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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT0245531.

Identifying novel data-driven subgroups in congenital heart disease using multi-modal measures of brain structure.

Individuals with congenital heart disease (CHD) have an increased risk of neurodevelopmental impairments. Given the hypothesized complexity linking genomics, atypical brain structure, cardiac diagnoses and their management, and neurodevelopmental outcomes, unsupervised methods may provide unique insight into neurodevelopmental variability in CHD. Using data from the Pediatric Cardiac Genomics Consortium Brain and Genes study, we identified data-driven subgroups of individuals with CHD from measures of brain structure. Using structural magnetic resonance imaging (MRI; N = 93; cortical thickness, cortical volume, and subcortical volume), we identified subgroups that differed primarily on cardiac anatomic lesion and language ability. In contrast, using diffusion MRI (N = 88; white matter connectivity strength), we identified subgroups that were characterized by differences in associations with rare genetic variants and visual-motor function. This work provides insight into the differential impacts of cardiac lesions and genomic variation on brain growth and architecture in patients with CHD, with potentially distinct effects on neurodevelopmental outcomes.

Association Between Seasonal Fontan Timing, Viral Infection Burden, and Post-Operative Length of Stay.

The Fontan procedure (FP) is typically a semi-elective surgery performed between 2 and 5 years of age to complete staged single ventricle palliation. Optimal timing for the FP, particularly in relation to seasonal infectious burden, remains unclear. We queried the Pediatric Health Information System (PHIS) database for all admissions for viral respiratory infections (VRI) from January 2006 to September 2015 and separately for all admissions with a primary procedure code of FP. The PHIS query generated 2,767,142 admissions for VRI and 6349 admissions for the FP from 45 children's hospitals. Of all FP, 2124 (33.5%) were performed from October through March. The median length of stay after Fontan procedure was 9 days (IQR 7-15). Median length of stay after FP was correlated with VRI burden (correlation coefficient = 0.3, p = 0.03). April through August (weeks 18 through 35) had the lowest VRI admission burden and FP length of stay was significantly shorter during this time (13.6 ± 14.8 days vs 14.9 ± 20.3 days, p = 0.03). The FP is frequently performed during the viral respiratory season. This timing is associated with an increased post-operative length of stay after the FP. For elective FP, ideal timing that avoids the viral respiratory season and minimizes post-operative LOS is April through August.

Altered erythropoiesis in newborns with congenital heart disease.

BACKGROUND: Fetal hypoxia has been implicated in fetal growth restriction in congenital heart disease (CHD) and leads to stress erythropoiesis in utero. The objective is to assess erythropoiesis and its association with growth in newborns with CHD. METHODS: Fetuses with prenatally diagnosed CHD from 2013 to 2018 were retrospectively reviewed. Pregnancies with multiple gestation, genetic abnormalities, major extra-cardiac anomalies, and placental abruption were excluded. Complete blood count tests at birth were compared to published normative values. Spearman correlation assessed associations of red blood cell (RBC) indices with birth anthropometrics and prenatal Doppler measures. RESULTS: A total of 160 newborns were included. Median gestational age was 38.3 (37.3, 39.0) weeks. Infants ≥37 weeks gestation had lower hemoglobin (Hgb), hematocrit, and elevated nucleated RBC (nRBC), mean corpuscular volume, and mean corpuscular hemoglobin compared to reference. No differences in RBC indices were observed in infants <34 and 34-37 weeks gestation. There was no difference in Hgb and nRBC between CHD subgroups. Neither Hgb nor nRBC were associated with birth anthropometrics or Doppler patterns. CONCLUSIONS: Term infants with CHD demonstrated multiple alterations in erythrocyte indices suggesting ineffective stress erythropoiesis in late gestation resulting in lower Hgb at birth. Altered erythropoiesis was not correlated to growth or Doppler patterns. IMPACT: Newborns with congenital heart disease (CHD) born at term gestation demonstrated altered erythropoiesis. Term newborns with CHD have decreased hemoglobin levels despite having red blood cell indices consistent with stress erythropoiesis, suggesting an incomplete compensatory response to in utero physiologic disturbances associated with CHD. The etiology is unknown; however, it may be influenced by multiple risk factors during pregnancy in the maternal-fetal dyad. Alterations in red blood cell indices were not associated with outcomes of fetal growth.

