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Stroke, thromboembolism, and bleeding are the most recognized complications associated with pediatric ventricular assist devices (VADs) and the leading cause of death and disability on VAD support. Recently, newer antithrombotic strategies like bivalirudin have emerged that appear to be associated with a reduction in the neurologic event rates, especially for smaller pediatric-specific VADs like the Berlin Heart and PediMag/CentriMag systems where the risk of stroke is the highest. While contemporary antithrombotic therapies have likely contributed to lowering adverse event rates, we speculate that clotting and bleeding adverse events may have dropped because of a variety of other seemingly small changes to antithrombotic management that are independent of the antithrombotic agents used. This view is supported by recent reports documenting low stroke rates with anticoagulants other than bivalirudin, a drug that may have a wider therapeutic window but is not available in all locations throughout the world. The primary purpose of this report is 1) to summarize contemporary antithrombotic regimens used for smaller pediatric VADs today associated with low event rates in the United States and abroad and () to review 10 practical lessons learned and pitfalls to avoid that we believe to be important to reducing bleeding and clotting events based on our collective experience managing pediatric VADs over the past 20 years irrespective of the antithrombotic agents used.

Research evaluating hemostatic agents for the treatment of clinically significant bleeding has been hampered by inconsistency and lack of standardized primary clinical trial outcomes. Clinical trials of hemostatic agents in both cardiac surgery and mechanical circulatory support, such as extracorporeal membrane oxygenation and ventricular assist devices, are examples of studies that lack implementation of universally accepted outcomes.A subgroup of experts convened by the National Heart, Lung, and Blood Institute and the US Department of Defense developed consensus recommendations for primary outcomes in cardiac surgery and mechanical circulatory support.For cardiac surgery the primary efficacy endpoint of total allogeneic blood products (units vs mL/kg for pediatric patients) administered intraoperatively and postoperatively through day 5 or hospital discharge is recommended. For mechanical circulatory support outside the perioperative period the recommended primary outcome for extracorporeal membrane oxygenation is a 5-point ordinal score of thrombosis and bleeding severity adapted from the Common Terminology Criteria for Adverse Events version 5.0. The recommended primary endpoint for ventricular assist device is freedom from disabling stroke (Common Terminology Criteria for Adverse Events AE ≥ grade 3) through day 180.The proposed composite risk scores could impact the design of upcoming clinical trials and enable comparability of future investigations. Harmonizing and disseminating global consensus definitions and management guidelines can also reduce patient heterogeneity that would confound standardized primary outcomes in future research.

Individuals with Fontan circulation are at risk of late mortality from both cardiac and noncardiac causes. Despite the known risk of mortality, referral indications for advanced heart failure care vary between centers, and many individuals die from Fontan circulation-related complications either after late consideration for advanced heart failure therapies or having never seen a heart failure specialist. There is a critical need for guidelines to direct appropriately timed referral for advanced heart failure consultation. The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Fontan Committee has developed recommended thresholds for advanced heart failure referral to guide primary cardiologists. These recommendations are divided into 4 categories of clinical Fontan circulatory dysfunction including (1) cardiac/systemic ventricular dysfunction, (2) Fontan pathway dysfunction, (3) lymphatic dysfunction, and (4) extracardiac dysfunction.

Children on ventricular assist device (VAD) support can present several unique challenges, including small patient size, univentricular or biventricular congenital heart disease (1V- or 2V-CHD) and need for biventricular VAD (BiVAD) support. While cardiac catheterization can provide valuable information, it is an invasive procedure with inherent risks. We sought to evaluate the safety of catheterization in pediatric patients on VAD support. We performed a retrospective review of patients on VAD support who underwent catheterization at Lucile Packard Children's Hospital between January 1, 2014 and September 1, 2019. Using definitions adapted from Pedimacs, adverse events (AEs) after catheterization were identified, including arrhythmia; major bleeding or acute kidney injury within 24 hours; respiratory failure persisting at 24 hours; and stroke, pericardial effusion, device malfunction, bacteremia or death within 7 days. AEs were categorized as related or unrelated to catheterization. Sixty procedures were performed on 39 patients. Underlying diagnoses were dilated cardiomyopathy (48%), 1V-CHD (35%), 2V-CHD (8%), and other (8%). Devices were implantable continuous flow (72%), paracorporeal pulsatile (18%) and paracorporeal continuous flow (10%). Catheterizations were performed on patients in the ICU (60%), on inotropic support (42%), with deteriorating clinical status (37%) and on BiVAD support (12%). There were 9 AEs possibly related to catheterization including 6 episodes of respiratory failure, 2 major bleeding events, and 1 procedural arrhythmia. AE occurrence was associated with ICU status ( P = 0.01), BiVAD support ( P = 0.04) and procedural indication to evaluate worsening clinical status ( P = 0.04). Despite high medical acuity, catheterization can be performed with an acceptable AE profile in children on VAD support.

High-quality evidence guiding optimal transfusion and other supportive therapies to reduce bleeding is needed to improve outcomes for patients with either severe bleeding or hemostatic disorders that are associated with poor outcomes. Alongside challenges in performing high-quality clinical trials in patient populations who are at risk of bleeding or who are actively bleeding, the interpretation of research evaluating hemostatic agents has been limited by inconsistency in the choice of primary trial outcomes. This lack of standardization of primary endpoints or outcomes decreases the ability of clinicians to assess the validity of endpoints and compare research results across studies, impairs meta-analytic efforts, and, ultimately, delays the translation of research results into clinical practice. To address this challenge, an international panel of experts was convened by the National Heart Lung and Blood Institute and the US Department of Defense on September 23 and 24, 2019, to develop expert opinion, consensus-based recommendations for primary clinical trial outcomes for pivotal trials in pediatric and adult patients with six categories in various clinical settings. This publication documents the conference proceedings from the workshop funded by the National Heart Lung and Blood Institute and the US Department of Defense that consolidated expert opinion regarding clinically meaningful outcomes across a wide range of disciplines to provide guidance for outcomes of future trials of hemostatic products and agents for patients with active bleeding.

