The molecular landscape of sepsis severity in infants: enhanced coagulation, innate immunity, and T cell repression.

Introduction: Sepsis remains a major cause of mortality and morbidity in infants. In recent years, several gene marker strategies for the early identification of sepsis have been proposed but only a few have been independently validated for adult cohorts and applicability to infant sepsis remains unclear. Biomarkers to assess disease severity and risks of shock also represent an important unmet need. Methods: To elucidate characteristics driving sepsis in infants, we assembled a multi-transcriptomic dataset from public microarray datasets originating from five independent studies pertaining to bacterial sepsis in infant < 6-months of age (total n=335). We utilized a COmbat co-normalization strategy to enable comparative evaluation across multiple studies while preserving the relationship between cases and controls. Results: We found good concordance with only two out of seven of the published adult sepsis gene signatures (accuracy > 80%), highlighting the narrow utility of adult-derived signatures for infant diagnosis. Pseudotime analysis of individual subjects' gene expression profiles showed a continuum of molecular changes forming tight clusters concurrent with disease progression between healthy controls and septic shock cases. In depth gene expression analyses between bacteremia, septic shock, and healthy controls characterized lymphocyte activity, hemostatic processes, and heightened innate immunity during the molecular transition toward a state of shock. Discussion: Our analysis revealed the presence of multiple significant transcriptomic perturbations that occur during the progression to septic shock in infants that are characterized by late-stage induction of clotting factors, in parallel with a heightened innate immune response and a suppression of adaptive cell functionality.

The Society of Thoracic Surgeons Congenital Heart Surgery Database: 2023 Update on Outcomes and Research.

The Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database (CHSD) continues to be the most comprehensive database of congenital and pediatric cardiothoracic surgical procedures in the world and contains information on 664,210 operations as of June 30, 2023. The 35th harvest of the STS CHSD data was undertaken in Spring 2023, spanning the 4-year period January 1, 2019, through December 31, 2022, and included 144,919 operations performed at 114 participating sites in North America. The harvest analysis was successfully executed by the STS Research and Analytic Center. The overall unadjusted mortality rate was 2.68% and has remained stable over the 4 years included in the current harvest window. Mortality is highest in neonates (7.4%) and lowest in children (1.1%). As in prior analyses, observed mortality and postoperative length of stay in the database increase with an increase in STS-European Association for Cardio-Thoracic Surgery (STAT) Congenital Heart Surgery Mortality Categories. This quality report summarizes contemporary outcomes, provides the odds ratios for the CHSD risk model variables based on this analysis, and describes on-going efforts to improve data collection and augment analytical approaches. Lastly, 5 research publications completed in the last year using data from the CHSD are also summarized.

From Surgical to Total Transcatheter Stage I Palliation: Exploring Evidence and Perspectives.

Neonates with single ventricle physiology and ductal-dependent systemic circulation, such as those with hypoplastic left heart syndrome, undergo palliation in the first days of life. Over the past decades, variations on the traditional Stage 1 palliation, also known as Norwood operation, have emerged. These include the hybrid palliation and the total transcatheter approach. Here, we review the current evidence and data on different Stage 1 approaches, with a focus on their advantages, challenges, and future perspectives. Overall, although controversy remains regarding the superiority or inferiority of one approach to another, outcomes after the Norwood and the hybrid palliation have improved over time. However, both procedures still represent high-risk approaches that entail exposure to sternotomy, surgery, and potential cardiopulmonary bypass. The total transcatheter Stage 1 palliation spares patients the surgical and cardiopulmonary bypass insults and has proven to be an effective strategy to bridge even high-risk infants to a later palliative surgery, complete repair, or transplant. As the most recently proposed approach, data are still limited but promising. Future studies will be needed to better define the advantages, challenges, outcomes, and overall potential of this novel approach.

Differential Regulation of Immune-Related Genes in the Developing Heart.

In many congenital heart defects, it can be difficult to ascertain primary pathology from secondary consequences from altered flow through the developing heart. The molecular differences between the growing right and left ventricles (RV and LV, respectively) following the completion of septation and the impact of sex on these mechanisms have not been investigated. We analyzed RNA-seq data derived from twelve RV and LVs, one with Hypoplastic Left Heart Syndrome (HLHS), to compare the transcriptomic landscape between the ventricles during development. Differential gene expression analysis revealed a large proportion of genes unique to either the RV or LV as well as sex bias. Our GO enrichment and network analysis strategy highlighted the differential role of immune functions between the RV and LV in the developing heart. Comparatively, RNA-seq analysis of data from C57Bl6/J mice hearts collected at E14 resulted in the enrichment of similar processes related to T cells and leukocyte migration and activation. Differential gene expression analysis of an HLHS case highlighted significant downregulation of chromatin organization pathways and upregulation of genes involved in muscle organ development. This analysis also identified previously unreported upregulation of genes involved in IL-17 production pathways. In conclusion, differences exist between the gene expression profiles of RV versus LV with the expression of immune-related genes being significantly different between these two chambers. The pathogenesis of HLHS may involve alterations in the expression of chromatin and muscle gene organization as well as upregulation of the IL-17 response pathway.

