Risk Factors and Outcomes Associated with Gaps in Care in Children with Congenital Heart Disease

Adults with congenital heart disease (CHD) benefit from cardiology follow-up at recommended intervals of ≤ 2 years. However, benefit for children is less clear given limited studies and unclear current guidelines. We hypothesize there are identifiable risks for gaps in cardiology follow-up in children with CHD and that gaps in follow-up are associated with differences in healthcare utilization. Our cohort included children < 10 years old with CHD and a healthcare encounter from 2008 to 2013 at one of four North Carolina (NC) hospitals. We assessed associations between cardiology follow-up and demographics, lesion severity, healthcare access, and educational isolation (EI). We compared healthcare utilization based on follow-up. Overall, 60.4% of 6,969 children received cardiology follow-up within 2 years of initial encounter, including 53.1%, 58.1%, and 79.0% of those with valve, shunt, and severe lesions, respectively. Factors associated with gaps in care included increased drive time to a cardiology clinic (Hazard Ratio (HR) 0.92/15-min increase), EI (HR 0.94/0.2-unit increase), lesion severity (HR 0.48 for shunt/valve vs severe), and older age (HR 0.95/month if < 1 year old and 0.94/year if > 1 year old; p < 0.05). Children with a care gap subsequently had more emergency department (ED) visits (Rate Ratio (RR) 1.59) and fewer inpatient encounters and procedures (RR 0.51, 0.35; p < 0.05). We found novel factors associated with gaps in care for cardiology follow-up in children with CHD and altered health care utilization with a gap. Our findings demonstrate a need to mitigate healthcare barriers and generate clear cardiology follow-up guidelines for children with CHD.

Impact of Prenatal Diagnosis of Critical Congenital Heart Disease on Preoperative and Postoperative Outcomes

The objective of this study was to assess the relationship of prenatal diagnosis of critical congenital heart disease (CHD) to preoperative and postoperative patient findings. Retrospective analysis of neonates with critical CHD who underwent cardiothoracic surgery at one of four centers in North Carolina between 2008 and 2013. Surgical data collected by sites for submission to the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) and the North Carolina CHD Lifespan Database were queried. There were 715 patients with STS records; 558 linked to the NC-CHD database. Patients with prenatal diagnosis had a lower incidence of preoperative risk factors, including need for mechanical ventilation and presence of shock. However, prenatally diagnosed patients had worse short-term outcomes, including higher operative mortality, higher incidence of select postoperative complications, and longer LOS. There was no difference in one-year mortality. Our findings are consistent with current literature which suggests that prenatal diagnosis of critical CHD is associated with a more optimized preoperative clinical status. However, we found that patients with prenatal diagnoses had less favorable postoperative outcomes. This needs to be investigated further, but may be secondary to patient-specific factors, such as CHD disease severity.

The Fontan immunophenotype and post-transplant outcomes in children: A multi-institutional study

BACKGROUND

Patients after Fontan palliation represent a growing pediatric population requiring heart transplant (HTx) and often have lymphopenia (L) and/or hypogammaglobinemia that may be exacerbated by protein-losing enteropathy (PLE, P). The post-HTx effects of this altered immune phenotype are not well studied.

METHODS

In this study of the Pediatric Heart Transplant Society Registry, 106 Fontan patients who underwent HTx between 2005 and 2018 were analyzed. The impact of lymphopenia and PLE on graft survival, infection, rejection, and malignancy was analyzed at 1 and 5 years post-HTx.

RESULTS

The following combinations of lymphopenia and PLE were noted: +L+P, n = 37; +L-P, n = 23; -L+P, n = 10; and -L-P, n = 36. Graft survival between the groups was similar within the first year after transplant (+L+P: 86%, +L-P: 86%, -L+P: 87%, -L-P: 89%, p = .9). Freedom from first infection post-HTx was greatest among -L-P patients compared to patients with either PLE, lymphopenia, or both; with a 22.1% infection incidence in the -L-P group and 41.4% in all others. These patients had a significantly lower infection rate in the first year after HTx (+L+P: 1.03, +L-P: 1, -L+P: 1.3, -L-P: 0.3 infections/year, p < .001) and were similar to a non-single ventricle CHD control group (0.4 infections/year). Neither freedom from rejection nor freedom from malignancy 1 and 5 years post-HTx, differed among the groups.

CONCLUSIONS

Fontan patients with altered immunophenotype, with lymphopenia and/or PLE, are at increased risk of infection post-HTx, although have similar early survival and freedom from rejection and malignancy. These data may encourage alternative immunosuppression strategies and enhanced monitoring for this growing subset of patients.

Single-drug immunosuppression is associated with noninferior medium-term survival in pediatric heart transplant recipients

BACKGROUND

Patients are usually maintained on at least 2 immunosuppressive drugs (ISDs) after the first year post heart transplant. Anecdotally, some children are switched to single-drug monotherapy (a single ISD) for various reasons and varying durations. Outcomes associated with differences in immunosuppression after heart transplantation are unknown for children.

OBJECTIVES

A priori we defined a noninferiority hypothesis for monotherapy compared to ≥2 ISDs. The primary outcome was graft failure, a composite of death and retransplantation. Secondary outcomes included rejection, infection, malignancy, cardiac allograft vasculopathy and dialysis.

METHODS

This international, multicenter, retrospective, observational cohort study used data from the Pediatric Heart Transplant Society. We included patients who underwent first-time heart transplant <18 years of age between 1999 and 2020 with ≥1 year of follow-up data available.