Height Versus Body Surface Area to Normalize Cardiovascular Measurements in Children Using the Pediatric Heart Network Echocardiographic Z-Score Database.

Normalizing cardiovascular measurements for body size allows for comparison among children of different ages and for distinguishing pathologic changes from normal physiologic growth. Because of growing interest to use height for normalization, the aim of this study was to develop height-based normalization models and compare them to body surface area (BSA)-based normalization for aortic and left ventricular (LV) measurements. The study population consisted of healthy, non-obese children between 2 and 18 years of age enrolled in the Pediatric Heart Network Echo Z-Score Project. The echocardiographic study parameters included proximal aortic diameters at 3 locations, LV end-diastolic volume, and LV mass. Using the statistical methodology described in the original project, Z-scores based on height and BSA were determined for the study parameters and tested for any clinically significant relationships with age, sex, race, ethnicity, and body mass index (BMI). Normalization models based on height versus BSA were compared among underweight, normal weight, and overweight (but not obese) children in the study population. Z-scores based on height and BSA were calculated for the 5 study parameters and revealed no clinically significant relationships with age, sex, race, and ethnicity. Normalization based on height resulted in lower Z-scores in the underweight group compared to the overweight group, whereas normalization based on BSA resulted in higher Z-scores in the underweight group compared to the overweight group. In other words, increasing BMI had an opposite effect on height-based Z-scores compared to BSA-based Z-scores. Allometric normalization based on height and BSA for aortic and LV sizes is feasible. However, height-based normalization results in higher cardiovascular Z-scores in heavier children, and BSA-based normalization results in higher cardiovascular Z-scores in lighter children. Further studies are needed to assess the performance of these approaches in obese children with or without cardiac disease.

Recruitment, retention, and adherence in a clinical trial: The Pediatric Heart Network's Marfan Trial experience.

BACKGROUND/AIMS: The Pediatric Heart Network Marfan Trial was a randomized trial comparing atenolol versus losartan on aortic root dilation in 608 children and young adults with Marfan syndrome. Barriers to enrollment included a limited pool of eligible participants, restrictive entry criteria, and a diverse age range that required pediatric and adult expertise. Retention was complicated by a 3-year commitment to a complex study and medication regimen. The Network partnered with the Marfan Foundation, bridging the community with the research. The aims of this study are to report protocol and medication adherence and associated predictive factors, and to describe recruitment and retention strategies. METHODS: Recruitment, retention, and adherence to protocol activities related to the primary outcome were measured. Retention was measured by percentage of enrolled participants with 3-year outcome data. Protocol adherence was calculated by completion rates of study visits, ambulatory electrocardiography (Holter monitoring), and quarterly calls. Medication adherence was assessed by the number of tablets or the amount of liquid in bottles returned. Centers were ranked according to adherence (high, medium, and low tertiles). Recruitment, retention, and adherence questionnaires were completed by sites. Descriptive statistics summarized recruitment, retention, and adherence, as well as questionnaire results. Regression modeling assessed predictors of adherence. RESULTS: Completion rates for visits, Holter monitors, and quarterly calls were 99%, 94%, and 96%, respectively. Primary outcome data at 3 years were obtained for 88% of participants. The mean percentage of medication taken was estimated at 89%. Site and age were associated with all measures of adherence. Young adult and African American participants had lower levels of adherence. Higher adherence sites employed more strategies; had more staffing resources, less key staff turnover, and more collaboration with referring providers; utilized the Foundation's resources; and used a greater number of strategies to recruit, retain, and promote protocol and medication adherence. CONCLUSION: Overall adherence was excellent for this trial conducted within a National Institutes of Health-funded clinical trial network. Strategies specifically targeted to young adults and African Americans may have been beneficial. Many strategies employed by higher adherence sites are ones that any site could easily use, such as greeting families at non-study hospital visits, asking for family feedback, providing calendars for tracking schedules, and recommending apps for medication reminders. Additional key learnings include adherence differences by age, race, and site, the value of collaborative learning, and the importance of partnerships with patient advocacy groups. These lessons could shape recruitment, retention, and adherence to improve the quality of future complex trials involving rare conditions.

Tricuspid atresia with restrictive foramen ovale: A rare combination with implications on fetal growth.