Single Ventricular Assist Device Care and Outcomes for Failed Stage I Palliation: A Single-Center Decade of Experience.

Single ventricular assist device (SVAD) use before and after stage I palliation (S1P) is increasing with limited data on outcomes. To address this knowledge gap, we conducted a single-center retrospective review to assess pre- and post-SVAD clinical status, complications, and outcomes. We leveraged a granular, longitudinal, local database that captures end-organ support, procedural interventions, hematologic events, laboratory data, and antithrombotic strategy. We identified 25 patients between 2013 and 2023 implanted at median age of 53 days (interquartile range [IQR] = 16-130); 80% had systemic right ventricles and underwent S1P. Median SVAD days were 54 (IQR = 29-86), and 40% were implanted directly from ECMO. Compared to preimplant, there was a significant reduction in inotrope use ( p = 0.013) and improved weight gain ( p = 0.008) post-SVAD. Complications were frequent including bleeding (80%), stroke (40%), acute kidney injury (AKI) (40%), infection (36%), and unanticipated catheterization (56%). Patients with in-hospital mortality had significantly more bleeding complications ( p = 0.02) and were more likely to have had Blalock-Thomas-Taussig shunts pre-SVAD ( p = 0.028). Survival to 1 year postexplant was 40% and included three recovered and explanted patients. At 1 year posttransplant, all survivors have technology dependence or neurologic injury. This study highlights the clinical outcomes and ongoing support required for successful SVAD use in failed single-ventricle physiology before or after S1P.

Lung Re-transplantation after prolonged veno-venous extracorporeal membrane oxygenation (ECMO) in a child with chronic lung allograft dysfunction.

BACKGROUND: Extracorporeal Membrane Oxygenation (ECMO) may be used as a bridge to lung transplantation in selected patients with end-stage respiratory failure. Historically, ECMO use in this setting has been associated with poor outcomes Puri V et.al, J Thorac Cardiovasc Surg, 140:427. More recently, technical advances and the implementation of rehabilitation and ambulation while awaiting transplantation on ECMO have led to improved surgical and post-transplant outcomes Kirkby S et.al, J Thorac Dis, 6:1024. METHODS: We illustrate the case of a 6-year-old child who received prolonged ECMO support as a bridge to lung re-transplantation secondary to Chronic Lung Allograft Dysfunction (CLAD). RESULTS: Early rehabilitation was key in improving the overall pre-transplant conditioning during ECMO. CONCLUSIONS: Despite challenges associated with awake/ambulatory ECMO, the use of this strategy as a bridge to lung transplantation is feasible and has resulted in improved pre-transplant conditioning and post-transplant outcomes.

Outcomes of the Kawashima: A Society of Thoracic Surgeons Congenital Heart Surgery Database Analysis.

BACKGROUND: We aimed to evaluate the effect of age at operation on postoperative outcomes in children undergoing a Kawashima operation. METHODS: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for Kawashima procedures from January 1, 2014, to June 30, 2020. Patients were stratified by age at operation in months: 0 to <4, 4 to <8, 8 to <12, and >12. Subsequently, outcomes for those in whom the Kawashima was not the index operation and for those undergoing hepatic vein incorporation (Fontan completion or hepatic vein-to-azygos vein connection) were evaluated. RESULTS: We identified 253 patients who underwent a Kawashima operation (median age, 8.6 months; median weight, 7.4 kg): 12 (4.7%), 0 to <4 months; 96 (37.9%), 4 to <8 months; 81 (32.0%), 8 to <12 months; and 64 (25.3%), >12 months. Operative mortality was 0.8% (n = 2), with major morbidity or mortality in 17.4% (n = 44), neither different across age groups. Patients <4 months had a longer postoperative length of stay (12.5 vs 9.3 days; P = .03). The Kawashima was not the index operation of the hospital admission in 15 (5.9%); these patients were younger (6.0 vs 8.4 months; P = .05) and had more preoperative risk factors (13/15 [92.9%] vs 126/238 [52.9%]; P < .01). We identified 173 patients undergoing subsequent hepatic vein incorporation (median age, 3.9 years; median weight, 15.0 kg) with operative mortality in 6 (3.5%) and major morbidity or mortality in 30 (17.3%). CONCLUSIONS: The Kawashima is typically performed between 4 and 12 months with low mortality. Morbidity and mortality were not affected by age. Hepatic vein incorporations may be higher risk than in traditional Fontan procedures, and ways to mitigate this should be sought.

