Prolonged pleural drainage and chylothorax are common in postoperative Fontan patients and are associated with increased morbidity and mortality. Multiple medical and interventional treatment strategies exist and vary between centers. This is a retrospective multicenter observational cohort study of pediatric patients who underwent Fontan operation at 8 pediatric cardiac surgical institutions from 1/1/2019 to 12/31/2021. Data were obtained from institutional records and collected from the Pediatric Cardiac Critical Care Consortium (PC4). 185 patients underwent Fontan operation with median age of 3.8 years [IQR 3.2-4.5]. Chest tube drainage for > 14 days occurred in 40 patients (22%). Chylothorax occurred in 33 patients (18%, incidence 9.1-26.2% across centers). Compared to non-chylothorax patients, those with chylothorax had lower preoperative ventricular end diastolic pressures (8 vs. 9 mm Hg, p = 0.019), greater chest tube utilization (13 vs. 7 days, p = < 0.001), ICU LOS (7 vs. 4 days, p = 0.001), hospital LOS (12 vs. 9 days, p < 0.001), and more weight loss (- 2.7% vs. 0.8%, p = 0.019). Using a receiver-operating characteristic curve, chest tube output > 18.8 mL/kg/day on POD 2 predicted chylothorax with an AUC of 0.73. Common chylothorax treatments were diet modification (n = 15, 45%) and sildenafil (n = 14, 52%). Interventional procedures were used in six chylothorax patients (18%). Postoperative chylothorax in Fontan patients was associated with increased chest tube utilization, postoperative interventions, greater weight loss, and longer ICU and hospital LOS. Center level variation suggests outcomes and resource utilization could be improved with further studies and establishment of best practices.

BACKGROUND:Infants with single ventricle heart disease (SVHD) suffer morbidity from insufficient pulmonary blood flow, which may be related to impaired arginine metabolism. No prior study has reported quantitative mapping of arginine metabolites to evaluate the relationship between circulating metabolite levels and outcomes. METHODS:Prospective cohort study of 75 SVHD cases peri-Stage 2 and 50 healthy controls. We targeted pre- and post-op absolute serum quantification of 9 key members of the arginine metabolism pathway by tandem mass spectrometry. Primary outcomes were length of stay (LOS) and post-Stage 2 hypoxemia. RESULTS:Pre-op cases showed alteration in 6 metabolites including decreased arginine and increased asymmetric dimethyl arginine (ADMA) levels compared to controls. Post-op cases demonstrated decreased arginine and citrulline levels persisting through 48 h. Adjusting for clinical variables, lower pre-op and 2 h post-op concentrations of multiple metabolites, including arginine and citrulline, were associated with longer post-op LOS (p < 0.01). Increased ADMA at 24 h was associated with greater post-op hypoxemia burden (p < 0.05). CONCLUSION:Arginine metabolism is impaired in interstage SVHD infants and is further deranged following Stage 2 palliation. Patients with greater metabolite alterations experience greater post-op morbidity. Decreased arginine metabolism may be an important driver of pathology in SVHD. IMPACT:Interstage infants with SVHD have significantly altered arginine-nitric oxide metabolism compared to healthy children with deficiency of multiple pathway intermediates persisting through 48 h post-Stage 2 palliation. After controlling for clinical covariates and classic catheterization-derived predictors of Stage 2 readiness, both lower pre-operation and lower post-operation circulating metabolite levels were associated with longer post-Stage 2 LOS while increased post-Stage 2 ADMA concentration was associated with greater post-op hypoxemia. Arginine metabolism mapping offers potential for development using personalized medicine strategies as a biomarker of Stage 2 readiness and therapeutic target to improve pulmonary vascular health in infants with SVHD.