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

Ventricular assist device (VAD) support for children with single ventricle (SV) heart disease remains challenging. We performed a single-center retrospective review of SV patients on VAD support and examined survival to transplant using the Kaplan-Meier method. Patients transplanted were compared with those who died on support. Between 2009 and 2017, there were 14 SV patients with 1,112 patient-days of VAD support. Stages of palliation included pre-Glenn (n = 5), Glenn (n = 5), and Fontan (n = 4). Eight patients (57%) were successfully bridged to transplant at a median 107 days. Deaths occurred early (n = 6, median 16 days) and in smaller patients (10.1 vs. 28.3 kg, P = 0.04). All Fontan patients survived to transplant, whereas only 20% of Glenn patients survived to transplant. Adverse events occurred in 79% (n = 11). Five patients met hospital discharge criteria, with two patients (one pre-Glenn, one Glenn) discharged and transplanted after 219 and 174 days of VAD support. All transplanted patients were discharged at a median 21 days posttransplant. SV patients in various stages of palliation can be successfully bridged to transplant with VAD support. With use of intracorporeal continuous-flow devices, longer-term support and hospital discharge are possible.

Objective To determine the association between continuous flow ventricular assist devices and the incidence of vasoplegia following orthotopic heart transplant in children. Moreover, to propose a novel clinical definition of vasoplegia for use in pediatric populations. Methods This is a single-center, retrospective cohort study set in the cardiovascular intensive care unit of a tertiary children's hospital. All patients aged 3 years and older who underwent orthotopic heart transplant at Stanford University between April 1, 2014, and July 31, 2017, were included. Vasoplegia was defined by the use of vasoconstrictive medication, diastolic hypotension, preserved systolic heart function, and absence of infection or right atrial pressure or central venous pressure Results Of 44 eligible patients, 21 were supported using a continuous flow ventricular assist device. Following heart transplant, 14 patients (32%) developed vasoplegia by the study definition. Development of vasoplegia was associated with pretransplant use of a continuous flow ventricular assist device (52% vs 13%) with a relative risk of 4.02 (95% confidence interval, 1.30-12.45; P = .009). No other variables were predictive of vasoplegia in univariable analysis. Presence of vasoplegia was not associated with adverse outcomes, although there were trends towards higher incidence of acute kidney injury and increased length of hospital stays. Conclusions Children receiving continuous flow ventricular assist device support are at increased risk for vasoplegia following orthotopic heart transplant, using a novel definition of vasoplegia. Anticipation of this complication will allow for prompt intervention, thereby minimizing hemodynamic instability and impact on patient outcomes.

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 (

BACKGROUND Routine surveillance biopsy (RSB) is performed to detect asymptomatic acute rejection (AR) after heart transplantation (HT). Variation in pediatric RSB across institutions is high. We examined center-based variation in RSB and its relationship to graft loss, AR, coronary artery vasculopathy (CAV), and cost of care during the first year post-HT. METHODS We linked the Pediatric Health Information System (PHIS) and Scientific Registry of Transplant Recipients (SRTR, 2002-2016), including all primary-HT aged 0-21 years. We characterized centers by RSB frequency (defined as median biopsies performed among recipients aged ≥12 months without rejection in the first year). We adjusted for potential confounders and center effects with mixed-effects regression analysis. RESULTS We analyzed 2867 patients at 29 centers. After adjusting for patient and center differences, increasing RSB frequency was associated with diagnosed AR (OR 1.15 p = 0.004), a trend toward treated AR (OR 1.09 p = 0.083), and higher hospital-based cost (US$390 315 vs. $313 248, p

AIM To describe the clinical and hemodynamic characteristics of Fontan failure in children listed for heart transplant. METHODS In a nested study of the Pediatric Heart Transplant Society, 16 centers contributed information on Fontan patients listed for heart transplant between 2005and 2013. Patients were classified into four mutually exclusive phenotypes: Fontan with abnormal lymphatics (FAL), Fontan with reduced systolic function (FRF), Fontan with preserved systolic function (FPF), and Fontan with "normal" hearts (FNH). Primary outcome was waitlist and post-transplant mortality. RESULTS 177 children listed for transplant were followed over a median 13 (IQR 4-31) months, 84 (47%) were FAL, 57 (32%) FRF, 22 (12%) FNH, and 14 (8%) FPF. Hemodynamic characteristics differed between the 4 groups: Fontan pressure (FP) was most elevated with FPF (median 22, IQR 18-23, mmHg) and lowest with FAL (16, 14-20, mmHg); cardiac index (CI) was lowest with FRF (2.8, 2.3-3.4, L/min/m2). In the entire cohort, 66% had FP >15 mmHg, 21% had FP >20 mmHg, and 10% had CI

Introduction: Gaps in insurance coverage have been associated with diminished access to health care for children with chronic illness. Continuity of coverage is associated with improved long-term clinical outcomes among adolescent heart transplant (HT) recipients, but the relationship between insurance status and post-transplant outcomes has not been described across all pediatric HT recipients. Hypothesis: HT recipients with changes in insurance status will have worse outcomes as opposed to those with continuous coverage. Methods: We queried the United Network for Organ Sharing (UNOS) registry for patients age 0-18 receiving isolated HT or heart re-transplant between 2006 and 2019 and included them in the analysis if they survived at least one year post-transplant. Patients were categorized by insurance coverage at wait listing, HT, and one year follow-up. Cox proportional hazards models were used to characterize the association between coverage pattern and long-term patient survival. Results: Among the 3,247 patients in the analysis, insurance coverage patterns included continuous private (37%), continuous public (46%), gain of private (6%), and loss of private (11%). Patients who had continuous public insurance were more likely to be Black or Hispanic, adolescent, and require ICU care. In a multivariate Cox model, continuous public insurance was associated with increased mortality risk (HR = 1.46, P = 0.014), while loss of private insurance trended towards increased risk (HR = 1.14, P = 0.014). Figure 1 illustrates Kaplan-Meier conditional survival curves according to insurance trajectory. Multivariate sub-group analysis by Black race demonstrated no differences in outcomes by coverage pattern. Conclusions: In comparison to those with continuous private insurance, having continuous public insurance is associated with higher risk of adverse outcomes in pediatric HT recipients, but it does not account for disparate outcomes in Black patients.

We present the successful perioperative management of an 11-year-old patient presenting for heart transplant with a left ventricular assist device, symptomatic acquired von Willebrand syndrome, and recent preoperative intracranial hemorrhage. A brief review of the pathophysiology of acquired von Willebrand syndrome is included. As the number of pediatric patients supported with ventricular assist devices continues to increase, the management of symptomatic acquired von Willebrand syndrome during the perioperative period is an important consideration for anesthesiologists.