RESULTS

Our analysis included 3493 patients with a median time post-transplant of 6.7 years. There were 893 patients (25.6%) switched to monotherapy at least once with the remaining 2600 patients always on ≥2 ISDs. The median time on monotherapy after the first year post-transplant was 2.8 years (range 1.1-5.9 years). We found an adjusted hazard ratio (HR) of 0.65 (95%CI: 0.47-0.88) favoring monotherapy compared to ≥2 ISDs (p = 0.002). There were no meaningful differences in the incidence of secondary outcomes between groups, except for a lower rate of cardiac allograft vasculopathy in patients on monotherapy (HR 0.58, 95%CI: 0.45-0.74).

CONCLUSIONS

For pediatric heart transplant recipients placed on monotherapy, immunosuppression with a single ISD after the first year post-transplant was noninferior to standard therapy with ≥2 ISDs in the medium term.

CONDENSED ABSTRACT

Some children are switched to a single immunosuppressive drug (ISD) for various reasons after heart transplant, but outcomes associated with differences in immunosuppression are unknown for children. We assessed graft failure in children on a single ISD (monotherapy) compared to ≥2 ISDs in a cohort of 3493 children with a first heart transplant. We found an adjusted hazard ratio of 0.65 (95%CI: 0.47-0.88) favoring monotherapy. We concluded that for pediatric heart transplant recipients placed on monotherapy, immunosuppression with a single ISD after the first year post-transplant was non-inferior to standard therapy with ≥2 ISDs in the medium term.

Initial Counseling Prior to Palliation for Hypoplastic Left Heart Syndrome: 2021 vs 2011

We sought to examine current practices and changes in practice regarding initial counseling for families of patients with hypoplastic left heart syndrome (HLHS) given the evolution of options and outcomes over time. Counseling (Norwood with Blalock-Taussig-Thomas shunt (NW-BTT), NW with right ventricle to pulmonary artery conduit (NW-RVPA), hybrid palliation, heart transplantation, or non-intervention/hospice (NI)) for patients with HLHS were queried via questionnaire of pediatric care professionals in 2021 and compared to identical questionnaire from 2011. Of 322 respondents in 2021 (39% female), 299 respondents were cardiologists (92.9%), 17cardiothoracic surgeons (5.3%), and 6 were nurse practitioners (1.9%). Respondents were largely from North America (96.9%). In 2021, NW-RVPA procedure was the preferred palliation for standard risk HLHS patient (61%) and was preferred across all US regions (p < 0.001). NI was offered as an option by 71.4% of respondents for standard risk patients and was the predominant strategy for patients with end-organ dysfunction, chromosomal abnormality, and prematurity (52%, 44%, and 45%, respectively). The hybrid procedure was preferred for low birth-weight infants (51%). In comparison to the identical 2011 questionnaire (n = 200), the NW-RVPA was endorsed more in 2021 (61% vs 52%, p = 0.04). For low birth-weight infants, hybrid procedure was more recommended than in 2011 (51% vs 21%, p < 0.001). The NW-RVPA operation is the most recommended strategy throughout the US for infants with HLHS. The hybrid procedure for low birth-weight infants is increasingly recommended. NI continues to be offered even in standard risk patients with HLHS.

Third-Grade Academic Performance and Episodes of Cardiac Care Among Children with Congenital Heart Defects

Children with congenital heart defects (CHDs) are at risk for poor academic performance. The degree to which receipt of health care services is associated with adverse academic outcomes is not known. We examined the association between episodes of cardiac care and third-grade performance in children with CHD. We identified subjects between 1/1/2008 and 4/30/2012 among 5 centers in North Carolina. We classified children by CHD type and linked subjects to the state educational records. Any inpatient or outpatient cardiac encounter on a date of service was considered an encounter. We calculated the number of encounters by adding the number of inpatient or outpatient cardiac visits prior to the date of the end-of-grade (EOG) tests. We estimated the odds of failing third-grade reading or math EOG tests by episodes of care stratified at the 50th percentile, controlling for CHD type, maternal education, sex, race/ethnicity, birth weight, and gestational age. A total of 184 children had third-grade EOG scores linked to health care records. The median number of episodes of care was 4 (range: 1-60). Those with visits ˃ 50th percentile (> 4 encounters/year over the 4.3 year observation period) had 2.09 (95% CI 1.04, 4.21) greater odds of failing the math EOG compared to those ≤ 50th percentile (1-4 encounters). The third-grade math score declined by 1.5 points (P < 0.008) for every 10 episodes of care. There was no association of episodes of care on third-grade reading performance. Children with CHD with > 4 episodes of cardiac care/year may be at risk for delays in third-grade academic performance. Strategies to minimize school absenteeism may improve academic success in this population.

Worsening racial disparity in waitlist mortality for pediatric heart transplant candidates since the 2016 Pediatric Heart Allocation Policy revision

BACKGROUND

The US Pediatric Heart Allocation Policy (PHAP) was revised in March 2016, with the goal of reducing waitlist mortality. We evaluated the hypothesis that these changes, which increased status exceptions, have worsened racial disparities in waitlist outcomes.

METHODS

Children in the Pediatric Heart Transplant Study database listed for first heart transplant from January 2012 - June 2020 were included and stratified by listing before (Era 1) or after (Era 2) the PHAP revision.

RESULTS

A total of 4,089 children were listed during the study period. Compared with white children (n = 2648), non-white children (n = 1441) were more likely to have an underlying diagnosis of cardiomyopathy in both eras. Waitlist mortality was similar in white and non-white children in Era 1, but comparatively worse for non-white children in Era 2. In multivariable analysis controlling for diagnosis, age, and severity markers, non-white children had a significantly higher waitlist mortality only in Era 2 (Era 1: sHR 1.22 [95%CI 0.90 - 1.66] vs. Era 2: sHR 1.57 [95%CI 1.17 - 2.10]).

CONCLUSIONS

Widening racial disparities in waitlist mortality may be an unintended consequence of the 2016 PHAP revision. Additional analyses may inform the degree to which this policy vs. unrelated changes in care differentially contribute to these disparities.

