Lower Opportunity ZIP Code Is Associated with Worse Outcomes after Listing in Pediatric Heart Transplantation.

BACKGROUND: The Child Opportunity Index (COI) comprehensively measures children's social determinants of health. We describe association between COI and outcomes after listing for heart transplantation. METHODS: We conducted a retrospective review of the United Network for Organ Sharing (UNOS) database for U.S. children listed for heart transplant between 2012 and 2020. ZIP codes were utilized to assign COI. Primary outcome was survival from time of listing. Secondary outcomes included waitlist survival, one-year post-transplant survival, and conditional one-year post-transplant survival. Cox regression was performed adjusting for payor, age, race, diagnosis, and support at listing for all outcomes except waitlist survival, for which Fine-Gray competing risk analysis was performed. RESULTS: Of 5723 children listed, 109 were excluded due to missing ZIP codes. Race/ethnicity and payor were associated with COI (p<0.001). Patients living in very low COI ZIP codes compared to all others had increased mortality from time of listing (HR 1.16, CI 1.03 - 1.32, p=0.02) with 1-, 5-, and 9-year survival of 79.3% vs 82.2%, 66.5% vs 73.0%, and 53.6% vs 64.7% respectively, were more likely to be removed from the waitlist due to death or being too sick (subdistribution HR 1.26, 95% CI 1.10-1.42), and had increased mortality conditional on one-year post-transplant survival (HR 1.38, 1.09 - 1.74, p=0.008) with 1-, 3-, and 5- year survival of 94.7% vs 97.3%, 87.0% vs 93.1%, and 78.6% vs 86.9%. CONCLUSIONS: Children living in lower opportunity ZIP codes had poorer survival from time of listing, poorer waitlist survival, and poorer conditional one-year post-transplant survival.

A comprehensive pediatric cardio-oncology program: a single institution approach to cardiovascular care for pediatric patients with cancer and childhood cancer survivors.

Cardiovascular complications related to cancer therapies are broad and variable in onset. These complications are the leading cause of non-cancer related morbidity and mortality in childhood cancer survivors and can also impact ongoing cancer treatment. Despite this understanding, dedicated cardio-oncology programs are lacking in pediatric cardiology. In an attempt to respond to these concerns, a risk-stratified, comprehensive cardio-oncology program was established to address the cardiovascular needs including prevention, early diagnosis, and management of patients with and at risk for cardiovascular complications of cancer therapy. This manuscript describes a single institution's experience of building and managing a multidisciplinary pediatric cardio-oncology program with close collaboration among cardiologists, oncologists, advanced cardiology and oncology practice providers, and allied health providers such as a dietitian and psychologist to provide comprehensive cardiovascular care for childhood cancer patients and survivors. In developing this program, emphasis was on the childhood cancer survivor population, as various cardiovascular complications can present many years after cancer treatment.

Cardiovascular remodelling in response to exercise training in patients after the Fontan procedure: a pilot study.

BACKGROUND: The cardiovascular adaptations associated with structured exercise training in Fontan patients remain unknown. We hypothesised that short-term training causes cardiac remodelling and parallel improvement in maximal exercise capacity (VO2 max) in these patients. METHODS AND RESULTS: Five patients, median age 19.5 (17.6-21.3) years, with a history of Fontan operation meeting inclusion/exclusion criteria, participated in a 3-month training programme designed to improve endurance. Magnetic resonance images for assessment of cardiac function, fibrosis, cardiac output, and liver elastography to assess stiffness were obtained at baseline and after training. Maximal exercise capacity (VO2 max) and cardiac output Qc (effective pulmonary blood flow) at rest and during exercise were measured (C2H2 rebreathing) at the same interval. VO2 max increased from median (IQR) 27.2 (26-28.7) to 29.6 (28.5-32.2) ml/min/kg (p = 0.04). There was an improvement in cardiac output (Qc) during maximal exercise testing from median (IQR) 10.3 (10.1-12.3) to 12.3 (10.9-14.9) l/min, but this change was variable (p = 0.14). Improvement in VO2 max correlated with an increase in ventricular mass (r = 0.95, p = 0.01), and improvement in Quality-of-life inventory (PedsQL) Cardiac scale scores for patient-reported symptoms (r = 0.90, p = 0.03) and cognitive problems (r = 0.89, p = 0.04). The correlation between VO2 max and Qc showed a positive trend but was not significant (r = 0.8, p = 0.08). No adverse cardiac or liver adaptations were noted. CONCLUSION: Short-term training improved exercise capacity in this Fontan pilot without any adverse cardiac or liver adaptations. These results warrant further study in a larger population and over a longer duration of time. TRIAL REGISTRATION NUMBER: NCT03263312, Unique Protocol ID: STU 122016-037; Registration Date: 18 January, 2017.