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.

BACKGROUND Currently, there are no simple tools to evaluate the acute heart failure (HF) symptom severity in children hospitalized with acute decompensated HF (ADHF). We sought to develop an inpatient HF score (HFS) that could be used as a clinical tool and for clinical trials. METHODS Pediatric HF clinicians at Stanford reviewed the limitations of existing HFSs, which include lack of calibration to the inpatient setting, omission of gastrointestinal symptoms, need for multiple age-based tools, and scores that prioritize treatment intensity over patient symptoms. To address these, we developed an acute HFS corresponding to the 3 cardinal symptoms of HF: difficulty with breathing, feeding, and activity. The score was iteratively improved over a 3-year pilot phase until no further changes were made. The inter-rater reliability (IRR) across a range of providers was assessed using the final version. Peak HFSs were analyzed against mortality and length of stay (LOS) for all pediatric HF discharges between July and October 2019. RESULTS The final HFS was a 4-point ordinal severity score for each of the 3 symptom domains (total score 0-12). Among clinicians who scored 12 inpatients with ADHF simultaneously, the intraclass correlation (ICC) was 0.94 (respiratory ICC = 0.89, feeding ICC = 0.85, and activity ICC = 0.80). Score trajectory reflected our clinical impression of patient response to HF therapies across a range of HF syndromes including 1- and 2-ventricle heart disease and reduced or preserved ejection fraction. Among the 28 patients hospitalized during a 3-months period (N = 28), quartiles of peak score were associated with LOS (p < 0.01) and in-hospital mortality (p < 0.01): HFS 0 to 3 (median LOS of 5 days and mortality of 0%), HFS 4 to 6 (median LOS of 18 days and mortality of 0%), HFS 5 to 9 (median LOS of 29 days and mortality of 23%), and HFS 10 to 12 (median LOS of 121 days and mortality of 50%). CONCLUSION This simple acute HFS may be a useful tool to quantify and monitor day-to-day HF symptoms in children hospitalized with ADHF regardless of etiology or age group. The score has excellent IRR across provider levels and is associated with major hospital outcomes supporting its clinical validity. Validation in a multicenter cohort is warranted.

Improving the outcomes of pediatric patients with congenital heart disease with end-stage heart failure depends on the collaboration of all stakeholders; this includes providers, patients and families, and industry representatives. Because of the rarity of this condition and the heterogeneity of heart failure etiologies that occur at pediatric centers, learnings must be shared between institutions and all disciplines to move the field forward. To foster collaboration, excel discovery, and bring data to the bedside, a new, collaborative quality improvement science network-ACTION (Advanced Cardiac Therapies Improving Outcomes Network)-was developed to meet the needs of the field. Existing gaps in care and the methods of improvement that will be used are described, along with the mission and vision, utility of real-world data for regulatory purposes, and the organizational structure of ACTION is described.

Background - Cardiac resynchronization therapy (CRT) studies in pediatric and/or congenital heart disease (CHD) patients have shown an improvement in ejection fraction and heart failure symptoms. However, a survival benefit of CRT in this population has not been established. This study aimed to evaluate the impact of CRT upon heart transplant-free survival in pediatric and CHD patients, using a propensity score-matched analysis. Methods - This single-center study compared CRT patients (implant date 2004-2017) and controls, matched by 1:1 propensity-score matching (PSM) using 21 comprehensive baseline indices for risk stratification. CRT patients were Results - Of 133 patients who received CRT during the study period, 84 met all study inclusion criteria. 133 controls met all criteria at an outpatient encounter. Following PSM, 63 matched CRT-control pairs were identified with no significant difference between groups across all baseline indices. Heart transplant or death occurred in 12 (19%) PSM-CRT subjects and 37 (59%) PSM-controls with a median follow-up of 2.7 years (quartiles 0.8-6.1 years). CRT was associated with markedly reduced risk of heart transplant or death (hazard ratio 0.24 [95% CI 0.12-0.46], p Conclusions - In pediatric and CHD patients with symptomatic systolic heart failure and electrical dyssynchrony, CRT was associated with improved heart transplant-free survival.

Background Despite the routine use of hemodynamic assessment in pediatric heart transplant (HT) patients, expected intracardiac pressure measurements in patients free of significant complications are incompletely described. A better understanding of the range of intracardiac pressures in these HT patients is important for the clinical interpretation of these indices and consequent management of patients. Methods We conducted a retrospective chart review of pediatric HT recipients who had undergone HT between January 2010 and December 2015 at Lucile Packard Children's Hospital. We analyzed intracardiac pressures measured in the first 12 mo after HT. We excluded those with rejection, graft coronary artery disease, mechanical support, or hemodialysis. We used a longitudinal general additive model with bootstrapping technique to generate age and donor-recipient size-specific curves to characterize filling pressures through 1-y post-HT. Results Pressure measurements from the right atrium, pulmonary artery, and pulmonary capillary wedge pressure were obtained in 85 patients during a total of 829 catheterizations. All pressure measurements were elevated in the immediate post-HT period and decreased to a stable level by post-HT day 90. Pressure measurements were not affected by age group, donor-recipient size differences, or ischemic time. Conclusions Intracardiac pressures are elevated in the early post-HT period and decrease to levels typical of the native heart by 90 d. Age, donor-to-recipient size differences, and ischemic time do not contribute to differences in expected intracardiac pressures in the first year post-HT.

