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

OBJECTIVE

In the SVR trial (Single Ventricle Reconstruction), newborns with hypoplastic left heart syndrome were randomly assigned to receive a modified Blalock-Taussig-Thomas shunt (mBTTS) or a right ventricle-to-pulmonary artery shunt (RVPAS) at Norwood operation. Transplant-free survival was superior in the RVPAS group at 1 year, but no longer differed by treatment group at 6 years; both treatment groups had accumulated important morbidities. In the third follow-up of this cohort (SVRIII [Long-Term Outcomes of Children With Hypoplastic Left Heart Syndrome and the Impact of Norwood Shunt Type]), we measured longitudinal outcomes and their risk factors through 12 years of age.

METHODS

Annual medical history was collected through record review and telephone interviews. Cardiac magnetic resonance imaging (CMR), echocardiogram, and cycle ergometry cardiopulmonary exercise tests were performed at 10 through 14 years of age among participants with Fontan physiology. Differences in transplant-free survival and complication rates (eg, arrhythmias or protein-losing enteropathy) were identified through 12 years of age. The primary study outcome was right ventricular ejection fraction (RVEF) by CMR, and primary analyses were according to shunt type received. Multivariable linear and Cox regression models were created for RVEF by CMR and post-Fontan transplant-free survival.

RESULTS

Among 549 participants enrolled in SVR, 237 of 313 (76%; 60.7% male) transplant-free survivors (mBTTS, 105 of 147; RVPAS, 129 of 161; both, 3 of 5) participated in SVRIII. RVEF by CMR was similar in the shunt groups (RVPAS, 51±9.6 [n=90], and mBTTS, 52±7.4 [n=75]; P=0.43). The RVPAS and mBTTS groups did not differ in transplant-free survival by 12 years of age (163 of 277 [59%] versus 144 of 267 [54%], respectively; P=0.11), percentage predicted peak Vo2 for age and sex (74±18% [n=91] versus 72±18% [n=84]; P=0.71), or percentage predicted work rate for size and sex (65±20% versus 64±19%; P=0.65). The RVPAS versus mBTTS group had a higher cumulative incidence of protein-losing enteropathy (5% versus 2%; P=0.04) and of catheter interventions (14 versus 10 per 100 patient-years; P=0.01), but had similar rates of other complications.

CONCLUSIONS

By 12 years after the Norwood operation, shunt type has minimal association with RVEF, peak Vo2, complication rates, and transplant-free survival. RVEF is preserved among the subgroup of survivors who underwent CMR assessment. Low transplant-free survival, poor exercise performance, and accruing morbidities highlight the need for innovative strategies to improve long-term outcomes in patients with hypoplastic left heart syndrome.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT0245531.

Researching COVID to enhance recovery (RECOVER) pediatric study protocol: Rationale, objectives and design

Importance

The prevalence, pathophysiology, and long-term outcomes of COVID-19 (post-acute sequelae of SARS-CoV-2 [PASC] or "Long COVID") in children and young adults remain unknown. Studies must address the urgent need to define PASC, its mechanisms, and potential treatment targets in children and young adults.

Observations

We describe the protocol for the Pediatric Observational Cohort Study of the NIH's RE searching COV ID to E nhance R ecovery (RECOVER) Initiative. RECOVER-Pediatrics is an observational meta-cohort study of caregiver-child pairs (birth through 17 years) and young adults (18 through 25 years), recruited from more than 100 sites across the US. This report focuses on two of five cohorts that comprise RECOVER-Pediatrics: 1) a de novo RECOVER prospective cohort of children and young adults with and without previous or current infection; and 2) an extant cohort derived from the Adolescent Brain Cognitive Development (ABCD) study ( n =10,000). The de novo cohort incorporates three tiers of data collection: 1) remote baseline assessments (Tier 1, n=6000); 2) longitudinal follow-up for up to 4 years (Tier 2, n=6000); and 3) a subset of participants, primarily the most severely affected by PASC, who will undergo deep phenotyping to explore PASC pathophysiology (Tier 3, n=600). Youth enrolled in the ABCD study participate in Tier 1. The pediatric protocol was developed as a collaborative partnership of investigators, patients, researchers, clinicians, community partners, and federal partners, intentionally promoting inclusivity and diversity. The protocol is adaptive to facilitate responses to emerging science.

Conclusions and Relevance

RECOVER-Pediatrics seeks to characterize the clinical course, underlying mechanisms, and long-term effects of PASC from birth through 25 years old. RECOVER-Pediatrics is designed to elucidate the epidemiology, four-year clinical course, and sociodemographic correlates of pediatric PASC. The data and biosamples will allow examination of mechanistic hypotheses and biomarkers, thus providing insights into potential therapeutic interventions.

Clinical Trialsgov Identifier

Clinical Trial Registration: http://www.clinicaltrials.gov . Unique identifier: NCT05172011.

Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred that were related to difficulties with: (1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and (2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by: (1) adding additional study sites, (2) increasing the frequency of meetings with site coordinators, and (3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms.

Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred related to difficulties with: 1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and 2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by 1) adding additional study sites, 2) increasing the frequency of meetings with site coordinators and 3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms.

Trial registration number

ClinicalTrials.gov Registration Number: NCT02692443.

Development of the Residual Lesion Score for congenital heart surgery: the RAND Delphi methodology

BACKGROUND AND OBJECTIVE

The Residual Lesion Score is a novel tool for assessing the achievement of surgical objectives in congenital heart surgery based on widely available clinical and echocardiographic characteristics. This article describes the methodology used to develop the Residual Lesion Score from the previously developed Technical Performance Score for five common congenital cardiac procedures using the RAND Delphi methodology.

METHODS

A panel of 11 experts from the field of paediatric and congenital cardiology and cardiac surgery, 2 co-chairs, and a consultant were assembled to review and comment on validity and feasibility of measuring the sub-components of intraoperative and discharge Residual Lesion Score for five congenital cardiac procedures. In the first email round, the panel reviewed and commented on the Residual Lesion Score and provided validity and feasibility scores for sub-components of each of the five procedures. In the second in-person round, email comments and scores were reviewed and the Residual Lesion Score revised. The modified Residual Lesion Score was scored independently by each panellist for validity and feasibility and used to develop the "final" Residual Lesion Score.

RESULTS

The Residual Lesion Score sub-components with a median validity score of ≥7 and median feasibility score of ≥4 that were scored without disagreement and with low absolute deviation from the median were included in the "final" Residual Lesion Score.

CONCLUSION

Using the RAND Delphi methodology, we were able to develop Residual Lesion Score modules for five important congenital cardiac procedures for the Pediatric Heart Network's Residual Lesion Score study.

Costs associated with acute kidney injury in critically Ill neonates with patent Ductus arteriosus: pediatric health information system (PHIS) analysis

OBJECTIVE

Compare costs of hospitalization between critically-ill neonates with patent ductus arteriosus (PDA) who did and did not develop acute kidney injury (AKI).

STUDY DESIGN

Using the Children's Hospital Association's Pediatric Health Information System (PHIS) database, we ascertained the marginal estimated total cost of hospitalization between those who did and did not develop AKI.

RESULTS

Query of 49 PHIS centers yielded 14,217 neonates with PDA, 1697 with AKI and 12,520 without AKI. Predictors of cost included AKI, birth weight, ethnicity, race, length of stay (LOS), and Feudtner Complex Chronic Conditions Classification System. LOS was the strongest predictor (AKI: median 71 days [IQR 28-130]; No AKI: 28 days [10-76]; p < 0.01). Neonates with AKI had $48,416 greater costs (95% CI: $43,804-53,227) after adjusting for these predictors (AKI: $190,063, 95% CI $183,735-196,610; No AKI: $141,647, 95% CI $139,931-143,383 l; p < 0.01).

CONCLUSION

AKI is independently associated with increased hospital costs in critically-ill neonates with PDA.

Active vs Traditional Methods of Recruiting Children for a Clinical Trial in Rural Primary Care Clinics: A Cluster-Randomized Clinical Trial

IMPORTANCE

To our knowledge, there are no published randomized clinical trials of recruitment strategies. Rigorously evaluated successful recruitment strategies for children are needed.

OBJECTIVE

To evaluate the feasibility of 2 recruitment methods for enrolling rural children through primary care clinics to assess whether either or both methods are sufficiently effective for enrolling participants into a clinical trial of a behavioral telehealth intervention for children with overweight or obesity.

DESIGN, SETTING, AND PARTICIPANTS

This cluster-randomized clinical trial of 2 recruitment methods was conducted at 4 primary care clinics in 4 separate states. Each clinic used both recruitment methods in random order. Clinic eligibility criteria included at least 40% pediatric patients with Medicaid coverage and at least 100 potential participants. Eligibility criteria for children included a rural home address, age 6 to 11 years, and body mass index at or above the 85th percentile. Recruitment began February 3, 2020, and randomization of participants occurred on August 17, 2020. Data were analyzed from October 3, 2021, to April 21, 2022.

INTERVENTIONS

Two recruitment methods were assessed: the active method, for which a list of potential participants seen within the past year at each clinic was generated through the electronic health record and consecutively approached by research staff based on visit date to the clinic, and the traditional method, for which recruitment included posters, flyers, social media, and press release. Clinics were randomized to the order in which the 2 methods were implemented in 4-week periods, followed by a 4-week catch-up period using the method found most effective in previous periods.