Children with single ventricle heart disease typically require a series of three operations, (1) Norwood, (2) Glenn, and (3) Fontan, which ultimately results in complete separation of the pulmonary and systemic circuits to improve pulmonary/systemic circulation. In the last stage, the Fontan operation, the inferior vena cava (IVC) is connected to the pulmonary arteries (PAs), allowing the remainder of deoxygenated blood to passively flow to the pulmonary circuit. It is hypothesized that optimizing the Fontan anatomy would lead to decreased power loss and more balanced hepatic flow distribution. One approach to optimizing the geometry is to create a patient-specific digital twin to simulate various configurations of the Fontan conduit, which requires a computational model of the proximal PA anatomy and resistance, as well as the distal Pulmonary Vascular Resistance (PVR), at the Glenn stage. To that end, an optimization pipeline was developed using 3D computational fluid dynamics (CFD) and 0D lumped parameter (LP) simulations to iteratively refine the PVR of each lung by minimizing the simulated flow and pressure error relative to patients’ cardiac magnetic resonance (CMR) and catheterization (CATH) data. While the PVR can also be estimated directly by computing the ratio of pressure gradients and flow from CATH and CMR data, the computational approach can separately identify the different components of PVR along the Glenn pathway, allowing for a more detailed depiction of the Glenn vasculature. Results indicate good correlation between the optimized PVR of the CFD and LP models (n = 16), with an intraclass correlation coefficient (ICC) of 0.998 (p = 0.976) and 0.991 (p = 0.943) for the left and right lung, respectively. Furthermore, compared to CMR flow and CATH pressure data, the optimized PVR estimates result in mean outlet flow and pressure errors of less than 5%. The optimized PVR estimates also agree well with the computed PVR estimates from CATH pressure and CMR flow for both lungs, yielding a mean difference of less than 4%.

Motivation: There is currently limited data examining longitudinal changes in hemodynamics and vascular properties in Fontan patients living at altitude. Goal(s): We aimed to assess hemodynamic parameters and vessel morphology in Fontan patients at a single high-altitude surgical center and assess correlations between these parameters and post-Fontan outcomes. Approach: We retrospectively reviewed patients undergoing Fontan operation from 1999 to 2021. We analyzed data from cardiac magnetic resonance imaging and cardiac catheterization. Results: Our findings highlight post-Fontan changes in flow, pressure, and area. The changes in systemic and caval flow, along with pressure variations, offer insights into the effects of Fontan circulation. Impact: This study advances our understanding of Fontan circulation at high-altitude, paving the way for improved prognostic information and long-term outcomes in this patient population.

AbstractPreliminary evidence suggests perturbations of the kynurenine pathway (KP) of tryptophan metabolism in infants with single ventricle heart disease (SVHD). In 72 infants with SVHD undergoing stage 2 palliation (S2P) and 41 controls, we quantified serum KP metabolite concentrations via tandem mass spectroscopy pre‐S2P and post‐S2P at 2, 24, and 48 h and assessed metabolite relationships with post‐S2P outcomes (length of stay, hypoxemia burden, and intubation duration). Pre‐S2P, SVHD infants had lower tryptophan and serotonin levels and higher kynurenic acid, 3‐hydroxykynurenine, and picolinic acid levels than controls. Post‐S2P, metabolites peaked at 2 h, with return to baseline by 48 h for all except kynurenic acid, which remained elevated. Metabolite concentrations pre‐S2P were poorly associated with outcomes. A lower serotonin peak 2 h post‐S2P was associated with longer length of stay and intubation duration. Multiple metabolites at 24 and 48 h correlated with outcomes; notably, elevated kynurenic acid was associated with worse results for all three outcomes. Our results confirm that interstage SVHD infants have altered KP activity compared to controls. Further, the link between outcomes and KP metabolites post‐S2P—but not at baseline—demonstrates that acute, perioperative changes in tryptophan catabolism may be more important to tolerating S2P physiology than chronic interstage changes.