Risk of Sudden Death in Patients With RASopathy Hypertrophic Cardiomyopathy.

BACKGROUND: Genetic defects in the RAS/mitogen-activated protein kinase pathway are an important cause of hypertrophic cardiomyopathy (RAS-HCM). Unlike primary HCM (P-HCM), the risk of sudden cardiac death (SCD) and long-term survival in RAS-HCM are poorly understood. OBJECTIVES: The study's objective was to compare transplant-free survival, incidence of SCD, and implantable cardioverter-defibrillator (ICD) use between RAS-HCM and P-HCM patients. METHODS: In an international, 21-center cohort study, we analyzed phenotype-positive pediatric RAS-HCM (n = 188) and P-HCM (n = 567) patients. The between-group differences in cumulative incidence of all outcomes from first evaluation were compared using Gray's tests, and age-related hazard of all-cause mortality was determined. RESULTS: RAS-HCM patients had a lower median age at diagnosis compared to P-HCM (0.9 years [IQR: 0.2-5.0 years] vs 9.8 years [IQR: 2.0-13.9 years], respectively) (P < 0.001). The 10-year cumulative incidence of SCD from first evaluation was not different between RAS-HCM and P-HCM (4.7% vs 4.2%, respectively; P = 0.59). The 10-year cumulative incidence of nonarrhythmic deaths or transplant was higher in RAS-HCM compared with P-HCM (11.0% vs 5.4%, respectively; P = 0.011). The 10-year cumulative incidence of ICD insertions, however, was 5-fold lower in RAS-HCM compared with P-HCM (6.9% vs 36.6%; P < 0.001). Nonarrhythmic deaths occurred primarily in infancy and SCD primarily in adolescence. CONCLUSIONS: RAS-HCM was associated with a higher incidence of nonarrhythmic death or transplant but similar incidence of SCD as P-HCM. However, ICDs were used less frequently in RAS-HCM compared to P-HCM. In addition to monitoring for heart failure and timely consideration of advanced heart failure therapies, better risk stratification is needed to guide ICD practices in RAS-HCM.

HeartWatch: Implementing a Pediatric Heart Center Program to Prevent Cardiac Arrests Outside the ICU.

Pediatric patients with cardiovascular disease are at increased risk of cardiopulmonary arrest. Despite utilization of Cardiac Pediatric Early Warning Scores to identify patients at risk of decompensation, our institution had a twofold increase in cardiac arrests (CAs) in the acute care cardiology unit (ACCU) over 2 years. Through a quality improvement initiative, we developed a watcher program, HeartWatch, to reduce the CA arrest rate in the ACCU by 50% over the first year of implementation. Methods: HeartWatch aims to identify patients not adequately captured by Cardiac Pediatric Early Warning Scores who are at high risk for sudden decompensation. Inclusion criteria were developed and evaluated during pilot and implemented phases (April 2020-April 2021) and then monitored in a sustained phase through June 2022. Our primary outcome was the reduction in the out-of-ICU CA rate. Results: During the 13 months, we enrolled 169 patients, and the CA rate decreased from 0.7 to 0.33 per 1,000 patient days, a 53% reduction. The CA rate further decreased to 0.28 events per 1,000 patient days, a 60% reduction, by June 2022. The most common indications for HeartWatch inclusion were high-risk single-ventricle patients (31%) and patients with diminished ventricular function (20%). Conclusions: Implementation of HeartWatch was associated with a meaningful reduction in CA in the ACCU. Creating shared mental models for high-risk patients is essential for patient safety. Future work will optimize local processes that focus on the sustainability of our gains. We will also evaluate opportunities to adapt and implement a similar framework in other institutions to assess reproducibility.

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.).

Diversity of Dystrophin Gene Mutations and Disease Progression in a Contemporary Cohort of Duchenne Muscular Dystrophy.