MAIN OUTCOMES AND MEASURES

For each recruitment method, the number and proportion of randomized children among those who were approached was calculated.

RESULTS

A total of 104 participants were randomized (58 girls [55.8%]; mean age, 9.3 [95% CI, 9.0-9.6] years). Using the active method, 535 child-parent dyads were approached and 99 (18.5% [95% CI, 15.3%-22.1%]) were randomized. Using the traditional method, 23 caregivers expressed interest, and 5 (21.7% [95% CI, 7.5%-43.7%]) were randomized. All sites reached full enrollment using the active method and no sites achieved full enrollment using the traditional method. Mean time to full enrollment was 26.3 (range, 21.0-31.0) days.

CONCLUSIONS AND RELEVANCE

This study supports the use of the active approach with local primary care clinics to recruit children with overweight and obesity from rural communities into clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04142034.

Use of physiologically‐based pharmacokinetic modeling to inform dosing of the opioid analgesics fentanyl and methadone in children with obesity

Obesity is an increasingly alarming public health threat, with nearly 20% of children classified as obese in the United States today. Children with obesity are commonly prescribed the opioids fentanyl and methadone, and accurate dosing is critical to reducing the risk of serious adverse events associated with overexposure. However, pharmacokinetic studies in children with obesity are challenging to conduct, so there is limited information to guide fentanyl and methadone dosing in these children. To address this clinical knowledge gap, physiologically‐based pharmacokinetic models of fentanyl and methadone were developed in adults and scaled to children with and without obesity to explore the interplay of obesity, age, and pharmacogenomics. These models included key obesity‐induced changes in physiology and pharmacogenomic effects. Model predictions captured observed concentrations in children with obesity well, with an overall average fold error of 0.72 and 1.08 for fentanyl and methadone, respectively. Model simulations support a reduced fentanyl dose (1 vs. 2 μg/kg/h) starting at an earlier age (6 years) in virtual children with obesity, highlighting the importance of considering both age and obesity status when selecting an infusion rate most likely to achieve steady‐state concentrations within the target range. Methadone dosing simulations highlight the importance of considering genotype in addition to obesity status when possible, as cytochrome P450 (CYP)2B6*6/*6 virtual children with obesity required half the dose to match the exposure of wildtype children without obesity. This physiologically‐based pharmacokinetic modeling approach can be applied to explore dosing of other critical drugs in children with obesity.

Evaluation of mRNA-1273 Covid-19 Vaccine in Children 6 to 11 Years of Age

BACKGROUND

Vaccination of children to prevent coronavirus disease 2019 (Covid-19) is an urgent public health need. The safety, immunogenicity, and efficacy of the mRNA-1273 vaccine in children 6 to 11 years of age are unknown.

METHODS

Part 1 of this ongoing phase 2-3 trial was open label for dose selection; part 2 was an observer-blinded, placebo-controlled expansion evaluation of the selected dose. In part 2, we randomly assigned children (6 to 11 years of age) in a 3:1 ratio to receive two injections of mRNA-1273 (50 μg each) or placebo, administered 28 days apart. The primary objectives were evaluation of the safety of the vaccine in children and the noninferiority of the immune response in these children to that in young adults (18 to 25 years of age) in a related phase 3 trial. Secondary objectives included determination of the incidences of confirmed Covid-19 and severe acute respiratory syndrome coronavirus 2 infection, regardless of symptoms. Interim analysis results are reported.

RESULTS

In part 1 of the trial, 751 children received 50-μg or 100-μg injections of the mRNA-1273 vaccine, and on the basis of safety and immunogenicity results, the 50-μg dose level was selected for part 2. In part 2 of the trial, 4016 children were randomly assigned to receive two injections of mRNA-1273 (50 μg each) or placebo and were followed for a median of 82 days (interquartile range, 14 to 94) after the first injection. This dose level was associated with mainly low-grade, transient adverse events, most commonly injection-site pain, headache, and fatigue. No vaccine-related serious adverse events, multisystem inflammatory syndrome in children, myocarditis, or pericarditis were reported as of the data-cutoff date. One month after the second injection (day 57), the neutralizing antibody titer in children who received mRNA-1273 at a 50-μg level was 1610 (95% confidence interval [CI], 1457 to 1780), as compared with 1300 (95% CI, 1171 to 1443) at the 100-μg level in young adults, with serologic responses in at least 99.0% of the participants in both age groups, findings that met the prespecified noninferiority success criterion. Estimated vaccine efficacy was 88.0% (95% CI, 70.0 to 95.8) against Covid-19 occurring 14 days or more after the first injection, at a time when B.1.617.2 (delta) was the dominant circulating variant.

CONCLUSIONS

Two 50-μg doses of the mRNA-1273 vaccine were found to be safe and effective in inducing immune responses and preventing Covid-19 in children 6 to 11 years of age; these responses were noninferior to those in young adults. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; KidCOVE ClinicalTrials.gov number, NCT04796896.).

Diastolic Dysfunction With Preserved Ejection Fraction After the Fontan Procedure

Background Heart failure phenotyping in single-ventricle Fontan patients is challenging, particularly in patients with normal ejection fraction (EF). The objective of this study was to identify Fontan patients with abnormal diastolic function, who are high risk for heart failure with preserved ejection fraction (HFpEF), and characterize their cardiac mechanics, exercise function, and functional health status. Methods and Results Data were obtained from the Pediatric Heart Network Fontan Cross-sectional Study database. EF was considered abnormal if <50%. Diastolic function was defined as abnormal if the diastolic pressure:volume quotient (lateral E:e'/end-diastolic volume) was >90th percentile (≥0.26 mL-1). Patients were divided into: controls=normal EF and diastolic function; systolic dysfunction (SD) = abnormal EF with normal diastolic function; diastolic dysfunction (DD) = normal EF with abnormal diastolic pressure:volume quotient. Exercise function was quantified as percent predicted peak VO2. Physical Functioning Summary Score (FSS) was reported from the Child Health Questionnaire. A total of 239 patients were included, 177 (74%) control, 36 (15%) SD, and 26 (11%) DD. Median age was 12.2 (5.4) years. Arterial elastance, a measure of arterial stiffness, was higher in DD (3.6±1.1 mm Hg/mL) compared with controls (2.5±0.8 mm Hg/mL), P<0.01. DD patients had lower predicted peak VO2 compared with controls (52% [20] versus 67% [23], P<0.01). Physical FSS was lower in DD (45±13) and SD (44±13) compared with controls (50±7), P<0.01. Conclusions Fontan patients with abnormal diastolic function and normal EF have decreased exercise tolerance, decreased functional health status, and elevated arterial stiffness. Identification of patients at high risk for HFpEF is feasible and should be considered when evaluating Fontan patients.

Safety of sildenafil in extremely premature infants: a phase I trial

OBJECTIVE

To characterize the safety of sildenafil in premature infants.

STUDY DESIGN

A phase I, open-label trial of sildenafil in premature infants receiving sildenafil per usual clinical care (cohort 1) or receiving a single IV dose of sildenafil (cohort 2). Safety was evaluated based on adverse events (AEs), transaminase levels, and mean arterial pressure monitoring.

RESULTS

Twenty-four infants in cohort 1 (n = 25) received enteral sildenafil. In cohort 2, infants received a single IV sildenafil dose of 0.25 mg/kg (n = 7) or 0.125 mg/kg (n = 2). In cohort 2, there was one serious AE related to study drug involving hypotension associated with a faster infusion rate than specified by the protocol. There were no AEs related to elevated transaminases.

CONCLUSION

Sildenafil was well tolerated by the study population. Drug administration times and flush rates require careful attention to prevent infusion-related hypotension associated with faster infusions of IV sildenafil in premature infants.

CLINICAL TRIAL

ClinicalTrials.gov Identifier: NCT01670136.

Clinically Suspected Myocarditis Temporally Related to COVID-19 Vaccination in Adolescents and Young Adults

BACKGROUND

Understanding the clinical course and short-term outcomes of suspected myocarditis following COVID-19 vaccination has important public health implications in the decision to vaccinate youth.

METHODS

We retrospectively collected data on patients <21 years-old presenting before 7/4/2021 with suspected myocarditis within 30 days of COVID-19 vaccination. Lake Louise criteria were used for cardiac magnetic resonance imaging (cMRI) findings. Myocarditis cases were classified as confirmed or probable based on the Centers for Disease Control and Prevention definitions.

