Objective This study investigates the prevalence of human pegivirus (HPgV) among SARS-CoV-2-positive individuals within the broader context of viral co-infections that may modulate COVID-19 outcomes. We further assess whether HPgV co-infection is associated with COVID-19 severity. HPgV is a widely circulating but rarely monitored human virus with documented immunomodulatory effects in other viral infections, including HIV and Ebola. While HPgV prevalence is low in the general U.S. population (1–2%), it rises markedly in the setting of chronic viral co-infections, particularly HIV (15–40%). Given its immunologic effects and persistence, HPgV represents a biologically plausible but unexplored viral co-factor SARS-CoV-2 infection. Methods We analyzed four cohorts: SARS-CoV-2–positive individuals, ICU patients with respiratory symptoms but SARS-CoV-2–negative, HIV-positive individuals as a positive control for HPgV detection, and uninfected controls. Results HPgV prevalence among COVID-19 patients was low (2.1%) and comparable to population estimates. As expected, HPgV prevalence was substantially higher in the HIV cohort (34%), validating assay performance and cohort stratification. Among HPgV-positive COVID-19 cases, most experienced mild disease, with directional trends toward reduced severity despite high baseline risk factors. Healthcare workers in the control group showed unexpectedly elevated HPgV prevalence (9.6%). Conclusions HPgV is an unmonitored but widely circulating viral co-infection in humans that may influence host responses to SARS-CoV-2. Although limited by small sample size, these findings are descriptive and hypothesis-generating, supporting further investigation of HPgV and other immunomodulatory viral co-infections in COVID-19. Larger studies will be required to determine whether the observed patterns are reproducible and clinically meaningful.

Severe pulmonary valve insufficiency complicates the management of many procedures requiring right ventricular outflow tract (RVOT) reconstruction. Originally described in Tetralogy of Fallot (TOF), neopulmonary valve reconstruction using right atrial (RA) appendage tissue has proven effective in restoring RVOT competence, out to at least out to 8-years in our experience. Certain technical considerations can facilitate efficient and reliable neopulmonary valve reconstruction. As surgeons gain experience and proficiency from routine cases, they can extend the application of RA appendage pulmonary valve reconstruction to more complex repairs.

We sought to identify the optimal management strategy of infants with high-risk hypoplastic left heart syndrome and variants (HR-SV) and identify factors associated with futility. Patients with birth weight ≤ 2.5 kg or gestation ≤ 35 weeks, and age ≤ 30 days at admission were included (N = 398). Norwood (n = 225), hybrid (pulmonary artery band (PAB) + ductal stent, n = 76), and PAB with prostaglandin (PAB/PGE, n = 77) were compared from the National Pediatric Cardiology Quality Improvement Collaborative database. Transplantation referral (n = 1) and comfort care (n = 19) occurred. Baseline factors, 1-year survival, and stage 2 completion were reviewed. Norwood had higher gestational age, birth weight, and younger age at intervention than hybrid and PAB/PGE; while more PAB/PGE and hybrid had chromosomal and other organ abnormalities. Norwood had higher survival (70

BACKGROUND:Combined heart-liver transplantation (CHLT) is a high-risk procedure that is infrequently performed in select patients with end-stage heart and liver disease. This study details a single center experience with simultaneous (en bloc or sequential) CHLT. METHODS:This is a single center retrospective review of 12 simultaneous CHLT performed over a 12-year period. Studied variables included basic clinical data, intraoperative and postoperative details, and outcomes. A comparison of our outcomes to the national cohort was also performed using the UNOS registry. RESULTS:Twelve CHLTs (five pediatric, seven adult) were performed between 2011 and 2023. Mean age was 32 years (range 7-62 years, 75% male). Congenital heart disease with cardiac cirrhosis (58%) and amyloidosis (25%) were the most common indications. Liver and heart wait list times were 125 and 116 days, respectively. The majority of CHLTs were performed en-bloc (n = 8; 67%) and four (33%) were performed sequentially (liver following heart). Mean post-operative ICU and total length of stay (LOS) were 16 and 28 days, respectively, with six patients requiring unplanned return to OR (three for hemoperitoneum, three for hemopericardium). There were no intraoperative deaths, and one patient died on POD 1 from hyperacute rejection. None of the patients required re-transplant after a median follow-up of 37.5 months. Both overall and graft survival for the cohort at 1-, 3-, and 5-years remained 92%. CONCLUSION:CHLT remains the only viable option for carefully selected patients with end-stage heart and liver failure and is associated with excellent patient outcomes.