Disparities in Loss to Follow-Up Among Adults With Congenital Heart Disease in North Carolina

Background

The AHA/ACC Adult Congenital Heart Disease guidelines recommend that most adults with congenital heart disease (CHD) follow-up with CHD cardiologists every 1 to 2 years because longer gaps in care are associated with adverse outcomes. This study aimed to determine the proportion of patients in North Carolina who did not have recommended follow-up and to explore predictors of loss to follow-up.

Methods

Patients ages ≥18 years with a healthcare encounter from 2008 to 2013 in a statewide North Carolina database with an ICD-9 code for CHD were assessed. The proportion with cardiology follow-up within 24 months following index encounter was assessed with Kaplan-Meier estimates. Cox regression was utilized to identify demographic factors associated with differences in follow-up.

Results

2822 patients were identified. Median age was 35 years; 55% were female. 70% were white, 22% black, and 3% Hispanic; 36% had severe CHD. The proportion with 2-year cardiology follow-up was 61%. Those with severe CHD were more likely to have timely follow-up than those with less severe CHD (72% vs 55%, P < .01). Black patients had a lower likelihood of follow-up than white patients (56% vs 64%, P = .01). Multivariable Cox regression identified younger age, non-severe CHD, and non-white race as risk factors for a lower likelihood of follow-up by 2 years.

Conclusion

39% of adults with CHD in North Carolina are not meeting AHA/ACC recommendations for follow-up. Younger and minority patients and those with non-severe CHD were particularly vulnerable to inadequate follow-up; targeted efforts to retain these patients in care may be helpful.

Standardized Training for Physicians Practicing Pediatric Cardiac Critical Care

OBJECTIVES

In the vast majority of Children's Hospitals, the critically ill patient can be found in one of three locations: the PICU, the neonatal ICU, and the cardiac ICU. Training, certification, and maintenance of certification for neonatology and critical care medicine are over seen by the Accreditation Council for Graduate Medical Education and American Board of Pediatrics. There is no standardization of training or oversight of certification and maintenance of certification for pediatric cardiac critical care.

DATA SOURCES

The curricula from the twenty 4th year pediatric cardiac critical care training programs were collated, along with the learning objectives from the Pediatric Cardiac Intensive Care Society published "Curriculum for Pediatric Cardiac Critical Care Medicine."

STUDY SELECTION

This initiative is endorsed by the Pediatric Cardiac Intensive Care Society as a first step toward Accreditation Council for Graduate Medical Education oversight of training and American Board of Pediatrics oversight of maintenance of certification.

DATA EXTRACTION

A taskforce was established of cardiac intensivists, including the directors of all 4th year pediatric cardiac critical care training programs.

DATA SYNTHESIS

Using modified Delphi methodology, learning objectives, rotational requirements, and institutional requirements for providing training were developed.

CONCLUSIONS

In the current era of increasing specialized care in pediatric cardiac critical care, standardized training for pediatric cardiac critical care is paramount to optimizing outcomes.

Causes of Death in Infants and Children with Congenital Heart Disease

With improved surgical outcomes, infants and children with congenital heart disease (CHD) may die from other causes of death (COD) other than CHD. We sought to describe the COD in youth with CHD in North Carolina (NC). Patients from birth to 20 years of age with a healthcare encounter between 2008 and 2013 in NC were identified by ICD-9 code. Patients who could be linked to a NC death certificate between 2008 and 2016 were included. Patients were divided by CHD subtypes (severe, shunt, valve, other). COD was compared between groups. Records of 35,542 patients < 20 years old were evaluated. There were 15,277 infants with an annual mortality rate of 3.5 deaths per 100 live births. The most frequent COD in infants (age < 1 year) were CHD (31.7%), lung disease (16.1%), and infection (11.4%). In 20,265 children (age 1 to < 20 years), there was annual mortality rate of 9.7 deaths per 1000 at risk. The most frequent COD in children were CHD (34.2%), neurologic disease (10.2%), and infection (9.5%). In the severe subtype, CHD was the most common COD. In infants with shunt-type CHD disease, lung disease (19.5%) was the most common COD. The mortality rate in infants was three times higher when compared to children. CHD is the most common underlying COD, but in those with shunt-type lesions, extra-cardiac COD is more common. A multidisciplinary approach in CHD patients, where development of best practice models regarding comorbid conditions such as lung disease and neurologic disease could improve outcomes in this patient population.

Causes of Death and Cardiovascular Comorbidities in Adults With Congenital Heart Disease

Background Little is known about the contemporary mortality experience among adults with congenital heart disease (CHD). The objectives of this study were to assess the age at death, presence of cardiovascular comorbidities, and most common causes of death among adults with CHD in a contemporary cohort within the United States. Methods and Results Patients with CHD who had a healthcare encounter between 2008 and 2013 at 1 of 5 comprehensive CHD centers in North Carolina were identified by International Classification of Diseases, Ninth Revision (ICD-9), code. Only patients who could be linked to a North Carolina death certificate between 2008 and 2016 and with age at death ≥20 years were included. Median age at death and underlying cause of death based on death certificate data were analyzed. The prevalence of acquired cardiovascular risk factors was determined from electronic medical record data. Among the 629 included patients, the median age at death was 64.2 years. Those with severe CHD (n=157, 25%), shunts (n=202, 32%), and valvular lesions (n=174, 28%) had a median age at death of 46.0, 65.0, and 73.3 years, respectively. Cardiovascular death was most common in adults with severe CHD (60%), with 40% of those deaths caused by CHD. Malignancy and ischemic heart disease were the most common causes of death in adults with nonsevere CHD. Hypertension and hyperlipidemia were common comorbidities among all CHD severity groups. Conclusions The most common underlying causes of death differed by lesion severity. Those with severe lesions most commonly died from underlying CHD, whereas those with nonsevere disease more commonly died from non-CHD causes.