RESULTS

We report on 139 adolescents and young adults with 140 episodes of suspected myocarditis (49 confirmed, 91 probable) at 26 centers. Most patients were male (N=126, 90.6%) and White (N=92, 66.2%); 29 (20.9%) were Hispanic; and median age was 15.8 years (range 12.1-20.3, IQR 14.5-17.0). Suspected myocarditis occurred in 136 patients (97.8%) following mRNA vaccine, with 131 (94.2%) following the Pfizer-BioNTech vaccine; 128 (91.4%) occurred after the 2nd dose. Symptoms started a median of 2 days (range 0-22, IQR 1-3) after vaccination. The most common symptom was chest pain (99.3%). Patients were treated with nonsteroidal anti-inflammatory drugs (81.3%), intravenous immunoglobulin (21.6%), glucocorticoids (21.6%), colchicine (7.9%) or no anti-inflammatory therapies (8.6%). Twenty-six patients (18.7%) were in the ICU, two were treated with inotropic/vasoactive support, and none required ECMO or died. Median hospital stay was 2 days (range 0-10, IQR 2-3). All patients had elevated troponin I (N=111, 8.12 ng/mL, IQR 3.50-15.90) or T (N=28, 0.61 ng/mL, IQR 0.25-1.30); 69.8% had abnormal electrocardiograms and/or arrythmias (7 with non-sustained ventricular tachycardia); and 18.7% had left ventricular ejection fraction (LVEF) <55% on echocardiogram. Of 97 patients who underwent cMRI at median 5 days (range 0-88, IQR 3-17) from symptom onset, 75 (77.3%) had abnormal findings: 74 (76.3%) had late gadolinium enhancement, 54 (55.7%) had myocardial edema, and 49 (50.5%) met Lake Louise criteria. Among 26 patients with LVEF <55% on echocardiogram, all with follow-up had normalized function (N=25).

CONCLUSIONS

Most cases of suspected COVID-19 vaccine myocarditis occurring in persons <21 years have a mild clinical course with rapid resolution of symptoms. Abnormal findings on cMRI were frequent. Future studies should evaluate risk factors, mechanisms, and long-term outcomes.

Remestemcel-L Therapy for COVID-19-Associated Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory syndrome in children (MIS-C) is a serious postinfectious immune dysregulation associated with coronavirus disease 2019 that may present with severe and life-threatening cardiovascular dysfunction, hemodynamic instability, shock, and multisystem organ failure. Optimal treatment is unknown. Current standard of care consists of nonspecific anti-inflammatory and antithrombotic therapies. Interventions that target MIS-C's distinctive clinical features and immunophenotype are indicated. Remestemcel-L, an investigational mesenchymal stromal cell therapy, is a promising candidate for treatment of MIS-C because of its beneficial anti-inflammatory, immunomodulatory, endothelial function and vascular stabilizing effects, which align well with the pathophysiology of MIS-C. Here, we present the first two patients with life-threatening MIS-C ever treated with remestemcel-L under an expanded access program. Both were previously healthy children without any indication of previous coronavirus disease 2019 infection or exposure. They presented with severe clinical illness including myocardial dysfunction, hemodynamic instability, hypotension, acute kidney injury, and shock. At the time of hospital admission, both had negative polymerase chain reaction (PCR) test results and positive serology results for severe acute respiratory syndrome coronavirus 2. Both children received standard of care MIS-C treatment. Although the patients showed some clinical improvement, left ventricular ejection fraction remained reduced and inflammatory biomarkers remained significantly elevated. When treated with two intravenous doses of remestemcel-L separated by 48 hours, rapid normalization of left ventricular ejection fraction, notable reductions in biomarkers of systemic and cardiac inflammation, and improved clinical status occurred. Neither child experienced adverse effects associated with remestemcel-L administration. This treatment appears promising as a novel immunomodulatory cellular therapy for children with clinically significant cardiovascular manifestations of MIS-C.

Intraoperative methylprednisolone and neurodevelopmental outcomes in infants after cardiac surgery

BACKGROUND

Neurodevelopmental impairment is a significant consequence for survivors of surgery for critical congenital heart disease. This study sought to determine if intraoperative methylprednisolone during neonatal cardiac surgery is associated with neurodevelopmental outcomes at 12 months of age and to identify early prognostic variables associated with neurodevelopmental outcomes.

METHODS

A planned secondary analysis of a two-center, double-blind, randomized, placebo-controlled trial of intraoperative methylprednisolone in neonates undergoing cardiac surgery was performed. A brain injury biomarker was measured perioperatively. Bayley Scales of Infant and Toddler Development-III (BSID-III) were performed at 12 months of age. Two sample t-tests and generalized linear models were used.

RESULTS

There were 129 participants (n=61 methylprednisolone, n=68 placebo). There were no significant differences in BSID-III scores and brain injury biomarker levels between the two treatment groups. Participants who underwent a palliative (vs. corrective) procedure had lower mean BSID-III cognitive (101+15 vs. 106+14, p=0.03) and motor scores (85+18 vs. 94+16, p<0.01). Longer ventilation time was associated with lower motor scores. Longer cardiac intensive care unit (CICU) stay was associated with lower cognitive, language, and motor scores. Cardiopulmonary bypass time, aortic cross clamp time, and deep hypothermic circulatory arrest were not associated with BSID-III scores.

CONCLUSIONS

Neurodevelopmental outcomes were not associated with intraoperative methylprednisolone or intraoperative variables. Participants who underwent a neonatal palliative (vs. corrective) procedure had longer CICU stays and worse neurodevelopmental outcomes at 1 year. This work suggests that interventions focused solely on the operative period may not be associated with a long-term neurodevelopmental benefit.

Six-Year Neurodevelopmental Outcomes for Children With Single-Ventricle Physiology

OBJECTIVES

To determine if neurodevelopmental deficits in children with single-ventricle physiology change with age and early developmental scores predict 6-year outcomes.

METHODS

In the Single Ventricle Reconstruction Trial, Bayley Scales of Infant Development, Second Edition, were administered at 14 months of age, and parents completed the Behavior Assessment System for Children, Second Edition (BASC-2) annually from the ages of 2 to 6 years. Scores were classified as average, at risk, or impaired. We calculated sensitivities, specificities, and positive and negative predictive values of earlier tests on 6-year outcomes.

RESULTS

Of 291 eligible participants, 244 (84%) completed the BASC-2 at 6 years; more Single Ventricle Reconstruction participants than expected on the basis of normative data scored at risk or impaired on the BASC-2 Adaptive Skills Index at that evaluation (28.7% vs 15.9%; P < .001). Children with Adaptive Skills Composite scores <2 SD below the mean at the age of 6 were more likely to have had delayed development at 14 months, particularly on the Psychomotor Development Index (sensitivity of 79%). However, the positive predictive value of the 14-month Mental Development Index and Psychomotor Development Index for 6-year BASC-2 Adaptive Scores was low (44% and 36%, respectively). Adaptive Skills Composite score impairments at the age of 6 were poorly predicted by using earlier BASC-2 assessments, with low sensitivities at the ages of 3 (37%), 4 (48%), and 5 years (55%).

CONCLUSIONS

Many children with hypoplastic left heart syndrome who have low adaptive skills at the age of 6 years will not be identified by screening at earlier ages. With our findings, we highlight the importance of serial evaluations for children with critical congenital heart disease throughout development.

Capacity Building for a New Multicenter Network Within the ECHO IDeA States Pediatric Clinical Trials Network

Introduction: Research capacity building is a critical component of professional development for pediatrician scientists, yet this process has been elusive in the literature. The ECHO IDeA States Pediatric Clinical Trials Network (ISPCTN) seeks to implement pediatric trials across medically underserved and rural populations. A key component of achieving this objective is building pediatric research capacity, including enhancement of infrastructure and faculty development. This article presents findings from a site assessment inventory completed during the initial year of the ISPCTN. Methods: An assessment inventory was developed for surveying ISPCTN sites. The inventory captured site-level activities designed to increase clinical trial research capacity for pediatrician scientists and team members. The inventory findings were utilized by the ISPCTN Data Coordinating and Operations Center to construct training modules covering 3 broad domains: Faculty/coordinator development; Infrastructure; Trials/Research concept development. Results: Key lessons learned reveal substantial participation in the training modules, the importance of an inventory to guide the development of trainings, and recognizing local barriers to clinical trials research. Conclusions: Research networks that seek to implement successfully completed trials need to build capacity across and within the sites engaged. Our findings indicate that building research capacity is a multi-faceted endeavor, but likely necessary for sustainability of a unique network addressing high impact pediatric health problems. The ISPCTN emphasis on building and enhancing site capacity, including pediatrician scientists and team members, is critical to successful trial implementation/completion and the production of findings that enhance the lives of children and families.

Site-Level Variation in the Characteristics and Care of Infants With Neonatal Opioid Withdrawal

BACKGROUND AND OBJECTIVES

Variation in pediatric medical care is common and contributes to differences in patient outcomes. Site-to-site variation in the characteristics and care of infants with neonatal opioid withdrawal syndrome (NOWS) has yet to be quantified. Our objective was to describe site-to-site variation in maternal-infant characteristics, infant management, and outcomes for infants with NOWS.

METHODS

Cross-sectional study of 1377 infants born between July 1, 2016, and June 30, 2017, who were ≥36 weeks' gestation, with NOWS (evidence of opioid exposure and NOWS scoring within the first 120 hours of life) born at or transferred to 1 of 30 participating hospitals nationwide. Site-to-site variation for each parameter within the 3 domains was measured as the range of individual site-level means, medians, or proportions.

RESULTS

Sites varied widely in the proportion of infants whose mothers received adequate prenatal care (31.3%-100%), medication-assisted treatment (5.9%-100%), and prenatal counseling (1.9%-75.5%). Sites varied in the proportion of infants with toxicology screening (50%-100%) and proportion of infants receiving pharmacologic therapy (6.7%-100%), secondary medications (1.1%-69.2%), and nonpharmacologic interventions including fortified feeds (2.9%-90%) and maternal breast milk (22.2%-83.3%). The mean length of stay varied across sites (2-28.8 days), as did the proportion of infants discharged with their parents (33.3%-91.1%).

