A three-stage intrathymic development pathway for the mucosal-associated invariant T cell lineage.

Mucosal-associated invariant T cells (MAIT cells) detect microbial vitamin B2 derivatives presented by the antigen-presenting molecule MR1. Here we defined three developmental stages and checkpoints for the MAIT cell lineage in humans and mice. Stage 1 and stage 2 MAIT cells predominated in thymus, while stage 3 cells progressively increased in abundance extrathymically. Transition through each checkpoint was regulated by MR1, whereas the final checkpoint that generated mature functional MAIT cells was controlled by multiple factors, including the transcription factor PLZF and microbial colonization. Furthermore, stage 3 MAIT cell populations were expanded in mice deficient in the antigen-presenting molecule CD1d, suggestive of a niche shared by MAIT cells and natural killer T cells (NKT cells). Accordingly, this study maps the developmental pathway and checkpoints that control the generation of functional MAIT cells.

--Connecting Transcriptomics with Computational Modeling to Reveal Developmental Adaptations in Pediatric Human Atrial Tissue.

Nearly 1% of babies are born with congenital heart disease (CHD) - many of whom will require heart surgery within the first few years of life. A detailed understanding of cardiac maturation can help to expand our knowledge on cardiac diseases that develop during gestation, identify age-appropriate drug therapies, and inform clinical care decisions related to surgical repair and postoperative management. Yet, to date, our knowledge of the temporal changes that cardiomyocytes undergo during postnatal development is limited. In this study, we collected right atrial tissue samples from pediatric patients (n=117) undergoing heart surgery. Patients were stratified into five age groups. We measured age-dependent adaptations in cardiac gene expression, and used computational modeling to simulate action potential and calcium transients. Enrichment of differentially expressed genes (DEGs) revealed age-dependent changes in several key biological processes (e.g., cell cycle, structural organization), cardiac ion channels, and calcium handling genes. Gene-associated changes in ionic currents exhibited age-dependent trends, with changes in calcium handling (INCX) and repolarization (IK1) most strongly associated with an age-dependent decrease in the action potential plateau potential and increase in triangulation, respectively. We observed a shift in repolarization reserve, with lower IKr expression in younger patients, a finding potentially tied to an increased amplitude of IKs that could be triggered by elevated sympathetic activation in pediatric patients. Collectively, this study provides valuable insights into age-dependent changes in human cardiac gene expression and electrophysiology, shedding light on molecular mechanisms underlying cardiac maturation and function throughout development.

Wellbeing in Children and Adolescents with Fontan Physiology.

OBJECTIVE: To assess health-related quality of life (HRQOL) and global quality of life (QOL) in children and adolescents with Fontan physiology and identify key predictors influencing these outcomes. STUDY DESIGN: Cross-sectional analysis of 73 children and adolescents enrolled in the Australia and New Zealand Fontan Registry aged 6-17 years, at least 12 months post-Fontan operation. Assessments included the Pediatric Quality of Life Inventory (PedsQL) for HRQOL and a developmentally-tailored visual analogue scale (0-10) for global QOL, along with validated sociodemographic, clinical, psychological, relational, and parental measures. Clinical data were provided by the Australia and New Zealand Fontan Registry. RESULTS: Participants (mean age: 11.5 ± 2.6 years, 62% male) reported lower overall HRQOL (P < .001), and lower scores across all HRQOL domains (all P < .0001), compared with normative data. Median global QOL score was 7.0 (IQR 5.8-8.0), with most participants (79%) rating their global QOL ≥6. Anxiety and depressive symptoms requiring clinical assessment were reported by 21% and 26% of participants, respectively. Age, sex, and perceived seriousness of congenital heart disease explained 15% of the variation in HRQOL scores, while depressive symptoms and treatment-related anxiety explained an additional 37% (final model: 52% of variance explained). For global QOL, sociodemographic and clinical factors explained 13% of the variance in scores, while depressive symptoms explained a further 25% (final model: 38% of variance explained). Parental factors were not associated with child QOL outcomes. CONCLUSIONS: Children and adolescents with Fontan physiology experience lower HRQOL than community-based norms, despite reporting fair overall QOL. Psychological factors predominantly influenced QOL outcomes, indicating strategies to bolster psychological health could improve QOL in this population.