Orthotopic Heart Transplantation in a Patient With Gitelman Syndrome and Dilated Cardiomyopathy

Gitelman syndrome (GS) is a rare hereditary tubulopathy affecting the distal tubule leading to significant electrolyte disturbances.¹ Although generally a benign condition, rare associations with arrhythmias and sudden cardiac death have been reported.¹ A paucity of literature exists associating GS with cardiomyopathy. We present a child with dilated cardiomyopathy and GS who was successfully treated with orthotopic heart transplantation.

Home Oxygen Therapy for Children. An Official American Thoracic Society Clinical Practice Guideline

Background: Home oxygen therapy is often required in children with chronic respiratory conditions. This document provides an evidence-based clinical practice guideline on the implementation, monitoring, and discontinuation of home oxygen therapy for the pediatric population.

Methods: A multidisciplinary panel identified pertinent questions regarding home oxygen therapy in children, conducted systematic reviews of the relevant literature, and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach to rate the quality of evidence and strength of clinical recommendations.

Results: After considering the panel’s confidence in the estimated effects, the balance of desirable (benefits) and undesirable (harms and burdens) consequences of treatment, patient values and preferences, cost, and feasibility, recommendations were developed for or against home oxygen therapy specific to pediatric lung and pulmonary vascular diseases.

Conclusions: Although home oxygen therapy is commonly required in the care of children, there is a striking lack of empirical evidence regarding implementation, monitoring, and discontinuation of supplemental oxygen therapy. The panel formulated and provided the rationale for clinical recommendations for home oxygen therapy based on scant empirical evidence, expert opinion, and clinical experience to aid clinicians in the management of these complex pediatric patients and identified important areas for future research.

Renal injury and recovery in pediatric patients after ventricular assist device implantation and cardiac transplant

BACKGROUND

The use of ventricular assist devices (VADs) in children with heart failure may be of particular benefit to those with accompanying renal failure, as improved renal function is seen in some, but not all recipients. We hypothesized that persistent renal dysfunction at 7 days and/or 1 month after VAD implantation would predict chronic kidney disease (CKD) 1 year after heart transplantation (HT).

METHODS

Linkage analysis of all VAD patients enrolled in both the PEDIMACS and PHTS registries between 2012 and 2016. Persistent acute kidney injury (P-AKI), defined as a serum creatinine ≥1.5× baseline, was assessed at post-implant day 7. Estimated glomerular filtration rate (eGFR) was determined at implant, 30 days thereafter, and 12 months post-HT. Pre-implant eGFR, eGFR normalization (to ≥90 mL/min/1.73 m² ), and P-AKI were used to predict post-HT CKD (eGFR <90 mL/min/1.73 m² ).

RESULTS

The mean implant eGFR was 85.4 ± 46.5 mL/min/1.73 m² . P-AKI was present in 19/188 (10%). Mean eGFR at 1 month post-VAD implant was 131.1 ± 62.1 mL/min/1.73 m² , significantly increased above baseline (P < 0.001). At 1 year post-HT (n = 133), 60 (45%) had CKD. Lower pre-implant eGFR was associated with post-HT CKD (OR 0.99, CI: 0.97-0.99, P = 0.005); P-AKI was not (OR 0.96, CI: 0.3-3.0, P = 0.9). Failure to normalize renal function 30 days after implant was highly associated with CKD at 1 year post-transplant (OR 12.5, CI 2.8-55, P = 0.003).

CONCLUSIONS

Renal function improves after VAD implantation. Lower pre-implant eGFR and failure to normalize renal function during the support period are risk factors for CKD development after HT.

Bacterial infections after pediatric heart transplantation: Epidemiology, risk factors and outcomes

BACKGROUND

Bacterial infections represent a major cause of morbidity and mortality in heart transplant recipients. However, data describing the epidemiology and outcomes of these infections in children are limited.

METHODS

We analyzed the Pediatric Heart Transplant Study database of patients transplanted between 1993 and 2014 to determine the etiologies, risk factors and outcomes of children with bacterial infections post-heart transplantation.

RESULTS

Of 4,458 primary transplants in the database, there were 4,815 infections that required hospitalization or intravenous therapy, 2,047 (42.51%) of which were bacterial. The risk of bacterial infection was highest in the first month post-transplant, and the bloodstream was the most common site (24.82%). In the early post-transplant period (<30 days post-transplant), coagulase-negative staphylococci were the most common pathogens (16.97%), followed by Enterobacter sp (11.99%) and Pseudomonas sp (11.62%). In the late post-transplant period, community-acquired pathogens Streptococcus pneumoniae (6.27%) and Haemophilus influenzae (2.82%) were also commonly identified. Patients' characteristics independently associated with acquisition of bacterial infection included younger age (p < 0.0001) and ventilator (p < 0.0001) or extracorporeal membrane oxygenation (p = 0.03) use at time of transplant. Overall mortality post-bacterial infection was 33.78%, and previous cardiac surgery (p < 0.001) and multiple sites of infection (p = 0.004) were independent predictors of death.

CONCLUSIONS

Bacteria were the most common causes of severe infections in pediatric heart transplant recipients and were associated with high mortality rates. The risk of acquiring a bacterial infection was highest in the first month post-transplant, and a large proportion of the infections were caused by multidrug-resistant pathogens.

Is Endomyocardial Biopsy a Safe and Useful Procedure in Children with Suspected Cardiomyopathy?