CONCLUSIONS

Considerable site-to-site variation exists in all 3 domains. The magnitude of the observed variation makes it unlikely that all infants are receiving efficient and effective care for NOWS. This variation should be considered in future clinical trial development, practice implementation, and policy development.

Exercise Capacity and Predictors of Performance After Fontan: Results from the Pediatric Heart Network Fontan 3 Study

Impaired exercise following Fontan is a surrogate of morbidity. Single-center longitudinal data exist, but there is a lack of contemporary multi-center data. Ramp cycle ergometry was re-performed in consented participants who had originally participated in the Pediatric Heart Network's Fontan cross-sectional study. Annualized change was evaluated at maximal and submaximal exercise. Associations between these outcomes and patient characteristics were analyzed. There were 336 participants in Fontan 3, mean age 23.2 years. Paired measurements of peak oxygen consumption (peak VO₂) were available for 95; peak exercise data at Fontan 3 were available for 275. Percent-predicted peak VO₂ declined by 0.8 ± 1.7% per year (p < 0.001). At Fontan 3, the lowest performing peak VO₂ tertile had the highest rate of overweight and obesity (p < 0.001). Female gender was more prevalent in the highest performing tertile (p = 0.004). Paired data at the ventilatory anaerobic threshold (VO₂ at VAT) were available for 196; VAT data at Fontan 3 were available for 311. Percent-predicted VO₂ at VAT decreased by 0.8 ± 2.6% per year (p < 0.001). At Fontan 3, VO₂ at VAT was better preserved than peak VO₂ across all tertiles, with higher rates of overweight and obesity in the lower performing group (p = 0.001). Female gender (p < 0.001) and left ventricular morphology (p = 0.03) were associated with better performance. Submaximal exercise is better preserved than maximal in the Fontan population, but declined at the same rate over the study period. The overall longitudinal rate of decline in exercise performance is slower than what has been described previously.

IDeA States Pediatric Clinical Trials Network for Underserved and Rural Communities

The National Institutes of Health's Environmental Influences on Child Health Outcomes (ECHO) program aims to study high-priority and high-impact pediatric conditions. This broad-based health initiative is unique in the National Institutes of Health research portfolio and involves 2 research components: (1) a large group of established centers with pediatric cohorts combining data to support longitudinal studies (ECHO cohorts) and (2) pediatric trials program for institutions within Institutional Development Awards states, known as the ECHO Institutional Development Awards States Pediatric Clinical Trials Network (ISPCTN). In the current presentation, we provide a broad overview of the ISPCTN and, particularly, its importance in enhancing clinical trials capabilities of pediatrician scientists through the support of research infrastructure, while at the same time implementing clinical trials that inform future health care for children. The ISPCTN research mission is aligned with the health priority conditions emphasized in the ECHO program, with a commitment to bringing state-of-the-science trials to children residing in underserved and rural communities. ISPCTN site infrastructure is critical to successful trial implementation and includes research training for pediatric faculty and coordinators. Network sites exist in settings that have historically had limited National Institutes of Health funding success and lacked pediatric research infrastructure, with the initial funding directed to considerable efforts in professional development, implementation of regulatory procedures, and engagement of communities and families. The Network has made considerable headway with these objectives, opening two large research studies during its initial 18 months as well as producing findings that serve as markers of success that will optimize sustainability.

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

BACKGROUND/AIMS

The Pediatric Heart Network Marfan Trial was a randomized trial comparing atenolol versus losartan on aortic root dilation in 608 children and young adults with Marfan syndrome. Barriers to enrollment included a limited pool of eligible participants, restrictive entry criteria, and a diverse age range that required pediatric and adult expertise. Retention was complicated by a 3-year commitment to a complex study and medication regimen. The Network partnered with the Marfan Foundation, bridging the community with the research. The aims of this study are to report protocol and medication adherence and associated predictive factors, and to describe recruitment and retention strategies.

METHODS

Recruitment, retention, and adherence to protocol activities related to the primary outcome were measured. Retention was measured by percentage of enrolled participants with 3-year outcome data. Protocol adherence was calculated by completion rates of study visits, ambulatory electrocardiography (Holter monitoring), and quarterly calls. Medication adherence was assessed by the number of tablets or the amount of liquid in bottles returned. Centers were ranked according to adherence (high, medium, and low tertiles). Recruitment, retention, and adherence questionnaires were completed by sites. Descriptive statistics summarized recruitment, retention, and adherence, as well as questionnaire results. Regression modeling assessed predictors of adherence.

RESULTS

Completion rates for visits, Holter monitors, and quarterly calls were 99%, 94%, and 96%, respectively. Primary outcome data at 3 years were obtained for 88% of participants. The mean percentage of medication taken was estimated at 89%. Site and age were associated with all measures of adherence. Young adult and African American participants had lower levels of adherence. Higher adherence sites employed more strategies; had more staffing resources, less key staff turnover, and more collaboration with referring providers; utilized the Foundation's resources; and used a greater number of strategies to recruit, retain, and promote protocol and medication adherence.

CONCLUSION

Overall adherence was excellent for this trial conducted within a National Institutes of Health-funded clinical trial network. Strategies specifically targeted to young adults and African Americans may have been beneficial. Many strategies employed by higher adherence sites are ones that any site could easily use, such as greeting families at non-study hospital visits, asking for family feedback, providing calendars for tracking schedules, and recommending apps for medication reminders. Additional key learnings include adherence differences by age, race, and site, the value of collaborative learning, and the importance of partnerships with patient advocacy groups. These lessons could shape recruitment, retention, and adherence to improve the quality of future complex trials involving rare conditions.

Longitudinal study of anthropometry in Fontan survivors: Pediatric Heart Network Fontan study

BACKGROUND

Growth abnormalities in single-ventricle survivors may reduce quality of life (QoL) and exercise capacity.

METHODS

This multicenter, longitudinal analysis evaluated changes in height and body mass index (BMI) compared to population norms and their relationship to mortality, ventricular morphology, QoL, and exercise capacity in the Pediatric Heart Network Fontan studies.

RESULTS

Fontan 1 (F1) included 546 participants (12 ± 3.4 years); Fontan 2 (F2), 427 (19 ± 3.4 years); and Fontan 3 (F3), 362 (21 ± 3.5 years), with ~60% male at each time point. Height z-score was -0.67 ± -1.27, -0.60 ± 1.34, and- 0.43 ± 1.14 at F1-F3, lower compared to norms at all time points (P ≤ .001). BMI z-score was similar to population norms. Compared to survivors, participants who died had lower height z-score (P ≤ .001). Participants with dominant right ventricle (n = 112) had lower height z-score (P ≤ .004) compared to dominant left (n = 186) or mixed (n = 64) ventricular morphologies. Higher height z-score was associated with higher Pediatric Quality of Life Inventory for the total score (slope = 2.82 ± 0.52; P ≤ .001). Increase in height z-score (F1 to F3) was associated with increased oxygen consumption (slope = 2.61 ± 1.08; P = .02), whereas, for participants >20 years old, an increase in BMI (F1 to F3) was associated with a decrease in oxygen consumption (slope = -1.25 ± 0.33; P ≤ .001).

CONCLUSIONS

Fontan survivors, especially those with right ventricular morphology, are shorter when compared to the normal population but have similar BMI. Shorter stature was associated with worse survival. An increase in height z-score over the course of the study was associated with better QoL and exercise capacity; an increase in BMI was associated with worse exercise capacity.

Corticosteroid Therapy in Neonates Undergoing Cardiopulmonary Bypass: Randomized Controlled Trial

BACKGROUND

The efficacy of intraoperative corticosteroids to improve outcomes following congenital cardiac operations remains controversial.

OBJECTIVES

The purpose of this study was to determine whether intraoperative methylprednisolone improves post-operative recovery in neonates undergoing cardiac surgery.

METHODS

Neonates undergoing cardiac surgery with cardiopulmonary bypass at 2 centers were enrolled in a double-blind randomized controlled trial of methylprednisolone (30 mg/kg) or placebo after the induction of anesthesia. The primary outcome was a previously validated morbidity-mortality composite that included any of the following events following surgery before discharge: death, mechanical circulatory support, cardiac arrest, hepatic injury, renal injury, or rising lactate level (>5 mmol/l).

RESULTS

Of the 190 subjects enrolled, 176 (n = 81 methylprednisolone, n = 95 placebo) were included in this analysis. A total of 27 (33%) subjects in the methylprednisolone group and 40 (42%) in the placebo group reached the primary study endpoint (odds ratio [OR]: 0.63; 95% confidence interval [CI]: 0.31 to 1.3; p = 0.21). Methylprednisolone was associated with reductions in vasoactive inotropic requirements and in the incidence of the composite endpoint in subjects undergoing palliative operations (OR: 0.38; 95% CI: 0.15 to 0.99; p = 0.048). There was a significant interaction between treatment effect and center. In this analysis, methylprednisolone was protective at 1 center, with an OR: 0.35 (95% CI: 0.15 to 0.84; p = 0.02), and not so at the other center, with OR: 5.13 (95% CI: 0.85 to 30.90; p = 0.07).