Comprehensive Characterization of Surface-Bound Proteins and Measurement of Fibrin Fiber Thickness on Extracorporeal Membrane Oxygenation Circuits Collected From Patients.

OBJECTIVE: To characterize surface-bound proteins and to measure the thickness of fibrin fibers bound to extracorporeal membrane oxygenation (ECMO) circuits used in children. DESIGN: Single-center observational prospective study, April to November 2021. SETTING: PICU, Royal Children's Hospital, Melbourne, Australia. PATIENTS: Patients aged less than 18 years on venoarterial ECMO and without preexisting disorder. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: ECMO circuits were collected from six patients. Circuit samples were collected from five different sites, and subsequently processed for proteomic and scanning electron microscopy (SEM) studies. The concentration of proteins bound to ECMO circuit samples was measured using a bicinchoninic acid protein assay, whereas characterization of the bound proteome was performed using data-independent acquisition mass spectrometry. The Reactome Over-representation Pathway Analyses tool was used to identify functional pathways related to bound proteins. For the SEM studies, ECMO circuit samples were prepared and imaged, and the thickness of bound fibrin fibers was measured using the Fiji ImageJ software, version 1.53c (https://imagej.net/software/fiji/). Protein binding to ECMO circuit samples and fibrin networks showed significant intra-circuit and interpatient variation. The median (range) total protein concentration was 19.0 (0-76.9) µg/mL, and the median total number of proteins was 2011 (1435-2777). A total of 933 proteins were commonly bound to ECMO circuit samples from all patients and were functionally involved in 212 pathways, with signal transduction, cell cycle, and metabolism of proteins being the top three pathway categories. The median intra-circuit fibrin fiber thickness was 0.20 (0.15-0.24) µm, whereas the median interpatient fibrin fiber thickness was 0.18 (0.15-0.21) µm. CONCLUSIONS: In this report, we have characterized proteins and fiber fibrin thickness bound to ECMO circuits in six children. The techniques and approaches may be useful for investigating interactions between blood, coagulation, and the ECMO circuit and have the potential for circuit design.

Reconstruction of Fibrous Skeleton of the Heart for Double-Valve Replacement in A Pediatric Patient - Modified Commando Procedure.

The so-called Commando procedure, initially described by David and colleagues, consists in the reconstruction of the mitro-aortic fibrous lamina by a patch that enlarges both annuli. Its use has been described to upsize the aortic and mitral annulus for double valve replacement in adolescents. We describe a modified technique of this reconstruction of the fibrous skeleton of the heart, combined with Konno procedure to further enlarge the aortic annulus. In modified Commando procedure, following the reconstruction of aortomitral continuity with a bovine pericardium CardioCel patch (Admedus Regen Pty Ltd, Perth, WA, Australia), an aortic valved conduit that was made on the bench in order to have bottom skirt that enabled the suturing of the composite conduit far inside the left ventricle outflow tract. Coronary buttons were implanted at the supra-commissural level. The advantages of this modified Commando procedure are (1) the creation of a new aortic annulus when the integrity of this annulus has been compromised, (2) the upsizing of both annuli to any possible size of aortic and mitral prostheses, and (3) the relief of any residual left ventricular outflow tract obstruction.

The Children's National Hospital Outcomes Registry: a plea for a benchmarking tool that provides longitudinal outcomes for patients and families.

Surgical advancements in paediatric cardiovascular surgery have led to improved survival rates for those patients with the most complex CHDs leading to greater numbers of patients who are living well into adulthood. Despite this new era of long-term survival, our current reporting systems continue to focus largely on using short-term postoperative outcomes as the criteria to both rate and rank hospitals. Using such limited criteria to rate and rank hospitals may mislead the intended audiences: patients and families. The goal of this article is to describe the creation of a local benchmarking report which aims to retrospectively review long-term outcomes from our single centre. This report is updated annually and published on our cardiac surgery webpage in an effort to be as transparent as possible for our patient and family communities.

Transcatheter occlusion of venovenous collaterals in the total cavopulmonary Fontan circulation.

