVRIII protocol included short axis steady-state free precession imaging to assess single ventricle systolic function and flow quantification. There were 313 eligible SVRIII participants and 237 enrolled, ages ranging from 10 to 12.5 years. 177/237 (75%) participants underwent CMR. The most common reasons for not undergoing CMR exam were requirement for anesthesia (n = 14) or ICD/pacemaker (n = 11). A total of 168/177 (94%) CMR studies were diagnostic for RVEF. Median exam time was 54 [IQR 40–74] minutes, cine function exam time 20 [IQR 14–27] minutes, and flow quantification time 18 [IQR 12–25] minutes. There were 69/177 (39%) studies noted to have intra-thoracic artifacts, most common being susceptibility artifact from intra-thoracic metal. Not all artifacts resulted in non-diagnostic exams. These data describe the use and limitations of CMR for the assessment of cardiac function in a prospective trial setting in a grade-school-aged pediatric population with congenital heart disease. Many of the limitations are expected to decrease with the continued advancement of CMR technology.

Long-term outcomes of tricuspid valve intervention during stage 2 palliation in patients with a single right ventricle

ObjectivesIn patients with single ventricle physiology and a systemic right ventricle, tricuspid valve regurgitation increases the risk of adverse outcomes, and tricuspid valve intervention at the time of staged palliation further increases that risk in the postoperative period. However, long-term outcomes of valve intervention in patients with significant regurgitation during stage 2 palliation have not been established. The purpose of this study is to evaluate the long-term outcomes after tricuspid valve intervention during stage 2 palliation in patients with right ventricular dominant circulation in a multicenter study. MethodsThe study was performed using the Single Ventricle Reconstruction Trial and Single Ventricle Reconstruction Follow-up 2 Trial datasets. Survival analysis was performed to describe the association among valve regurgitation, intervention, and long-term survival. Cox proportional hazards modeling was used to estimate the longitudinal association of tricuspid intervention and transplant-free survival. ResultsPatients with tricuspid regurgitation at stage 1 or 2 had worse transplant-free survival (hazard ratio, 1.61; 95% confidence interval, 1.12-2.32; hazard ratio, 2.3; 95% confidence interval 1.39-3.82). Those with regurgitation who underwent concomitant valve intervention at stage 2 were significantly more likely to die or undergo heart transplantation compared with those with regurgitation who did not (hazard ratio, 2.93; confidence interval, 2.16-3.99). Patients with tricuspid regurgitation at the time of the Fontan had favorable outcomes regardless of valve intervention. ConclusionsThe risks associated with tricuspid regurgitation in patients with single ventricle physiology do not appear to be mitigated by valve intervention at the time of stage 2 palliation. Patients who underwent valve intervention for tricuspid regurgitation at stage 2 had significantly worse survival compared with patients with tricuspid regurgitation who did not.

Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study.

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred that were related to difficulties with: (1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and (2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by: (1) adding additional study sites, (2) increasing the frequency of meetings with site coordinators, and (3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms.

Discussion

Discussion

Preterm Birth Is Associated With Adverse Cardiac Remodeling and Worse Outcomes in Patients With a Functional Single Right Ventricle

To assess the effects of preterm birth on cardiac structure and function and transplant-free survival in patients with hypoplastic left heart syndrome and associated anomalies throughout the staged palliation process. Data from the Single Ventricle Reconstruction trial were used to assess the impact of prematurity on echocardiographic measures at birth, Norwood, Stage II, and 14months in 549 patients with a single functional right ventricle. Medical history was recorded once a year using medical records or telephone interviews. Cox regression models were applied to analyze transplant-free survival to age 6years. Causal mediation analysis was performed to estimate the mediating effect of birth weight within this relationship. Of the 549 participants, 64 (11.7%) were born preterm. Preterm-born participants had lower indexed right ventricle end-diastolic volumes at birth but higher volumes than term-born participants by age 14months. Preterm-born participants had an increased risk of death or heart transplantation from birth to age 6years, with an almost linear increase in the observed risk as gestational age decreased below 37weeks. Of the total effect of preterm birth on transplant-free survival, 27.3% (95% CI 2.5-59.0%) was mediated through birth weight. Preterm birth is associated with adverse right ventricle remodeling and worse transplant-free survival throughout the palliation process, in part independently of low birth weight. Further investigation into this vulnerable group may allow development of strategies that mitigate the impact of prematurity on outcomes in patients with hypoplastic left heart syndrome.