Background There is inadequate power to perform a valid clinical trial in pediatric heart transplantation (HT) using a conventional end-point, because the disease is rare and hard end-points, such as death or graft loss, are infrequent. We sought to develop and validate a surrogate end-point involving the cumulative burden of post-transplant complications to predict death/graft loss to power a randomized clinical trial of maintenance immunosuppression in pediatric HT. Methods Pediatric Heart Transplant Study (PHTS) data were used to identify all children who underwent an isolated orthotopic HT between 2005 and 2014 who survived to 6 months post-HT. A time-varying Cox model was used to develop and evaluate a surrogate end-point comprised of 6 major adverse transplant events (MATEs) (acute cellular rejection [ACR], antibody-mediated rejection [AMR], infection, cardiac allograft vasculopathy [CAV], post-transplant lymphoproliferative disease [PTLD] and chronic kidney disease [CKD]) occurring between 6 and 36 months, where individual events were defined according to international guidelines. Two thirds of the study cohort was used for score development, and one third of the cohort was used to test the score. Results Among 2,118 children, 6.4% underwent graft loss between 6 and 36 months post-HT, whereas 39% developed CKD, 34% ACR, 34% infection, 9% AMR, 4% CAV and 2% PTLD. The best predictive score involved a simple MATE score sum, yielding a concordance probability estimate (CPE) statistic of 0.74. Whereas the power to detect non-inferiority (NI), assuming the NI hazard ratio of 1.45 in graft survival was 10% (assuming 200 subjects and 6% graft loss rate), the power to detect NI assuming a 2-point non-inferiority margin was >85% using the MATE score. Conclusion The MATE score reflects the cumulative burden of MATEs and has acceptable prediction characteristics for death/graft loss post-HT. The MATE score may be useful as a surrogate end-point to power a clinical trial in pediatric HT.

In this study we sought to quantify hazards associated with various donor factors into a cumulative risk scoring system (the Pediatric Heart Donor Assessment Tool, or PH-DAT) to predict 1-year mortality after pediatric heart transplantation (PHT).PHT data with complete donor information (5,732) were randomly divided into a derivation cohort and a validation cohort (3:1). From the derivation cohort, donor-specific variables associated with 1-year mortality (exploratory p-value0.2) were incorporated into a multivariate logistic regression model. Scores were assigned to independent predictors (p0.05) based on relative odds ratios (ORs).The final model had an acceptable predictive value (c-statistic = 0.62). The significant 5 variables (ischemic time, stroke as the cause of death, donor-to-recipient height ratio, donor left ventricular ejection fraction, glomerular filtration rate) were used for the scoring system. The validation cohort demonstrated a strong correlation between the observed and expected rates of 1-year mortality (r = 0.87). The risk of 1-year mortality increases by 11% (OR 1.11 [1.08 to 1.14]; p0.001) in the derivation cohort and 9% (OR 1.09 [1.04 to 1.14]; p = 0.001) in the validation cohort with an increase of 1-point in score. Mortality risk increased 5 times from the lowest to the highest donor score in this cohort. Based on this model, a donor score range of 10 to 28 predicted 1-year recipient mortality of 11% to 31%.This novel pediatric-specific, donor risk scoring system appears capable of predicting post-transplant mortality. Although the PH-DAT may benefit organ allocation and assessment of recipient risk while controlling for donor risk, prospective validation of this model is warranted.

Purpose Routine surveillance biopsy (RSB) is performed to detect asymptomatic acute rejection (AR) after heart transplantation (HT). Variation in pediatric RSB across institutions is high. We examined center-based variation in RSB use and its relationship to graft loss, AR, coronary artery vasculopathy (CAV), and cost of care during the first year post-HT. Methods We linked the Pediatric Health Information System (PHIS) and Scientific Registry of Transplant Recipients (SRTR, 2002-2016), including all primary-HT aged 0-21. We scored institutional RSB strategy by the median number of first-year biopsies in recipients aged ≥12 months without rejection. Mixed effects regression analysis was used to adjust for potential confounders and center effects. Results Of 2,867 patients at 29 centers, we identified an inflection at the top-tertile of centers (834 patients at 10 centers with RSB-score≥4). Higher-RSB centers (i.e. those in the top-tertile) had more patients on pre-HT ventilator/ECMO (23% vs 18% p=0.04) and fewer with a positive crossmatch (13% vs 17% p=0.007). After adjusting for patient and center differences, higher RSB frequency was associated with diagnosed AR (OR 1.15 p=0.004), a trend toward treated AR (OR 1.09 p=0.083) and higher cost (US$450,708 vs 342,170, p Conclusion Higher RSB frequency is associated with increased diagnosis, but not treatment, of AR one-year post-HT. Graft survival and CAV appear unchanged at medium term follow-up. De-intensification at high-frequency institutions may be safe and reduce costs, but further study of differences in treated rejections are necessary.

Purpose Studies suggest that pediatric heart transplant (HT) waitlist mortality has declined. The impact of factors like refinements to the heart allocation system, patient selection, greater ABO incompatible (ABO-I) HT and VAD support are unknown. We examined the 20-year trend in waitlist mortality to identify factors associated with declining mortality and whether allocational inefficiencies persist. Methods All children Results Overall 11,374 patients met inclusion criteria (3,248 in Era 1; 5,378 in Era 2; 2,748 in Era 3). Waitlist mortality declined significantly across eras (21%, 17%, 13%, P Conclusion Pediatric HT waitlist mortality has declined significantly over the past 20 years. There is evidence to suggest that greater VAD use, revisions to organ allocation, refinements in patient selection and ABO-I transplant may all contribute. Organ allocation inefficiencies persist under the current allocation system suggesting opportunities for allocation improvement may still exist.

Purpose Establishing baseline metrics for pediatric acute heart failure (AHF) is critical for developing quality improvement (QI) metrics aimed at improving outcomes and resource utilization. Benchmark data from adult AHF demonstrate median length of stay (LOS) is 4 days and 30-day HF-related readmission (HFread) rate is 6%. Our pilot study aims to describe current pediatric AHF LOS and 30-day HFread. Methods A retrospective data analysis from 4 pediatric centers was performed from July 1, 2019 to June 30, 2020 among children hospitalized for AHF who survived hospitalization, including those who received were listed and underwent heart transplant and ventricular assist device implantation. Data collection included cardiac diagnosis, LOS, and 30-day HFread. Descriptive statistics were performed for analysis. Results A total of 120 patients with 179 AHF hospitalizations were analyzed from 4 pediatric HF centers. The median LOS was 13 days (IQR 4-40). Diagnoses with median LOS >13 days included dilated cardiomyopathy, restrictive cardiomyopathy, myocarditis, other congenital heart disease excluding failing Glenn and Fontan palliated CHD (Table). Thirty-day HFread was 20%. Diagnoses associated with 30-day HFread >20% included dilated cardiomyopathy, failing Fontan, and failing Glenn. Conclusion Based on this pilot study, children hospitalized with AHF have considerably longer hospital LOS and higher readmission rates compared to national benchmarks for adults hospitalized with AHF. Identifying risk factors for prolonged LOS and HFread can help direct future QI initiatives. Initial AHF QI projects should include clear communication of management goals during hospitalization and at discharge.