Endomyocardial biopsy (EMB) is a common procedure used to aid in the diagnosis, prognosis and treatment of suspected pediatric cardiomyopathy. In suspected cardiomyopathy, no multicenter experience has previously reported on the safety and utility of EMBs. Retrospectively, adverse event (AE) and patient and procedural characteristics were obtained at seven institutions participating in the Congenital Cardiac Catheterization Outcomes Project for both a cardiomyopathy (n = 158) and a post-transplant surveillance (n = 2665) cohort. Descriptive information regarding biopsy indication, pathology and clinical management based on EMB findings were retrospectively obtained. High-severity AEs were more common in the cardiomyopathy cohort when compared to the post-transplant surveillance cohort. The cardiomyopathy cohort was younger, more hemodynamically vulnerable and required more cardiorespiratory support during the procedure. The eight high-severity AEs in the cardiomyopathy group included one myocardial perforation, two ECMO cannulations and three deaths following the EMB. Factors associated with high-severity AEs included performing another catheter-based intervention during the EMB and longer fluoroscopy time. Notably, an increased number of biopsy attempts did not increase the risk of an AE. Suspected myocarditis was the most common indication. Diagnostic EMB pathology and thus alteration to clinical management based on pathology occurred more frequently in patients with suspected myocarditis. In conclusion, there is an increased incidence of high-severity AEs in patients undergoing EMB for suspected cardiomyopathy. EMB may be more clinically useful in the management of suspected myocarditis. The increased risk of high-severity AEs when additional interventions are performed highlights the hemodynamic vulnerability in patients with suspected cardiomyopathy.

Clinical Issues and Controversies in Heart Failure and Transplantation

Heart failure is a common problem among children admitted in the intensive care unit and is associated with significant morbidity and mortality. As such, the 2014 meeting of the Pediatric Cardiac Intensive Care Society included a session on Clinical Controversies in Heart Failure and Transplantation. This review contains the summaries of the podium presentations of this session and will cover some of the challenging aspects of caring for these patients including medical and mechanical support, fluid overload states, high-risk populations including those after heart transplantation, and end-of-life considerations.

Predicting graft loss by 1 year in pediatric heart transplantation candidates: an analysis of the Pediatric Heart Transplant Study database

BACKGROUND

Pediatric data on the impact of pre-heart transplantation (HTx) risk factors on early post-HTx outcomes remain inconclusive. Thus, among patients with previous congenital heart disease or cardiomyopathy, disease-specific risk models for graft loss were developed with the use pre-HTx recipient and donor characteristics.

METHODS AND RESULTS

Patients enrolled in the Pediatric Heart Transplant Study (PHTS) from 1996 to 2006 were stratified by pre-HTx diagnosis into cardiomyopathy and congenital heart disease cohorts. Logistic regression identified independent, pre-HTx risk factors. Risk models were constructed for 1-year post-HTx graft loss. Donor factors were added for model refinement. The models were validated with the use of patients transplanted from 2007 to 2009. Risk factors for graft loss were identified in patients with cardiomyopathy (n=896) and congenital heart disease (n=965). For cardiomyopathy, independent risk factors were earlier year of transplantation, nonwhite race, female sex, diagnosis other than dilated cardiomyopathy, higher blood urea nitrogen, and panel reactive antibody >10%. The recipient characteristic risk model had good accuracy in the validation cohort, with predicted versus actual survival of 97.5% versus 95.3% (C statistic, 0.73). For patients with congenital heart disease, independent risk factors were nonwhite race, history of Fontan, ventilator dependence, higher blood urea nitrogen, panel reactive antibody >10%, and lower body surface area. The risk model was less accurate, with 86.6% predicted versus 92.4% actual survival, in the validation cohort (C statistic, 0.63). Donor characteristics did not enhance model precision.

CONCLUSIONS

Risk factors for 1-year post-HTx graft loss differ on the basis of pre-HTx cardiac diagnosis. Modeling effectively stratifies the risk of graft loss in patients with cardiomyopathy and may be an adjunctive tool in allocation policies and center performance metrics.

Neurodevelopmental outcome after cardiac surgery utilizing cardiopulmonary bypass in children

Introduction:

Modulating the stress response and perioperative factors can have a paramount impact on the neurodevelopmental outcome of infants who undergo cardiac surgery utilizing cardiopulmonary bypass.

Materials and Methods:

In this single center prospective follow-up study, we evaluated the impact of three different anesthetic techniques on the neurodevelopmental outcomes of 19 children who previously underwent congenital cardiac surgery within their 1^st year of life. Cases were done from May 2011 to December 2013. Children were assessed using the Stanford-Binet Intelligence Scales (5^th edition). Multiple regression analysis was used to test different parental and perioperative factors that could significantly predict the different neurodevelopmental outcomes in the entire cohort of patients.

Results:

When comparing the three groups regarding the major cognitive scores, a high-dose fentanyl (HDF) patients scored significantly higher than the low-dose fentanyl (LDF) + dexmedetomidine (DEX) (LDF + DEX) group in the quantitative reasoning scores (106 ± 22 vs. 82 ± 15 P = 0.046). The bispectral index (BIS) value at the end of surgery for the -LDF group was significantly higher than that in LDF + DEX group (P = 0.011). For the entire cohort, a strong correlation was seen between the standard verbal intelligence quotient (IQ) score and the baseline adrenocorticotropic hormone level, the interleukin-6 level at the end of surgery and the BIS value at the end of the procedure with an R² value of 0.67 and P < 0.04. There was an inverse correlation between the cardiac Intensive Care Unit length of stay and the full-scale IQ score (R = 0.4675 and P 0.027).

