Methylprednisolone for Heart Surgery in Infants - A Randomized, Controlled Trial.

BACKGROUND: Although perioperative prophylactic glucocorticoids have been used for decades, whether they improve outcomes in infants after heart surgery with cardiopulmonary bypass is unknown. METHODS: We conducted a multicenter, prospective, randomized, placebo-controlled, registry-based trial involving infants (<1 year of age) undergoing heart surgery with cardiopulmonary bypass at 24 sites participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database. Registry data were used in the evaluation of outcomes. The infants were randomly assigned to receive prophylactic methylprednisolone (30 mg per kilogram of body weight) or placebo, which was administered into the cardiopulmonary-bypass pump-priming fluid. The primary end point was a ranked composite of death, heart transplantation, or any of 13 major complications. Patients without any of these events were assigned a ranked outcome based on postoperative length of stay. In the primary analysis, the ranked outcomes were compared between the trial groups with the use of odds ratios adjusted for prespecified risk factors. Secondary analyses included an unadjusted odds ratio, a win ratio, and safety outcomes. RESULTS: A total of 1263 infants underwent randomization, of whom 1200 received either methylprednisolone (599 infants) or placebo (601 infants). The likelihood of a worse outcome did not differ significantly between the methylprednisolone group and the placebo group (adjusted odds ratio, 0.86; 95% confidence interval [CI], 0.71 to 1.05; P = 0.14). Secondary analyses (unadjusted for risk factors) showed an odds ratio for a worse outcome of 0.82 (95% CI, 0.67 to 1.00) and a win ratio of 1.15 (95% CI, 1.00 to 1.32) in the methylprednisolone group as compared with the placebo group, findings suggestive of a benefit with methylprednisolone; however, patients in the methylprednisolone group were more likely than those in the placebo group to receive postoperative insulin for hyperglycemia (19.0% vs. 6.7%, P<0.001). CONCLUSIONS: Among infants undergoing surgery with cardiopulmonary bypass, prophylactic use of methylprednisolone did not significantly reduce the likelihood of a worse outcome in an adjusted analysis and was associated with postoperative development of hyperglycemia warranting insulin in a higher percentage of infants than placebo. (Funded by the National Center for Advancing Translational Sciences and others; STRESS ClinicalTrials.gov number, NCT03229538.).

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

BACKGROUND: Understanding the clinical course and short-term outcomes of suspected myocarditis after the coronavirus disease 2019 (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 July 4, 2021, with suspected myocarditis within 30 days of COVID-19 vaccination. Lake Louise criteria were used for cardiac MRI findings. Myocarditis cases were classified as confirmed or probable on the basis of 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 the median age was 15.8 years (range, 12.1-20.3; interquartile range [IQR], 14.5-17.0). Suspected myocarditis occurred in 136 patients (97.8%) after the mRNA vaccine, with 131 (94.2%) after the Pfizer-BioNTech vaccine; 128 (91.4%) occurred after the second dose. Symptoms started at 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 intensive care unit, 2 were treated with inotropic/vasoactive support, and none required extracorporeal membrane oxygenation 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 ECGs and arrhythmias (7 with nonsustained ventricular tachycardia); and 18.7% had left ventricular ejection fraction <55% on echocardiogram. Of 97 patients who underwent cardiac MRI at a 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 left ventricular ejection fraction <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 cardiac MRI were frequent. Future studies should evaluate risk factors, mechanisms, and long-term outcomes.