The Relationship of Family Factors to Psychosocial Outcomes in Children with Hypoplastic Left Heart Syndrome at 6 Years of Age

The objective of this study was to describe the relationships between family factors and outcomes for children with hypoplastic left heart syndrome (HLHS). This cross-sectional study was ancillary to the Pediatric Heart Network Single Ventricle Reconstruction Extension Study to examine family factors including parental mental health, quality of life (QOL), family resources, function and management, and their relationships to child psychosocial outcomes (adaptive behavior, internalizing and externalizing behaviors and health-related quality of life [HRQOL]) at 6years of age. Participants were parents (115 mothers, 71 fathers) of children with HLHS. Parents reported anxiety, QOL and family resources that were worse than the general population; 33% reported family dysfunction. There were no meaningful differences between reports from mothers and fathers. Parental perception of better child health was associated with better family management of the condition (P<.05). Several family management factors explained a moderate amount of variance in adaptive behavior (ΔR2=0.08-0.14), adaptive skills (ΔR2=0.19-0.21), and HRQOL scores (ΔR2=0.04-0.18); little variance was explained in internalizing problems (ΔR2=0.02-0.03) (all P<.05) above and beyond demographic and clinical variables. HLHS has a significant impact on both children and families. Relationships between child and family characteristics may impose risk or protection. Improved understanding of these associations should guide counseling and tailored interventions.

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

BackgroundThe 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. MethodsTransplant-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. ConclusionsEvaluation 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.

Cumulative In-Hospital Costs Associated With Single-Ventricle Palliation

BackgroundIn the SVR (Single Ventricle Reconstruction) Trial, 1-year survival in recipients of right ventricle to pulmonary artery shunts (RVPAS) was superior to that in those receiving modified Blalock-Taussig-Thomas shunts (MBTTS), but not in subsequent follow-up. Cost analysis is an expedient means of evaluating value and morbidity. ObjectivesThe purpose of this study was to evaluate differences in cumulative hospital costs between RVPAS and MBTTS. MethodsClinical data from SVR and costs from Pediatric Health Information Systems database were combined. Cumulative hospital costs and cost-per-day-alive were compared serially at 1, 3, and 5 years between RVPAS and MBTTS. Potential associations between patient-level factors and cost were explored with multivariable models. ResultsIn total, 303 participants (55% of the SVR cohort) from 9 of 15 sites were studied (48% MBTTS). Observed total costs at 1 year were lower for MBTTS ($701,260 ± 442,081) than those for RVPAS ($804,062 ± 615,068), a difference that was not statistically significant (P = 0.10). Total costs were also not significantly different at 3 and 5 years (P = 0.21 and 0.32). Similarly, cost-per-day-alive did not differ significantly for either group at 1, 3, and 5 years (all P > 0.05). In analyses of transplant-free survivors, total costs and cost-per-day-alive were higher for RVPAS at 1 year (P = 0.05 for both) but not at 3 and 5 years (P > 0.05 for all). In multivariable models, aortic atresia and prematurity were associated with increased cost-per-day-alive across follow-up (P < 0.05). ConclusionsTotal costs do not differ significantly between MBTTS and RVPAS. The magnitude of longitudinal costs underscores the importance of efforts to improve outcomes in this vulnerable population.

0484 Trouble Sleeping Predicts Future Decreased Quality of Life in Young Children with Fontan Circulation

Abstract Introduction Children with congenital heart disease who undergo a Fontan procedure are at higher risk of reduced health-related quality of life (HR-QOL) compared to age-matched peers. We have previously shown that current sleep disturbances are associated with decreased HR-QOL, but there is no existing longitudinal data on the relationship between sleep disturbance and HR-QOL in children with Fontan circulation. Methods We analyzed data from the Pediatric Heart Network Single Ventricle Reconstruction follow up study to evaluate associations between parent-reported trouble sleeping with HR-QOL as measured by the child health questionnaire (CHQ, measured at age 6 years) as well as the Pediatric Quality of Life questionnaire (PedsQL, measured at baseline as well as age 4, 5 and 6 years) in children with Fontan circulation. Presence of trouble sleeping was assessed at baseline and quality of life was assessed at baseline (age 3 years old) and annually for 3 years. Analysis was performed using the Wilcoxon sum rank test. Results 227 participants had data at baseline (age 3 years), and 196 participants completed HR-QOL measures at all time points. Parent-reported trouble sleeping was reported “often” or “almost always” in 11% of participants. Baseline trouble sleeping predicted decreased HR-QOL at all future time points, particularly psychosocial HR-QOL. Psychosocial HR-QOL as measured by the Peds QL was significantly lower at all time points in the group with trouble sleeping. At age 6 years, psychosocial HR-QOL remained significantly lower in the group with trouble sleeping at baseline on both the PedsQL (median score 78 [interquartile range 63, 90] vs 65 [58, 83], p=0.03) and the CHQ (median t-score 54 [47, 59] vs 47 [42, 53], p=0.002). Conclusion Trouble sleeping in children with Fontan circulation predicts future decreased HR-QOL. Better understanding of sleep problems is needed in children with Fontan circulation as sleep disorder treatment may lead to improved HR-QOL in this at-risk population. Support (If Any) Funding to DC from the American Heart Association and NIH-NHLBI. Single Ventricle Reconstruction study data obtained from the Pediatric Heart Network.

Chromosome 22q11 copy number variants and single ventricle CHD.