Abnormal dystrophin production due to mutations in the dystrophin gene causes Duchenne Muscular Dystrophy (DMD). Cases demonstrate considerable genetic and disease progression variability. It is unclear if specific gene mutations are prognostic of outcomes in this population. We conducted a retrospective cohort study of DMD patients followed at 17 centers across the USA and Canada from 2005 to 2015 with goal of understanding the genetic variability of DMD and its impact on clinical outcomes. Cumulative incidence of clinically relevant outcomes was stratified by genetic mutation type, exon mutation location, and extent of exon deletion. Of 436 males with DMD, 324 (74.3%) underwent genetic testing. Deletions were the most common mutation type (256, 79%), followed by point mutations (45, 13.9%) and duplications (23, 7.1%). There were 131 combinations of mutations with most mutations located along exons 45 to 52. The number of exons deleted varied between 1 and 52 with a median of 3 exons deleted (IQR 1-6). Subjects with mutations starting at exon positions 40-54 had a later onset of arrhythmias occurring at median age 25 years (95% CI 18-∞), p = 0.01. Loss of ambulation occurred later at median age of 13 years (95% CI 12-15) in subjects with mutations that started between exons 55-79, p = 0.01. There was no association between mutation type or location and onset of cardiac dysfunction. We report the genetic variability in DMD and its association with timing of clinical outcomes. Genetic modifiers may explain some phenotypic variability.

Learning networks in pediatric heart failure and transplantation.

BACKGROUND: Learning networks have emerged in medicine as a novel organizational structure that contains elements of quality improvement, education, and research with the goal of effecting rapid improvements in clinical care. In this article, the concept of a learning network is defined and highlighted in the field of pediatric heart failure and transplantation. METHODS: Learning networks are defined, with particular attention paid to the recent creation of the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) for children with heart failure and those being supported with ventricular assist devices (VAD). RESULTS: The mission, goals, and organizational structure of ACTION are described, and recent initiatives promoted by ACTION are highlighted, such as stroke reduction initiatives, practice harmonization protocols, and use of ACTION data to support the recent US Food and Drug Administration approval of newer VAD for pediatric patients. CONCLUSIONS: The learning network, exemplified by ACTION, is distinguished from traditional clinical research collaboratives by contributions in research, quality improvement, patient-reported outcomes, and education, and serves as an effective vehicle to drive clinical improvement in the care of children with advanced heart failure.

Feasibility and safety of quantitative adenosine stress perfusion cardiac magnetic resonance imaging in pediatric heart transplant patients with and without coronary allograft vasculopathy.

BACKGROUND: Pediatric heart transplant patients require cardiac catheterization to monitor for coronary allograft vasculopathy. Cardiac catheterization has no safe and consistent method for measuring microvascular disease. Stress perfusion cardiac magnetic resonance imaging (MRI) assessing microvascular disease has been performed in adults. OBJECTIVE: To investigate the feasibility and safety of performing cardiac MRI with quantitative adenosine stress perfusion testing in pediatric heart transplant patients with and without coronary allograft vasculopathy. MATERIALS AND METHODS: All pediatric heart transplant patients with coronary vasculopathy at our institution were asked to participate. Age- and gender-matched pediatric heart transplant patients without vasculopathy were recruited for comparison. Patients underwent cardiac MRI with adenosine stress perfusion testing. RESULTS: Sixteen pediatric heart transplant patients, ages 6-22 years, underwent testing. Nine patients had vasculopathy by angiography. No heart block or other complications occurred during the study. The myocardial perfusion reserve for patients with vasculopathy showed no significant difference with comparison patients (median: 1.43 vs. 1.48; P=0.49). Values for both groups were lower than expected values based on previous adult studies. The patients were also analyzed for time after transplant and the number of rejection episodes. Patients within 6 years of transplantation had a nonsignificant trend toward a higher myocardial perfusion reserve (median: 1.57) versus patients with older transplants (median: 1.47; P=0.46). Intra- and interobserver reproducibility were 97% and 92%, respectively. CONCLUSION: Myocardial perfusion reserve is a safe and feasible method for estimating myocardial perfusion in pediatric heart transplant patients. There is no reliable way to monitor microvascular disease in pediatric patients. This method shows potential and deserves investigation in a larger cohort.

Electronic Mental Health Screening in a Pediatric Heart Failure and Transplant Clinic.