Conclusions:

Patients in the HDF group demonstrated overall higher neurodevelopmental scores, although it did not reach statistical significance except in fluid reasoning scores. Our results may point to a possible correlation between blunting the stress response and improvement of the neurodevelopmental outcome.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Cardiovascular function and treatment in β-thalassemia major: a consensus statement from the American Heart Association

This aim of this statement is to report an expert consensus on the diagnosis and treatment of cardiac dysfunction in β-thalassemia major (TM). This consensus statement does not cover other hemoglobinopathies, including thalassemia intermedia and sickle cell anemia, in which a different spectrum of cardiovascular complications is typical. There are considerable uncertainties in this field, with a few randomized controlled trials relating to treatment of chronic myocardial siderosis but none relating to treatment of acute heart failure. The principles of diagnosis and treatment of cardiac iron loading in TM are directly relevant to other iron-overload conditions, including in particular Diamond-Blackfan anemia, sideroblastic anemia, and hereditary hemochromatosis. Heart failure is the most common cause of death in TM and primarily results from cardiac iron accumulation. The diagnosis of ventricular dysfunction in TM patients differs from that in nonanemic patients because of the cardiovascular adaptation to chronic anemia in non-cardiac-loaded TM patients, which includes resting tachycardia, low blood pressure, enlarged end-diastolic volume, high ejection fraction, and high cardiac output. Chronic anemia also leads to background symptomatology such as dyspnea, which can mask the clinical diagnosis of cardiac dysfunction. Central to early identification of cardiac iron overload in TM is the estimation of cardiac iron by cardiac T2* magnetic resonance. Cardiac T2* <10 ms is the most important predictor of development of heart failure. Serum ferritin and liver iron concentration are not adequate surrogates for cardiac iron measurement. Assessment of cardiac function by noninvasive techniques can also be valuable clinically, but serial measurements to establish trends are usually required because interpretation of single absolute values is complicated by the abnormal cardiovascular hemodynamics in TM and measurement imprecision. Acute decompensated heart failure is a medical emergency and requires urgent consultation with a center with expertise in its management. The first principle of management of acute heart failure is control of cardiac toxicity related to free iron by urgent commencement of a continuous, uninterrupted infusion of high-dose intravenous deferoxamine, augmented by oral deferiprone. Considerable care is required to not exacerbate cardiovascular problems from overuse of diuretics or inotropes because of the unusual loading conditions in TM. The current knowledge on the efficacy of removal of cardiac iron by the 3 commercially available iron chelators is summarized for cardiac iron overload without overt cardiac dysfunction. Evidence from well-conducted randomized controlled trials shows superior efficacy of deferiprone versus deferoxamine, the superiority of combined deferiprone with deferoxamine versus deferoxamine alone, and the equivalence of deferasirox versus deferoxamine.

Cardiac management in neuromuscular diseases

This article addresses the pathophysiology, diagnostic approaches, and therapeutic options in the more common forms of muscular dystrophy, especially those seen in pediatric and young adult populations. The major emphasis is on the dystrophinopathies because their treatment options are templates for those used in various other forms of dystrophy. Most patients with cardiomyopathy are treated with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, with other agents added as the disease progresses. Destination therapies and transplantation options are mentioned where appropriate. Some dystrophies can have significant conduction abnormalities requiring pacemaker treatment. Others with ventricular tachydysrhythmias may necessitate internal cardiac defibrillator placement.

Combined heart-lung transplantation: a perspective on the past and the future

During the last 20 years, there has been a shift away from combined heart-lung transplantation (HLT) in favor of bilateral lung transplantation. This paradigm shift allowed for the donor heart to be transplanted to another patient. However, HLT remains to be the definitive surgical treatment for certain congenital heart disorders and Eisenmenger's syndrome. With a growing population of adult patients with congenital heart disease, there remains a need for HLT. This article provides a perspective on the past and the future of HLT.

Aggressive coronary artery vasculopathy after combined heart-lung transplantation

Combined heart-lung transplantation remains as a treatment option for patients with cardiopulmonary failure. There is speculation that lung grafts protect the heart from developing graft vasculopathy after combined heart-lung transplantation. This protective mechanism is more likely, at best, a delay in the onset of coronary artery vasculopathy. We present our experiences in two cases of an aggressive form of cardiac allograft vasculopathy after combined heart-lung transplantation that resulted in the death of both patients.

Endomyocardial biopsy and selective coronary angiography are low-risk procedures in pediatric heart transplant recipients: results of a multicenter experience

BACKGROUND

No prior reports documenting the safety and diagnostic yield of cardiac catheterization and endomyocardial biopsy (EMB) in heart transplant recipients include multicenter data.

METHODS

Data on the safety and diagnostic yield of EMB procedures performed in heart transplant recipients were recorded in the Congenital Cardiac Catheterization Outcomes Project database at 8 pediatric centers during a 3-year period. Adverse events (AEs) were classified according to a 5-level severity scale. Generalized estimating equation models identified risk factors for high-severity AEs (HSAEs; Levels 3-5) and non-diagnostic biopsy samples.

RESULTS

A total of 2,665 EMB cases were performed in 744 pediatric heart transplant recipients (median age, 12 years [interquartile range, 4.8, 16.7]; 54% male). AEs occurred in 88 cases (3.3%), of which 28 (1.1%) were HSAEs. AEs attributable to EMB included tricuspid valve injury, transient complete heart block, and right bundle branch block. Amongst 822 cases involving coronary angiography, 10 (1.2%) resulted in a coronary-related AE. There were no myocardial perforations or deaths. Multivariable risk factors for HSAEs included fewer prior catheterizations (p = 0.006) and longer case length (p < 0.001). EMB yielded sufficient tissue for diagnosis in 99% of cases. Longer time since heart transplant was the most significant predictor of a non-diagnostic biopsy sample (p < 0.001).

