The teammate trial: Study design and rationale tacrolimus and everolimus against tacrolimus and MMF in pediatric heart transplantation using the major adverse transplant event (MATE) score.

BACKGROUND: Currently there are no immunosuppression regimens FDA-approved to prevent rejection in pediatric heart transplantation (HT). In recent years, everolimus (EVL) has emerged as a potential alternative to standard tacrolimus (TAC) as the primary immunosuppressant to prevent rejection that may also reduce the risk of cardiac allograft vasculopathy (CAV), chronic kidney disease (CKD) and cytomegalovirus (CMV) infection. However, the 2 regimens have never been compared head-to-head in a randomized trial. The study design and rationale are reviewed in light of the challenges inherent in rare disease research. METHODS: The TEAMMATE trial (IND 127980) is the first multicenter randomized clinical trial (RCT) in pediatric HT. The primary purpose is to evaluate the safety and efficacy of EVL and low-dose TAC (LD-TAC) compared to standard-dose TAC and mycophenolate mofetil (MMF). Children aged <21 years at HT were randomized (1:1 ratio) at 6 months post-HT to either regimen, and followed for 30 months. Children with recurrent rejection, multi-organ transplant recipients, and those with an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m2 were excluded. The primary efficacy hypothesis is that, compared to TAC/MMF, EVL/LD-TAC is more effective in preventing 3 MATEs: acute cellular rejection (ACR), CKD and CAV. The primary safety hypothesis is that EVL/LD-TAC does not have a higher cumulative burden of 6 MATEs (antibody mediated rejection [AMR], infection, and post-transplant lymphoproliferative disorder [PTLD] in addition to the 3 above). The primary endpoint is the MATE score, a composite, ordinal surrogate endpoint reflecting the frequency and severity of MATEs that is validated against graft loss. The study had a target sample size of 210 patients across 25 sites and is powered to demonstrate superior efficacy of EVL/LD-TAC. Trial enrollment is complete and participant follow-up will be completed in 2023. CONCLUSION: The TEAMMATE trial is the first multicenter RCT in pediatric HT. It is anticipated that the study will provide important information about the safety and efficacy of everolimus vs tacrolimus-based regimens and will provide valuable lessons into the design and conduct of future trials in pediatric HT.

Supplemental nutrition, feeding disorders, and renourishment in pediatric heart failure through transplantation.

BACKGROUND: Tube feeds are used commonly in children listed for heart transplant; however, rates of renourishment and development of feeding disorders are not sufficiently characterized. METHODS: Retrospective review of pediatric heart transplant recipients from January 1, 2014, to January 3, 2021. Demographics, anthropometric, and nutritional data were collected from heart transplant listing through 3 years post-transplant. Renourishment rates, presence of a feeding disorder, and need for a gastric feeding tube were analyzed. Multivariable analysis was conducted to identify risks for poor nutritional outcomes. RESULTS: Of 104 patients, 35 (34%) and 36 (35%) were malnourished at heart transplant listing and transplant, respectively, persisting in 21/91 (23%) 1 year postheart transplant. Forty (38%) received tube feeds at listing, 42 (40%) at heart transplant, and 18/90 (20%) 1 year post-transplant. Rates of feeding disorders fell from 23% at transplantation to 10% 1 year post-transplant. Feeding disorders were associated with younger age at heart transplant (p < .001) and congenital heart disease (p = .03). Forty-six percent of infants required a gastric feeding tube. Renourishment occurred in 20% during listing and was associated with ventricular assist device support (p = .03) and noncalorically dense feeds (p = .03). Malnutrition at transplant was associated with inferior post-transplant survival (6/36 (17%) vs. 2/68 (3%); p = .02). CONCLUSIONS: Malnourishment requiring tube feeds is common in pediatric heart transplant candidates; however, most patients who eventually survive to transplant remain malnourished at time of transplantation and 1 year later. While some children develop feeding disorders, they generally resolve by 1 year post-transplant.

Major Adverse Dystrophinopathy Events (MADE) Score as Marker of Cumulative Morbidity and Risk for Mortality in Boys with Duchenne Muscular Dystrophy.