Adults with heart failure and transplant are at increased risk for psychiatric comorbidities. The prevalence and impact of psychiatric comorbidities have not been well studied in pediatric heart failure and transplant. This quality improvement project sought to evaluate the feasibility of utilizing electronic mental health screening measures during pediatric heart failure and transplant clinics and to explore the prevalence and severity of self-reported depressive, anxiety, and suicidal ideation symptoms. Patients aged 11 years and older who presented to a pediatric heart failure and transplant clinic were administered the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7). Medical chart review and a survey were used to examine additional variables of interest. There were no significant differences in moderate and severe mental health symptoms between gender, medical diagnoses, or those with recent hospitalizations. Pediatric patients with heart failure or transplant reported higher prevalence of anxiety and depressive symptoms, and similar suicidal ideation compared to the general adolescent population. Moreover, rates of depression and anxiety symptoms as well as suicidal ideation were comparable to pediatric patients with diabetes, lupus, inflammatory bowel disease, and cystic fibrosis. Results suggest electronic mental health screening is feasible for use during outpatient cardiology clinic visits and provides valuable mental health information.

Carvedilol Does Not Improve Exercise Performance in Fontan Patients: Results of a Crossover Trial.

Increased circulating catecholamines are associated with worse exercise performance in adult heart failure patients. Patients with Fontan physiology have increased circulating catecholamines and theoretically could benefit from beta blockade. We hypothesized that carvedilol would improve exercise performance in Fontan patients. A double-blind, placebo-controlled, crossover trial of carvedilol was performed. Single ventricle patients between the ages of 10 and 35 years with a previous Fontan operation who were able to complete a maximal exercise test (respiratory exchange ratio > 1.0) were included. Two 12-week treatment arms were separated by a 6-week washout period. Exercise testing was performed at beginning and end of each treatment arm. Primary endpoint was improvement in peak oxygen consumption/kg (pVO2) from baseline. Of the 26 subjects enrolled, 23 completed the study. Four subjects did not reach goal maximum carvedilol dose, vs. 1 for placebo (p = 0.14). The mean change in pVO2 between treatments was not different (carvedilol = - 2.1 mL/kg/min v. placebo = - 1.42, p = 0.28). Carvedilol therapy decreased peak heart rate by 4.2 ± 20.2 bpm, (p < 0.01) leading to an increase in peak oxygen pulse (p < 0.01). Serum N-terminal-proBNP increased with carvedilol therapy (mean change of + 23.77 pg/mL) compared to placebo (mean change of - 5.37 pg/mL, p = 0.03). There were no serious adverse events related to study drug. Carvedilol was not associated with improved exercise performance and was associated with mildly increased N-terminal-proBNP. This study does not support the routine administration of carvedilol to healthy Fontan patients.Clinical Trials Registration ClinicalTrials.gov Identifier: NCT02946892. Registered October 27, 2016. Retrospectively Registered. https://clinicaltrials.gov/ct2/show/NCT02946892.

Heart Failure After Cavopulmonary Connection: Conversion to Biventricular Circulatory Support.

Mechanical support of patients with superior cavopulmonary connection is challenging; multiple factors contribute to failure: elevated pulmonary vascular resistance, aortopulmonary collateral flow, venovenous collaterals, ventricular dysfunction, and atrioventricular valve regurgitation. We report 2 cases of conversion from a single ventricle circulation to biventricular mechanical support by reestablishing caval continuity. Both patients have demonstrated recovery of end-organ function and participation in rehabilitation. This method of support results in improved systemic venous pressures and pulmonary blood flow compared with systemic mechanical circulatory support with a cavopulmonary connection and transfers some of the complexity of the transplant to the ventricular assist device implant.

Center Donor Refusal Rate Is Associated With Worse Outcomes After Listing in Pediatric Heart Transplantation.

BACKGROUND: Pediatric donor heart acceptability differs among transplant centers. However, the impact of center donor acceptance on waitlist and posttransplant outcomes has not been investigated. The aim of our study was to investigate associations between transplant center refusal rate (RR) and outcomes after listing. METHODS: Retrospective analysis was performed using United Network for Organ Sharing/Organ Procurement and Transplant Network pediatric (<18 y) heart transplant data from 2007 to 2017. Center RR was defined as the median number of refusals per listed patient. Associations between RR center quartile and waitlist time, waitlist removal for death or clinical deterioration, posttransplant survival, and survival after listing were investigated. RESULTS: There were 5552 listed patients in 59 centers who met inclusion criteria. The lowest quartile RR centers had a median RR of ≤1 per listed patient, and highest RR centers percentile had a median RR of ≥4. Highest RR centers had shorter time to first offer (19 versus 38 d; P < 0.001), with longer waitlist times (203 versus 145 d; P < 0.001), were more likely to remove patients from the waitlist due to death or deterioration (24.1% versus 14.6%; P < 0.001), less likely to transplant listed patients (63.1% versus 77.6%; P < 0.001), and had a lower likelihood of survival 1 year after listing (79.2% versus 91.6%; odds ratio, 1.6; 95% confidence interval, 1.2-2.0; P < 0.001) compared with low RR centers. CONCLUSIONS: Patients listed at high RR centers had worse survival from listing despite having shorter times to first offer.