Ventricular function and tissue characterization by cardiac magnetic resonance imaging following hospitalization for multisystem inflammatory syndrome in children: a prospective study.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a severe life-threatening manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that often presents with acute cardiac dysfunction and cardiogenic shock. While recovery from acute illness is excellent, the long-term myocardial impact is unknown. OBJECTIVE: To compare cardiac MRI findings in children 6-9 months after their hospitalization with MIS-C against MRI findings in healthy controls to assess for residual myocardial disease. MATERIALS AND METHODS: We prospectively performed cardiac MRI on 13 children 6-9 months following their hospitalization with MIS-C: eight of these children had a history of left ventricle ejection fraction (LVEF) < 50%, persistent symptoms, or electrocardiogram (ECG) abnormalities and underwent clinical MRI; five of these children without cardiac abnormalities during their hospitalization underwent research MRIs. We compared their native T1 and T2 mapping values with those of 20 normal controls. RESULTS: Cardiac MRI was performed at 13.6 years of age (interquartile range [IQR] 11.9-16.4 years) and 8.2 months (IQR 6.8-9.6 months) following hospitalization. Twelve children displayed normal ejection fraction: left ventricle (LV) 57.2%, IQR 56.1-58.4; right ventricle (RV) 53.1%, IQR 52.0-55.7. One had low-normal LVEF (52%). They had normal extracellular volume (ECV) and normal T2 and native T1 times compared to controls. There was no qualitative evidence of edema. One child had late gadolinium enhancement (LGE) with normal ejection fraction, no edema, and normal T1 and T2 times. When stratifying children who had MIS-C according to history of LVEF <55% on echocardiography, there was no difference in MRI values. CONCLUSION: Although many children with MIS-C present acutely with cardiac dysfunction, residual myocardial damage 6-9 months afterward appears minimal. Long-term implications warrant further study.

Development of a Model to Identify Febrile Children at Low Risk for Multisystem Inflammatory Syndrome.

OBJECTIVES: The case definition for multisystem inflammatory syndrome in children (MIS-C) is broad and encompasses symptoms and signs commonly seen in children with fever. Our aim was to identify clinical predictors that, independently or in combination, identify febrile children presenting to the emergency department (ED) as low risk for MIS-C. METHODS: We conducted a retrospective single-center study of otherwise healthy children 2 months to 20 years of age presenting to the ED with fever and who had a laboratory evaluation for MIS-C between April 15, 2020, and October 31, 2020. We excluded children with a diagnosis of Kawasaki disease. Our outcome was an MIS-C diagnosis defined by the Centers for Disease Control and Prevention criteria. We conducted multivariable logistic regression analyses to identify variables independently associated with MIS-C. RESULTS: Thirty-three patients with and 128 patients without MIS-C were analyzed. Of those with MIS-C, 16 of 33 (48.5%) had hypotension for age, signs of hypoperfusion, or required ionotropic support. Four variables were independently associated with the presence of MIS-C; known or suspected SARS CoV-2 exposure (adjusted odds ratio [aOR], 4.0; 95% confidence interval [CI], 1.4-11.9) and the following 3 symptoms and signs: abdominal pain on history (aOR, 4.8; 95% CI, 1.7-15.0), conjunctival injection (aOR, 15.2; 95% CI, 5.4-48.1), and rash involving the palms or soles (aOR, 12.2; 95% CI, 2.4-69.4). Children were at low risk of MIS-C if none of the 3 symptoms or signs were present (sensitivity 87.9% [95% CI, 71.8-96.6]; specificity 62.5% [53.5-70.9], negative predictive value 95.2% [88.3-98.7]). Of the 4 MIS-C patients without any of these 3 factors, 2 were ill-appearing in the ED and the other 2 had no cardiovascular involvement during their clinical course. CONCLUSIONS: A combination of 3 clinical symptoms and signs had moderate to high sensitivity and high negative predictive value for identifying febrile children at low risk of MIS-C. If validated, these factors could aid clinicians in determining the need to obtain or forego an MIS-C laboratory evaluation during SARS-CoV-2 prevalent periods in febrile children.

Discriminating Multisystem Inflammatory Syndrome in Children Requiring Treatment from Common Febrile Conditions in Outpatient Settings.