Background Patients listed for heart transplant after their 18 th birthday purportedly wait longer to receive a donor heart compared to patients listed before their 18 th birthday. It is unclear whether there is an actual difference in wait times and whether any difference in wait time is associated with lower likelihood of transplant and/or higher risk of mortality. Methods Organ procurement and transplant network data were used to identify all patients listed for heart transplant between 2006 and 2014 within a one year period before and after their 18 th birthday. The primary study endpoint was the waiting time to receive a donor heart. Secondary endpoints included the probability of transplant and waitlist mortality. Regression discontinuity analysis was used to analyze the effect of age on either side of the sharp cut-off value of age 18 years (6,574 days of life), when allocation of donor hearts transitions from the pediatric to adult allocation system. Results A total of 360 patients met the study inclusion criteria, including 207 (57.5%) listed during the 12-month period prior to the 18 th birthday under the pediatric allocation system, and 153 (42.5%) listed during the 12 months after the 18 th birthday under the adult allocation system. The pediatric cohort was more likely to be listed status 1A. Otherwise, the two groups shared similar baseline characteristics. Overall, patients listed after the 18 th birthday waited 8.5 months longer to receive a transplant than adolescents listed before the 18 th birthday (P=0.01), had a 47% lower probability of receiving a transplant (P=0.001) but no difference in waitlist mortality (P=0.37). Conclusion Patients listed for heart transplant shortly after their 18 th birthday have significantly longer wait-times compared to patients listed shortly before their 18 th birthday, a lower probability of transplant but no significant difference in waitlist mortality. For medically fragile adolescents at high risk of death, birth date may be one factor to be aware of in timing of heart transplant listing.

Management of mechanical circulatory support in children with congenital heart disease (CHD) is challenging due to physiologic variations and anatomic limitations to device placement. In this study we examine the use of Berlin Heart EXCOR in CHD patients.CHD patients were identified from the EXCOR Pediatric Study data set (2007 to 2010). Mortality and serious adverse events were compared between CHD and non-CHD cohorts, and predictors of poor outcomes in the CHD cohort were identified.CHD was present in 29% (n = 59, 18 with 1-ventricle physiology) of all EXCOR patients (N = 204). Successful bridge (transplant or wean) was less likely in CHD patients compared with non-CHD patients (48% vs 80%; p0.01). Among CHD patients, no neonates, 25% of infants (30 days to 1 year) and 65% of children (1 year) were successfully bridged. Pre-implant congenital heart surgery (CHS) and extracorporeal membrane oxygenation (ECMO) on the same admission occurred in 60% of children ≤1 year of age (83% of neonates, 50% of infants), with 8% survival. Regardless of age, patients who did not have CHS and ECMO had 61% survival. Smaller pump, pre-implant bilirubin1.2 mg/dl and renal dysfunction were independently associated with mortality.End-organ function at implant reliably predicts adverse outcomes and should be considered when making implant decisions. EXCOR use in neonates and infants with CHD should be approached cautiously. If patients have undergone pre-implant CHS and ECMO, EXCOR support may not provide any survival benefit. EXCOR support in non-infants with CHD is challenging but can be consistently successful with appropriate patient selection.

To describe the safety and efficacy of warfarin for patients with Kawasaki disease and giant coronary artery aneurysms (CAAs, ≥8 mm). Giant aneurysms are managed with combined anticoagulation and antiplatelet therapies, heightening risk of bleeding complications.We reviewed the time in therapeutic range; percentage of international normalization ratios (INRs) in range (%); bleeding events, clotting events; INRs ≥6; INRs ≥5 and6; and INRs1.5.In 9 patients (5 male), median age 14.4 years (range 7.1-22.8 years), INR testing was prescribed weekly to monthly and was done by home monitor (n = 5) or laboratory (n = 3) or combined (1). Median length of warfarin therapy was 7.2 years (2.3-13.3 years). Goal INR was 2.0-3.0 (n = 6) or 2.5-3.5 (n = 3), based on CAA size and history of CAA thrombosis. All patients were treated with aspirin; 1 was on dual antiplatelet therapy and warfarin. The median time in therapeutic range was 59% (37%-85%), and median percentage of INRs in range was 68% (52%-87%). INR6 occurred in 3 patients (4 events); INRs ≥5 6 in 7 patients (12 events); and INR1.5 in 5 patients (28 events). The incidence of major bleeding events and clinically relevant nonmajor bleeding events were each 4.3 per 100 patient-years (95% CI 0.9-12.6). New asymptomatic coronary thrombosis was detected by imaging in 2 patients.Bleeding and clotting complications are common in patients with Kawasaki disease on warfarin and aspirin, with INRs in range only two-thirds of the time. Future studies should evaluate the use of direct oral anticoagulants in children as an alternative to warfarin.

As survival with pediatric left ventricular assist devices (LVADs) has improved, decisions regarding the optimal support strategy may depend more on quality of life and functional status (FS) rather than mortality alone. Limited data are available regarding the FS of children supported with LVADs. We sought to compare the FS of children supported with LVADs vs vasoactive infusions to inform decision making around support strategies.Organ Procurement and Transplant Network data were used to identify all United States children aged between 1 and 21 years at heart transplant (HT) between 2006 and 2015 for dilated cardiomyopathy and supported with an LVAD or vasoactive infusions alone at HT. FS was measured using the 10-point Karnofsky and Lansky scale.Of 701 children who met the inclusion criteria, 430 (61%) were supported with vasoactive infusions, and 271 (39%) were supported with an LVAD at HT. Children in the LVAD group had higher median FS scores at HT than children in the vasoactive infusion group (6 vs 5, p0.001) but lower FS scores at listing (4 vs 6, p0.001). The effect persisted regardless of patient location at HT (home, hospital, intensive care) or device type. Discharge by HT occurred in 46% of children in the LVAD group compared with 26% of children in the vasoactive infusion cohort (p = 0.001). Stroke was reported at HT in 3% of children in the LVAD cohort and in 1% in the vasoactive infusion cohort (p = 0.04).Among children with dilated cardiomyopathy undergoing HT, children supported with LVADs at HT have higher FS than children supported with vasoactive infusions at HT, regardless of device type or hospitalization status. Children supported with LVADs at HT were more likely to be discharged from the hospital but had a higher prevalence of stroke at HT.