A comprehensive strategy in donor acceptance: Impact on pediatric waitlist and heart transplant outcomes.

Significant inter- and intra-center practice variability is present in pediatric donor heart acceptability. This may contribute to variation in the donor refusal rate and may impact waitlist time, morbidity, mortality, and transplant rates. In order to reduce practice variability, our center developed and implemented a comprehensive strategy regarding donor acceptance in September 2017. The aim of this study was to assess the impact of this strategy on waitlist time and outcomes as well as early post-transplant outcomes. We performed a single-center, retrospective analysis of all pediatric (<18 years) patients listed for single-organ heart transplant at our center from September 2015 to September 2018. Patients were divided into those listed before (Group 1) and after implementation of the comprehensive strategy (Group 2). The primary end-point was waitlist time. Secondary end-points included waitlist removal due to death or clinical deterioration, donor refusals per listed patient, early post-transplant outcomes (graft failure, mechanical ventilation time, inotropic support, length of hospital stay) and 1-year post-transplant survival. Of 78 listed patients, 54 were transplanted (29 in Group 1), 9 were removed due to death or clinical deterioration (7 in Group 1) and 15 were removed due to clinical improvement (12 in Group 1). The waitlist time was significantly shorter in Group 2 (17 days, IQR 7-53) vs Group 1 (90 days, IQR 14-162); P = .006. The number of donor refusals was lower in Group 2 (1, IQR 0-2.2) vs Group 1 (4, IQR 2-19); P < .001. The percentage of refused donors with normal function (Left ventricular ejection fraction > 50%) was lower in Group 2 vs Group 1 (53% vs 84%; P < .001). Difference in removal from the waitlist for death or deterioration in Group 2 vs Group 1 (n = 2, 7% vs n = 7, 20%, P = .18) did not reach statistical significance. There was no difference in post-transplant outcomes between groups. The waitlist time and donor refusals significantly decreased after implementation of a comprehensive donor acceptance strategy without impacting transplant outcomes. This analysis supports the need for a comprehensive approach to donor organ acceptance within a pediatric transplant center.

A Validated Model for Sudden Cardiac Death Risk Prediction in Pediatric Hypertrophic Cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy is the leading cause of sudden cardiac death (SCD) in children and young adults. Our objective was to develop and validate a SCD risk prediction model in pediatric hypertrophic cardiomyopathy to guide SCD prevention strategies. METHODS: In an international multicenter observational cohort study, phenotype-positive patients with isolated hypertrophic cardiomyopathy <18 years of age at diagnosis were eligible. The primary outcome variable was the time from diagnosis to a composite of SCD events at 5-year follow-up: SCD, resuscitated sudden cardiac arrest, and aborted SCD, that is, appropriate shock following primary prevention implantable cardioverter defibrillators. Competing risk models with cause-specific hazard regression were used to identify and quantify clinical and genetic factors associated with SCD. The cause-specific regression model was implemented using boosting, and tuned with 10 repeated 4-fold cross-validations. The final model was fitted using all data with the tuned hyperparameter value that maximizes the c-statistic, and its performance was characterized by using the c-statistic for competing risk models. The final model was validated in an independent external cohort (SHaRe [Sarcomeric Human Cardiomyopathy Registry], n=285). RESULTS: Overall, 572 patients met eligibility criteria with 2855 patient-years of follow-up. The 5-year cumulative proportion of SCD events was 9.1% (14 SCD, 25 resuscitated sudden cardiac arrests, and 14 aborted SCD). Risk predictors included age at diagnosis, documented nonsustained ventricular tachycardia, unexplained syncope, septal diameter z-score, left ventricular posterior wall diameter z score, left atrial diameter z score, peak left ventricular outflow tract gradient, and presence of a pathogenic variant. Unlike in adults, left ventricular outflow tract gradient had an inverse association, and family history of SCD had no association with SCD. Clinical and clinical/genetic models were developed to predict 5-year freedom from SCD. Both models adequately discriminated between patients with and without SCD events with a c-statistic of 0.75 and 0.76, respectively, and demonstrated good agreement between predicted and observed events in the primary and validation cohorts (validation c-statistic 0.71 and 0.72, respectively). CONCLUSION: Our study provides a validated SCD risk prediction model with >70% prediction accuracy and incorporates risk factors that are unique to pediatric hypertrophic cardiomyopathy. An individualized risk prediction model has the potential to improve the application of clinical practice guidelines and shared decision making for implantable cardioverter defibrillator insertion. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT0403679.