BACKGROUND: Venovenous collaterals are abnormal connections between the systemic and pulmonary venous systems. They are commonly seen in the Fontan circulation and may lead to significant hypoxaemia. Transcatheter closure of venovenous collaterals is a potential but controversial treatment as the long-term benefits and outcomes are not well understood. METHODS: This retrospective cohort study utilised data from the Australian and New Zealand Fontan Registry. Patients who underwent transcatheter venovenous collateral occlusion for hypoxemia from the year 2000 onwards were included. Atriopulmonary and Kawashima-type Fontan circulations were excluded to reflect a more contemporary Fontan cohort. RESULTS: Nineteen patients (age 19.3 ± 7.8 years, 53% female) underwent transcatheter venovenous collateral occlusion. Compared to baseline, mean oxygen saturation was improved at latest follow-up (90.5% vs 87.0%; p = 0.003). Nine patients achieved a clinically significant response (defined as an increase of at least 5% to 90% or greater), and this was associated with lower baseline Fontan pressures (12.9 v 15.6 mmHg; p = 0.02). No heart failure hospitalisations, arrhythmia, transplant referrals, or mortality were observed during the median follow-up period of 4 years. Two patients experienced thromboembolic events and five patients underwent re-intervention. CONCLUSION: Transcatheter occlusion of venovenous collaterals in Fontan patients with chronic hypoxaemia resulted in a modest increase in oxygenation over a median follow-up of 4 years and longer-term prognosis did not appear to be adversely affected. Lower Fontan pressures at baseline were associated with a greater improvement in oxygenation.

Exercise Capacity and Reoperation Late After Transatrial Fallot Repair.

BACKGROUND: The exercise capacity long after repair of tetralogy of Fallot, when performed exclusively with a transatrial repair, is unclear. It is also unknown whether echocardiography and cardiopulmonary exercise testing can predict the risk of reoperation in this patient group. METHOD: We retrospectively reviewed the clinical records of 59 patients who underwent cardiopulmonary exercise testing after transatrial Fallot repair at a single centre. Patients underwent cardiopulmonary exercise testing at a mean age of 16.6±4.4 years, and at 15.3±4.1 years after Fallot repair. RESULTS: At testing, the volume of oxygen consumption at maximal exercise (VO2 max) was 71%±13% and the oxygen pulse was 80%±17% of predicted values. Seventeen (17) patients (29%) had a VO2 max superior to 80% of the predicted value. Thirty-two (32) patients (56%) had severe pulmonary regurgitation, three (5%) had moderate pulmonary regurgitation, and 12 (21%) had mild pulmonary regurgitation. After a mean of 7.8±3.9 years following cardiopulmonary exercise testing (23±5.3 years after the repair), 21 (40%) patients underwent reoperation. Right ventricular dilation and systolic function on echocardiography were both significantly associated with subsequent reoperation rates. Patients who had severe right ventricular dilation were eight times more likely to undergo subsequent reoperation (hazard ratio 8.67; 1.82-41.3; p=0.007). No cardiopulmonary exercise testing variable independently predicted reoperation. CONCLUSIONS: The exercise capacity at adolescence following transatrial repair of tetralogy of Fallot is maintained at around 70% of predicted values. Only the patients with normal right ventricular size and normal right ventricular function seemed to be protected from reoperation over the subsequent decade. We found no exercise variables which predicted reoperation.

Prolonged Enteral Tube Feeding in Infants With a Functional Single Ventricle Is Associated With Adverse Outcomes After Fontan Completion.

OBJECTIVES: To define the baseline characteristics of long-term tube-fed (TF) single ventricle patients, investigate associations between long-term enteral tube feeding and growth, and determine associations with long-term outcomes after Fontan procedure. STUDY DESIGN: We performed a retrospective cohort study of patients in the Australia and New Zealand Fontan Registry undergoing treatment at the Royal Children's Hospital, the Children's Hospital at Westmead, Royal Melbourne Hospital, and Royal Prince Alfred Hospital from 1981 to 2018. Patients were defined as TF or non-tube-fed (NTF) based on enteral tube feeding at the age of 90 days. Feeding groups were compared regarding body mass index (BMI) trajectory, BMI at last follow-up, and long-term incidence of severe Fontan failure. RESULTS: Of 390 patients (56 [14%] TF, 334 [86%] NTF), TF was associated with right ventricular dominance, hypoplastic left heart syndrome, Norwood procedure, increased procedures prior to Fontan, extracardiac conduit Fontan, Fontan fenestration, and atrioventricular valve repair/replacement. TF patients were less likely to be in the higher compared with lowest 0-6 month BMI trajectory (P < .01; P = .03), had lower 6 month weight-for-age z-scores (P < .01) and length-for-age z-scores (P = .01). TF were less likely to be overweight/obese at pediatric follow-up (hazard ratio [HR] = 0.31, 95% CI: 0.12-0.80; P = .02) and more likely to be underweight at adult follow-up (HR = 16.51; 5% CI: 2.70-101.10; P < .01). TF compared with NTF was associated with increased risk of severe Fontan failure (HR = 4.13; 95% CI = 1.65-10.31; P < .01). CONCLUSIONS: Prolonged infant enteral tube feeding is an independent marker of poor growth and adverse clinical outcomes extending long-term post-Fontan procedure.