CHD is an important phenotypic feature of chromosome 22q11.2 copy number variants. Biventricular repair is usually possible, however there are rare reports of patients with chromosome 22q copy number variants and functional single ventricle cardiac disease. This is a single centre retrospective review of patients with chromosome 22q copy number variants who underwent staged single ventricle reconstructive surgery between 1 July, 1984 and 31 December, 2020. Seventeen patients met inclusion criteria. The most common diagnosis was hypoplastic left heart syndrome (n = 8) and vascular anomalies were present in 13 patients. A microdeletion of the chromosome 22 A-D low-copy repeat was present in 13 patients, and the remaining had a duplication. About half of the patients had documented craniofacial abnormalities and/or hypocalcaemia, and developmental delay was very common. Fifteen patients had a Norwood operation, 10 patients had a superior cavopulmonary anastomosis, and 7 patients had a Fontan. Two patients had cardiac transplantation after Fontan. Overall survival is 64% at 1 year, and 58% at 5 and 10 years. Most deaths occurred following Norwood operation (n = 5). CHD necessitating single ventricle reconstruction associated with chromosome 22q copy number variants is not common, but typically occurs as a variant of hypoplastic left heart syndrome with the usual cytogenetic microdeletion. The most common neonatal surgical intervention performed is the Norwood, where most of the mortality burden occurs. Associated anomalies and medical issues may cause additional morbidity after cardiac surgery, but survival is similar to infants with other types of single ventricle disease.

Relation of Norwood Shunt Type and Frequency of Arrhythmias at 6 Years (from the Single Ventricle Reconstruction Trial)

The Norwood procedure with a right ventricular to pulmonary artery shunt (RVPAS) decreases early mortality, but requires a ventriculotomy, possibly increasing risk of ventricular arrhythmias (VAs) compared with the modified Blalock-Taussig shunt (MBTS). The effect of shunt and Fontan type on arrhythmias by 6 years of age in the SVRII (Single Ventricle Reconstruction Extension Study) was assessed. SVRII data collected on 324 patients pre-/post-Fontan and annually at 2 to 6 years included antiarrhythmic medications, electrocardiography (ECG) at Fontan, and Holter/ECG at 6 years. ECGs and Holters were reviewed for morphology, intervals, atrioventricular conduction, and arrhythmias. Isolated VA were seen on 6-year Holter in >50% of both cohorts (MBTS 54% vs RVPAS 60%), whereas nonsustained ventricular tachycardia was rare and observed in RVPAS only (2.7%). First-degree atrioventricular block was more common in RVPAS than MBTS (21% vs 8%, p = 0.01), whereas right bundle branch block, QRS duration, and QTc were similar. Antiarrhythmic medication usage was common in both groups, but most agents also supported ventricular function (e.g., digoxin, carvedilol). Of the 7 patients with death or transplant between 2 and 6 years, none had documented VAs, but compared with transplant-free survivors, they had somewhat longer QRS (106 vs 93 ms, p = 0.05). Atrial tachyarrhythmias varied little between MBTS and RVPAS but did vary by Fontan type (lateral tunnel 41% vs extracardiac conduit 29%). VAs did not vary by Fontan type. In conclusion, at 6-year follow-up, benign VAs were common in the SVRII population. However, despite the potential for increased VAs and sudden death in the RVPAS cohort, these data do not support significant differences or increased risk at 6 years. The findings highlight the need for ongoing surveillance for arrhythmias in the SVR population.

Shunt resistance is associated with clinically important outcomes after the Norwood operation

BackgroundIn single-ventricle physiology, focus on pulmonary vascular resistance neglects the resistance in the conduit supplying the pulmonary inflow. MethodsConduit length and diameter, which can approximate conduit resistance, are available in the public dataset of Single Ventricle Reconstruction (SVR) trial. Conduit resistance was then calculated for SVR trial participants and the relationship with clinically important variables (death or transplant at 1 year, pulmonary artery size at second-stage palliation, pulmonary-to-systemic blood flow ratio, and supplemental oxygen requirement) was explored. To validate this calculated resistance, calculated resistance was compared with catheterization measurements at a single institution (not included in the SVR trial). ResultsIn the institutional dataset, calculated and measured resistances had an intraclass correlation of 0.78 for modified Blalock–Taussig shunts (MBTS). Within the SVR trial, transplant-free survivors had a lower MBTS resistance (median, 8.3 Woods Units [WU]. interquartile range [IQR], 6.5-11.1 WU) than patients who died or required transplantation (median, 13.0 WU; IQR, 9.4-16.6 WU, P = .0001). When we controlled for left pulmonary artery diameter after the Norwood procedure in the SVR trial, for each unit increase in MBTS resistance, the left pulmonary artery diameter at stage II decreased (–0.006 ± 0.002 cm, P = .005). When we controlled for pulmonary vascular resistance, greater MBTS resistance was associated with a decrease in log pulmonary-to-systemic blood flow ratio (–0.04 ± 0.015, P = .0048) in the SVR trial. Patients in the SVR trial requiring supplemental oxygen on admission for stage II palliation had greater MBTS resistance (median. 11.1 WU; IQR, 6.6-16.6 WU) than patients not requiring oxygen (median 8.3, WU; IQR, 6.5-11.1 WU, P = .015). ConclusionsConduit resistance is associated with important clinical outcomes after Norwood; however, further studies are required to guide conduit resistance optimization.