Epidemiology and Outcomes of Acute Decompensated Heart Failure in Children.

BACKGROUND: Acute decompensated heart failure (ADHF) is a highly morbid condition among adults. Little is known about outcomes in children with ADHF. We analyzed the Pediatric Cardiac Critical Care Consortium registry to determine the epidemiology, contemporary treatments, and predictors of mortality in critically ill children with ADHF. METHODS: Cardiac intensive care unit (CICU) patients ≤18 years of age meeting Pediatric Cardiac Critical Care Consortium criteria for ADHF were included. ADHF was defined as systolic or diastolic dysfunction requiring continuous vasoactive or diuretic infusion, respiratory support, or mechanical circulatory support. Demographics, diagnosis, therapies, complications, and mortality are described for the cohort. Predictors of CICU mortality were identified using logistic regression. RESULTS: Among 26 294 consecutive admissions (23 centers), 1494 (6%) met criteria for analysis. Median age was 0.93 years (interquartile range, 0.1-9.3 years). Patients with congenital heart disease (CHD) comprised 57% of the cohort. Common therapies included the following: vasoactive infusions (88%), central venous catheters (86%), mechanical ventilation (59%), and high flow nasal cannula (46%). Common complications were arrhythmias (19%), cardiac arrest (10%), sepsis (7%), and acute renal failure requiring dialysis (3%). Median length of CICU stay was 7.9 days (interquartile range, 3-18 days) and the CICU readmission rate was 22%. Overall, CICU mortality was 15% although higher for patients with CHD versus non-CHD (19% versus 11%; P<0.001). Independent risk factors associated with CICU mortality included age <30 days, CHD, vasoactive infusions, ventricular tachycardia, mechanical ventilation, sepsis, pulmonary hypertension, extracorporeal membrane oxygenation, and cardiac arrest. CONCLUSIONS: ADHF in children is characterized by comorbidities, high mortality rates, and frequent readmission, especially among patients with CHD. Opportunities exist to determine best practices around appropriate use of mechanical support, cardiac arrest prevention, and optimal heart transplantation candidacy to improve outcomes for these patients.

Implantable Cardioverter Defibrillator Use in Males with Duchenne Muscular Dystrophy and Severe Left Ventricular Dysfunction.

Duchenne muscular dystrophy (DMD) is characterized by myocardial fibrosis and left ventricular (LV) dysfunction. Implantable cardioverter defibrillator (ICD) use has not been characterized in this population but is considered for symptomatic patients with severe LV dysfunction (SLVD) receiving guideline-directed medical therapy (GDMT). We evaluated ICD utilization and efficacy in patients with DMD. Retrospective cohort study of DMD patients from 17 centers across North America between January 2, 2005 and December 31, 2015. ICD use and its effect on survival were evaluated in patients with SLVD defined as ejection fraction (EF) < 35% and/ or shortening fraction (SF) < 16% on final echocardiogram. SLVD was present in 57/436 (13.1%) patients, of which 12 (21.1%) died during the study period. Of these 12, (mean EF 20.9 ± 6.2% and SF 13.7 ± 7.2%), 8 received GDMT, 5 received steroids, and none received an ICD. ICDs were placed in 9/57 (15.8%) patients with SLVD (mean EF 31.2 ± 8.5% and SF 10.3 ± 4.9%) at a mean age of 20.4 ± 6.3 years; 8/9 received GDMT, 7 received steroids, and all were alive at study end; mean ICD duration was 36.1 ± 26.2 months. Nine ICDs were implanted at six different institutions, associated with two appropriate shocks for ventricular tachycardia in two patients, no inappropriate shocks, and one lead fracture. ICD use may be associated with improved survival and minimal complications in DMD cardiomyopathy with SLVD. However, inconsistent GDMT utilization may be a significant confounder. Future studies should define optimal indications for ICD implantation in patients with DMD cardiomyopathy.