Restrictive atrial communication is rarely reported in tricuspid atresia but when present it can lead to important morbidity. We describe two fetuses with tricuspid atresia with restrictive foramen ovale who were found to have fetal growth failure. Fetal echocardiography detected a restrictive atrial communication by flow acceleration on color Doppler and significant right atrial dilation in one patient; the atrial septum was not well interrogated in the other patient. Restrictive foramen ovale in tricuspid atresia may be associated with fetal growth failure. Color Doppler interrogation of the atrial septum on fetal echocardiogram may help identify this condition prenatally.

Congenital heart disease and aortic arch variants associated with mutation in PHOX2B.

PURPOSE: Congenital central hypoventilation syndrome (CCHS, OMIM 209880) is a rare autosomal dominant disorder caused by mutation in PHOX2B that manifests as a consequence of abnormal neural crest cell migration during embryogenesis. Unlike other neurocristopathies, however, its impact on the cardiovascular system has not been previously assessed. This study was an effort to characterize the association between congenital heart disease (CHD) and mutations in PHOX2B in patients with CCHS. METHODS: A retrospective review of patients with CCHS in conjunction with functional analysis of PHOX2B mutations associated with CHD was performed. To substantiate functional implications of identified variants, we conducted protein structure analyses and in silico mutagenesis were conducted. RESULTS: The prevalence of CHD among patients with CCHS was significantly greater (30%; p < 0.001) than that of the current estimated prevalence of CHD. The majority of patients had anomalies involving the proximal aortic arch and/or proximal coronary arteries. Variants associated with CHD in this cohort appear to disrupt DNA binding of PHOX2B via alteration of its homeobox domain. CONCLUSION: This is the first report of an association between CHD and mutation in PHOX2B. Results are highly suggestive that alteration or elimination of the homeobox domain conveys significant risk for associated CHD or aortic arch variation.

Fetal somatic growth trajectory differs by type of congenital heart disease.

BackgroundThe growth trajectories of common measurements, including estimated fetal weight (EFW), head circumference (HC), and abdominal circumference (AC), in fetuses with congenital heart disease (CHD) have not been described for different cardiac lesions. We hypothesized that (i) fetuses with CHD have differential growth in utero, and (ii) different categories of CHD demonstrate different in utero growth curves.MethodsWe performed a retrospective observational cohort study of pregnancies with known fetal CHD seen from January 2000 to June 2013. For analysis, the infants were divided into single ventricle (SV), biventricular conotruncal, d-transposition of great arteries (d-TGA), biventricular septal defects (SD; including atrial, ventricular, and atrioventricular SD), and all others (Other).ResultsA total of 194 newborns met inclusion criteria. There was significant differential growth of EFW in all CHD types, except d-TGA, starting with low z-scores before 25 weeks gestation, improving toward normal around 30-32 weeks gestation, and then again differential growth with advancing gestation. SV and SD groups had significant differential growth of HC starting early in gestation and linearly progressing negative z-scores with advancing gestation.ConclusionWe observed differences in the fetal growth curves throughout gestation for the major categories of CHD, including significant differential growth in even "simple" CHD, such as SD.

Diastolic dysfunction is associated with exercise impairment in patients with sickle cell anemia.

BACKGROUND: Left ventricular diastolic dysfunction (DD) is an independent risk factor for mortality in sickle cell anemia (SCA) and is associated with increased extracellular volume (ECV) on cardiac MRI (CMR). Exercise impairment is common in SCA, but its causes and prognostic value are not well understood. OBJECTIVE: To study the effects of DD and ECV on cardiopulmonary exercise test (CPET) in patients with SCA. METHODS AND RESULTS: As part of a prospective study to characterize the cardiomyopathy of SCA (NCT02410811), 20 children and adults with SCA underwent CMR, echocardiography, and cycle ergometer CPET (age range 8-43 years). Maximum exercise was reached in 18 patients and 17 (94%) had reduced exercise capacity (%predicted VO2 less than 80%). Six patients had DD and none had systolic dysfunction. Patients with DD had lower exercise capacity compared to patients with normal diastolic function (%predicted VO2 48.2 ± 9.1% vs. 61.2 ± 11.7%; P = 0.01). The z-score of left ventricular lateral E/e' ratio, which is a marker of DD, was negatively associated with %predicted VO2 (r = -0.61, P = 0.01). All patients with moderate-to-severe exercise impairment (%predicted VO2  < 60%) had lateral E/e' z-score > 2. In a multivariate analysis, lateral E/e' z-score was independently associated with %predicted VO2 (P = 0.02). All participants had elevated ECV but the degree of elevation was not associated with exercise parameters. CONCLUSION: Left ventricular DD is associated with decreased exercise capacity in SCA. Interventions to prevent or delay DD could improve exercise capacity, quality of life, and long-term outcomes in SCA.