CONCLUSIONS

Intraoperative methylprednisolone failed to show an overall significant benefit on the incidence of the composite primary study endpoint. There was, however, a benefit in patients undergoing palliative procedures and a significant interaction between treatment effect and center, suggesting that there may be center or patient characteristics that make prophylactic methylprednisolone beneficial.

Population Pharmacokinetics of Milrinone in Infants, Children, and Adolescents

Milrinone is a type 3 phosphodiesterase inhibitor used to improve cardiac output in critically ill infants and children. Milrinone is primarily excreted unchanged in the urine, raising concerns for toxic accumulation in the setting of renal dysfunction of critical illness. We developed a population pharmacokinetic model of milrinone using nonlinear mixed-effects modeling in NONMEM to perform dose-exposure simulations in children with variable renal function. We included children aged <21 years who received intravenous milrinone per clinical care. Plasma milrinone concentrations were measured using a validated liquid chromatography-tandem mass spectrometry assay (range 1-5000 ng/mL). We performed dose-exposure simulations targeting steady-state therapeutic concentrations of 100-300 ng/mL previously established in adults and children with cardiac dysfunction. We simulated concentrations over 48 hours in typical subjects with decreasing creatinine clearance (CrCl), estimated using the updated bedside Schwartz equation. Seventy-four patients contributed 111 plasma samples (concentration range, 4-634 ng/mL). The median (range) postmenstrual age (PMA) was 3.7 years (0-18), and median weight (WT) was 13.1 kg (2.6-157.7). The median serum creatinine and CrCl were 0.5 mg/dL (0.1-3.1) and 117.2 mL/min/1.73 m2 (13.1-261.3), respectively. A 1-compartment model characterized the pharmacokinetic data well. The final model parameterization was: Clearance (L/h) = 15.9*(WT [kg] / 70)0.75 * (PMA1.12 / (67.71.12 +PMA1.12 )*(CrCl / 117)0.522 ; and Volume of Distribution (L) = 32.2*(WT [kg] / 70). A loading dose of 50 µg/kg followed by a continuous infusion of 0.5 µg/kg/min resulted in therapeutic concentrations, except when CrCl was severely impaired at ≤30 mL/min/1.73 m2 . In this setting, a 25 µg/kg loading dose and 0.25 µg/kg/min continuous infusion resulted in therapeutic exposures.

Behavior and Quality of Life at 6 Years for Children With Hypoplastic Left Heart Syndrome

OBJECTIVES

We measured behavioral, quality of life (QoL), and functional status outcomes for 6-year-old children with hypoplastic left heart syndrome enrolled in the Single Ventricle Reconstruction Trial. We sought to compare these outcomes with those in the normative population and to analyze risk factors for worse outcomes within the single-ventricle group.

METHODS

Parent-response instruments included the Vineland Adaptive Behavior Scales, Second Edition (Vineland-II) (primary outcome), Behavior Assessment System for Children 2, Pediatric Quality of Life Inventory 4.0, and other measures of QoL and functional status. We compared subjects with those in the normative sample using 1-sample Wilcoxon rank tests and assessed outcome predictors using multivariable regression.

RESULTS

Of 325 eligible patients, 250 (77%) participated. Compared with population norms, participants had lower scores on the Vineland-II motor skills domain (90 ± 17 vs 100 ± 15; P < .001), with 11% scoring >2 SDs below the normative mean. On nearly all major domains, more study subjects (3.3%-19.7%) scored outside the normal range than anticipated for the general population. Independent risk factors for lower Vineland-II scores included perioperative extracorporeal membrane oxygenation, male sex, use of regional cerebral perfusion, catheterization after stage 2 operation, visual problems, seizure history, and more complications after 2 years (R 2 = 0.32). Independent predictors of worse Behavior Assessment System for Children 2 (R 2 = 0.07-0.20) and Pediatric Quality of Life Inventory 4.0 (R 2 = 0.17-0.25) domain scores also included sociodemographic factors and measures of morbidity and/or greater course complexity.

CONCLUSIONS

At 6 years, children with hypoplastic left heart syndrome had difficulty in areas of adaptive behavior, behavioral symptoms, QoL, and functional status. Principal risks for adverse outcomes include sociodemographic factors and measures of greater course complexity. However, models reveal less than one-third of outcome variance.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Creation of a Multicenter Pediatric Inpatient Data Repository Derived from Electronic Health Records

BACKGROUND

Integration of electronic health records (EHRs) data across sites and access to that data remain limited.

OBJECTIVE

We developed an EHR-based pediatric inpatient repository using nine U.S. centers from the National Institute of Child Health and Human Development Pediatric Trials Network.

METHODS

A data model encompassing 147 mandatory and 99 optional elements was developed to provide an EHR data extract of all inpatient encounters from patients <17 years of age discharged between January 6, 2013 and June 30, 2017. Sites received instructions on extractions, transformation, testing, and transmission to the coordinating center.

RESULTS

We generated 177 staging reports to process all nine sites' 147 mandatory and 99 optional data elements to the repository. Based on 520 prespecified criteria, all sites achieved 0% errors and <2% warnings. The repository includes 386,159 inpatient encounters from 264,709 children to support study design and conduct of future trials in children.

CONCLUSION

Our EHR-based data repository of pediatric inpatient encounters utilized a customized data model heavily influenced by the PCORnet format, site-based data mapping, a comprehensive set of data testing rules, and an iterative process of data submission. The common data model, site-based extraction, and technical expertise were key to our success. Data from this repository will be used in support of Pediatric Trials Network studies and the labeling of drugs and devices for children.

The Relationship Between Pre-operative Left Ventricular Longitudinal Strain and Post-operative Length of Stay in Patients Undergoing Arterial Switch Operation Is Age Dependent

INTRODUCTION

Post-operative length of stay (LOS) after the arterial switch operation (ASO) is variable. The association between pre-operative non-invasive measures of ventricular function and post-operative course has not been well established. The aims of this study were to (1) evaluate the relationship between pre-operative non-invasive measures of ventricular function and post-operative LOS and (2) evaluate the change in ventricular function after ASO.

METHODS

Data were reviewed in consecutive ASO patients between 2010 and 2016. The primary outcome was post-operative LOS. Echocardiograms obtained during the pre-operative period and at the time of discharge were retrospectively analyzed using speckle-tracking echocardiography. Pearson's correlation between patient-specific, pre-operative, and echocardiographic data versus post-operative LOS was assessed.

RESULTS

Fifty-two patients were included in analyses, 39 neonates and 13 infants. Left ventricular (LV) longitudinal strain correlated with post-operative LOS for infants age > 28 days (r = 0.62, p = 0.03), but not for neonates (r = 0.14, p = 0.40). Operative age (r = - 0.42, p = 0.003), weight at surgery (r = - 0.48, p ≤ 0.001), and cardiopulmonary bypass time (r = 0.30, p = 0.045) also correlated with post-operative LOS. Standard 2D measures of ventricular function did not correlate with post-operative LOS. LV ejection fraction and longitudinal strain worsened post-operatively.

CONCLUSION

Higher pre-operative LV longitudinal strain (representing worse LV function) is associated with increased post-operative LOS after ASO in infants > 28 days, but not in neonates. LV ejection fraction and longitudinal strain worsened after ASO. Future studies should assess the utility of performing STE in risk stratifying patients prior to ASO.

Association of intraoperative circulating-brain injury biomarker and neurodevelopmental outcomes at 1 year among neonates who have undergone cardiac surgery

BACKGROUND

Neurodevelopmental disability is the most significant complication for survivors of infant surgery for congenital heart disease. In this study we sought to determine if perioperative circulating brain injury biomarker levels are associated with neurodevelopmental outcomes at 12 months.

METHODS

A secondary analysis of a randomized controlled trial of neonates who underwent cardiac surgery was performed. Glial fibrillary acidic protein (GFAP) was measured: (1) before skin incision; (2) immediately after bypass; (3) 4 and (4) 24 hours postoperatively. Linear regression models were used to determine an association with the highest levels of GFAP and Bayley Scales of Infant and Toddler Development third edition (BSID) composite scores.

RESULTS

There were 97 subjects who had cardiac surgery at a mean age of 9 ± 6 days and completed a BSID at 12.5 ± 0.6 months of age. Median (25th-75th percentile) levels of GFAP were 0.01 (0.01-0.02), 0.85 (0.40-1.55), 0.07 (0.05-0.11), and 0.03 (0.02-0.04) ng/mL at the 4 time points, respectively. In univariate analysis GFAP was negatively associated with cognitive, language, and motor composite scores. GFAP levels immediately after bypass differed between institutions; 1.57 (0.92-2.48) versus 0.77 (0.36-1.21) ng/mL (P = .01). After adjusting for center and potential confounders, GFAP was independently associated with BSID motor score (P = .04).

CONCLUSIONS

Higher GFAP levels at the time of neonatal cardiac operations were independently associated with decreased BSID motor scores at 12 months. GFAP might serve as a diagnostic means to acutely identify perioperative brain-specific injury and serve as a benchmark of therapeutic efficacy for investigational treatments, discriminate center-specific effects, and provide early prognostic information for intervention.