Changes in von Willebrand Factor Multimers, Concentration, and Function During Pediatric Extracorporeal Membrane Oxygenation.

OBJECTIVES: To investigate changes in von Willebrand factor (VWF) concentration, function, and multimers during pediatric extracorporeal membrane oxygenation (ECMO) and determine whether routine monitoring of VWF during ECMO would be useful in predicting bleeding. DESIGN: Prospective observational study of pediatric ECMO patients from April 2017 to May 2019. SETTING: The PICU in a large, tertiary referral pediatric ECMO center. PATIENTS: Twenty-five neonates and children (< 18 yr) supported by venoarterial ECMO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Arterial blood samples were collected within 24 hours pre-ECMO, daily for the first 5 days of ECMO, every second day until decannulation, and 24 hours post-ECMO. The STA R Max analyzer was used to measure VWF antigen (VWF:Ag) and ristocetin cofactor (VWF:RCo) activity. VWF collagen binding (VWF:CB) was measured using an enzyme-linked immunosorbent assay. VWF multimers were measured using the semi-automated Hydragel 11 VWF Multimer assay. Corresponding clinical data for each patient was also recorded. A total of 25 venoarterial ECMO patients were recruited (median age, 73 d; interquartile range [IQR], 3 d to 1 yr). The median ECMO duration was 4 days (IQR, 3-8 d) and 15 patients had at least one major bleed during ECMO. The percentage of high molecular weight multimers (HMWM) decreased and intermediate molecular weight multimers increased while patients were on ECMO, irrespective of a bleeding status. VWF:Ag increased and the VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios decreased while patients were on ECMO compared with the baseline pre-ECMO samples and healthy children. CONCLUSIONS: Neonates and children on ECMO exhibited a loss of HMWM and lower VWF:CB/VWF:Ag and VWF:RCo/VWF:Ag ratios compared with healthy children, irrespective of major bleeding occurring. Therefore, monitoring VWF during ECMO would not be useful in predicting bleeding in these patients and changes to other hemostatic factors should be investigated to further understand bleeding during ECMO.

Are dynamic measurements of central venous pressure in Fontan circulation during exercise or volume loading superior to resting measurements?

BACKGROUND: The main objective measure to assess the health of the Fontan circulation is the pressure measurement of the superior vena cava or pulmonary arteries. We reviewed the literature for benefits of measuring resting pressure in the Fontan circuit and explored whether dynamic measurement by volume loading or exercise has the potential to refine this diagnostic tool. METHODS: PubMed was searched for articles showing a relationship between resting post-operative central venous pressure or pulmonary artery pressure and Fontan failure. Relationships between post-operative central venous pressure or pulmonary artery pressure and volume loading changes, such as during exercise or volume loading during cardiac catheterization, were also queried. RESULTS: A total of 44 articles mentioned relationships between resting central venous pressure or pulmonary artery pressure and Fontan failure. Only 26 included an analysis between the variables and only seven of those articles found pressure to be predictive of Fontan failure. Ten articles examined the relationship between exercise or volume loading and outcomes and demonstrated a large individual variation of pressures under these dynamic conditions. CONCLUSIONS: Based on current literature, there is not a lot of strong evidence to show that elevated resting central venous pressure or pulmonary artery pressure is predictive of Fontan failure. Some individuals experience dramatic increases in central venous pressure or pulmonary artery pressure under increased loading conditions with exercise or bolus fluid infusion, while others experience increases closer to that of a healthy control population. Further studies are needed to examine whether more dynamic and continuous monitoring of systemic venous pressures might better predict outcomes in patients with Fontan circulation.