Comparing apples to apples: Exploring public reporting of congenital cardiac surgery outcomes based on common congenital heart operations.

OBJECTIVE: We sought to simplify reporting of outcomes in congenital heart surgery that compares well-defined patient groups and accommodates multiple stakeholder needs while being easily understandable. METHODS: We selected 19 commonly performed congenital heart surgeries ranging in complexity from repair of atrial septal defects to the Norwood procedure. Strict inclusion/exclusion criteria ensured the creation of 19 well-defined diagnosis/procedure cohorts. Preoperative, procedural, and postoperative data were collected for consecutive eligible patients from 9 centers between January 1, 2016, and December 31, 2021. Unadjusted operative mortality rates and hospital length of stay for each of the 19 diagnosis/procedure cohorts were summarized in aggregate and stratified by each center. RESULTS: Of 8572 eligible cases included, numbers in the 19 diagnosis/procedure cohorts ranged from 73 for tetralogy of Fallot repair after previous palliation to 1224 for ventricular septal defect (VSD) repair for isolated VSD. In aggregate, the unadjusted mortality ranged from 0% for atrial septal defect repair to 28.4% for hybrid stage I. There was significant heterogeneity in case mix and mortality for different diagnosis/procedure cohorts across centers (eg, arterial switch operation/VSD, n = 7-42, mortality 0%-7.4%; Norwood procedure, n = 16-122, mortality 5.3%-25%). CONCLUSIONS: Reporting of institutional case volumes and outcomes within well-defined diagnosis/procedure cohorts can enable centers to benchmark outcomes, understand trends in mortality, and direct quality improvement. When made public, this type of report could provide parents with information on institutional volumes and outcomes and allow them to better understand the experience of each program with operations for specific congenital heart defects.

Outcomes After Hybrid Palliation for Infants With Critical Left Heart Obstruction.

BACKGROUND: Hybrid palliation (bilateral pulmonary artery banding with or without ductal stenting) is an initial management strategy for infants with critical left heart obstruction and serves as palliation until subsequent operations are pursued. OBJECTIVES: This study sought to determine patient characteristics and factors associated with subsequent outcomes for infants who underwent hybrid palliation. METHODS: From 2005 to 2019, 214 of 1,236 prospectively enrolled infants within the Congenital Heart Surgeons' Society's critical left heart obstruction cohort underwent hybrid palliation across 24 institutions. Multivariable hazard modeling with competing risk methodology was performed to determine risk and factors associated with outcomes of biventricular repair, Fontan procedure, transplantation, or death. RESULTS: Preoperative comorbidities (eg, prematurity, low birth weight, genetic syndrome) were identified in 70% of infants (150 of 214). Median follow-up was 7 years, ranging up to 17 years. Overall 12-year survival was 55%. At 5 years after hybrid palliation, 9% had biventricular repair, 36% had Fontan procedure, 12% had transplantation, 35% died without surgical endpoints, and 8% were alive without an endpoint. Factors associated with transplantation were absence of ductal stent, older age, absent interatrial communication, smaller aortic root size, larger tricuspid valve area z-score, and larger left ventricular volume. Factors associated with death were low birth weight, concomitant genetic syndrome, cardiopulmonary bypass use during hybrid palliation, moderate to severe tricuspid valve regurgitation, and smaller ascending aortic size. CONCLUSIONS: Mortality remains high after hybrid palliation for infants with critical left heart obstruction. Nonetheless, hybrid palliation may facilitate biventricular repair for some infants and for others may serve as stabilization for intended functional univentricular palliation or primary transplantation.

Hypoplastic Left Heart Syndrome With Low Birth Weight or Prematurity: What Is the Optimal Approach?