Variable phenotype in a novel mutation in PHOX2B.

We evaluated a family with three siblings, two of whom ages 2 years and 19 months, had long segment colonic agangliosis and anisocoria. The mother also had anisocoria. All three affected family members were mildly dysmorphic with a flat facial profile, square appearance to the face, depressed nasal bridge, and anteverted nares. Genetic testing identified a novel heterozygous mutation, c.234C>G, resulting in a premature stop codon in exon 1 of the PHOX2B gene. Screening for neural crest tumors was performed in the siblings and to date has been negative. This family supports a strong association between non polyalanine tract mutations, autonomic dysfunction, and Hirschsprung disease, but suggests mutation outside of the polyalanine tract may not dictate severe phenotype with significant respiratory compromise. A unique finding in this family is the association of congenital heart disease in two of the affected patients. These malformations may be a sporadic isolated finding or the result of environmental factors or a modifying allele. Given the association between congenital heart disease and aberrant neural crest cell development, however, findings are suggestive that congenital heart disease may be a rare feature of PHOX2B mutation which has not been previously reported.

Translating clinical trials into clinical practice: a survey assessing the potential impact of the Pediatric Heart Network Infant Single Ventricle Trial.

BACKGROUND: A few studies have evaluated the impact of clinical trial results on practice in paediatric cardiology. The Infant Single Ventricle (ISV) Trial results published in 2010 did not support routine use of the angiotensin-converting enzyme inhibitor enalapril in infants with single-ventricle physiology. We sought to assess the influence of these findings on clinical practice. METHODS: A web-based survey was distributed via e-mail to over 2000 paediatric cardiologists, intensivists, cardiothoracic surgeons, and cardiac advance practice nurses during three distribution periods. The results were analysed using McNemar's test for paired data and Fisher's exact test. RESULTS: The response rate was 31.5% (69% cardiologists and 65% with >10 years of experience). Among respondents familiar with trial results, 74% reported current practice consistent with trial findings versus 48% before trial publication (p<0.001); 19% used angiotensin-converting enzyme inhibitor in this population "almost always" versus 36% in the past (p<0.001), and 72% reported a change in management or improved confidence in treatment decisions involving this therapy based on the trial results. Respondents familiar with trial results (78%) were marginally more likely to practise consistent with the trial results than those unfamiliar (74 versus 67%, p=0.16). Among all respondents, 28% reported less frequent use of angiotensin-converting enzyme inhibitor over the last 3 years. CONCLUSIONS: Within 5 years of publication, the majority of respondents was familiar with the Infant Single Ventricle Trial results and reported less frequent use of angiotensin-converting enzyme inhibitor in single-ventricle infants; however, 28% reported not adjusting their clinical decisions based on the trial's findings.

Growth Asymmetry, Head Circumference, and Neurodevelopmental Outcomes in Infants with Single Ventricles.

OBJECTIVE: To assess the variability in asymmetric growth and its association with neurodevelopment in infants with single ventricle (SV). STUDY DESIGN: We analyzed weight-for-age z-score minus head circumference-for-age z-score (HCAZ), relative head growth (cm/kg), along with individual growth variables in subjects prospectively enrolled in the Infant Single Ventricle Trial. Associations between growth indices and scores on the Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI) of the Bayley Scales of Infant Development-II (BSID-II) at 14 months were assessed. RESULTS: Of the 230 subjects enrolled in the Infant Single Ventricle trial, complete growth data and BSID-II scores were available in 168 (73%). Across the cohort, indices of asymmetric growth varied widely at enrollment and before superior cavopulmonary connection (SCPC) surgery. BSID-II scores were not associated with these asymmetry indices. In bivariate analyses, greater pre-SCPC HCAZ correlated with higher MDI (r = 0.21; P = .006) and PDI (r = 0.38; P < .001) and a greater HCAZ increase from enrollment to pre-SCPC with higher PDI (r = 0.15; P = .049). In multivariable modeling, pre-SCPC HCAZ was an independent predictor of PDI (P = .03), but not MDI. CONCLUSION: In infants with SV, growth asymmetry was not associated with neurodevelopment at 14 months, but pre-SCPC HCAZ was associated with PDI. Asymmetric growth, important in other high-risk infants, is not a brain-sparing adaptation in infants with SV. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00113087.