Neurocognitive Dysfunction and Smaller Brain Volumes in Adolescents and Adults With a Fontan Circulation.

BACKGROUND: Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors. METHODS: In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected. RESULTS: Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls (P<0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure (P<0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P=0.01 and working memory, P=0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning (P<0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes (P<0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions (P<0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains (P<0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations (P≤0.04). CONCLUSIONS: Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount.

Platelet Phenotype and Function Changes With Increasing Duration of Extracorporeal Membrane Oxygenation.

OBJECTIVES: To investigate platelet pathophysiology associated with pediatric extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective observational study of neonatal and pediatric ECMO patients from September 1, 2016, to December 31, 2019. SETTING: The PICU in a large tertiary referral pediatric ECMO center. PATIENTS: Eighty-seven neonates and children (< 18 yr) supported by ECMO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Arterial blood samples were collected on days 1, 2, and 5 of ECMO and were analyzed by whole blood flow cytometry. Corresponding clinical data for each patient was also recorded. A total of 87 patients were recruited (median age, 65 d; interquartile range [IQR], 7 d to 4 yr). The median duration of ECMO was 5 days (IQR, 3-8 d) with a median length of stay in PICU and hospital of 18 days (IQR, 10-29 d) and 35 days (IQR, 19-75 d), respectively. Forty-two patients (48%) had at least one major bleed according to a priori determined definitions, and 12 patients (14%) had at least one thrombotic event during ECMO. Platelet fibrinogen receptor expression decreased (median fluorescence intensity [MFI], 29,256 vs 26,544; p = 0.0005), while von Willebrand Factor expression increased (MFI: 7,620 vs 8,829; p = 0.0459) from day 2 to day 5 of ECMO. Platelet response to agonist, Thrombin Receptor Activator Peptide 6, also decreased from day 2 to day 5 of ECMO, as measured by binding with anti-P-selectin, PAC-1 (binds activated GPIIb/IIIa), and anti-CD63 monoclonal antibodies (P-selectin area under the curve [AUC]: 63.46 vs 42.82, respectively, p = 0.0022; PAC-1 AUC: 93.75 vs 74.46, p = 0.0191; CD63 AUC: 55.69 vs 41.76, p = 0.0020). CONCLUSIONS: The loss of platelet response over time may contribute to bleeding during ECMO. These novel insights may be useful in understanding mechanisms of bleeding in pediatric ECMO and monitoring platelet markers clinically could allow for prediction or early detection of bleeding and thrombosis.

Being born with a single cardiac ventricle: What do we tell prospective parents.

Single ventricle cardiac disease remains one of the most extreme forms of congenital heart disease. It encompasses a wide variety of lesions characterised by the existence of one small ventricular cavity. We now realise that survival of this group is much longer than expected, well into adulthood for the majority with current techniques, albeit with a considerable burden of disease for many. Here we give a up to date review of single ventricle cardiac disease. We include discussion regarding prenatal assessment and planning, usual treatment pathways, short and long term outcomes and a discussion on the future for this patient group. We combine this information to give a contemporary perspective on our counselling approach appropriate for those who are the first contact and primary conveyors of this information to families.