OBJECTIVES: To examine whether patients with multisystem inflammatory syndrome in children (MIS-C) demonstrated well-defined clinical features distinct from other febrile outpatients, given the difficulties of seeing acute care visits during the severe acute respiratory syndrome coronavirus 2 pandemic and the risks associated with both over- and underdiagnosis of MIS-C. STUDY DESIGN: This case-controlled study compared patients diagnosed with and treated for MIS-C at a large urban children's hospital with patients evaluated for fever at outpatient acute care visits during the peak period of MIS-C. Symptomatology and available objective data were extracted. Comparisons were performed using t tests with corrections for multiple comparisons, and multivariable logistic regression to obtain ORs. RESULTS: We identified 44 patients with MIS-C between April 16 and June 10, 2020. During the same period, 181 pediatric patients were evaluated for febrile illnesses in participating outpatient clinics. Patients with MIS-C reported greater median maximum reported temperature height (40°C vs 38.9, P < .0001), and increased frequency of abdominal pain (OR 12.5, 95% CI [1.65-33.24]), neck pain (536.5, [2.23-129,029]), conjunctivitis (31.3, [4.6-212.8]), oral mucosal irritation (11.8, [1.4-99.4]), extremity swelling or rash (99.9, [5-1960]), and generalized rash (7.42, [1.6-33.2]). Patients with MIS-C demonstrated lower absolute lymphocyte (P < .0001) and platelet counts (P < .05) and greater C-reactive protein concentrations (P < .001). CONCLUSIONS: Patients treated for MIS-C due to concern for potential cardiac injury show combinations of features distinct from other febrile patients seen in outpatient clinics during the same period.

Weight impacts 1-year congenital heart surgery outcomes independent of race/ethnicity and payer.

Body mass index, race/ethnicity, and payer status are associated with operative mortality in congenital heart disease (CHD). Interactions between these predictors and impacts on longer term outcomes are less well understood. We studied the effect of body mass index, race/ethnicity, and payer on 1-year outcomes following elective CHD surgery and tested the degree to which race/ethnicity and payer explained the effects of body mass index. Patients aged 2-25 years who underwent elective CHD surgery at our centre from 2010 to 2017 were included. We assessed 1-year unplanned cardiac re-admissions, re-interventions, and mortality. Step-wise, multivariable logistic regression was performed.Of the 929 patients, 10.4% were underweight, 14.9% overweight, and 8.5% obese. Non-white race/ethnicity comprised 40.4% and public insurance 29.8%. Only 0.5% died prior to hospital discharge with one additional death in the first post-operative year. Amongst patients with continuous follow-up, unplanned re-admission and re-intervention rates were 14.7% and 12.3%, respectively. In multivariable analyses adjusting for surgical complexity and surgeon, obese, overweight, and underweight patients had higher odds of re-admission than normal-weight patients (OR 1.40, p = 0.026; OR 1.77, p < 0.001; OR 1.44, p = 0.008). Underweight patients had more than twice the odds of re-intervention compared with normal weight (OR 2.12, p < 0.001). These associations persisted after adjusting for race/ethnicity, payer, and surgeon.Pre-operative obese, overweight, and underweight body mass index were associated with unplanned re-admission and/or re-intervention 1-year following elective CHD surgery, even after accounting for race/ethnicity and payer status. Body mass index may be an important modifiable risk factor prior to CHD surgery.

Impact of dipyridamole on adenosine dosing in pediatric and young adult patients after heart transplantation.

BACKGROUND: Relative contraindications to adenosine use have included heart transplant and dipyridamole. We previously demonstrated the safety and efficacy of adenosine-induced atrioventricular (AV) block in healthy young heart transplant recipients while suspending dipyridamole therapy (dual antiplatelet agent). This prospective follow-up study evaluated the safety and efficacy of adenosine use in the same cohort of heart transplant recipients while on dipyridamole. METHODS: Adenosine was incrementally dosed until AV block occurred (maximum 200 mcg/kg up to 12 mg). The primary outcome was clinically significant asystole (≥12 seconds). Secondary outcomes included maximal adenosine dose, AV block duration, dysrhythmias, and clinical symptoms. Outcomes were compared to the parent study. RESULTS: Thirty of 39 eligible patients (5-24 years) were tested. No patient (0%, CI 0%-8%) experienced clinically significant asystole. AV block occurred in 29/30 patients (97%, CI 86%-100%). The median dose causing AV block was 50mcg/kg (vs 100 mcg/kg off dipyridamole; P = .011). Seventeen patients (57%, CI 39%-72%) required less adenosine to achieve AV block on dipyridamole; six (20%) required more. AV block occurred at doses ≥25 mcg/kg in all patients. In pairwise comparison to prior testing off dipyridamole, no significant change occurred in AV block duration, frequency of cardiac ectopy, or incidence of reported symptoms. No atrial fibrillation/flutter occurred. CONCLUSIONS: AV block often occurs at twofold lower adenosine doses in healthy young heart transplant recipients taking oral dipyridamole, compared with previous testing of this cohort off dipyridamole. Results suggest that initial dosing of 25 mcg/kg (maximum 0.8 mg) with stepwise escalation poses low risk of prolonged asystole on dipyridamole.