CONCLUSIONS

In the current era, cardiac catheterizations involving EMB can be performed in pediatric heart transplant recipients with a low AE rate and high diagnostic yield. Risk of HSAEs is increased in early post-transplant biopsies and with longer case length. Longer time since heart transplant is associated with non-diagnostic EMB samples.

Risk factors for late renal dysfunction after pediatric heart transplantation: a multi-institutional study

Renal dysfunction is a major determinant of outcome after HTx. Using a large, multi-institutional database, we sought to identify factors associated with late renal dysfunction after pediatric HTx. All patients in the PHTS database with eGFR ≥60 mL/min/1.73 m(2) at one yr post-HTx (n = 812) were analyzed by Cox regression for association with risk factors for eGFR <60 mL/min/1.73 m(2) at >1 yr after HTx. Freedom from late renal dysfunction was 71% and 57% at five and 10 yr. Multivariate risk factors for late renal dysfunction were earlier era of HTx (HR 1.84; p < 0.001), black race (HR 1.42; p = 0.048), rejection with hemodynamic compromise in the first year after HTx (HR 1.74; p = 0.038), and lowest quartile eGFR at one yr post-HTx (HR 1.83; p < 0.001). Renal function at HTx was not associated with onset of late renal dysfunction. Eleven patients (1.4%) required chronic dialysis and/or renal transplant during median follow-up of 4.1 yr (1.5-12.6). Late renal dysfunction is common after pediatric HTx, with blacks at increased risk. Decreased eGFR at one yr post-HTx, but not at HTx, predicts onset of late renal dysfunction. Future research on strategies to minimize late renal dysfunction after pediatric HTx may be of greatest benefit if focused on these subgroups.

Pediatric sub-specialist controversies in the treatment of congenital heart disease in trisomy 13 or 18

Trisomy 13 and 18 are associated with congenital heart disease. Cardiac palliation has been reported in the literature, but is not usually done in this population. Thus, a multi-disciplinary team may experience controversy in formulating a care plan that includes cardiac intervention. Our objective was to determine differences in recommendations for cardiac intervention in this population between physicians specializing in pediatric cardiac critical care, neonatology, and genetics. A web-based survey was performed between April 2007 and August 2008. This survey evaluated surgical and transcatheter cardiac palliations that had been performed for individuals with trisomy 13 or 18 at the respondent's institution, the respondent's recommendations for cardiac intervention in hypothetical symptomatic patients with trisomy 13 or trisomy 18 and the influence of parental preference on these recommendations. Eight hundred fifty-nine responses were obtained from a primarily academic practice setting (59%). Cardiologists were most likely to recommend intervention; low risk interventions were recommended by 32% of cardiologists, 7% of neonatologists and 20% of geneticists. Parental request to intervene resulted in a 3 fold increased in the likelihood of all specialist recommending intervention. Counseling of families frequently occurred by multiple sub specialists (50%) and there was frequently (71%) a difference in opinion. Individuals with trisomy 13 or 18 are receiving cardiac intervention at many institutions. Cardiologists were more likely than geneticists or neonatologists to recommend intervention on all heart lesions other than single ventricle palliation which no specialists recommended. Parental wishes that "everything be done" significantly influenced all specialists' recommendations.

Outcome of pediatric patients with dilated cardiomyopathy listed for transplant: a multi-institutional study

BACKGROUND

The course of dilated cardiomyopathy (DCM) leading to heart failure in children varies; survival with conventional treatment is 64% at 5 years. Heart transplantation (HTx) enables improved survival; however, outcomes from listing for transplant are not well described. This study reports survival of patients with DCM from listing with the availability of mechanical bridge to transplant.

METHODS

Patients with a primary diagnosis of DCM (n = 1,098) were identified from a multi-institutional, prospective, registry of patients aged < 18 years listed for HTx from January 1, 1993, to December 31, 2006.

RESULTS

Characteristics of DCM patients at listing included a mean age of 7.3 years; 51% male, 64% white ethnicity, 77% United Network for Organ Sharing status I, 66% on inotropic support, 28% mechanically ventilated, and 15% on mechanical support. Waitlist mortality was 11%, and 75% underwent HTx at 2 years after listing. Overall 10-year survival after listing was 72%, with higher risk of death associated with arrhythmias, mechanical ventilation, and extracorporeal membrane oxygenation (ECMO) support, but not ventricular assist device (VAD) support. Survival at 10 years post-HTx was 72%, with a higher risk of death associated with black race, older age, mechanical ventilation, longer ischemic time, and earlier era of transplant.

CONCLUSIONS

Transplantation for DCM in the pediatric population offers enhanced survival compared with the natural history. Overall waitlist mortality for DCM is low, with the exception of patients on ECMO, mechanically ventilated, or with arrhythmias. DCM patients fared well after transplant, making HTx a key therapeutic intervention.

Acute dilated cardiomyopathy in a patient with deficiency of long-chain 3-hydroxyacyl-CoA dehydrogenase

Deficiency of long-chain 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase (LCHADD) is a rare inborn error of metabolism. It is associated with hypertrophic cardiomyopathy and less frequently with dilated cardiomyopathy. The incidence and pathophysiology of cardiac involvement in LCHADD is poorly understood. This report describes the acute decompensation of a 3-year-old girl who had LCHADD with rapidly developing dilated cardiomyopathy. A review of the literature and possible causes of cardiomyopathy in LCHADD are explored.

Amplatzer septal occluder associated with late pulmonary venous obstruction requiring surgical removal with acquired aorta to left atrial fistula

The Amplatzer septal occluder is currently the preferred device for the transcatheter closure of secundum atrial septal defects. Multiple studies have shown that device complications with the Amplatzer occluder are rare and often acute in presentation. The investigators describe the first reported case of late obstruction of the right pulmonary veins with an Amplatzer septal occluder and, in the same patient, an unusual intraoperative finding of a noncoronary aortic sinus to left atrium fistula after device removal.