Background: Overlapping symptoms from cardiomyopathy, respiratory insufficiency, and skeletal myopathy confound assessment of heart failure in Duchenne Muscular Dystrophy. We developed an ordinal scale of multiorgan clinical variables that reflect cumulative disease burden-the Major Adverse Dystrophinopathy Event (MADE) Score. We hypothesized that a higher MADE score would be associated with increased mortality in boys with Duchenne Muscular Dystrophy. The Cooperative International Neuromuscular Research Group Duchenne Natural History Study dataset was utilized for validation. Methods: Duchenne Natural History Study variables were selected based on clinical relevance to prespecified domains: Cardiac, Pulmonary, Myopathy, Nutrition. Severity points (0-4) were assigned and summed for study visits. MADE score for cohorts defined by age, ambulatory status, and survival were compared at enrollment and longitudinally.Associations between MADE score and mortality were examined. Results: Duchenne Natural History Study enrolled 440 males, 12.6 ±6.1 years old, with 3,559 visits over 4.6 ±2.8 years, 45 deaths. MADE score increased with age and nonambulatory status. Mean MADE score per visit was 19 ±10 for those who died vs. 9.8 ±9.3 in survivors p=0.03. Baseline MADE score >12 predicted mortality independent of age (78% sensitivity, CPE.70). Rising MADE score trajectory was associated with mortality in models adjusted for enrollment age, follow-up time, and ambulatory status, all p<.001. Conclusion: A multiorgan severity score, MADE, was developed to track cumulative morbidities that impact heart failure in Duchenne muscular dystrophy. MADE score predicted Duchenne Natural History Study mortality. MADE score can be used for serial heart failure assessment in males and may serve as an endpoint for Duchenne muscular dystrophy clinical research.

Establishing Baseline Metrics of Heart Failure Medication Use in Children: A Collaborative Effort from the ACTION Network.

Heart failure metrics specific to the pediatric population are required to successfully implement quality improvement initiatives in children with heart failure. Medication use at the time of discharge following admission for decompensated heart failure has been identified as a potential quality metric in this population. This study aimed to report medication use at discharge in the current era for children admitted with acute decompensated heart failure. All patients < 21 years of age with an index admission (1/1/2011-12/31/2019) for acute heart failure and a coexisting diagnosis of cardiomyopathy were identified from the Pediatric Health Information System. Medication use patterns were described and compared across age groups and centers. A total of 2288 patients were identified for inclusion. An angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker (ACEi/ARB) was prescribed in 1479 (64.6%), beta blocker in 1132 (49.5%), and mineralocorticoid receptor antagonist (MRA) in 864 (37.8%) patients at discharge. The use of ACEi/ARB at discharge has decreased over time (64.6% vs. 69.6%, p = 0.001) and the use of beta blockers has increased (49.5% vs. 36.8%, p < 0.001) compared to a historical cohort (2001-2010). There is considerable variability in medication use across centers with an overall increase in beta blocker and decrease in ACEi/ARB use over time. Collaborative efforts are needed to standardize care and define quality metrics to identify best practices in the management of pediatric heart failure.

Growth stunting in single ventricle patients after heart transplantation.

BACKGROUND: Malnutrition is common among children with single ventricle (SV) congenital heart disease (CHD). The impact of heart transplantation (HT) on nutritional status in SV patients is understudied. Our aim was to evaluate anthropometric changes in SV patients after HT, compared with those transplanted for cardiomyopathy (CM). METHODS: We performed a single-center retrospective chart review of SV and CM patients < 18 years who underwent HT from January 01, 2010 to December 05, 2017. Wasting and stunting were defined as z-scores for weight-for-age or height-for-age ≤-2, respectively. Changes in these indices between HT and 3 years post-HT were analyzed. RESULTS: Of 86 eligible patients, 28 (33%) had SV CHD and 58 (67%) had CM. Data were available at 3 years post-HT for 57 patients. At transplant, wasting was equally present in SV versus CM patients (7/28, 25% vs. 9/58, 16%, P = .22), which remained true at 3 years post-HT (2/16, 13% vs. 3/41, 7%, P = .61). At transplant, stunting was more common in SV than CM patients (17/28, 61% vs. 8/58, 14%, P < .001). At 3 years post-HT, 6 of 16 (38%) SV patients and 3 of 41 (7%) CM patients remained stunted (P = .01). Among all patients, wasting decreased from transplant to end-point (19% vs. 9%, P = .05), but stunting did not (29% vs. 16%, P = .2), such that wasting and stunting were associated at transplant (P < .001) but not at end-point (P = .17). CONCLUSIONS: Longitudinal growth remains impaired for several years after HT in SV patients, even when weight gain is achieved, suggesting that some factors contributing to growth impairment persist despite resolution of SV physiology.