BACKGROUND:The modified Blalock-Taussig-Thomas shunt (mBTTS) is a critical palliative procedure for infants with single-ventricle physiology, but thrombosis-related occlusion affects 8% to 12% of infants and carries nearly 50% mortality. Meanwhile, existing antithrombotic strategies fail to address the hemodynamic factors driving thrombosis, highlighting the need for a deeper understanding of flow dynamics in shunt failure. OBJECTIVES:This study aims to identify how mBTTS geometry influences hemodynamics and thrombosis risk, providing quantitative guidance for surgical planning and shunt design optimization. METHODS:We used patient-specific imaging data to test 54 idealized mBTTS configurations, systematically varying key geometric factors: pulmonary artery diameter, shunt diameter, and insertion angle. Using computational fluid dynamics, we analyzed how these variables influence wall shear rate, elongation strain rate, and turbulence intensity, as well as hemodynamic parameters known to influence thrombosis risk, to identify patterns linked to thrombosis. RESULTS:We computationally identified optimal geometric configurations. Peak wall shear rate and elongation strain rate were primarily located at bifurcation points, whereas peak turbulence intensity was concentrated within the shunt channel. Shunt insertion distal to the right carotid artery with a 60° insertion angle and with a 4.0-mm shunt graft demonstrated the most favorable hemodynamic profiles for clot prevention in infants. Statistical analysis confirmed strong correlations between geometric parameters and flow characteristics. CONCLUSIONS:Results provide a framework for optimizing mBTTS design to reduce thrombosis risk based on hemodynamic risk factors, including actionable recommendations for shunt placement and design. These insights provide a foundation for hemodynamically guided surgical interventions with the potential to improve survival rates in this high-risk patient population and for broader applications in cardiovascular surgery.

Vascular rings represent a heterogeneous set of aberrant great vessel anatomic configurations which can cause respiratory symptoms or dysphagia due to tracheal or oesophageal compression. These symptoms can be subtle and may present at varied ages. More recently, many have been identified in patients without symptoms, including fetal echocardiogram, resulting in a conundrum for practitioners when attempting to determine who will benefit from surgical correction. Here, we provide a review of vascular rings and a guide to the practitioner on when to consider additional imaging or referral. Additionally, we discuss the changing landscape regarding asymptomatic patients and fetal echocardiogram.

Background: Pulmonary hypertension in children is progressive with wide variability in prognosis. This document provides an evidence-based clinical practice guideline for the management of children with progressive pulmonary hypertension despite optimal therapy. Methods: A multidisciplinary panel identified pertinent questions regarding the management of children with pulmonary hypertension that has progressed despite optimal therapy, conducted systematic reviews of the relevant literature, and applied the Grading of Recommendations, Assessment, Development and Evaluation approach to develop clinical recommendations. Results: After reviewing the research evidence, the panel considered the balance of desirable (benefits) and undesirable (harms and burdens) effects of the interventions in each proposed question. Valuation of our main outcomes was also considered, together with resources required, equity, acceptability, and feasibility. Recommendations were developed for or against interventional strategies specific to children with pulmonary hypertension that has progressed despite optimal therapy. Conclusions: Although there is a growing population of children with pulmonary hypertension, there is a striking lack of empirical evidence regarding management of those whose disease has progressed despite optimal pharmacotherapy. The panel formulated and provided the rationale for clinical recommendations for or against interventional strategies on the basis of this limited empirical evidence, coupled with expert opinion, to aid clinicians in the management of these complex pediatric patients. In addition, we identified important areas for future research.