Variation in care for infants undergoing the Stage II palliation for hypoplastic left heart syndrome

BACKGROUND

The Single Ventricle Reconstruction trial randomised neonates with hypoplastic left heart syndrome to a systemic-to-pulmonary-artery shunt strategy. Patients received care according to usual institutional practice. We analysed practice variation at the Stage II surgery to attempt to identify areas for decreased variation and process control improvement.

METHODS

Prospectively collected data were available in the Single Ventricle Reconstruction public-use database. Practice variation across 14 centres was described for 397 patients who underwent Stage II surgery. Data are centre-level specific and reported as interquartile ranges across all centres, unless otherwise specified.

RESULTS

Preoperative Stage II median age and weight across centres were 5.4 months (interquartile range 4.9-5.7) and 5.7 kg (5.5-6.1), with 70% performed electively. Most patients had pre-Stage-II cardiac catheterisation (98.5-100%). Digoxin was used by 11/14 centres in 25% of patients (23-31%), and 81% had some oral feeds (68-84%). The majority of the centres (86%) performed a bidirectional Glenn versus hemi-Fontan. Median cardiopulmonary bypass time was 96 minutes (75-113). In aggregate, 26% of patients had deep hypothermic circulatory arrest >10 minutes. In 13/14 centres using deep hypothermic circulatory arrest, 12.5% of patients exceeded 10 minutes (8-32%). Seven centres extubated 5% of patients (2-40) in the operating room. Postoperatively, ICU length of stay was 4.8 days (4.0-5.3) and total length of stay was 7.5 days (6-10).

CONCLUSIONS

In the Single Ventricle Reconstruction Trial, practice varied widely among centres for nearly all perioperative factors surrounding Stage II. Further analysis may facilitate establishing best practices by identifying the impact of practice variation.

Population Pharmacokinetics of Intramuscular and Intravenous Ketamine in Children

Ketamine is an N-methyl D-aspartate receptor antagonist used off-label to facilitate dissociative anesthesia in children undergoing invasive procedures. Available for both intravenous and intramuscular administration, ketamine is commonly used when vascular access is limited. Pharmacokinetic (PK) data in children are sparse, and the bioavailability of intramuscular ketamine in children is unknown. We performed 2 prospective PK studies of ketamine in children receiving either intramuscular or intravenous ketamine and combined the data to develop a pediatric population PK model using nonlinear mixed-effects methods. We applied our model by performing dosing simulations targeting plasma concentrations previously associated with analgesia (>100 ng/mL) and anesthesia awakening (750 ng/mL). A total of 113 children (50 intramuscular and 63 intravenous ketamine) with a median age of 3.3 years (range 0.02 to 17.6 years), and median weight of 14 kg (2.4 to 176.1) contributed 275 plasma samples (149 after intramuscular, 126 after intravenous ketamine). A 2-compartment model with first-order absorption following intramuscular administration and first-order elimination described the data best. Allometrically scaled weight was included in the base model for central and peripheral volume of distribution (exponent 1) and for clearance and intercompartmental clearance (exponent 0.75). Model-estimated bioavailability of intramuscular ketamine was 41%. Dosing simulations suggest that doses of 2 mg/kg intravenously and 8 mg/kg or 6 mg/kg intramuscularly, depending on age, provide adequate sedation (plasma ketamine concentrations >750 ng/mL) for procedures lasting up to 20 minutes.

A pharmacokinetic model for amiodarone in infants developed from an opportunistic sampling trial and published literature data

Amiodarone is a first-line antiarrhythmic for life-threatening ventricular fibrillation or ventricular tachycardia in children, yet little is known about its pharmacokinetics (PK) in this population. We developed a population PK (PopPK) model using samples collected via an opportunistic study design of children receiving amiodarone per standard of care supplemented by amiodarone PK data from the literature. Both study data and literature data were predominantly from infants < 2 years old, so our analysis was restricted to this group. The final combined dataset consisted of 266 plasma drug concentrations in 45 subjects with a median (interquartile range) postnatal age of 40.1 (11.0-120.4) days and weight of 3.9 (3.1-5.1) kg. Since the median sampling time after the first dose was short (study: 95 h; literature: 72 h) relative to the terminal half-life estimated in adult PopPK studies, values of the deep compartment volume and flow were fixed to literature values. A 3-compartment model best described the data and was validated by visual predictive checks and non-parametric bootstrap analysis. The final model included body weight as a covariate on all volumes and on both inter-compartmental and elimination clearances. The empiric Bayesian estimates for clearance (CL), volume of distribution at steady state, and terminal half-life were 0.25 (90% CL 0.14-0.36) L/kg/h, 93 (68-174) L/kg, and 266 (197-477) h, respectively. These studies will provide useful information for future PopPK studies of amiodarone in infants and children that could improve dosage regimens.

Two Brothers With Dextro-Transposition of the Great Arteries

Dextro-transposition of the great arteries (d-TGA) is a common cause of cyanotic heart disease in neonates. Current thought is d-TGA is a sporadic occurrence in families with an unclear etiology. We describe a case of brothers with d-TGA. Genetic testing revealed that both are heterozygous for two gene variations that are associated with congenital heart disease.

Heart failure after the Norwood procedure: An analysis of the Single Ventricle Reconstruction Trial

BACKGROUND

Heart failure results in significant morbidity and mortality in young children with hypoplastic left heart syndrome (HLHS) after the Norwood procedure.

METHODS

We studied subjects enrolled in the prospective Single Ventricle Reconstruction (SVR) Trial who survived to hospital discharge after a Norwood operation and were followed up to age 6 years. The primary outcome was heart failure, defined as heart transplant listing after Norwood hospitalization, death attributable to heart failure, or symptomatic heart failure (New York Heart Association [NYHA] Class IV). Multivariate modeling was undertaken using Cox regression methodology to determine variables associated with heart failure.

RESULTS

Of the 461 subjects discharged home following a Norwood procedure, 66 (14.3%) met the criteria for heart failure. Among these, 15 died from heart failure, 39 were listed for transplant (22 had a transplant, 12 died after listing, and 5 were alive and not yet transplanted), and 12 had NYHA Class IV heart failure but were never listed. The median age at heart failure identification was 1.28 (interquartile range 0.30 to 4.69) years. Factors associated with early heart failure included post-Norwood lower fractional area change, need for extracorporeal membrane oxygenation, non-Hispanic ethnicity, Norwood perfusion type, and total support time (p < 0.05).

CONCLUSIONS

By 6 years of age, heart failure developed in nearly 15% of children after the Norwood procedure. Although transplant listing was common, many patients died from heart failure before receiving a transplant or without being listed. Shunt type did not impact the risk of developing heart failure.

Longer Ischemic Time is Associated with Increased Ventricular Stiffness as Measured by Pressure-Volume Loop Analysis in Pediatric Heart Transplant Recipients

BACKGROUND

The purpose of this study was to investigate the associations between clinical factors and cardiac function as measured by pressure-volume loops (PVLs) in a pediatric heart transplant cohort.

METHODS

Patients (age < 20 years) who underwent heart transplantation presenting for a clinically indicated catheterization were enrolled. PVLs were recorded using microconductance catheters (CD Leycom^®, Zoetermeer, Netherlands). Demographic data, serum B-type natriuretic peptide (BNP), time from transplant, ischemic time, presence of transplant coronary artery disease, donor-specific antibodies, and history of rejection were recorded at the time of catheterization. PVL data included contractility indices: end-systolic elastance and preload recruitable stroke work; ventricular-arterial coupling index; ventricular stiffness constant, Beta; and isovolumic relaxation time constant, tau. Associations between PVL measures and clinical data were investigated using non-parametric statistical tests.

RESULTS

A total of 18 patients were enrolled. Median age was 8.7 years (IQR 5-14 years). There were ten males and eight females. Six patients had a history of rejection and ten had positive donor-specific antibodies. There was no transplant coronary artery disease. Median BNP was 100 pg/mL (IQR 46-140). Time from transplant to PVL obtained during catheterization procedure was 4.1 years (IQR 1.7-7.8 year). No single clinical characteristic was statistically significant when correlated with PVL data. However, longer ischemic time was associated with worse Beta (r = 0.49, p = 0.05).

CONCLUSIONS

Our study found that longer ischemic times are associated with increased left ventricular stiffness. No other single clinical variable is associated with cardiac dysfunction as determined by PVL analysis.

Transplant-Free Survival and Interventions at 6 Years in the SVR Trial

BACKGROUND

In the SVR trial (Single Ventricle Reconstruction), 1-year transplant-free survival was better for the Norwood procedure with right ventricle-to-pulmonary artery shunt (RVPAS) compared with a modified Blalock-Taussig shunt in patients with hypoplastic left heart and related syndromes. At 6 years, we compared transplant-free survival and other outcomes between the groups.

METHODS

Medical history was collected annually using medical record review, telephone interviews, and the death index. The cohort included 549 patients randomized and treated in the SVR trial.