Significant mortality, morbidity and resource utilization associated with advanced heart failure in congenital heart disease in children and young adults.

BACKGROUND: Children with congenital heart disease (CHD) are at risk for advanced heart failure (AHF). We sought to define the mortality and resource utilization in CHD-related AHF in children and young adults. METHODS: All hospitalizations in the Pediatric Health Information System database involving patients ≤21 years old with a CHD diagnosis and heart failure requiring at least 7 days of continuous inotropic support between 2004 and 2015 were included. Hospitalizations including CHD surgery were excluded. RESULTS: Of 465,482 CHD hospitalizations, AHF was present in 2,712 (0.6%) [58% infant, 55% male, 30% single ventricle]. AHF therapies frequently used included extracorporeal membrane oxygenation (ECMO) (15%) and cardiac transplant (16%). Ventricular assist device (VAD) support was rare (3%), although VAD use significantly increased from 2004 to 2015 (P < .0010). Hospital mortality in CHD with AHF was 26%, with higher mortality associated with single ventricle heart disease (OR 1.64, 95% CI 1.23-2.19; P = .0009), infancy (OR 1.71, 95% CI 1.17-2.5; P = .0057), non-white race (OR 1.28, 95% CI 1.04-1.59; p=0.0234), and chronic complex comorbidities (OR 1.76, 95% CI 1.34-2.30; P < .0001). Over the 11-year study period, despite the significant increase in CHD-related AHF hospitalizations (P < .0001), hospital mortality improved (P = .0011). Median hospital costs were $252,000, a 6-fold increase above those without AHF, and was primarily driven by hospital length of stay (P < .0001). CONCLUSION: AHF in children with CHD in uncommon but increasing and is associated with significant morbidity, mortality and resource utilization. Approximately 1 in 5 children do not survive to hospital discharge. Many risk factors for mortality may not be modifiable, and further study is needed to identify modifiable risk factors and improve care for this complex population.

Long-term surveillance biopsy: Is it necessary after pediatric heart transplant?

Due to limited and conflicting data in pediatric patients, long-term routine surveillance endomyocardial biopsy (RSB) in pediatric heart transplant (HT) remains controversial. We sought to characterize the rate of positive RSB and determine factors associated with RSB-detected rejection. Records of patients transplanted at a single institution from 1995 to 2015 with >2 year of post-HT biopsy data were reviewed for RSB-detected rejections occurring >2 year post-HT. We illustrated the trajectory of significant rejections (ISHLT Grade ≥3A/2R) among total RSB performed over time and used multivariable logistic regression to model the association between time and risk of rejection. We estimated Kaplan-Meier freedom from rejection rates by patient characteristics and used the log-rank test to assess differences in rejection probabilities. We identified the best-fitting Cox proportional hazards regression model. In 140 patients, 86% did not have any episodes of significant RSB-detected rejection >2 year post-HT. The overall empirical rate of RSB-detected rejection >2 year post-HT was 2.9/100 patient-years. The percentage of rejection among 815 RSB was 2.6% and remained stable over time. Years since transplant remained unassociated with rejection risk after adjusting for patient characteristics (OR = 0.98; 95% CI 0.78-1.23; P = 0.86). Older age at HT was the only factor that remained significantly associated with risk of RSB-detected rejection under multivariable Cox analysis (P = 0.008). Most pediatric patients did not have RSB-detected rejection beyond 2 years post-HT, and the majority of those who did were older at time of HT. Indiscriminate long-term RSB in pediatric heart transplant should be reconsidered given the low rate of detected rejection.

Impact of ventricular assist device implantation on the nutritional status of children awaiting heart transplantation.