Intrauterine fetal demise after prenatal diagnosis of congenital heart disease: assessment of risk.

OBJECTIVES: Elective deliveries in fetal congenital heart disease (CHD) attempt to balance fetal and neonatal risk with the goal of optimizing overall outcome. However, the magnitude of the risk for intrauterine fetal demise (IUFD) is unclear. This study aimed to (1) determine the rate of IUFD and (2) identify fetal risk factors associated with IUFD. METHODS: Retrospective review of pregnancies complicated by CHD between 1998 and 2010. Data were collected regarding pregnancy outcome, extracardiac anomalies (ECA), genetic and cardiac diagnoses, severity of valve regurgitation, gestational age at birth and birth weight. Fisher's exact test and odds ratios were used to compare outcomes between groups. RESULTS: A total of 501 pregnancies analyzed resulted in 445 live births, 22 IUFD, 16 terminations and 18 unknown outcomes. Amongst IUFD, 27% had a genetic diagnosis, 50% had an ECA and 27% had severe valve regurgitation. IUFD odds increased threefold with ECA and sevenfold with severe valve regurgitation. IUFD occurred in 1.2% without risk factors. CONCLUSIONS: IUFD in fetuses with CHD is associated with ECA, genetic syndromes and severe valve regurgitation. In absence of these fetal characteristics, the occurrence of IUFD is low, although it remains higher than in fetuses without CHD.

Diagnosis of congenital heart disease in an era of universal prenatal ultrasound screening in southwest Ohio.

OBJECTIVES: Diagnostic ultrasound is widespread in obstetric practice, yet many babies with major congenital heart disease remain undiagnosed. Factors affecting prenatal diagnosis of major congenital heart disease are not well understood. This study aims to document prenatal detection rates for major congenital heart disease in the Greater Cincinnati area, and identify factors associated with lack of prenatal diagnosis. METHODS: All living infants diagnosed with major congenital heart disease by 4 months of age at our centre were prospectively identified. Prenatal care data were obtained by parent interview. Neonatal records were reviewed for postnatal data. Obstetricians were contacted for diagnostic ultrasound data. RESULTS: A total of 100 infants met the inclusion criteria. In all, 95 infants were analysed, of whom 94 were offered diagnostic ultrasound. In all, 41 had a prenatal diagnosis of major congenital heart disease. The rate of prenatal detection varied by cardiac lesion, with aortic arch abnormalities, semilunar valve abnormalities, and venous anomalies going undetected in this sample. Among subjects without prenatal detection, the highest proportion consisted of those having Level 1 diagnostic ultrasound only (66%). Prenatal detection was not significantly influenced by maternal race, education level, income, or insurance type. CONCLUSIONS: Despite nearly universal diagnostic ultrasound, detection rates of major congenital heart disease remain low in southwest Ohio. An educational outreach programme including outflow tract sweeps for community-level obstetrical personnel may improve detection rates.

Relationship between echocardiographic LV mass and ECG based left ventricular voltages in an adolescent population: related or random?

BACKGROUND: In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes. OBJECTIVES: Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes. METHODS: Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation. RESULTS: A total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14-18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%). CONCLUSION: There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics.

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

BACKGROUND: Morbidity 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. METHODS: We 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. RESULTS: Thirty-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. CONCLUSIONS: Shunt 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.

Achieving an Optimal Outcome After Stage 1 Palliation for Hypoplastic Left Heart Syndrome and Variants: Frequency, Associated Factors, and Subsequent Outcomes.