Early Peritoneal Dialysis and Postoperative Outcomes in Infants After Pediatric Cardiac Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: Peritoneal dialysis (PD) is used in several cardiac surgical units after cardiac surgery, and early initiation of PD after surgery may have the potential to influence postoperative outcomes. This systematic review and meta-analysis aims to summarize the evidence for the association between early PD after cardiac surgery and postoperative outcomes. DATA SOURCES: MEDLINE, Embase, and PubMed from 1981 to November 1, 2021. STUDY SELECTION: Observational studies and randomized trials reporting on early PD after pediatric cardiac surgery. DATA EXTRACTION: Random-effects meta-analysis was used to estimate the pooled odds ratios (ORs) and their 95% CIs for postoperative mortality and pooled mean difference (MD) (95% CI) for duration of mechanical ventilation and ICU length of stay. DATA SYNTHESIS: We identified nine studies from the systematic review, and five were considered suitable for meta-analysis. Early initiation of PD after cardiac surgery was associated with a reduction in postoperative mortality (OR, 0.43 (95% CI, 0.23-0.80); number of estimates = 4). Early commencement of PD shortened duration of mechanical ventilation (MD [95% CI], -1.09 d [-1.86 to -0.33 d]; I2 = 56.1%; p = 0.06) and intensive care length of stay (MD [95% CI], -2.46 d [-3.57 to -1.35 d]; I2 = 18.7%; p = 0.30], respectively. All three estimates had broad 95% prediction intervals (crossing null) denoting major heterogeneity between studies and wide range of possible study estimates in similar future studies. Overall, studies reporting on the effects of early PD included only a subset of infants undergoing cardiac surgery (typically high-risk infants), so selection bias may be a major issue in published studies. CONCLUSIONS: This review suggests that early initiation of PD may be associated with beneficial postoperative outcomes in infants after cardiac surgery. However, these results were based on studies of varying qualities and risk of bias. Early identification of high-risk infants after cardiac surgery is important so that prevention or early mitigation strategies can be applied to this cohort. Future prospective studies in high-risk populations are needed to study the role of early PD in influencing postoperative outcomes.

Cardiopulmonary bypass in a child with erythropoietic protoporphyria.

Children with erythropoietic porphyria are generally under the care of paediatric dermatologists. When these children undergo major surgery, they are at risk of unusual complications due to their photosensitivity. Dermatologists may be consulted prior to surgery for advice. We describe a case of a child with erythropoietic porphyria undergoing open heart surgery, utilising an exchange transfusion alongside other strategies to minimise the risk of photosensitivity-induced haemolysis.

Very preterm and very low birthweight infant with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, and discontinuous pulmonary arteries.

Prematurity and low birthweight are associated with increased mortality in infants undergoing cardiac surgery. Pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation carries one of the highest risks of mortality. We present a patient who was born at 28 weeks of gestation at 1.2 kg, with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, coronary artery atresia, and discontinuous pulmonary arteries, who successfully underwent palliation with a modified Blalock-Taussig shunt, pulmonary arterioplasty, and subsequently a bidirectional Glenn.

Adolescents and adults with Fontan circulation: insights from the PREpArE-Fontan registry.

The Patient Registry for Adolescents and Adults with Stable Fontan Circulation aims to describe a contemporary cohort of Fontan patients who could be eligible for a clinical trial investigating macitentan, an endothelin receptor antagonist. This international, non-interventional, multicentre, cross-sectional, observational registry enrolled patients with "stable" Fontan circulation ≥10 years following extra-cardiac conduit or lateral tunnel procedure. Main exclusion criteria were NYHA functional class IV, reoperation of Fontan circulation, or signs of disease worsening. Patient characteristics at enrolment are described; available data were collected during a single registration visit. Of the 266 screened patients, 254 were included in this analysis. At enrolment, median (interquartile range) age was 24 (20;30) years, 37%/63% of patients were from the USA/Europe, 54% were male, 54%/47% had undergone extra-cardiac conduit/lateral tunnel procedures, and 95% were in NYHA functional class I or II. History of arrhythmia was more common in older patients and patients with lateral tunnel; overall prevalence was 19%. Most laboratory values were within the normal range but mean creatinine clearance was abnormally low (87.7 ml/min). Angiotensin-converting enzyme inhibitors were used by 48% of patients and their use was associated with creatinine clearance <90 ml/min (p = 0.007), as was Fontan completion at an older age (p = 0.007). 53.4% of patients had clinical characteristics that could potentially meet an endothelin receptor antagonist trial's eligibility criteria. The PREpArE-Fontan registry describes a cohort of patients who could potentially participate in an endothelin receptor antagonist trial and identified early subtle signs of Fontan failure, even in "stable" patients.

Effect of Nitric Oxide via Cardiopulmonary Bypass on Ventilator-Free Days in Young Children Undergoing Congenital Heart Disease Surgery: The NITRIC Randomized Clinical Trial.