RESULTS

Transplant-free survival for the RVPAS versus modified Blalock-Taussig shunt groups did not differ at 6 years (64% versus 59%, P=0.25) or with all available follow-up of 7.1±1.6 years (log-rank P=0.13). The RVPAS versus modified Blalock-Taussig shunt treatment effect had nonproportional hazards (P=0.009); the hazard ratio (HR) for death or transplant favored the RVPAS before stage II surgery (HR, 0.66; 95% confidence interval, 0.48-0.92). The effect of shunt type on death or transplant was not statistically significant between stage II to Fontan surgery (HR, 1.36; 95% confidence interval, 0.86-2.17; P=0.17) or after the Fontan procedure (HR, 0.76; 95% confidence interval, 0.33-1.74; P=0.52). By 6 years, patients with RVPAS had a higher incidence of catheter interventions (0.38 versus 0.23/patient-year, P<0.001), primarily because of more interventions between the stage II and Fontan procedures (HR, 1.72; 95% confidence interval, 1.00-3.03). Complications did not differ by shunt type; by 6 years, 1 in 5 patients had had a thrombotic event, and 1 in 6 had had seizures.

CONCLUSIONS

By 6 years, the hazards of death or transplant and catheter interventions were not different between the RVPAS versus modified Blalock-Taussig shunt groups. Children assigned to the RVPAS group had 5% higher transplant-free survival, but the difference did not reach statistical significance, and they required more catheter interventions. Both treatment groups have accrued important complications.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Population Pharmacokinetics of Trimethoprim-Sulfamethoxazole in Infants and Children

Trimethoprim (TMP)-sulfamethoxazole (SMX) is used to treat various types of infections, including community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and Pneumocystis jirovecii infections in children. Pharmacokinetic (PK) data for infants and children are limited, and the optimal dosing is not known. We performed a multicenter, prospective PK study of TMP-SMX in infants and children. Separate population PK models were developed for TMP and SMX administered by the enteral route using nonlinear mixed-effects modeling. Optimal dosing was determined on the basis of the matching adult TMP exposure and attainment of the surrogate pharmacodynamic (PD) target for efficacy, a free TMP concentration above the MIC over 50% of the dosing interval. Data for a total of 153 subjects (240 samples for PK analysis) with a median postnatal age of 8 years (range, 0.1 to 20 years) contributed to the analysis for both drugs. A one-compartment model with first-order absorption and elimination characterized the TMP and SMX PK data well. Weight was included in the base model for clearance (CL/F) and volume of distribution (V/F). Both TMP and SMX CL/F increased with age. In addition, TMP and SMX CL/F were inversely related to the serum creatinine and albumin concentrations, respectively. The exposure achieved in children after oral administration of TMP-SMX at 8/40 mg/kg of body weight/day divided into administration every 12 h matched the exposure achieved in adults after administration of TMP-SMX at 320/1,600 mg/day divided into administration every 12 h and achieved the PD target for bacteria with an MIC of 0.5 mg/liter in >90% of infants and children. The exposure achieved in children after oral administration of TMP-SMX at 12/60 and 15/75 mg/kg/day divided into administration every 12 h matched the exposure achieved in adults after administration of TMP-SMX at 640/3,200 mg/day divided into administration every 12 h in subjects 6 to <21 years and 0 to <6 years of age, respectively, and was optimal for bacteria with an MIC of up to 1 mg/liter.

An anthropometric survey of US pre-term and full-term neonates

BACKGROUND

Anthropometric data prove valuable for screening and monitoring various medical conditions. In young infants, however, only weight, length and head circumference are represented in publicly accessible databases.

AIM

To characterise length and circumferential measures in pre-term and full-term infants up to 90 days post-natal.

SUBJECTS AND METHODS

In eight US medical centres, trained raters recorded humeral, ulnar, femoral, tibial and fibular lengths along with mid-upper arm, mid-thigh, chest, abdominal and neck circumference. Data were pooled by post-menstrual age into 1-week intervals and population curves created using the lambda, mu and sigma (LMS) method. Goodness-of-fit was assessed by examining de-trended quantile-quantile plots, Q statistics and fitted centiles overlaid on empirical centiles.

RESULTS

In total, 2097 infants were enrolled in this study with a mean ± SD gestational age and post-natal age of 37.1 ± 3.3 weeks and 27.3 ± 25.3 days, respectively. A re-scale option was used to describe all curves. The resultant models reliably characterised anthropometric measures from 33-52 weeks PMA, with less certainty at the extremes (27-55 weeks).

CONCLUSION

The population curves generated under this investigation expand existing reference data on a comprehensive set of anthropometric traits in infants through the first 90 days post-natal.

Longitudinal Outcomes of Patients With Single Ventricle After the Fontan Procedure

BACKGROUND

Multicenter longitudinal objective data for survival into adulthood of patients who have undergone Fontan procedures are lacking.

OBJECTIVES

This study sought to describe transplant-free survival and explore relationships between laboratory measures of ventricular performance and functional status over time.

METHODS

Exercise testing, echocardiography, B-type natriuretic peptide, functional health assessment, and medical history abstraction were repeated 9.4 ± 0.4 years after the Fontan Cross-Sectional Study (Fontan 1) and compared with previous values. Cox regression analysis explored risk factors for interim death or cardiac transplantation.

RESULTS

From the original cohort of 546 subjects, 466 were contacted again, and 373 (80%) were enrolled at 21.2 ± 3.5 years of age. Among subjects with paired testing, the percent predicted maximum oxygen uptake decreased (69 ± 14% vs. 61 ± 16%; p < 0.001; n = 95), ejection fraction decreased (58 ± 11% vs. 55 ± 10%; p < 0.001; n = 259), and B-type natriuretic peptide increased (median [interquartile range] 13 [7 to 25] pg/mol vs. 18 [9 to 36] pg/mol; p < 0.001; n = 340). At latest follow-up, a lower Pediatric Quality of Life Inventory physical summary score was associated with poorer exercise performance (R² adjusted = 0.20; p < 0.001; n = 274). Cumulative complications since the Fontan procedure included additional cardiac surgery (32%), catheter intervention (62%), arrhythmia treatment (32%), thrombosis (12%), and protein-losing enteropathy (8%). Since Fontan 1, 54 subjects (10%) have received a heart transplant (n = 23) or died without transplantation (n = 31). The interval risk of death or/cardiac transplantation was associated with poorer ventricular performance and functional health status assessed at Fontan 1, but it was not associated with ventricular morphology, the subject's age, or the type of Fontan connection.

CONCLUSIONS

Interim transplant-free survival over 12 years in this Fontan cohort was 90% and was independent of ventricular morphology. Exercise performance decreased and was associated with worse functional health status. Future interventions might focus on preserving exercise capacity. (Relationship Between Functional Health Status and Ventricular Performance After Fontan-Pediatric Heart Network; NCT00132782).

Preoperative Feeding Neonates With Cardiac Disease

BACKGROUND

The potential for necrotizing enterocolitis (NEC) in neonates requiring cardiac surgery has contributed largely to wide feeding practice variations and a hesitation to initiate enteral feeding during the preoperative period, specifically those patients with hypoplastic left heart syndrome.

METHODS

A retrospective chart review of neonates undergoing cardiac surgery at a single institution between July 2011 and July 2013 was performed. The primary objective of this study was to determine if preoperative feeding was associated with NEC in neonates requiring cardiac surgery. Univariable and multivariable analyses were performed to evaluate the relationship between preoperative feeding and NEC. Secondary outcomes including growth failure, total ventilator days, total length of stay, and tube-assisted feeds at discharge were analyzed.

RESULTS

One hundred thirty consecutive neonates who required cardiac surgery were included in the analysis. Preoperative feeding occurred in 61% (n = 79). The overall prevalence of NEC was 9% (12/130), including three neonates with surgical NEC. There was no difference in the prevalence of NEC between the preoperative feeding and nil per os (NPO) groups. Preoperative NPO status was associated with longer ventilator-dependent days ( P = .01) but was not associated with worsened growth failure, longer length of stay, or increased prevalence of tube-assisted feeds at discharge.

CONCLUSION

In this study cohort, preoperative feeding was associated with a low prevalence of NEC. Larger prospective studies evaluating the safety and benefits of preoperative feeding in cardiac neonates are warranted.

A preliminary comparison of two-dimensional speckle tracking echocardiography and pressure-volume loop analysis in patients with Fontan physiology: The role of ventricular morphology

OBJECTIVE

Speckle tracking echocardiography (STE) may be a useful modality for assessing ventricular performance in patients with single ventricle physiology. However, STE's ability to accurately assess ventricular performance in this population is unknown. The objective of this study was to perform a preliminary comparison of STE measures of myocardial deformation to reference standard measures of function derived from pressure-volume loop (PVL) analysis.

DESIGN

This was a secondary analysis of a prospective study investigating PVLs in patients with Fontan physiology. PVLs were recorded using microconductance catheters. PVL indices included end-systolic elastance (Ees), arterial elastance (Ea), ventriculo-arterial coupling (Ea/Ees), and the isovolumic relaxation time constant (tau). Patients were included if they had an echocardiogram within 1 month of their catheterization. STE was performed retrospectively using vendor independent software.

RESULTS

Seventeen patients had echocardiograms available for analysis, 12 were right ventricular (RV) dominant. The median age was 8 years (IQR 5-17 years). Circumferential strain (r=-.72, P≤.01) and strain rate (r=-.61, P=.04) correlated with Ea/Ees in those with RV-dominant morphology. Longitudinal strain rate correlated with Ees in those with LV-dominant morphology (r=-.98, P≤.01). Longitudinal EDSR correlated with tau in those with LV-dominant morphology (r=-.90, P=.04).