Mechanical circulatory support in the form of ventricular assist devices (VADs) in children has undergone rapid growth in the last decade. With expansion of device options available for larger children and adolescents, the field of outpatient VAD support has flourished, with many programs unprepared for the clinical, programmatic, and administrative responsibilities. From preimplantation VAD evaluation and patient education to postimplant VAD management, the VAD program, staffed with an interdisciplinary team, is essential to providing safe, effective, and sustainable care for a new technology in an exceedingly complex patient population. Herein, this paper describes the Boston Children's Hospital VAD experience over a decade and important lessons learned from developing a pediatric program focusing on a high-risk but low-volume population. We highlight the paramount role of the VAD coordinator, clinical infrastructure requirements, as well as innovation in care spanning inpatient and outpatient VAD supports at Boston Children's Hospital.

Objectives The objective was to review the use of Impella devices (Abiomed Inc, Danvers, MA) for temporary circulatory support in pediatric and adolescent patients (age ≤ 21 yrs). Background Options for minimally invasive circulatory support in children are limited, and published data are confined to case reports and small case series. Methods This was a retrospective, multicenter review of Impella implants in pediatric and adolescent patients from 2009-15, using standardized data collection and INTERMACS definitions. Results A total of 39 implants were performed in 38 patients from 16 centers. Median age and weight were 16 yrs (4–21 yrs) and 62 kg (15–134 kg). The primary indication for implant was cardiogenic shock in 28 patients (72%). Cardiac allograft rejection, myocarditis, or cardiomyopathy were the underlying diagnosis in 23 patients (59%); 11 patients had congenital heart disease. The median duration of support was 45 hr (1–1224 hr). Indications for explant included ventricular recovery in 16 patients, transition to another device in 12, death in 5, and transplant in 1. Survival was 85% at 7 days and 68% at 30 days. Major adverse events occurred in 8 patients: hemolysis in 3, bleeding in 2, stroke in 1 (unclear if related to Impella), sepsis in 1, and critical leg ischemia in 1. An increase in aortic regurgitation was noted in three patients, with no evidence of valve injury. Conclusion Temporary circulatory support with Impella devices is feasible in pediatric and adolescent patients, with acceptable risk profiles. More experience and follow up is needed to improve technical performance and patient selection. © 2017 Wiley Periodicals, Inc.

Background: There are limited data describing the functional status (FS) of children after heart transplant (HT). We sought to describe the FS of children surviving at least 1 year after HT, to evaluate the impact of HT on FS, and to identify factors associated with abnormal FS post-HT. Methods: Organ Procurement and Transplantation Network data were used to identify all US children Results: A total of 1633 children met study criteria. At the 1-year assessment, 64% were “fully active/no limitations” (FSS=10), 21% had “minor limitations with strenuous activity” (FSS=9); and 15% scored ≤8. In comparison with listing FS, FS at 1 year post-HT increased in 91% and declined/remained unchanged in 9%. A stepwise regression procedure selected the following variables for association with abnormal FS at 1 year post-HT: ≥18 years of age (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2–2.7), black race (OR, 1.5; 95% CI, 1.1–2.0), support with ≥inotropes at HT (OR, 1.7; 95% CI, 1.2–2.5), hospitalization status at HT (OR, 1.5; 95% CI, 1.0–2.19), chronic steroid use at HT (OR, 1.5; 95% CI, 1.0–2.2), and treatment for early rejection (OR, 2.0; 95% CI, 1.5–2.7). Conclusion: Among US children who survive at least 1 year after HT, FS is excellent for the majority of patients. HT is associated with substantial improvement in FS for most children. Early rejection, older age, black race, chronic steroid use, hemodynamic support at HT, and being hospitalized at HT are associated with abnormal FS post-HT.

Purpose Malnutrition in children is defined by international guidelines as the age-adjusted Z-score for weight or BMI. However, weights can be misleading in children with HF because of fluid retention leading to misclassification of malnutrition level. We sought to estimate the prevalence of sarcopenic malnutrition in pediatric HF patients by quantifying objectively muscle wasting (sarcopenia) relative to age-adjusted normative data for children. Methods All children listed for HT between 2012 and 2017 who underwent thoracic CT as part of transplant surgical planning were identified using a hospital database. The skeletal muscle index (SMI) was defined as the cross-sectional area of skeletal muscle at L3 index to patient, a known predictor of total muscle mass. Age adjusted Z-scores were calculated using normative data from the University of Michigan. Mild, moderate and severe were defined by cut-off Z-scores of -2 and -3, respectively. Results Among 28 children listed for HT, the median age was 10 (IQR 6, 13) years, the median weight was 26 (18, 40) kg, 39% were female, 82% had congenital heart disease. By ASPEN guidelines, the prevalence of mild, moderate and severe malnutrition was 14%, 29% and 25%. The median SMI was 39 cm2/m2 (Z-score, -1.7); the prevalence of sarcopenia by Z-score was 36%, 25% and 10% (figure) (P Conclusion Muscle wasting is common in children with advanced heart failure and can be profound. Conventional definitions for malnutrition in children may misclassify malnutrition severity in children with HF. Normative curves may be helpful for understanding the severity of muscle wasting in children with HF, and may help to guide nutritional replacement.

Purpose Currently there are no-FDA approved immunosuppressants specific to pediatric heart transplantation (HT). In recent years, everolimus (EVL) has emerged as an alternative to tacrolimus (TAC) as a primary immunosuppressant to prevent rejection that may also prevent kidney and coronary disease. However, the two regimens have never been evaluated systematically. Methods The TEAMMATE Trial (IND 127980) is designed to evaluate the safety and efficacy of EVL and low-dose (LD-TAC) compared to standard-therapy TAC and mycophenolate mofetil (MMF). The study design and rationale are reviewed in light of challenges inherent in rare disease research. Results The TEAMMATE trial is the first multicenter randomized clinical trial (RCT) in pediatric HT. The primary purpose is to evaluate the risk-benefit profile of the two regimens to prevent major adverse transplant events (MATE), and to support FDA approval of 1 or both regimens for pediatric HT. Children Conclusion The TEAMMATE trial is the first RCT in pediatric HT. It is anticipated that the study will provide important information about the safety and effectiveness of EVL and TAC and provide valuable lessons into the design and conduct of future trials in pediatric HT.