The Pediatric Heart Network’s Fontan Udenafil Exercise Longitudinal (FUEL) Trial (Mezzion Pharma Co. Ltd., NCT 02741115) demonstrated improvements in some measures of exercise capacity and in the myocardial performance index following 6 months of treatment with udenafil (87.5 mg twice daily). In this post hoc analysis, we evaluate whether subgroups within the population experienced a differential effect on exercise performance in response to treatment. The effect of udenafil on exercise was evaluated within subgroups defined by baseline characteristics, including peak oxygen consumption (VO 2 ), serum brain-type natriuretic peptide level, weight, race, gender, and ventricular morphology. Differences among subgroups were evaluated using ANCOVA modeling with fixed factors for treatment arm and subgroup and the interaction between treatment arm and subgroup. Within-subgroup analyses demonstrated trends toward quantitative improvements in peak VO 2 , work rate at the ventilatory anaerobic threshold (VAT), VO 2 at VAT, and ventilatory efficiency (VE/VCO 2 ) for those randomized to udenafil compared to placebo in nearly all subgroups. There was no identified differential response to udenafil based on baseline peak VO 2 , baseline BNP level, weight, race and ethnicity, gender, or ventricular morphology, although participants in the lowest tertile of baseline peak VO 2 trended toward larger improvements. The absence of a differential response across subgroups in response to treatment with udenafil suggests that the treatment benefit may not be restricted to specific sub-populations. Further work is warranted to confirm the potential benefit of udenafil and to evaluate the long-term tolerability and safety of treatment and to determine the impact of udenafil on the development of other morbidities related to the Fontan circulation. Trial Registration NCT0274115.

Children with single ventricle heart disease (SVHD) experience morbidity due to inadequate pulmonary blood flow. Using proteomic screening, our group previously identified members of the matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), and fibroblast growth factor (FGF) families as potentially dysregulated in SVHD. No prior study has taken a targeted approach to mapping circulating levels of these protein families or their relationship to pulmonary vascular outcomes in SVHD. We performed a prospective cohort study of 70 SVHD infants pre-Stage 2 palliation and 24 healthy controls. We report targeted serum quantification of 39 proteins in the MMP, TIMP, and FGF families using the SomaScan platform. Clinical variables were extracted from the medical record. Twenty of 39 tested proteins (7/14 MMPs, 2/4 TIMPs, and 11/21 FGFs) differed between cases and controls. On single variable testing, 6 proteins and no clinical covariates were associated with both post-Stage 2 hypoxemia and length of stay. Multiple-protein modeling identified increased circulating MMP 7 and MMP 17, and decreased circulating MMP 8 and FGFR2 as most associated with post-Stage 2 hypoxemia; increased MMP 7 and TIMP 4 and decreased circulating MMP 1 and MMP 8 were most associated with post-operation length of stay. The MMP, TIMP, and FGF families are altered in SVHD. Pre-Stage 2 imbalance of extracellular matrix (ECM) proteins-increased MMP 7 and decreased MMP 8-was associated with multiple adverse post-operation outcomes. Maintenance of the ECM may be an important pathophysiologic driver of Stage 2 readiness in SVHD.

IntroductionChildren with single ventricle heart disease (SVHD) experience significant morbidity across systems and time, with 70% of patients experiencing acute kidney injury, 33% neurodevelopmental impairment, 14% growth failure, and 5.5% of patients suffering necrotizing enterocolitis. Proteomics is a method to identify new biomarkers and mechanisms of injury in complex physiologic states.MethodsInfants with SVHD in the interstage period were compared to similar-age healthy controls. Serum samples were collected, stored at −80°C, and run on a panel of 1,500 proteins in single batch analysis (Somalogic Inc., CO). Partial Least Squares-Discriminant Analysis (PLS-DA) was used to compare the proteomic profile of cases and controls and t-tests to detect differences in individual proteins (FDR <0.05). Protein network analysis with functional enrichment was performed in STRING and Cytoscape.ResultsPLS-DA readily discriminated between SVHD cases (n = 33) and controls (n = 24) based on their proteomic pattern alone (Accuracy = 0.96, R2 = 0.97, Q2 = 0.80). 568 proteins differed between groups (FDR <0.05). We identified 25 up-regulated functional clusters and 13 down-regulated. Active biological systems fell into six key groups: angiogenesis and cell proliferation/turnover, immune system activation and inflammation, altered metabolism, neural development, gastrointestinal system, and cardiac physiology and development.ConclusionsWe report a clear differentiation in the circulating proteome of patients with SVHD and healthy controls with >500 circulating proteins distinguishing the groups. These proteomic data identify widespread protein dysregulation across multiple biologic systems with promising biological plausibility as drivers of SVHD morbidity.