BACKGROUND: Hypoplastic left heart syndrome with low birth weight or prematurity comprises a high-risk population with no optimal treatment pathway. Using the Pediatric Health Information System, we compared management approaches across the United States. METHODS: We analyzed neonates (≤30 days) with birth weight <2500 grams or gestational age <36 weeks between 2012 and 2021. Four strategies were identified: Norwood procedure, ductus arteriosus stent + pulmonary artery banding, pulmonary artery banding + prostaglandin infusion, or comfort care. Outcomes included hospital survival, discharge disposition, staged palliation completion, and 1-year transplant-free survival. RESULTS: Of 383 infants identified, 36.4% (n = 134) received comfort care, 43.9% (n = 165) Norwood, 12.4% (n = 49) ductal stent + pulmonary artery bands, and 8.8% (n = 34) pulmonary artery bands + prostaglandins. Neonates receiving comfort care had the lowest gestational age (35 weeks; interquartile range [IQR], 31.5-37 weeks) and birth weight (2.0 kg; IQR, 1.5-2.3 kg); 24.6% (33 of 134) had chromosomal anomalies. Infants undergoing primary Norwood had the highest birth weight (2.4 kg; IQR, 2.2-2.5 kg) and gestational age (37 weeks; IQR, 35-38 weeks). Glenn palliation was performed in 66.1% (109 of 165) compared with ductal stent + pulmonary artery band in 18.4% (9 of 49) and pulmonary artery band + prostaglandins in 35.3% (12 of 34). Only 11.3% (6 of 53) born <2 kg survived to 1 year, all after Norwood. Primary Norwood yielded higher hospital and 1-year transplant-free survival than hybrid strategies. CONCLUSIONS: Comfort care is routinely provided, particularly for infants with low birth weight, gestational age, or chromosomal anomalies. Primary Norwood offered the lowest hospital and 1-year mortality and highest palliation completion rates; birth weight was the most important factor determining 1-year survival.

Pulmonary Hypertension in Congenital Heart Disease: A Scientific Statement From the American Heart Association.

Patients with pulmonary hypertension associated with congenital heart disease make up an increasing proportion of the total pulmonary hypertension population who bring with them added complexity because of underlying anatomical and hemodynamic abnormalities. Currently, no consensus recommendations are available on how to best manage this group of patients for either the primary cardiologist or pulmonary hypertension subspecialist, including timing of referral. The purposes of this document are (1) to describe the various pulmonary hypertension groups and subgroups associated with congenital heart disease, (2) to describe imaging modalities used in patient evaluation, (3) to elucidate medical and surgical management considerations, (4) to highlight disparities within this population, and (5) to identify gaps and future research needs of patients with pulmonary hypertension associated with congenital heart disease.

Anticoagulation-Free Pediatric Extracorporeal Membrane Oxygenation: Single-Center Retrospective Study.

OBJECTIVES: To analyze hemorrhage and thrombosis data related to anticoagulation-free pediatric extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective cohort study. SETTINGS: High-volume ECMO single institution data. PATIENTS: Children (0-18 yr) supported with ECMO (>24 hr) with initial anticoagulation-free period of greater than or equal to 6 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Utilizing consensus American Thoracic Society definitions for hemorrhage and thrombosis on ECMO, we evaluated thrombosis and associated patient and ECMO characteristics during anticoagulation-free period. Thirty-five patients met inclusion criteria from 2018 to 2021 having a median age (interquartile range [IQR]) of 13.5 months (IQR, 3-91 mo), median ECMO duration of 135 hours (IQR, 64-217 hr), and 964 anticoagulation-free hours. Increased RBC transfusion needs were associated with longer anticoagulation-free periods ( p = 0.03). We identified 20 thrombotic events: only four during the anticoagulation-free period and occurring in three of 35 (8%) patients. Compared with those without thrombotic events, anticoagulation-free clotting events were associated with younger age (i.e., 0.3 mo [IQR, 0.2-0.3 mo] vs 22.9 mo [IQR, 3.6-112.9 mo]; p = 0.02), lower weight (2.7 kg [IQR, 2.7-3.25 kg] vs 13.2 kg [5.9-36.4 kg]; p = 0.006), support with lower median ECMO flow rate (0.5 kg [IQR, 0.45-0.55 kg] vs 1.25 kg [IQR, 0.65-2.5 kg]; p = 0.04), and longer anticoagulation-free ECMO duration (44.5 hr [IQR, 40-85 hr] vs 17.6 hr [IQR, 13-24.1]; p = 0.008). CONCLUSIONS: In selected high-risk-for-bleeding patients, our experience is that we can use ECMO in our center for limited periods without systemic anticoagulation, with lower frequency of patient or circuit thrombosis. Larger multicentered studies are required to assess weight, age, ECMO flow, and anticoagulation-free time limitations that are likely to pose risk for thrombotic events.