BACKGROUND: We sought to measure frequency of achieving an optimal outcome after stage 1 palliation (S1P) for hypoplastic left heart syndrome and variants, determine factors associated with optimal outcomes, and compare outcomes after stage 2 palliation (S2P) using the National Pediatric Cardiology Quality Improvement Collaborative database (2008-2016). METHODS AND RESULTS: This is a retrospective cohort study with optimal outcome defined a priori as meeting all of the following: (1) discharge after S1P in <19 days (top quartile), (2) no red flag or major event readmissions before S2P, and (3) performing S2P between 90 and 240 days of age. Optimal outcome was achieved in 256 of 2182 patients (11.7%). Frequency varied among centers from 0% to 25%. Factors independently associated with an optimal outcome after S1P were higher gestational age (odds ratio [OR], 1.1 per week [95% CI, 1.0-1.2]; P=0.02); absence of a genetic syndrome (OR, 2.5 [95% CI, 1.2-5]; P=0.02); not requiring a post-S1P catheterization (OR, 2.7 [95% CI, 1.5-4.8]; P=0.01), intervention (OR, 1.5 [95% CI, 1.1-2]; P=0.006), or a procedure (OR, 4.5 [95% CI, 2.8-7.1]; P<0.001) before discharge; and not having a post-S1P complication (OR, 2.7 [95% CI, 1.9-3.7]; P<0.001). Those with an optimal outcome after S1P had improved S2P outcomes including shorter length of stay, less ventilator days, shorter bypass time, and fewer postoperative complications. CONCLUSIONS: Identifying patients at lowest risk for poor outcomes during the home interstage period could shift necessary resources to those at higher risk, alter S2P postoperative expectations, and improve quality of life for families at lower risk.

Preoperative Hemodynamics Impact the Benefit of Fenestration on Fontan Postoperative Length of Stay.

BACKGROUND: Utilization of Fontan fenestration varies considerably by center. OBJECTIVES: Using a multicenter Pediatric Heart Network dataset linking surgical and preoperative hemodynamic variables, the authors evaluated factors associated with use of Fontan fenestration and the impact of fenestration on post-Fontan length of stay (LOS). METHODS: Patients 2 to 6 years old at Fontan surgery from 2010 to 2020 with catheterization<1 year prior were included. Factors associated with fenestration were evaluated using multivariable logistic regression adjusting for key covariates. Restrictive cubic spline analysis was used to evaluate potential cut-points for hemodynamic variables associated with longer postoperative LOS stratified by fenestration with multivariable linear regression to evaluate the magnitude of effect. RESULTS: Fenestration was used in 465 of 702 patients (66.2%). Placement of a fenestration was associated with center (range 27%-93% use, P < 0.0001) and Fontan type (OR: 14.1 for lateral tunnel vs extracardiac conduit, P < 0.0001). No hemodynamic variable was independently associated with fenestration. In a multivariable linear model adjusting for center, a center-fenestration interaction, prematurity, preoperative mean pulmonary artery pressure (mPAP), and cardiac index, fenestration was associated with shorter hospital LOS after Fontan (P = 0.0024). The benefit was most pronounced at mPAP ≥13 mm Hg (median LOS: 9 vs 12 days, P = 0.001). CONCLUSIONS: There is wide center variability in use of Fontan fenestration that is not explained by preoperative hemodynamics. Fenestration is independently associated with shorter LOS, and those with mPAP ≥13 mm Hg at pre-Fontan catheterization benefit the most. We propose this threshold as minimal criteria for fenestration.

Microcephaly is associated with early adverse neurologic outcomes in hypoplastic left heart syndrome.

BACKGROUND: Hypoplastic left heart syndrome (HLHS) is associated with significant mortality and morbidity. Fetal head growth abnormalities have been identified in a subset of HLHS fetuses, but it is unclear whether specific patterns of maladaptive growth affect clinical outcomes. We hypothesized that poor fetal head growth is associated with an increased frequency of adverse clinical outcomes. METHODS: We retrospectively examined a cohort of HLHS patients from midgestation to 1 y of age. Fetal and birth anthropometric measurements were analyzed using the Olsen standard, and clinical outcomes were obtained. RESULTS: A total of 104 HLHS patients were identified over a 12-y period; fetal data were available in 38 cases. HLHS neonates demonstrated a high incidence of microcephaly (12%), small head size (27%), and poor head growth (32%). All-cause mortality was 31% at 30 d and 43% at 1 y. Neurologic outcomes were observed in 12% of patients and were significantly increased with microcephaly (43 vs. 4%; P = 0.02). The average length of hospital stay following stage I palliation was 33.4 ± 33 d, correcting for early death. CONCLUSION: In term nonsyndromic HLHS, fetal and neonatal microcephaly are associated with early adverse neurologic outcomes but not mortality.