Purpose Pediatric ventricular assist device (VAD) therapy is a rapidly changing field where devices and applications are rapidly evolving. We sought to describe some of the most recent trends in pediatric VAD use and contemporary outcomes since UNOS began collecting VAD data on all listed patients regardless of whether they survived. Methods All children ≤21 years of age listed for isolated HT between Jan 2004 and 2019 and underwent VAD placement were identified using OPTN data. Descriptive statistics were used to characterize recent trends in VAD utilization. Waitlist survival in children with cardiomyopathy, CHD and single-ventricle heart disease were estimated using the Kaplan-Meier method. Results Overall, 2059 children met the study inclusion criteria of whom the median age was 11 (IQR 1, 17), median weight 38 (11,66) kg, 26% were black; 18.3 had congenital heart disease (CHD) including 5.1% with single-ventricle (SV) HD. Forty-nine percent were supported with a VAD at listing, 72% at transplant and 13% received a VAD but was not supported at listing or transplant. Overall, 64% received LVADs, 31% BIVADs, 2.5% RVADs 1.7% total artificial hearts (TAH). Implants of the Berlin Heart fell dipped sharply to 34 in 2015 after a peak of 63 but have rebounded since in the era of bivalirudin. As of 2018, the Heartware HVAD was the most commonly implanted VAD in children (N=61) followed by the Berlin Heart (N=48), CentriMag/PediMag (N=18) and Heartmate III (N=11). The fastest growing segment of VAD patients are single-ventricle patients (Figure). Conclusion The total number of pediatric VADs continues to grow at a brisk pace. The most recent era has seen growth of the Heartmate III and resurgence of the Berlin Heart EXCOR, after a brief decline in 2015. Single-ventricle and Heartmate III patients represent the fastest growing segment of the VAD population.

Purpose Ventricular assist device (VAD) support has drastically improved waitlist mortality for pediatric patients awaiting heart transplant (HT). However, VAD support for single ventricle (SV) patients remains challenging, particularly in smaller patients with non-Fontan physiology. Unfortunately, waitlist mortality and morbidity are also significant in this subset of SV patients, and the risks of VAD support should be examined in the context of waitlist risks. We examined clinical deterioration while on the waitlist for a subset of SV patients for whom VAD support remains challenging. Methods We performed a retrospective review of all single ventricle patients listed for HT at a single pediatric center from 2012-2018. Patients Results Thirty-three SV patients were included. Median weight was 7.6 kg (IQR 5.1, 11.5), 58% were s/p Glenn, 21% Norwood, 18% hybrid or banding, and 3% unrepaired. Over a median 89 day (43, 206) of waitlist time, 21 (64%) were transplanted, 8 (24%) died or were removed for deterioration, and 4 (12%) were alive waiting or removed for improvement. Of the 21 transplanted, 7 had escalation of support by time of HT, for an overall waitlist deterioration of 45% (n=15/33, Figure 1A). From listing to HT, inotrope use increased from 48% to 71%, intubation 19% to 24%, and VAD 5% to 19%. At time of HT, 43% were in ICU and 29% were NPO for feeding intolerance. Survival to HT was similar between patients on VAD versus not on VAD support (67% vs 78%, p-value = 0.65, Figure 1B). Conclusion Single ventricle infants are at high risk for death and clinical deterioration while waiting for HT. While VAD support remains challenging for this population, it can be a successful means of bridging to transplant.

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

Background Given poor outcomes, strategies to improve ventricular assist devices (VADs) for single-ventricle patients with bidirectional Glenn (BDG) palliation are needed. Methods This retrospective review describes an institutional experience with VAD support for patients with BDG from April 2011 to January 2019. Surgical strategies, complications, and causes of death are described. Survival to heart transplantation for various strategies are compared. Results A total of 7 patients with BDG (weights, 5.6 to 28.8 kg; ages, 7 months to 11 years) underwent VAD implantation. Three patients underwent implantation of Berlin Heart EXCOR devices (Berlin Heart, Inc, Spring, TX), 2 had HeartWare HVADs (Medtronic, Minneapolis, MN) implanted, and 2 patients underwent implantation of paracorporeal continuous flow devices. Four patients underwent ventricular inflow cannulation, and 3 underwent atrial inflow cannulation. At the time of VAD implantation, the BDG was left intact in 3 patients, taken down in 3 patients, and created de novo in 1 patient. Over a total of 420 VAD support days, 2 patients survived to heart transplantation, 1 patient with HeartWare ventricular cannulation and intact BDG (after 174 days) and another with Berlin Heart atrial cannulation and BDG take-down (after 72 days). There were 3 deaths within 2 weeks of VAD implantation (2 from respiratory failure, 1 from infection) and 2 deaths after 30 days as a result of strokes. Conclusions The surgical strategy and postoperative management of VAD with BDG are still evolving. Successful support can be achieved with (1) both pulsatile and continuous flow pumps, (2) atrial or ventricular cannulation, and (3) with or without BDG take-down. Surgical strategy should be determined by individual patient anatomy, physiology, and condition.

This study's objective was to investigate compassionate ventricular assist device deactivation (VADdeact) in children from the perspective of the pediatric heart failure provider.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.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.A total of 106 respondents met inclusion criteria of caring for pediatric VAD patients. Annual VAD volume per clinician ranged from4 (33%) to9 (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.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.