Characteristics of donor lungs declined on site and impact of lung allocation policy change.

OBJECTIVE: National and institutional data suggest an increase in organ discard rate (donor lungs procured but not implanted) after a new lung allocation policy was introduced in 2017. However, this measure does not include on-site decline rate (donor lungs declined intraoperatively). The objective of this study is to examine the impact of the allocation policy change on on-site decline. METHODS: We used a Washington University (WU) and our local organ procurement organization (Mid-America Transplant [MTS]) database to abstract data on all accepted lung offers from 2014 to 2021. An on-site decline was defined as an event in which the procuring team declined the organs intraoperatively, and the lungs were not procured. Logistic regression models were used to investigate potentially modifiable reasons for decline. RESULTS: The overall study cohort comprised 876 accepted lung offers, of which 471 donors were at MTS with WU or others as the accepting center and 405 at other organ procurement organizations with WU as the accepting center. At MTS, the on-site decline rate increased from 4.6% to 10.8% (P = .01) after the policy change. Given the greater likelihood of non-local organ placement and longer travel distance after policy change, the estimated cost of each on-site decline increased from $5727 to $9700. In the overall group, latest partial pressure of oxygen (odds ratio [OR], 0.993; 95% confidence interval [CI], 0.989-0.997), chest trauma (OR, 2.474; CI, 1.018-6.010), chest radiograph abnormality (OR, 2.902; CI, 1.289-6.532), and bronchoscopy abnormality (OR, 3.654; CI, 1.813-7.365) were associated with on-site decline, although lung allocation policy era was unassociated (P = .22). CONCLUSIONS: We found that nearly 8% of accepted lungs are declined on site. Several donor factors were associated with on-site decline, although lung allocation policy change did not have a consistent impact on on-site decline.

Virome Analysis and Association of Positive Coxsackievirus B Serology during Pregnancy with Congenital Heart Disease.

BACKGROUND: We have previously shown coxsackievirus B (CVB) to be a potent inducer of congenital heart disease (CHD) in mice. The clinical relevance of these findings in humans and the roles of other viruses in the pathogenesis of CHD remain unknown. METHODS: We obtained plasma samples, collected at all trimesters, from 89 subjects (104 pregnancies), 73 healthy controls (88 pregnancies), and 16 with CHD-affected birth (16 pregnancies), from the Perinatal Family Tissue Bank (PFTB). We performed CVB IgG/IgM serological assays on plasma. We also used ViroCap sequencing and PCR to test for viral nucleic acid in plasma, circulating leukocytes from the buffy coat, and in the media of a co-culture system. RESULTS: CVB IgG/IgM results indicated that prior exposure was 7.8 times more common in the CHD group (95% CI, 1.14-54.24, adj. p-value = 0.036). However, the CVB viral genome was not detected in plasma, buffy coat, or co-culture supernatant by molecular assays, although other viruses were detected. CONCLUSION: Detection of viral nucleic acid in plasma was infrequent and specifically no CVB genome was detected. However, serology demonstrated that prior CVB exposure is higher in CHD-affected pregnancies. Further studies are warranted to understand the magnitude of the contribution of the maternal blood virome to the pathogenesis of CHD.

Outcomes of Treatment for Infective Endocarditis Following Transcatheter Pulmonary Valve Replacement.

BACKGROUND: Recipients of transcatheter pulmonary valve replacement (TPVR) have shown increased risk of infective endocarditis (IE). Little is known about the outcomes of different management strategies, particularly surgery, for IE after TPVR. METHODS: We queried the Pediatric Health Information System database for cases of IE after TPVR performed from 2010-2020. We described patient demographics, hospital courses, admission complications, and treatment outcomes based on therapy offered, surgical or medical only. We compared outcomes of initial therapy. Data are expressed as median or percent. RESULTS: Sixty-nine cases of IE were identified, accounting for 98 related hospital admissions; 29% of patients recorded IE-related readmissions. Of those readmitted after initial medical therapy only, 33% had relapse IE. Rates of surgery were 22% during initial admission and 36% overall. Likelihood of surgical intervention increased with each subsequent admission. Renal and respiratory failure were more common in those given initial surgery. Mortality rate was 4.3% overall and 8% in the surgical cohort. CONCLUSION: Initial medical therapy may result in relapses/readmissions and possible delay of surgical therapy, which appears to be most effective for treatment of IE. For those treated only medically, a more aggressive course of therapy may be more likely to prevent relapse. Mortality following surgical therapy for IE after TPVR appears higher than reported for surgical pulmonary valve replacement generally.