The Risks of Being Tiny: The Added Risk of Low Weight for Neonates Undergoing Congenital Heart Surgery.

The aims of this study were (1) to describe the additive risk of performing cardiac surgery in neonates born ≤ 2.0 kg, after accounting for the baseline risks of low birth weight, and (2) to describe the additive risk of being born ≤ 2.0 kg in neonates undergoing cardiac surgery. We used a risk difference analysis in a retrospective cohort, 2006-2016. Neonates born ≤ 2.0 kg undergoing congenital heart surgery during initial postnatal admission were included. Data were standardized alternatingly for birth weight and cardiac surgical risk using national population data to estimate the number of deaths expected had they not required cardiac surgery or were they of normal weight. Of 105 neonates ≤ 2 kg, median birth weight was 1.6 kg (IQR 1.3-1.8 kg). Median gestational age was 33 weeks (IQR 31-35 weeks). Observed operative mortality was 14.3%; 0% for neonates ≤ 1.0 kg (CI 0-33.6%), 20.6% for neonates > 1.0-1.5 kg (CI 8.7-37.9%), and 12.9% for neonates > 1.5-2.0 kg (CI 5.7-23.9%). Among neonates ≤ 2.0 kg not undergoing cardiac surgery, expected mortality was 4.8% (CI 1.6-10.8); cardiac surgery increased the risk of mortality 9.5% (CI 1.7-17.4%). Conversely, the expected risk for normal birth weight neonates undergoing cardiac surgery was 5.7% (CI 2.1-12.0%); low birth weight increased the risk of mortality 8.6% (CI 0.5-16.6%). To continue making advancements in cardiac surgery, we must understand that the rate of mortality observed in normal weight infants is not a realistic target and that, despite advances, the risk attributable to the surgery remains higher among low birth weight patients.

Cardiac workup and monitoring in hospitalised children with COVID- 19.

Approximately, 1.7 million individuals in the United States have been infected with SARS-CoV-2, the virus responsible for the novel coronavirus disease-2019 (COVID-19). This has disproportionately impacted adults, but many children have been infected and hospitalised as well. To date, there is not much information published addressing the cardiac workup and monitoring of children with COVID-19. Here, we share the approach to the cardiac workup and monitoring utilised at a large congenital heart centre in New York City, the epicentre of the COVID-19 pandemic in the United States.

Registry-based trials: a potential model for cost savings?

BACKGROUND/AIMS: Registry-based trials have emerged as a potentially cost-saving study methodology. Early estimates of cost savings, however, conflated the benefits associated with registry utilisation and those associated with other aspects of pragmatic trial designs, which might not all be as broadly applicable. In this study, we sought to build a practical tool that investigators could use across disciplines to estimate the ranges of potential cost differences associated with implementing registry-based trials versus standard clinical trials. METHODS: We built simulation Markov models to compare unique costs associated with data acquisition, cleaning, and linkage under a registry-based trial design versus a standard clinical trial. We conducted one-way, two-way, and probabilistic sensitivity analyses, varying study characteristics over broad ranges, to determine thresholds at which investigators might optimally select each trial design. RESULTS: Registry-based trials were more cost effective than standard clinical trials 98.6% of the time. Data-related cost savings ranged from $4300 to $600,000 with variation in study characteristics. Cost differences were most reactive to the number of patients in a study, the number of data elements per patient available in a registry, and the speed with which research coordinators could manually abstract data. Registry incorporation resulted in cost savings when as few as 3768 independent data elements were available and when manual data abstraction took as little as 3.4 seconds per data field. CONCLUSIONS: Registries offer important resources for investigators. When available, their broad incorporation may help the scientific community reduce the costs of clinical investigation. We offer here a practical tool for investigators to assess potential costs savings.

Minimum Travel Distance Among Publicly Insured Infants with Severe Congenital Heart Disease: Potential Impact of In-state Restrictions.