Background: Infants with single ventricle heart disease (SVHD) have perturbed kynurenine pathway (KP) function prior to stage 2 palliation. Buildup of kynurenic acid—a byproduct of this pathway—is linked to worse outcomes post stage 2. To date, perturbations along the entire KP have not been delineated in SVHD infants at the time of stage 2 operation. Methods: This is a single center prospective cohort study of 75 infants with SVHD undergoing stage 2 palliation and 50 controls. Targeted analysis of KP metabolites was performed on serum samples via tandem mass spectroscopy prior to stage 2 (baseline) and post-operatively at 2, 24, and 48 hours. Results: Of the 9 KP metabolites, 7 were different between controls and SVHD at baseline (Figure 1A). SVHD infants had lower tryptophan and serotonin; and higher kynurenic acid, 3-hydroxykynurenine, anthranilic acid, picolinic acid, and 3-hydroxyanthranilic acid. After stage 2, there were time related changes in all KP metabolites except tryptophan (Figure 1B). Metabolite concentrations at baseline and 2 hours post-op were poorly correlated with outcomes. At 24 hours, decreases in tryptophan and serotonin along with elevations in kynurenine, kynurenic acid, 3-hydroxykynurine, and quinolinic acid concentrations correlated with outcomes (Figure 1C). At 48 hours, kynurenic acid remained positively correlated with all 3 outcomes (length of stay, hypoxia burden, and intubation length). Conclusions: We demonstrated numerous perturbations in the KP pathway at baseline in SVHD infants compared to controls. We also profiled the trajectory of each metabolite over the 48 hours post stage 2. The link between KP intermediates and poor outcomes post-operatively—but not at baseline—demonstrates that the acute, peri-operative changes in tryptophan catabolism in response to cardiopulmonary bypass are more important to tolerating new stage 2 physiology than chronic changes during the interstage period.

Youth with Fontan circulation (Fontan) are at-risk for impairments in attention and executive functioning (EF) due to a confluence of genetic, prenatal, surgical, and medical risk factors. We sought to describe attention and EF in this population, measured via standardized performance-based tests and caregiver rating scales. We then examined how weaknesses in attention and EF were related to outcomes in other neurobehavioral domains, including adaptive behavior and academic achievement. Our sample included 93 youth with Fontan who were referred for neuropsychological evaluations as part of standard clinical care. The cohort as a whole measured between 0.18 to 0.99 standard deviations below normative means across domains of attention, EF, academic achievement, and intellectual ability. In addition, caregiver-reported concerns for attention, EF, anxiety, and depression were elevated, and approximately 0.35 to 0.85 standard deviations above normative means. Lastly, caregiver-reported adaptive behavior measured 0.93 to 1.24 standard deviations below normative values. Academic outcomes were differentially affected by demographic and attention/EF variables, while depression and caregiver-reported EF predicted adaptive behavior. Findings from this study underscore the importance of routine neuropsychological evaluation as part of comprehensive, multidisciplinary care for individuals with Fontan, with the goal of enhancing neurobehavioral and functional outcomes across the lifespan.