BACKGROUND:Surgical main pulmonary artery (PA) banding is a palliative procedure to regulate pulmonary blood flow in patients with ventricular septal defects (VSD)(s). AIMS:We report on immediate and midterm outcomes of transcatheter PA debanding. METHODS:Single-center retrospective case series of children who underwent transcatheter debanding between 2017 and 2025. Baseline clinical and follow-up data were reviewed. RESULTS:Nine patients underwent transcatheter debanding at a median age of 9 months (Q1-Q3, 7-13) and a median weight of 8.0 kg (7.3-10.3). Surgical PA bands were placed for large or multiple VSDs, with or without aortic coarctation repair. Median time from banding to debanding was 6 months (9-13). Before debanding, right ventricular (RV) systolic pressure was 115% (84-126) of systemic pressure, and the peak right ventricle-to-PA (RV-PA) echocardiographic gradient was 76 mmHg (72-100). Debanding was performed using a balloon-to-angiographic band diameter ratio of 2.3 (2-3.1) and a balloon to angiographic pulmonary valve annulus ratio of 0.93 (0.90-1.02). Post debanding, RV systolic pressure and RV-PA gradient improved to 72% (62-75, p < 0.05) of the systemic pressure and 36 mmHg (30-46; p < 0.05), respectively. Band diameter increased from 4.6 mm (4.5-5.1) to 9.3 mm (8.3-11.0; p < 0.05). There were no major procedural complications. Peak RV-PA gradients remained low at 23 mmHg (12-51) at a median follow-up of 2 years (1-2.4). One patient required repeat balloon angioplasty, and one underwent surgical debanding along with VSD closure. CONCLUSION:Transcatheter PA debanding is safe and effective in selected patients, with sustained low echocardiography gradients in mid-term follow-up.

Rationale: Pulmonary complications are the most common non-cardiac complications following cardiopulmonary bypass (CPB) and result in lung dysfunction or injury. Electrical Impedance Tomography (EIT) can detect alterations in, and patterns of, lung dysfunction. We conducted a prospective observational study using EIT to assess changes in lung function, before and after CPB, in children. Methods: Patients <18 years old undergoing CPB for congenital heart disease were recruited. In the OR, EIT was recorded pre CPB upon intubation and post CPB after chest closure. Either Pressure Control (PC) or Volume Control (VC) were used keeping the setting uniform (i.e. same Vt or PC) before and after CPB. A low flow inflation maneuver was performed followed by positive end-expiratory pressure (PEEP) titration at 5, 7, and 9 cmH2O. Respiratory mechanics, regional compliance, and changes in end-expiratory lung impedance (EELZ) were studied. Results: 11 patients (median age 7 months) have been enrolled (recruitment is ongoing). 9 were extubated in the OR and 2 were extubated on the first post-op day. 8 patients with reliable EIT data were analyzed. Compliance of the respiratory system (Crs) decreased significantly after CPB [pre vs post; 0.75±0.17 vs 0.53±0.2 mL/cmH2O/Kg; p<0.001]. After CPB, anterior fraction of ventilation decreased [pre vs post; 55% (IQR 52-57) vs 35% (IQR 34-42); p<0.001] and posterior fraction of ventilation increased [pre vs post; 45% (IQR 42-47) vs 65% (IQR 58-66); p<0.001]. This was accompanied with anterior loss of compliance [pre vs post; 0.4±0.08 vs 0.2±0.09 mL/cmH2O/Kg; p<0.001] while posterior compliance remained unchanged (Figure 1). Increase in EELZ from PEEP 5 to 9 cmH2O was higher pre vs post CPB [25±9 vs 15±8; p=0.032], suggesting 40% lower lung volume at end-expiration after CPB. Conclusions: After CPB, anterior (and total) compliance decreases significantly with preferential posterior shift of ventilation. This is accompanied with lower increases in lung volume with PEEP titration. Together, these results suggest anterior lung dysfunction, which could possibly be attributed to injury directly related to surgical manipulation. Next steps include additional patient recruitment (n=30), pixelated EIT data analysis via R, and determining the association between duration of CPB/surgery and loss of regional compliance.