Travel distance to surgical centers may be increased when coverage restrictions prevent children with congenital heart disease (CHD) from receiving care at out-of-state congenital heart surgery centers. We estimated the minimum travel distance to congenital heart surgery centers among publicly insured infants with time-sensitive CHD surgical needs, under two different scenarios: if they were and were not restricted to in-state centers. Using 2012 Medicaid Analytic eXtract data from 40 states, we identified 4598 infants with CHD that require surgery in the first year of life. We calculated the minimum travel distance between patients' homes and the nearest cardiac surgery center, assuming patients were and were not restricted to in-state centers. We used linear regression to identify demographic predictors of distance under both scenarios. When patients were not restricted to in-state centers, mean minimum travel distance was 43.7 miles, compared to 54.1 miles when they were restricted. For 5.9% of patients, the difference in travel distance under the two scenarios exceeded 50 miles. In six states, the difference in mean minimum travel distance exceeded 20 miles. Under both scenarios, distance was positively predicted by rural status, residence in middle-income zip codes, and white/non-Hispanic or American Indian/Alaskan Native race/ethnicity. For some publicly insured infants with severe CHD, facilitating the receipt of out-of-state care could mitigate access barriers. Existing efforts to regionalize care at fewer centers should be designed to avoid exacerbating access barriers among publicly insured CHD patients.

Enhancing efficiency and scientific impact of a clinical trials network: the Pediatric Heart Network Integrated CARdiac Data and Outcomes (iCARD) Collaborative.

Recent years have seen an exponential increase in the variety of healthcare data captured across numerous sources. However, mechanisms to leverage these data sources to support scientific investigation have remained limited. In 2013 the Pediatric Heart Network (PHN), funded by the National Heart, Lung, and Blood Institute, developed the Integrated CARdiac Data and Outcomes (iCARD) Collaborative with the goals of leveraging available data sources to aid in efficiently planning and conducting PHN studies; supporting integration of PHN data with other sources to foster novel research otherwise not possible; and mentoring young investigators in these areas. This review describes lessons learned through the development of iCARD, initial efforts and scientific output, challenges, and future directions. This information can aid in the use and optimisation of data integration methodologies across other research networks and organisations.

Lessons learned in the use of clinical registry data in a multi-centre prospective study: the Pediatric Heart Network Residual Lesion Score Study.

BACKGROUND: Using existing data from clinical registries to support clinical trials and other prospective studies has the potential to improve research efficiency. However, little has been reported about staff experiences and lessons learned from implementation of this method in pediatric cardiology. OBJECTIVES: We describe the process of using existing registry data in the Pediatric Heart Network Residual Lesion Score Study, report stakeholders' perspectives, and provide recommendations to guide future studies using this methodology. METHODS: The Residual Lesion Score Study, a 17-site prospective, observational study, piloted the use of existing local surgical registry data (collected for submission to the Society of Thoracic Surgeons-Congenital Heart Surgery Database) to supplement manual data collection. A survey regarding processes and perceptions was administered to study site and data coordinating center staff. RESULTS: Survey response rate was 98% (54/55). Overall, 57% perceived that using registry data saved research staff time in the current study, and 74% perceived that it would save time in future studies; 55% noted significant upfront time in developing a methodology for extracting registry data. Survey recommendations included simplifying data extraction processes and tailoring to the needs of the study, understanding registry characteristics to maximise data quality and security, and involving all stakeholders in design and implementation processes. CONCLUSIONS: Use of existing registry data was perceived to save time and promote efficiency. Consideration must be given to the upfront investment of time and resources needed. Ongoing efforts focussed on automating and centralising data management may aid in further optimising this methodology for future studies.

The Optimal Timing of Stage 2 Palliation for Hypoplastic Left Heart Syndrome: An Analysis of the Pediatric Heart Network Single Ventricle Reconstruction Trial Public Data Set.