Background Inadequate pulmonary vascular growth results in morbidity for many children with single‐ventricle heart disease (SVHD). Endothelin 1 (ET1) is a potent vasoconstrictor and stimulator of pulmonary artery smooth muscle proliferation. Circulating ET1 levels and their association with outcomes have not been studied during early SVHD palliation. We aimed to define circulating levels of ET1 in patients with SVHD undergoing stage 2 palliation and evaluate their relationship to postoperative hypoxemia. We hypothesized that patients with SVHD with higher ET1 concentration would have a greater post–stage 2 hypoxemia. Methods and Results Prospective cohort study of 55 subjects with SVHD undergoing stage 2 palliation and 50 controls. Samples for ET1 analysis were collected at preoperation (systemic and pulmonary vein) and 2, 24, and 48 hours postoperation for cases and a single time point for controls. The primary outcome was percentage of first 48 postoperative hours with clinically significant hypoxemia (saturation, <70%). ET1 concentration was lower in preoperative cases than controls (2.2 versus 2.7 pg/mL; P=0.0015) and in the pulmonary vein than systemic vein (1.7 versus 2.2 pg/mL; P<0.001). ET1 level increased by 2 hours postoperation and trended back to baseline by 48 hours. Higher preoperative pulmonary vein ET1 and 2 hours postoperative ET1 were associated with larger hypoxemia burden (10.6% versus 2.7% [P=0.0081]; and 7.6% versus 3.2% [P=0.01], respectively). Multivariable testing demonstrated ET1 concentration and cardiopulmonary bypass time were associated with hypoxemia, whereas catheterization measurements and clinical variables were not. Conclusions Infants with SVHD with higher perioperative ET1 concentration experience more post–stage 2 hypoxemia. ET1 activity may be a modifiable risk factor of pulmonary vascular inadequacy for stage 2 palliation.

Non-invasive myocardial work (MW) by left ventricular (LV) pressure–strain loops (PSL) is a novel method for assessing myocardial function while adjusting for afterload, yet pediatric data remain lacking. The aims of this study were to investigate the different patterns of LV PSL and non-invasive MW in pediatric patients with hypertrophic (HCM) and dilated cardiomyopathy (DCM) and their association with exercise tolerance. We included 110 pediatric subjects (mean age, 13 ± 4 years, 35 DCM, 40 HCM, and 35 healthy controls). Standard and speckle-tracking echocardiography were performed. LV PSLs were generated, and global work index (GWI), MW efficiency (GWE), constructive work (GCW), and wasted work (GWW) were compared between groups. Regression analysis was used to assess the influence of ventricular function, dimensions, wall thickness, and wall stress on MW and to predict the association between MW and VO2 max as a surrogate of exercise capacity. Patients with DCM had significantly lower GWI compared to controls (GWI 479.6 ± 263.0 vs 1610.1 ± 211.0, P < 0.005). GWE was significantly reduced in DCM (79.3 ± 7.9 vs 95.2 ± 1.3, P < 0.005) due to significantly reduced GCW and increased GWW. HCM patients had significant reduction in GWI and GWE from normal (1237.7 ± 449.1 vs 1610.1 ± 211.0, P = 0.001 and 89.6 ± 4.9 vs 95.2 ± 1.3, P < 0.005, respectively), although less severe than with DCM. In a multivariate regression analysis, GWE had the highest association with VO2 max in both cohorts (DCM: β = 0.68, P = 0.001, HCM: β = 0.71, P = 0.007). Non-invasively assessed myocardial work and LV PSLs provide novel insights into the mechanisms of dysfunction in pediatric patients with cardiomyopathy with good prediction of clinical status and thus hold promise to further explore myocardial mechanistic with clinical relevance in different disease entities.

Conventional pediatric volumetric MRI acquisitions of a short-axis stack typically require multiple breath-holds under anesthesia. Here, we aimed to validate a vendor-optimized compressed-sensing approach to reduce scan time during short-axis balanced steady-state free precession (bSSFP) cine imaging. Imaging was performed in 28 patients (16±9 years) in this study on a commercial 3-tesla (T) scanner using retrospective electrocardiogram-gated cine bSSFP. Cine short-axis images covering both ventricles were acquired with conventional parallel imaging and a vendor-optimized parallel imaging/compressed-sensing approach. Qualitative Likert scoring for blood–myocardial contrast, edge definition, and presence of artifact was performed by two experienced radiologists. Quantitative comparisons were performed including biventricular size and function. A paired t-test was used to detect significant differences (P<0.05). Scan duration was 7±2 s/slice for conventional imaging (147±33 s total) vs. 4±2 s/slice for compressed sensing (83±28 s total). No significant differences were found with qualitative image scores for blood–myocardial contrast, edge definition, and presence of artifact. No significant differences were found in volumetric analysis between the two sequences. The number of breath-holds was 10±4 for conventional imaging and 5±3 for compressed sensing. Compressed sensing allowed for a 50% reduction in the number of breath-holds and a 43% reduction in the total scan time without differences in the qualitative or quantitative measurements as compared to the conventional technique.