Introduction: Infants with single ventricle disease experience high morbidity and mortality, especially in the interstage period between the first and second palliative surgery. Identifying high-risk infants may prompt interventions and improve outcomes. Myocardial stress or stretch triggers release of natriuretic peptides (N-terminal pro-brain natriuretic peptide [NTproBNP]; mid-regional pro-atrial natriuretic peptide [MRproANP]) that may be used as biomarkers. We modeled longitudinal biomarker trajectories and aimed to understand how these relate to clinical events in interstage infants. Methods: We prospectively collected biomarker samples from interstage infants enrolled in a prospective, multicenter study (NCT03877965), excluding preterm infants, those with creatinine >2mg/dL, and those on extracorporeal support. We performed nonlinear mixed effect modeling in NONMEM to describe the two phases of biomarker decline and evaluated covariate effects. We explored associations between model parameters, biomarker concentrations, and clinical events. Results: Across 10 sites, 50 infants contributed 142 MRproANP and 151 NTproBNP plasma samples in the interstage period. Table 1 shows cohort characteristics and clinical events. There was a >15x faster decline in biomarker concentrations in the first month after stage 1 palliation (S1P) which then slowed ( Figure 1A ). A biexponential model ( Table 2 ) with fast and slow elimination phases after S1P best described these trajectories. The coefficient of the slow elimination phase (ECH) of both biomarkers trended higher for in infants who died (median [range] MRproANP 610 [593, 628] v 492 [329, 1309] pmol/L; p=0.05; NTproBNP 13,199 [12,179, 14,219] v 8538 [2838, 27,523] pg/mL, p=0.14; Figure 1B/C ). Absolute NTproBNP concentrations were higher 15-28 days after S1P (14185 [12627, 15743] v 6822 [1672, 17997] pg/mL) in infants who died. Absolute MRproANP and NTproBNP concentrations at 29-60 days after S1P were lower in those with tachyarrhythmias, (219 [192, 411] v 508 [258, 2755] pmol/L; 2977 [939, 5177] v 8341 [726, 65078] pg/mL). Absolute MRproANP concentrations in the same timeframe were higher in those with bradyarrhythmias (704 [369, 2755] v 494 [192, 1191] pmol/L). Conclusion: A biexponential model described biomarker trajectories. An elevated ECH may identify interstage infants at increased risk of death. Utility of serial biomarker measurement to evaluate biomarker trajectories should be explored in future studies.

We assessed the reintervention rate, pulmonary valve function, and neopulmonary valve (NPV) annulus growth after primary tetralogy of Fallot (ToF) repair with NPV creation from right atrial appendage tissue, retrospectively comparing data from 19 ToF patients who underwent primary repair with NPV creation with a historical cohort of patients who underwent transannular patch (TAP) repair. The median age at NPV surgery was 3.5 months. No mortality was observed. The reintervention rate was similar between the NPV and TAP groups (5% vs 11%, respectively; P = 0.066). At 12 months, 56% of the NPV patients had freedom from moderate or greater pulmonary regurgitation, and the NPV annulus exhibited growth. NPV creation from right atrial appendage tissue is safe and can prevent early pulmonary regurgitation after ToF repair.