CONCLUSIONS

In this limited sample, circumferential measures of deformation correlated with PVL measures better in patients with RV morphology, while longitudinal measures correlated better with PVL measures in patients with LV morphology. Further validation and investigation into the clinical usefulness of these measures are warranted.

Preoperative echocardiographic measures of left ventricular mechanics are associated with postoperative vasoactive support in preterm infants undergoing patent ductus arteriosus ligation

OBJECTIVE

Preoperative risk factors associated with poor outcomes after patent ductus arteriosus ligation in preterm infants have not been well defined. The aim of this study was to determine the association between preoperative echocardiographic measures of left ventricular mechanics and postoperative clinical outcomes after patent ductus arteriosus ligation.

METHODS

Preterm infants less than 90 days of age with no other significant congenital anomalies who underwent patent ductus arteriosus ligation between 2007 and 2015 were considered for retrospective analysis. The primary outcome was peak postoperative vasoactive inotropic score. Conventional echocardiographic measures of ventricular size, function, and patent ductus arteriosus size were performed. Echocardiographic single-beat, pressure-volume loop analysis estimates of contractility (end-systolic elastance) and afterload (arterial elastance) were calculated. Ventriculoarterial coupling was assessed using the arterial elastance/end-systolic elastance ratio. Multivariable linear regression was performed using clinical and echocardiographic data.

RESULTS

Echocardiograms from 101 patients (42.5% male) were analyzed. We found a statistically significant association between vasoactive inotropic score and both end-systolic elastance and arterial elastance. No patient with arterial elastance/end-systolic elastance greater than 0.78 (n = 32) had a vasoactive inotropic score 20 or greater. Analysis of our secondary outcomes found associations between preoperative end-systolic elastance and postoperative urine output less than 1 mL/kg/h at 24 hours, creatinine change greater than 0.5 mg/dL, and time to first extubation.

CONCLUSIONS

End-systolic elastance and arterial elastance were the only predictors of postoperative vasoactive inotropic score after patent ductus arteriosus ligation in preterm infants. Those neonates with increased contractility and low afterload were at highest risk for elevated inotropic support. These findings suggest a role for echocardiographic end-systolic elastance and arterial elastance in the preoperative assessment of preterm infants undergoing patent ductus arteriosus ligation.

Effects of persistent Fontan fenestration patency on cardiopulmonary exercise testing variables

Cardiopulmonary exercise testing (CPET) aids in clinical assessment of patients with Fontan circulation. Effects of persistent fenestration on CPET variables have not been clearly defined. Associations between fenestration and CPET variables at anaerobic threshold (AT) and peak exercise were explored in the Pediatric Heart Network Fontan Cross-Sectional Study cohort. Fenestration patency was associated with a greater decrease in oxygen saturation from rest to peak exercise (fenestration -4.9 ± 3.8 v. nonfenestration -3 ± 3.5; P < .001). Physiological dead space at peak exercise was higher in fenestrated v. nonfenestrated (25.2 ± 16.1 v. 21.4 ± 15.2; P = .03). There was a weak association between fenestration patency and maximal work and heart rate. Fenestration patency was also weakly correlated with oxygen pulse, work and VE/VCO2 at AT. The effect of persistent fenestration on CPET measurements was minimal in this study, likely due to the cross-sectional design.

Speckle-Tracking Echocardiography Improves Pre-operative Risk Stratification Before the Total Cavopulmonary Connection

INTRODUCTION

Single-ventricle patients with elevated pulmonary vascular resistance (PVR) or end-diastolic pressure (EDP) are excluded from undergoing total cavopulmonary connection (TCPC). However, a subset of patients deemed to be at acceptable risk experience prolonged length of stay (LOS) after TCPC. Routine assessment of ventricular function has been inadequate in identifying these high-risk patients. Speckle-tracking echocardiography (STE) is a novel method for assessment of myocardial deformation that may be useful in single-ventricle patients. The aim of this study was to perform a contemporary preoperative risk assessment for prolonged LOS to determine whether STE improves risk stratification before TCPC.

METHODS

Our single institution's perioperative data were retrospectively collected. The primary outcome was postoperative LOS >14 days. Longitudinal and circumferential STE deformation measures were analyzed on echocardiograms obtained during preoperative catheterization. Patient-specific, echocardiographic, and catheterization data were included in multivariable logistic regression. Receiver operating characteristic area under the curves (AUC) were analyzed.

RESULTS

From 2007 to 2014, 135 patients who underwent TCPC were included in the analysis. The median LOS was 11 (IQR 9-14) days. The PVR (P < .01) and circumferential strain rate (CSR) (P < .01) were the only variables independently associated with LOS >14 days. For every 0.1 s-1 CSR increased, there was a 20% increased odds of prolonged LOS. The AUC for CSR was 0.70. The AUC for PVR and EDP combined was 0.68. The AUC for PVR, EDP, and CSR combined was 0.73.

CONCLUSION

Preoperative CSR is independently associated with LOS >14 days and improves preoperative risk stratification in patients undergoing TCPC.

Decline in ventricular function as a result of general anesthesia in pediatric heart transplant recipients

Echocardiography is frequently performed under anesthesia during procedures such as cardiac catheterization with EMB in pediatric HTx recipients. Anesthetic agents may depress ventricular function, resulting in concern for rejection. The aim of this study was to compare ventricular function as measured by echocardiography before and during GA in 17 pediatric HTx recipients. Nearly all markers of ventricular systolic function were significantly decreased under GA, including EF (-4.2% ±1.2, P < .01) and RV FAC (-0.05 ± 0.02, P = .04). Subjects in the first post-transplant year (n = 9) trended toward a more significant decrease in EF vs those beyond the first post-transplant year (n = 8; -6.0% ±1.2 vs -2.1 ± 2.0, P = .1). This information quantifies a decline in biventricular function that should be expected in pediatric HTx recipients while under GA and can assist the transplant clinician in avoiding unnecessary treatment of transient GA-induced ventricular dysfunction.

Validation of a Simple Score to Determine Risk of Early Rejection After Pediatric Heart Transplantation

OBJECTIVES

This study aimed to develop a reliable and feasible score to assess the risk of rejection in pediatric heart transplantation recipients during the first post-transplant year.

BACKGROUND

The first post-transplant year is the most likely time for rejection to occur in pediatric heart transplantation. Rejection during this period is associated with worse outcomes.

METHODS

The United Network for Organ Sharing database was queried for pediatric patients (age <18 years) who underwent isolated orthotopic heart transplantation from January 1, 2000 to December 31, 2012. Transplantations were divided into a derivation cohort (n = 2,686) and a validation (n = 509) cohort. The validation cohort was randomly selected from 20% of transplantations from 2005 to 2012. Covariates found to be associated with rejection (p < 0.2) were included in the initial multivariable logistic regression model. The final model was derived by including only variables independently associated with rejection. A risk score was then developed using relative magnitudes of the covariates' odds ratio. The score was then tested in the validation cohort.

RESULTS

A 9-point risk score using 3 variables (age, cardiac diagnosis, and panel reactive antibody) was developed. Mean score in the derivation and validation cohorts were 4.5 ± 2.6 and 4.8 ± 2.7, respectively. A higher score was associated with an increased rate of rejection (score = 0, 10.6% in the validation cohort vs. score = 9, 40%; p < 0.01). In weighted regression analysis, the model-predicted risk of rejection correlated closely with the actual rates of rejection in the validation cohort (R(2) = 0.86; p < 0.01).

CONCLUSIONS

The rejection score is accurate in determining the risk of early rejection in pediatric heart transplantation recipients. The score has the potential to be used in clinical practice to aid in determining the immunosuppressant regimen and the frequency of rejection surveillance in the first post-transplant year.

Validation of a Simple Score to Determine Risk of Hospital Mortality After the Norwood Procedure

The ability to quantify patient-specific hospital mortality risk before the Norwood procedure remains elusive. This study aimed to develop an accurate and clinically feasible score to assess the risk of hospital mortality in neonates undergoing the Norwood procedure. All patients (n = 549) in the publically available Pediatric Heart Network Single Ventricle Reconstruction trial database were included in the analysis. Patients were randomly divided into a derivation (75%) and validation (25%) cohort. Preoperative factors found to be associated with mortality upon univariable analysis (P < 0.2) were included in the logistic regression model. The score was derived by including variables independently associated with mortality (P < 0.05). A 20-point score using 6 variables (birth weight, clinical syndrome or abnormal karyotype, surgeon Norwood volume or year, anatomic subtype, ascending aorta size, and obstructed pulmonary venous return) was developed using relative magnitudes of the covariates׳ odds ratio. The score was then tested in the validation cohort. In weighted regression analysis, model predicted risk of mortality correlated closely with actual rates of mortality in the derivation (R² = 0.87, P < 0.01) and validation cohorts (R² = 0.82, P < 0.01). Patients were classified as low (score: 0-5), medium (6-10), or high risk (>10). Mortality differed significantly between risk groups in both the derivation (6% vs 22% vs 77%, P < 0.01) and validation (4% vs 30% vs 53%, P < 0.01) cohorts. This mortality score is accurate in determining risk of hospital mortality in neonates undergoing planned Norwood operations. The score has the potential to be used in clinical practice to aid in risk assessment before surgery. Clinical trial registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00115934.