BACKGROUND: In infants requiring 3-stage single-ventricle palliation for hypoplastic left heart syndrome, attrition after the Norwood procedure remains significant. The effect of the timing of stage 2 palliation (S2P), a physician-modifiable factor, on long-term survival is not well understood. We hypothesized that an optimal interval between the Norwood and S2P that both minimizes pre-S2P attrition and maximizes post-S2P survival exists and is associated with individual patient characteristics. METHODS: The National Institutes of Health/National Heart, Lung, and Blood Institute Pediatric Heart Network Single Ventricle Reconstruction Trial public data set was used. Transplant-free survival (TFS) was modeled from (1) Norwood to S2P and (2) S2P to 3 years by using parametric hazard analysis. Factors associated with death or heart transplantation were determined for each interval. To account for staged procedures, risk-adjusted, 3-year, post-Norwood TFS (the probability of TFS at 3 years given survival to S2P) was calculated using parametric conditional survival analysis. TFS from the Norwood to S2P was first predicted. TFS after S2P to 3 years was then predicted and adjusted for attrition before S2P by multiplying by the estimate of TFS to S2P. The optimal timing of S2P was determined by generating nomograms of risk-adjusted, 3-year, post-Norwood, TFS versus the interval from the Norwood to S2P. RESULTS: Of 547 included patients, 399 survived to S2P (73%). Of the survivors to S2P, 349 (87%) survived to 3-year follow-up. The median interval from the Norwood to S2P was 5.1 (interquartile range, 4.1-6.0) months. The risk-adjusted, 3-year, TFS was 68±7%. A Norwood-S2P interval of 3 to 6 months was associated with greatest 3-year TFS overall and in patients with few risk factors. In patients with multiple risk factors, TFS was severely compromised, regardless of the timing of S2P and most severely when S2P was performed early. No difference in the optimal timing of S2P existed when stratified by shunt type. CONCLUSIONS: In infants with few risk factors, progressing to S2P at 3 to 6 months after the Norwood procedure was associated with maximal TFS. Early S2P did not rescue patients with greater risk factor burdens. Instead, referral for heart transplantation may offer their best chance at long-term survival. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Prospective Study of Adenosine on Atrioventricular Nodal Conduction in Pediatric and Young Adult Patients After Heart Transplantation.

BACKGROUND: Supraventricular tachycardia is common after heart transplantation. Adenosine, the standard therapy for treating supraventricular tachycardia in children and adults without transplantation, is relatively contraindicated after transplantation because of a presumed risk of prolonged atrioventricular block in denervated hearts. This study tested whether adenosine caused prolonged asystole after transplantation and if it was effective in blocking atrioventricular nodal conduction in these patients. METHODS: This was a single-center prospective clinical study including healthy heart transplant recipients 6 months to 25 years of age presenting for routine cardiac catheterization during 2015 to 2016. After catheterization, a transvenous pacing catheter was placed and adenosine was given following a dose-escalation protocol until atrioventricular block was achieved. The incidence of clinically significant asystole (≥12 seconds after adenosine) was quantified. The effects of patient characteristics on adenosine dose required to produce atrioventricular block and duration of effect were also measured. RESULTS: Eighty patients completed adenosine testing. No patient (0%; 95% confidence interval, 0-3) required rescue ventricular pacing. Atrioventricular block was observed in 77 patients (96%; 95% confidence interval, 89-99). The median longest atrioventricular block was 1.9 seconds (interquartile range, 1.4-3.2 seconds), with a mean duration of adenosine effect of 4.3±2.0 seconds. No patient characteristic significantly predicted the adenosine dose to produce atrioventricular block or duration of effect. Results were similar across patient weight categories. CONCLUSIONS: Adenosine induces atrioventricular block in healthy pediatric and young adult heart transplant recipients with minimal risk when low initial doses are used (25 µg/kg; 1.5 mg if ≥60 kg) and therapy is gradually escalated. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02462941.

Intravenous Versus Oral Antibiotics for the Prevention of Treatment Failure in Children With Complicated Appendicitis: Has the Abandonment of Peripherally Inserted Catheters Been Justified?