Importance: In children undergoing heart surgery, nitric oxide administered into the gas flow of the cardiopulmonary bypass oxygenator may reduce postoperative low cardiac output syndrome, leading to improved recovery and shorter duration of respiratory support. It remains uncertain whether nitric oxide administered into the cardiopulmonary bypass oxygenator improves ventilator-free days (days alive and free from mechanical ventilation). Objective: To determine the effect of nitric oxide applied into the cardiopulmonary bypass oxygenator vs standard care on ventilator-free days in children undergoing surgery for congenital heart disease. Design, Setting, and Participants: Double-blind, multicenter, randomized clinical trial in 6 pediatric cardiac surgical centers in Australia, New Zealand, and the Netherlands. A total of 1371 children younger than 2 years undergoing congenital heart surgery were randomized between July 2017 and April 2021, with 28-day follow-up of the last participant completed on May 24, 2021. Interventions: Patients were assigned to receive nitric oxide at 20 ppm delivered into the cardiopulmonary bypass oxygenator (n = 679) or standard care cardiopulmonary bypass without nitric oxide (n = 685). Main Outcomes and Measures: The primary end point was the number of ventilator-free days from commencement of bypass until day 28. There were 4 secondary end points including a composite of low cardiac output syndrome, extracorporeal life support, or death; length of stay in the intensive care unit; length of stay in the hospital; and postoperative troponin levels. Results: Among 1371 patients who were randomized (mean [SD] age, 21.2 [23.5] weeks; 587 girls [42.8%]), 1364 (99.5%) completed the trial. The number of ventilator-free days did not differ significantly between the nitric oxide and standard care groups, with a median of 26.6 days (IQR, 24.4 to 27.4) vs 26.4 days (IQR, 24.0 to 27.2), respectively, for an absolute difference of -0.01 days (95% CI, -0.25 to 0.22; P = .92). A total of 22.5% of the nitric oxide group and 20.9% of the standard care group developed low cardiac output syndrome within 48 hours, needed extracorporeal support within 48 hours, or died by day 28, for an adjusted odds ratio of 1.12 (95% CI, 0.85 to 1.47). Other secondary outcomes were not significantly different between the groups. Conclusions and Relevance: In children younger than 2 years undergoing cardiopulmonary bypass surgery for congenital heart disease, the use of nitric oxide via cardiopulmonary bypass did not significantly affect the number of ventilator-free days. These findings do not support the use of nitric oxide delivered into the cardiopulmonary bypass oxygenator during heart surgery. Trial Registration: anzctr.org.au Identifier: ACTRN12617000821392.

Surveillance of End-Organ Damage in Fontan Patients Prior to Transition to Adult Care: Are We There Yet?

BACKGROUND: Recently published guidelines and consensus statements have outlined recommended screening practices for monitoring of end-organ dysfunction in Fontan patients. We reviewed the current approach to end-organ screening in a local population of Fontan patients at the time of transition to adult care. METHODS: Patient data from the Australia and New Zealand Fontan Registry and patient medical records were used to review investigations performed in Fontan patients transitioned from The Royal Children's Hospital Melbourne to an adult centre between 1 July 2015 and 30 June 2020. RESULTS: A total of 32 patients were referred for transition to an adult centre between 1 July 2015 and 30 June 2020 at a mean age of 18.5±0.7 years (12.7±2.5 years post-Fontan). Liver function tests were performed in 22 patients (69%) within 5 years prior to transition and were abnormal in 15 patients (68%). Liver ultrasound was performed in 13 patients (41%) within 5 years prior to the date of transition, of whom 10 (77%) had abnormal findings (features suggestive of hepatic fibrosis in seven [54%], cirrhosis in two [15%], and portal hypertension in three [23%]). Fourteen (14) patients (44%) had no record of a liver ultrasound being performed between the date of the Fontan procedure and the time of transition to adult care. Hepatocellular carcinoma was diagnosed in one patient at 18 months following transition. A total of 24 patients (75%) had a serum creatinine measured within the 5 years prior to transition, and two (8%) had an estimated glomerular filtration rate (eGFR) less than 90 mL/min/1.73 m2. No patient had a urine protein-creatinine ratio measured between the date of the Fontan procedure and the time of transition to adult care. CONCLUSIONS: In this study we have identified that the majority of patients transitioned from a tertiary paediatric centre to an adult centre within the last 5 years did not undergo routine surveillance for end-organ dysfunction. Routine screening for end-organ complications of the Fontan circulation should be incorporated into clinical practice and is an important part of Fontan patient care both pre- and post-transition to adult services.