Objective This study used cardiac magnetic resonance imaging to evaluate flow characteristics and ventricular hemodynamics for children with single right (hypoplastic left heart syndrome) and single left (hypoplastic right heart syndrome) systemic ventricle anatomy after Fontan palliation compared with normal biventricular controls. Methods Twenty children with single ventricle anatomy (hypoplastic left heart syndrome, n = 10; hypoplastic right heart syndrome, n = 10) underwent standardized 4-dimensional flow cardiac magnetic resonance and were compared with age-matched controls (n = 10). End-diastolic volume was partitioned into 4 defined components of variable kinetic energy (direct flow, retained inflow, delayed ejection, and residual volume) and compared between groups. Further, volumetric and functional parameters as defined by cardiac magnetic resonance were evaluated. Results Children with hypoplastic left heart syndrome had significantly increased indexed end-diastolic and end-systolic volumes compared with both hypoplastic right heart syndrome and control groups. Flow component analysis demonstrated diastolic inefficiency in both hypoplastic left heart syndrome and hypoplastic right heart syndrome groups compared with controls as defined by decreased direct flow and increased residual volumes. Decreased direct flow correlated with decreased ejection fraction and increased end-diastolic and end-systolic volume indices. Increased residual volume correlated with decreased ejection fraction and increased end-systolic volume index. Conclusions Fontan-palliated patients with single ventricle physiology (hypoplastic left heart syndrome and hypoplastic right heart syndrome) demonstrate altered and inefficient flow patterns in the systemic ventricle as defined by 4-dimensional flow cardiac magnetic resonance compared with normal biventricular controls. Decreased direct flow and increased residual volume indicate that diastolic ventricular dysfunction is prevalent after Fontan palliation. This study provides a foundation for future predictive modeling and cardiac magnetic resonance flow diagnostic studies in this high-risk patient population.

Despite significant morbidity among infants with single ventricle heart disease (SVHD), clinical monitoring is limited by poor understanding of the underlying pathobiology. Proteomics can identify novel biomarkers and important pathways in complex disease. No prior study has evaluated whether the proteome of SVHD infants differs from healthy controls, how it shifts after stage 2 palliation, or whether differences can predict post-operative outcomes. We present a prospective cohort study of cardiovascular proteomic phenotyping in infants with SVHD undergoing stage 2 palliation. Twenty-nine pre-stage-2 SVHD infants and 25 healthy controls were enrolled. Outcomes included postoperative hypoxemia and endotracheal intubation time. Serum samples were drawn pre-operatively (systemic and pulmonary vein) and at 24 hours postoperation. Targeted cardiovascular proteomic analysis included 184 proteins. Partial least squares discriminant analysis distinguished cases from controls (Accuracy = 0.98, R-2 = 0.93, Q(2) = 0.81) with decreased inflammatory mediators and increased modulators of vascular tone. Partial least squares discriminant analysis also distinguished cases pre-operation vs. post-operation (Accuracy=0.98, R-2=0.99, Q(2)= 0.92) with postoperative increase in both inflammatory and vascular tone mediators. Pre-operation pulmonary vein tissue inhibitor of metalloproteinase-1 (1.8x-fold, p=1.6 x 10(-4)) and nidogen-1 (1.5x-fold, p=1.7 x 10(-4)) were higher in subjects with longer endotracheal intubation time. Postoperation matrix metalloproteinase 7 levels were higher in subjects with greater postoperative hypoxemia (1.5x-fold, P= 1.97 x 10(-5)). Proteomic analysis identifies significant changes among SVHD infants preand post-stage 2, and healthy controls. Tissue inhibitor of metalloproteinase-1, nidogen-1, and matrix metalloproteinase 7 levels are higher in SVHD cases with greater morbidity suggesting an important role for regulation of extracellular matrix production. Proteomic profiling may identify high-risk SVHD infants.