Background: The modified Blalock-Taussig-Thomas shunt (mBTTS) is a critical palliative procedure for infants with single-ventricle physiology, but thrombosis-related occlusion affects 8-12% of cases and carries nearly 50% mortality. Meanwhile, existing antithrombotic strategies fail to address the hemodynamic factors driving thrombosis, highlighting the need for a deeper understanding of flow dynamics in shunt failure. Research Question: Can engineering principles inform and optimize procedural interventions to reduce flow-mediated platelet activation and subsequent aggregation? Aims: This study aims to identify how mBTTS geometry influences hemodynamics and thrombosis risk, providing quantitative guidance for surgical planning and shunt design optimization. Methods: We used patient-specific imaging data to construct 54 idealized mBTTS configurations, systematically varying key geometric factors; pulmonary artery diameter, shunt diameter, and insertion angle. Using computational fluid dynamics, we analyzed how these variables influence wall shear rate (WSR), elongational strain rate (ESR), and turbulence intensity (TI); hemodynamic parameters known to affect thrombosis risk, to identify patterns linked to thrombosis. Results: We computationally identified optimal geometric configurations. Peak Wall Shear Rate (WSR) and Elongational Strain Rate (ESR) were primarily located at bifurcation points, while peak Turbulence Intensity (TI) was concentrated within the shunt channel. Shunt insertion distal to the right carotid artery with a 60° insertion angle and with a 4.0mm shunt graft demonstrated the most favorable hemodynamic profiles to prevent clots. Statistical analysis confirmed strong correlations between geometric parameters and flow characteristics. Conclusion: Results provide a framework for optimizing mBTTS design to reduce thrombosis risk based on hemodynamic risk factors, including actionable recommendations for shunt placement and design. These insights provide a foundation for hemodynamically guided surgical interventions with potential to improve survival rates in this high-risk patient population and for broader applications in cardiovascular surgery.

We explore the innovative use of atrial appendage tissue for creating pulmonary valves in children, focusing on its application in Tetralogy of Fallot repair. We discuss the background, preclinical studies, surgical approach, and early clinical outcomes, demonstrating the potential of this technique in reducing pulmonary insufficiency and improving surgical outcomes.

This guideline provides evidence-based recommendations for managing pediatric patients with progressive pulmonary hypertension (PH) despite optimal medical therapy1. Key interventions systematically reviewed include atrial septal defect (ASD) intervention/atrial septostomy (creation and/or enlargement), pulmonary-to-systemic shunt (reverse Pott's shunt) creation, lung transplantation, and the use of extracorporeal membrane oxygenation (ECMO) support as bridge to other treatments (Table 1). These recommendations aim to guide clinicians managing this fragile patient population, with the strength of recommendation and evidence quality specifically annotated (Table 2). Also of note, these recommendations are primarily focused on patients with progressive pulmonary arterial hypertension despite use of multi-pathway pharmacotherapy; under certain circumstances, however, these recommendations may also apply to children with other types of progressive PH as discussed. As the literature discussing these interventions is only continuing to grow, clinicians are encouraged to consider individual patient circumstances. This summary is intended to provide practicing physicians with key points from the guideline.

Background: Patients with single right ventricular morphology (SRV) may exhibit impaired function with increased morbidity, mortality, and need for cardiac transplant due to progressive SRV failure after the Fontan procedure. The aim of the study was to longitudinally characterize the cardiac mechanics and trajectory of disease evolution of SRV failure in Fontan patients. Methods: We performed a case-controlled longitudinal study of 52 patients who underwent extracardiac Fontan palliation for SRV between 1994 and 2015 and compared echocardiographic measures of right ventricular (RV) function, RV-systemic vascular coupling and ventricular remodeling between patients who required heart transplants due to SRV failure (study group, n = 26) and those who did not (control group, n = 26). To define the trajectory, measurements were obtained at four matching time points equivalent in duration from Fontan. Results: RV circumferential shortening function declined in both groups over the time period, but was significantly lower (p < 0.01) in the study group farther from the Fontan. RV-systemic vascular coupling, assessed by systolic time interval measures and RV work, was preserved in the control group, but significantly altered (p < 0.001) in the study group. Relative wall thickness decreased, and the minor/major-axis ratio, as an index of ventricular geometry, increased in the study group, but both remained stable in the control group. Conclusions: This study suggests that positive ventricular remodeling with enhanced circumferential systolic function, and preserved RV-vascular coupling, appear to be adaptive and protective mechanisms against RV failure in Fontan with SRV. These indices of cardiac mechanics may serve as clinically relevant quantifiable markers of disease evolution, and early indicators for therapeutic intervention.