OBJECTIVE: To compare treatment failure leading to hospital readmission in children with complicated appendicitis who received oral versus intravenous antibiotics after discharge. BACKGROUND: Antibiotics are often employed after discharge to prevent treatment failure in children with complicated appendicitis, although existing studies comparing intravenous and oral antibiotics for this purpose are limited. METHODS: We identified all patients aged 3 to 18 years undergoing appendectomy for complicated appendicitis, who received postdischarge antibiotics at 35 childrens hospitals from 2009 to 2012. Discharge codes were used to identify study subjects from the Pediatric Health Information System database, and chart review confirmed eligibility, treatment assignment, and outcomes. Exposure status was based on outpatient antibiotic therapy, and analysis used optimal and full matching methods to adjust for demographic and clinical characteristics. Treatment failure (defined as an organ-space infection) requiring inpatient readmission was the primary outcome. Secondary outcomes included revisits from any cause to either the inpatient or emergency department setting. RESULTS: In all, 4579 patients were included (median: 99/hospital), and utilization of intravenous antibiotics after discharge ranged from 0% to 91.7% across hospitals. In the matched analysis, the rate of treatment failure was significantly higher for the intravenous group than the oral group [odds ratio (OR) 1.74, 95% confidence interval (CI) 1.05-2.88; risk difference: 4.0%, 95% CI 0.4-7.6%], as was the rate of all-cause revisits (OR 2.11, 95% CI 1.44-3.11; risk difference: 9.4%, 95% CI 4.7-14.2%). The rate of peripherally inserted central catheter line complications was 3.2% in the intravenous group, and drug reactions were rare in both groups (intravenous: 0.7%, oral: 0.5%). CONCLUSIONS: Compared with oral antibiotics, use of intravenous antibiotics after discharge in children with complicated appendicitis was associated with higher rates of both treatment failure and all-cause hospital revisits.

Comparison of Echocardiographic Diagnostic Criteria of Left Ventricular Noncompaction in a Pediatric Population.

BACKGROUND: There is controversy regarding the best echocardiographic diagnostic criteria for left ventricular noncompaction (LVNC). We assessed the diagnostic utility and reproducibility of the previously proposed echocardiographic diagnostic criteria in a pediatric population using a segmental approach. METHODS: Echocardiograms were matched for patients with and without a clinical diagnosis of LVNC. Blinded reviews of echocardiograms measured (1) depths of intertrabecular recesses (X/Y), (2) noncompaction-to-compaction ratio (NC/C), and (3) number of trabeculations, using a segmental approach. Measurements were analyzed for area under the receiver operating characteristic curves (AUC), sensitivity, and specificity. RESULTS: There were 30 echocardiograms in the initial cohort (15 LVNC cases, 15 controls). Median age was 1.7 years (IQR 0.2-6.9 years) and systolic function was decreased in 40%. Comparison of diagnostic criteria demonstrated the best interrater agreement and AUC with an X/Y ratio measured in end-diastole in the parasternal short axis in the apical anterolateral segment (κ 0.72, CI 0.43-1.00, p value <0.001), yielding 100% sensitivity and 70-86% specificity, among readers. The least predictive and reproducible method was the NC/C ratio. A validation cohort confirmed the superiority of the X/Y ratio, although the interrater agreement and AUC decreased. CONCLUSION: Measurements according to existing LVNC diagnostic criteria vary by echocardiographic view and segment. Modification of the Chin et al. criteria (Circulation 82:507-513, 1990) using an X/Y ratio <0.5 had the greatest interrater reliability and predictive validity when measured in end-diastole in the parasternal short axis in the apical anterolateral segment. The NC/C ratio had the lowest reliability and predictive validity.

When Is It Better to Wait? Surgical Timing and Recurrence Risk for Children Undergoing Repair of Subaortic Stenosis.

Recurrence of subaortic stenosis (SAS) after surgery is common in children. The effects of patient characteristics and surgical timing on disease recurrence are largely unknown. We performed a retrospective study, assessing the relative effects of patient age and left ventricular outflow tract (LVOT) gradient on the need for reoperation for recurrent SAS. We included all children <20 years of age who underwent initial surgical resection of SAS at our center, January 2003-December 2013. Stratified logistic regression was performed, considering the effects of patient demographics, clinical characteristics, echocardiographic parameters, and operative technique, and clustering standard errors by surgeon. The multivariable model was used to simulate predicted probabilities of recurrent SAS for children at varying ages and baseline LVOT gradients. Sixty-three patients (38 males) underwent initial operation for SAS. Patients were followed for a median of 3.7 years (IQR 1.2-7.1). Twenty-one percent of patients (n = 13) underwent reoperation for SAS. Twelve were male. For every 10 mmHg increase in preoperative peak gradient in boys, the odds of reoperation for SAS doubled (OR 2.01, CI 1.5-2.72, p < 0.001), and for every additional 6 months of age, the odds of reoperation decreased by 14% (OR 0.86, CI 0.84-0.88, p < 0.001). Both younger age and higher preoperative outflow tract gradient are independently associated with risk of reoperation. Clinicians should consider the age and rate of LVOT gradient change-and not just the absolute gradient-in determining initial surgical timing.