BACKGROUND: Malnutrition is common in pediatric heart failure and is associated with mortality. The effect of VAD support on malnutrition in children is unknown. We sought to compare the prevalence and severity of malnutrition at HT in children on VAD support vs OMT to inform decisions regarding support strategies. METHODS: Retrospective chart review involving all patients <18 years who underwent HT at Stanford between 1/1/2011 and 3/1/2018. Malnutrition diagnosis and severity were defined by ASPEN guidelines using the lowest age-adjusted z-score for weight (WAZ), height (HAZ), and BMI (BMIZ) when the patient was euvolemic. Changes in z-scores from baseline to HT and across groups were analyzed. RESULTS: A total of 104 patients (52 in each group) were included. Among all patients, WAZ (-0.9 vs 0.3, P < 0.001) and BMIZ (0 vs 0.6, P < 0.001) improved while HAZ (-0.9 vs -0.9, P = 0.4) did not. Compared to children on OMT, children on VAD experienced greater increases in WAZ (0.8 vs 0.3, P < 0.001) and BMIZ (0.7 vs 0.2, P < 0.003) at HT. The prevalence of moderate-to-severe malnutrition decreased in VAD patients (40% to 19%, P < 0.001) and increased in OMT patients (37% to 46%, P < 0.001), leading to a lower prevalence of moderate-to-severe malnutrition at HT (19% vs 46%, P = 0.003). CONCLUSIONS: Malnutrition is common in pediatric HT candidates. Compared to children on OMT, children on VAD support had greater improvement in nutritional status while awaiting HT, and a lower prevalence of malnutrition at HT.

Compassionate deactivation of ventricular assist devices in children: A survey of pediatric ventricular assist device clinicians' perspectives and practices.

OBJECTIVES: This study's objective was to investigate compassionate ventricular assist device deactivation (VADdeact) in children from the perspective of the pediatric heart failure provider. BACKGROUND: Pediatric VAD use is a standard therapy for advanced heart failure. Serious adverse events may affect relative benefit of continued support, leading to consideration of VADdeact. Perspectives and practices regarding VADdeact have been studied in adults but not in children. METHODS: A web-based anonymous survey of clinicians for pediatric VAD patients (<18 years) was sent to list-serves for the ISHLT Pediatric Council, the International Consortium of Circulatory Assist Clinicians Pediatric Taskforce, and the Pediatric Cardiac Intensivist Society. RESULTS: A total of 106 respondents met inclusion criteria of caring for pediatric VAD patients. Annual VAD volume per clinician ranged from <4 (33%) to >9 (20%). Seventy percent of respondents had performed VADdeact of a child. Response varied to VADdeact requests by parent or patient and was influenced by professional degree and region of practice. Except for the scenario of intractable suffering, no consensus on VADdeact appropriateness was reported. Age of child thought capable of making informed requests for VADdeact varied by subspecialty. The majority of respondents (62%) do not feel fully informed of relevant legal issues; 84% reported that professional society supported guidelines for VADdeact in children had utility. CONCLUSION: There is limited consensus regarding indications for VADdeact in children reported by pediatric VAD provider survey respondents. Knowledge gaps related to legal issues are evident; therefore, professional guidelines and educational resources related to pediatric VADdeact are needed.

A Quality Bundle to Support High-Risk Pediatric Ventricular Assist Device Implantation.

Pediatric ventricular assist device (VAD) implantation outcomes are increasingly promising for children with dilated cardiomyopathy and advanced decompensated heart failure (ADHF). VAD placement in patients with clinical features such as complex congenital cardiac anatomy, small body size, or major comorbidities remains problematic. These comorbidities have been traditionally prohibitive for VAD consideration leaving these children as a treatment-orphaned population. Here we describe the quality bundle surrounding these patients with ADHF considered high risk for VAD implantation at our institution. Over a 7-year period, a quality bundle aimed at the peri-operative care for children with high-risk features undergoing VAD implantation was incrementally implemented at a tertiary children's hospital. Patients were considered high risk if they were neonates (< 30 days), had single-ventricle physiology, non-dilated cardiomyopathy, biventricular dysfunction, or significant comorbidities. The quality improvement bundle evolved to include (1) structured team-based peri-operative evaluation, (2) weekly VAD rounds addressing post-operative device performance, (3) standardized anticoagulation strategies, and (4) a multidisciplinary system for management challenges. These measures aimed to improve communication, standardize management, allow for ongoing process improvement, and incorporate principles of a high-reliability organization. Between January 2010 and December 2017, 98 patients underwent VAD implantation, 48 (49%) of which had high-risk comorbidities and a resultant cohort survival-to-transplant rate of 65%. We report on the evolution of a quality improvement program to expand the scope of VAD implantation to patients with high-risk clinical profiles. This quality bundle can serve as a template for future large-scale collaborations to improve outcomes in these treatment-orphaned subgroups.