Introduction: In the Pediatric Heart Network double-blind Fontan Udenafil Exercise Longitudinal (FUEL) trial, treatment with udenafil (Mezzion Pharma Co Ltd) for 6 months was associated with modest improvements in exercise capacity and ventricular performance (NCT02741115). Measures of vascular function, which have been related to Fontan exercise capacity, were also obtained but have not been explored in detail. Methods: Endothelial function (Framingham reactive hyperemia index, FRHI; area under the curve to max occlusion, AUC Max ) and arterial stiffness (augmentation index, AI) were assessed with peripheral arterial tonometry. The primary outcome was the effect of udenafil vs. placebo on vascular function. Secondary outcomes included baseline, and 26-week change from baseline, measures of vascular function in subgroups of the udenafil arm, stratified by exercise response. Exercise response was defined by longitudinal change in peak oxygen consumption and categorized by 1) any positive change vs. other and 2) tertile of change. Results: Paired measures of vascular function were analyzed in 164 (82%) and 167 (84%) udenafil and placebo participants, respectively. There were no baseline differences between groups, including the use of vasoactive medications. Overall, there were no differences in change in measures of vascular function between treatment groups. In subgroup analysis, exercise responders demonstrated better baseline endothelial function (FRHI: 0.39 ± 0.37 vs. 0.29 ± 0.31, p=0.056; AUC Max : 6.53 ± 2.91 vs. 5.63 ± 2.21, p=0.023) and suggestion of a 26-week reduction in arterial stiffness (AI: -1.42 ± 10.3 vs. 1.69 ± 11.7, p=0.075). Analysis by tertile of exercise response showed that AI was significantly improved in the top tertile of exercise responders (-3.27 ± 8.4 vs. 2.62 ± 12.4 vs. 0.35 ± 11.1, p=0.022) compared with the lower tertiles. Conclusions: In the FUEL trial, treatment with udenafil was not associated with significant changes in measures of vascular function. Udenafil-treated participants with evidence of exercise responsiveness to therapy manifest better baseline endothelial function and a significant improvement in arterial stiffness. Vascular function may play a role in PDE-5 responsiveness in Fontan circulation.

Survivors of palliative surgery for single ventricle heart disease (SVHD) are at risk of poor neurodevelopmental outcomes and reduced exercise capacity. In healthy populations, reduced exercise capacity is related to decreased cognition suggesting a possible relationship between exercise capacity and neurodevelopment. Using cardiopulmonary exercise testing (CPET) and neuropsychological testing (NPT) as indicators of exercise capacity and neurodevelopment, respectively, we hypothesized that in SVHD, higher CPET measures are related to better NPT performance. Patients were retrospectively identified. CPET variables included VO2max, anaerobic threshold, peak heart rate, ventilatory efficiency, and respiratory exchange ratio. NPT instruments were divided into domains measuring attention, executive functioning, adaptive functioning, and emotional functioning. Linear regression was used to test for associations between CPET and NPT. 23 subjects with SVHD met inclusion criteria. On both CPET and NPT, the cohort scored worse than healthy, age-matched subjects. Higher VO2max and anaerobic threshold were associated with better parent-rated overall adaptive functioning (p = 0.01 and p = 0.02, respectively). Higher peak heart rate was related to better sustained visual attention (p = 0.01). In SVHD, CPET measures indicating better exercise capacity were positively associated with a subset of scores on NPT. Larger, multisite studies implementing cardiorespiratory fitness intervention and incorporating cognitive outcome measures will be needed to better characterize the relationship between neurodevelopment and functional capacity in this population. Results may assist in providing anticipatory guidance and optimizing post-Fontan developmental trajectories.

Sabapathy, Divya; Klawitter, Jelena; Silveira, Lori; Mitchell, Max; Morgan, Gareth; DiMaria, Michael; Twite, Mark; Frank, Benjamin; Davidson, Jesse Author Information