Hybrid approach for hypoplastic left heart syndrome: intermediate results after the learning curve

BACKGROUND

Lessons learned during the development of a novel hybrid approach have resulted in a reliable, reproducible alternative treatment for hypoplastic left heart syndrome (HLHS). Herein we report our results using this hybrid approach in a uniform risk cohort.

METHODS

This is a review of prospectively collected data on patients treated for HLHS using a hybrid approach (n = 40) between July 2002 and June 2007. The hybrid approach includes pulmonary artery bands, a ductal stent, and atrial septostomy as a neonate, comprehensive stage 2 procedure resulting in Glenn shunt physiology at six months and Fontan completion at two years.

RESULTS

Forty patients had a hybrid stage 1 with 36 undergoing a comprehensive stage 2 procedure. Fifteen patients have completed the Fontan procedure with 17 pending. Overall survival was 82.5% (33 of 40). The seven deaths included one at stage 1, two between stages 1 and 2, three at stage 2, and one between stages 2 and 3. One patient had successful heart transplantation during the interstage period.

CONCLUSIONS

The hybrid approach can yield acceptable intermediate results that are comparable with a traditional Norwood strategy. Potential advantages of the hybrid approach include the avoidance of circulatory arrest and shifting the major surgical stage to later in life. These data provide the platform for a prospective trial comparing these two surgical options to assess whether there is less cumulative impact with the hybrid approach, thereby improving end organ function, quality, and quantity of life.

Bench-to-bedside review: Developmental influences on the mechanisms, treatment and outcomes of cardiovascular dysfunction in neonatal versus adult sepsis

Sepsis is a significant cause of morbidity and mortality in neonates and adults, and the mortality rate doubles in patients who develop cardiovascular dysfunction and septic shock. Sepsis is especially devastating in the neonatal population, as it is one of the leading causes of death for hospitalized infants. In the neonate, there are multiple developmental alterations in both the response to pathogens and the response to treatment that distinguish this age group from adults. Differences in innate immunity and cytokine response may predispose neonates to the harmful effects of pro-inflammatory cytokines and oxidative stress, leading to severe organ dysfunction and sequelae during infection and inflammation. Underlying differences in cardiovascular anatomy, function and response to treatment may further alter the neonate's response to pathogen exposure. Unlike adults, little is known about the cardiovascular response to sepsis in the neonate. In addition, recent research has demonstrated that the mechanisms, inflammatory response, response to treatment and outcome of neonatal sepsis vary not only from that of adults, but vary among neonates based on gestational age. The goal of the present article is to review key pathophysiologic aspects of sepsis-related cardiovascular dysfunction, with an emphasis on defining known differences between adult and neonatal populations. Investigations of these relationships may ultimately lead to 'neonate-specific' therapeutic strategies for this devastating and costly medical problem.

Domino heart transplantation involving infants

Domino heart transplantation has been well described in adults, but has not previously been reported in infant patients. We report the successful transplantation of a 'domino' heart from a 3-month-old infant with primary pulmonary hypertension undergoing heart-lung transplantation, into a 3-month-old infant with complex congenital heart disease. Both infants have survived past 1 year post-transplant, and neither infant has experienced any clinically significant allograft-related complications. Echocardiography and cardiac catheterization of the domino heart have consistently demonstrated stable hypertrophy of the right ventricle (RV) and interventricular septum, but good right and left ventricular function. Domino heart transplant surgery may be an effective way to provide 'pre-conditioned' donor hearts to infants urgently in need of heart transplantation.

Increased calcium supplementation is associated with morbidity and mortality in the infant postoperative cardiac patient

OBJECTIVE

The purpose of this study was to assess the association of calcium replacement therapy with morbidity and mortality in infants after cardiac surgery involving cardiopulmonary bypass.

DESIGN

Retrospective chart review.

SETTING

The cardiac intensive care unit at a tertiary care children's hospital.

PATIENTS

Infants undergoing cardiac surgery involving cardiopulmonary bypass between October 2002 and August 2004.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total calcium replacement (mg/kg calcium chloride given) for the first 72 postoperative hours was measured. Morbidity and mortality data were collected. The total volume of blood products given during the first 72 hrs was recorded. Infants with confirmed chromosomal deletions at the 22q11 locus were noted. Correlation and logistic regression analyses were used to generate odds ratios and 95% confidence intervals, with p < .05 being significant. One hundred seventy-one infants met inclusion criteria. Age was 4 +/- 3 months and weight was 4.9 +/- 1.7 kg at surgery. Six infants had deletions of chromosome 22q11. Infants who weighed less required more calcium replacement (r = -.28, p < .001). Greater calcium replacement correlated with a longer intensive care unit length of stay (r = .27, p < .001) and a longer total hospital length of stay (r = .23, p = .002). Greater calcium replacement was significantly associated with morbidity (liver dysfunction [odds ratio, 3.9; confidence interval, 2.1-7.3; p < .001], central nervous system complication [odds ratio, 1.8; confidence interval, 1.1-3.0; p = .02], infection [odds ratio, 1.5; confidence interval, 1.0-2.2; p < .04], extracorporeal membrane oxygenation [odds ratio, 5.0; confidence interval, 2.3-10.6; p < .001]) and mortality (odds ratio, 5.8; confidence interval, 5.8-5.9; p < .001). Greater calcium replacement was not associated with renal insufficiency (odds ratio, 1.5; confidence interval, 0.9-2.3; p = .07). Infants with >1 sd above the mean of total calcium replacement received on average fewer blood products than the total study population.

CONCLUSIONS

Greater calcium replacement is associated with increasing morbidity and mortality. Further investigation of the etiology and therapy of hypocalcemia in this population is warranted.