Purpose In June 2018, the US Food and Drug Administration approved Prograf granules for pediatric solid-organ heart transplant without a US trial. This was due to concerns over compounding errors associated with pharmacy preparation of Prograf suspension for children who cannot swallow capsules. We reviewed our early experience converting children from Prograf suspension to granules to ensure safe transition practices. Methods All children transitioned from Prograf suspension to Prograf granules at a single center in 2019 were identified using pharmacy records. The starting dose for the transition from compounded liquid to granules was determined by using a one to one dosing conversion. The steady dose of Prograf pre and post conversion were compared, as was the time to reach a therapeutic level. Patients with modified target goals (e.g. secondary to infection) before or after conversion were excluded. Results Between January and September 2019, a total of 12 children were converted from Prograf suspension to Prograf granules of whom 9 met the inclusion criteria. Of these, the median age was 6.25 (IQR 4, 8) years, the median weight was 17 (15, 21) kg; 56% were female and 67% had prior congenital heart disease. Prior to conversion, the mean daily dose was 0.106 (SD 0.07) mg/kg. Following conversion, the mean daily dose was 0.112 (SD 0.08) mg/kg, a 15% increase on average. On average, 3 levels were obtained before a goal target level was achieved at a mean of 34 days after conversion. Conclusion Children transitioned from Prograf suspension to granules often required a dosing change to achieve the same target level on Prograf granules. The number of dose increases outnumbered dose decreases. Increasing the frequency of monitoring tacrolimus levels after conversion may help to foreshorten the period of time outside the goal range.

Purpose Malnutrition is an important complication of heart failure (HF) and associated with significant mortality. The serum pre-albumin level is often performed to evaluate patient nutritional status in HF, however its association with clinical malnutrition severity has not be determined. We sought to evaluate the association between pre-albumin and malnutrition severity using contemporary definitions of malnutrition. Methods All children listed for heart transplant (HT) between 2014 and 2017 were identified using a hospital database at a single center. Clinical malnutrition severity was determined by a certified pediatric dietitian using the American Society of Parenteral and Enteral Nutrition (ASPEN) guidelines. The pre-albumin level drawn around the time of the nutritional assessment was recorded. ANOVA for K groups with the Bonferroni correction was used to compare groups. Results Among 73 children who met the inclusion criteria, the median age at nutrition evaluation was 7.8 (Q1-Q3 1.3-12.6) years, the median weight-for-age Z-score was -1.5 (-2.3, 0.1), 36% were female, and 68% had congenital heart disease. Overall, malnutrition status by ASPEN guidelines was mild (25%), moderate (30%), severe (21%), or normal or obese (24%). Among the 73 subjects, the mean pre-albumin level was 20 (SD 10) mg/dl including 50% classified as normal. By ANOVA, there was no association between pre-albumin and clinical nutrition severity in children with HF (Figure). Variation within individual patients was high. Conclusion Pre-albumin does not appear to be a meaningful marker of malnutrition status in children with advanced heart failure. Pre-albumin levels vary markedly across malnutrition groups and within individual patients at a constant nutrition status, variability which may reflect its tendency to rise and fall as an acute phase reactant. Alternative strategies for estimating nutritional status are warranted.

Purpose The match run is the automated mechanism by which UNOS prioritizes donor hearts to waitlist candidates for heart transplant (HT) based on medical urgency. We sought to determine how well match runs perform in sequencing patients according to their medical urgency after implementation of the 2016 pediatric heart allocation revisions. Methods OPTN data were used to identify all match runs between March 21, 2016 and June 9, 2020 for each pediatric donor heart offered through UNOS to US waitlist candidates. The rank-order of candidates on the match run was compared to the rank-order based on medical urgency alone defined as the probability of survival on the day of the match run using a risk prediction model developed and validated during the prior 6 years. Results Overall, 634 donors generated 2,524 unique match runs during the study period when a total of 2,608 candidates were listed for pediatric HT. The median age of donors was 5 years (Q1, Q3, 1, 13), median weight 21 (11, 54) kg with the most common cause of death natural causes (26%), non-motor vehicle accidents (MVA) (22%) and MVA (16%). The risk-prediction model for death or deterioration included 8 variables (age, weight, cardiac diagnosis and cardiac support). When the survival model was applied to the match run candidates within zone, 26% of candidates were ranked out of survival order (i.e. had a rank-reversal) (Table). Of these, 69% of rank-reversals involved candidates within the same UNOS status levels whereas 41% involved candidates spread across UNOS status levels. Conclusion There is evidence to suggest that the 2016 revision to the pediatric donor heart allocation system fails to sequence waitlisted candidates according to medical urgency, which affects a substantial fraction of match runs. Misclassification of patient risk by UNOS status level and within UNOS status levels each contribute rank-reversals. Rank-ordering patients based on a continuous survival probability model could address both problems.

Purpose Several centers have considered the potential benefits of atrial inflow cannulation to provide mechanical circulatory support (MCS) among pediatric patients with small or restrictive ventricles particularly in those with potential for myocardial recovery. Limited pediatric data are available on contemporary outcomes of atrial cannulation. We sought to describe the characteristics, complications, and outcomes of children supported with atrial cannulation using the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) ventricular assist device (VAD) database. Methods Data were collected from the ACTION VAD database for all patients who underwent VAD implantation via atrial cannulation from 8/16/2012 to 9/8/2020. Patient characteristics, VAD types, complications, and outcomes were analyzed. Results Forty-one patients met the study criteria with 52 implants. Median age was 3.6 years (range 0.02 - 25.32), weight 13.6 kg (2.7-106), and BSA 0.6 (0.15 - 2.2). Diagnoses included dilated cardiomyopathy (42%), congenital heart disease (37%), transplant graft dysfunction (7%), restrictive and hypertrophic cardiomyopathies (5% each). VAD indications were bridge to decision (42%), bridge to transplant (42%), and bridge to recovery (17%). Eighty-four percent of patients were INTERMACS 1 or 2, 44% were on ECMO, and 63% were mechanically ventilated. Devices utilized included Berlin Heart Excor (40%), paracorporeal continuous flow devices (38%), Heartware (19%) and one Heartmate 3. Median support duration was 43.5 days (range 0-307). Overall mortality was 22%. Twenty patients (49%) were successfully transplanted, 7 (17%) recovered, and 5 (12%) are still alive on the device. Adverse events included major bleeding (24%), stroke (12%), sepsis (10%), right heart failure requiring RVAD (5%), and one instance of pump thrombosis. Conclusion Atrial cannulation in pediatric MCS can be performed across a variety of anatomic substrates and age ranges with outcomes and complication rates that are comparable to left ventricular cannulation strategies. This method may be advantageous in certain circumstances including patients with small or restrictive ventricles, potential for myocardial recovery, or multiple prior sternotomies to minimize surgical dissection. Further studies are needed to delineate the ideal patient population and benefits of varying atrial cannulation techniques.