Aortic Root Distortion and Aortic Insufficiency During Balloon Angioplasty of the Right Ventricular Outflow Tract Prior to Transcatheter Pulmonary Valve Replacement.

OBJECTIVE: To describe the significance of aortic root distortion (AD) and/or aortic valve insufficiency (AI) during balloon angioplasty of the right ventricular outflow tract (RVOT) performed to rule out coronary artery compression prior to transcatheter pulmonary valve (TPV) implantation. METHODS: AD/AI was assessed by retrospective review of all procedural aortographies performed to evaluate coronary anatomy prior to TPV implantation. AD/AI was also reviewed in all pre-post MPV implant echocardiograms to assess for progression. RESULTS: From 04/2007 to 3/2015, 118 pts underwent catheterization with intent for TPV implant. Mean age and weight were 24.5 ± 12 years and 64.3 ± 20 kg, respectively. Diagnoses were: TOF (53%), D-TGA/DORV (18%), s/p Ross (15%), and Truncus (9%). Types of RV-PA connections were: conduits (96), bioprosthetic valves (14), and other (7). Successful TPV implant occurred in 91 pts (77%). RVOT balloon angioplasty was performed in 43/118 pts (36%). Aortography was performed in 18/43 pts with AD/AI noted in 6/18 (33%); 2 with D-TGA (1 s/p Lecompte, 1 s/p Rastelli), 2 with TOF, 1 Truncus and 1 s/p Ross. Procedure was aborted in the 2 who developed severe AD/AI. TPV was implanted in 3/4 patients with mild AD/AI. Review of pre-post TPV implantation echocardiograms in 83/91 pts (91%) revealed no new/worsened AI in any patient. CONCLUSION: AD/AI is relatively common on aortography during simultaneous RVOT balloon angioplasty. Lack of AI progression by echocardiography post-TPV implant suggests these may be benign findings in most cases. However, AD/AI should be carefully evaluated in certain anatomic subtypes with close RVOT/aortic alignments.

The Norwood operation: Relative effects of surgeon and institutional volumes on outcomes and resource utilization.

BACKGROUND: Hypoplastic left heart syndrome is the most expensive birth defect managed in the United States, with a 5-year survival rate below 70%. Increasing evidence suggests that hospital volumes are inversely associated with mortality for infants with single ventricles undergoing stage 1 surgical palliation. Our aim was to examine the relative effects of surgeon and institutional volumes on outcomes and resource utilisation for these children. METHODS: A retrospective study was conducted using the Pediatric Health Information System database to examine the effects of the number of procedures performed per surgeon and per centre on mortality, costs, and post-operative length of stay for infants undergoing Risk Adjustment for Congenital Heart Surgery risk category six operations at tertiary-care paediatric hospitals, from 1 January, 2004 to 31 December, 2013. Multivariable modelling was used, adjusting for patient and institutional characteristics. Gaussian kernel densities were constructed to show the relative distributions of the effects of individual institutions and surgeons, before and after adjusting for the number of cases performed. RESULTS: A total of 2880 infants from 35 institutions met the inclusion criteria. Mortality was 15.0%. Median post-operative length of stay was 24 days (IQR 14-41). Median standardized inpatient hospital costs were $156,000 (IQR $108,000-$248,000) in 2013 dollars. In the multivariable analyses, higher institutional volume was inversely associated with mortality (p=0.001), post-operative length of stay (p=0.004), and costs (p=0.001). Surgeon volume was associated with none of the measured outcomes. Neither institutional nor surgeon volumes explained much of the wide variation in outcomes and resource utilization observed between institutions and between surgeons. CONCLUSIONS: Increased institutional - but not surgeon - volumes are associated with reduced mortality, post-operative length of stay, and costs for infants undergoing stage 1 palliation.