The effect of socioeconomic status on pediatric heart transplant outcomes at a single institution between 2013 and 2022.

BACKGROUND: Disparities in pediatric heart transplant outcomes based on socioeconomic status (SES) have been previously observed. However, there is a need to reevaluate these associations in contemporary settings with advancements in transplant therapies and increased awareness of health disparities. This retrospective study aims to investigate the relationship between SES and outcomes for pediatric heart transplant patients. METHODS: Data were collected through a chart review of 176 pediatric patients who underwent first orthotopic heart transplantation (OHT) at a single center from 2013 to 2021. The Area Deprivation Index (ADI), a composite score based on U.S. census data, was used to quantify SES. Cox proportional hazards models and generalized linear models were employed to analyze the association between SES and graft failure, rejection rates, and hospitalization rates. RESULTS: The analysis revealed no statistically significant differences in graft failure rates, rejection rates, or hospitalization rates between low-SES and high-SES pediatric heart transplant patients for our single-center study. CONCLUSION: There may be patient education, policies, and social resources that can help mitigate SES-based healthcare disparities. Additional multi-center research is needed to identify post-transplant care that promotes patient equity.

Reducing donor acceptance practice variation - Learnings from a discussion forum.

PURPOSE: Although waitlist mortality is unacceptably high, nearly half of donor heart offers are rejected by pediatric heart transplant centers. The Advanced Cardiac Therapy Improving Outcome Network (ACTION) and Pediatric Heart Transplant Society (PHTS) convened a multi-institutional donor decision discussion forum (DDDF) aimed at assessing donor acceptance practices and reducing practice variation. METHODS: A 1-h-long virtual DDDF for providers across North America, the United Kingdom, and Brazil was held monthly. Each session typically included two case presentations posing a real-world donor decision challenge. Attendees were polled before the presenting center's decision was revealed. Group discussion followed, including a review of relevant literature and PHTS data. Metrics of participation, participant agreement with presenting center decisions, and impact on future decision-making were collected and analyzed. RESULTS: Over 2 years, 41 cases were discussed. Approximately 50 clinicians attended each call. Risk factors influencing decision-making included donor quality (10), size discrepancy (8), and COVID-19 (8). Donor characteristics influenced 63% of decisions, recipient factors 35%. Participants agreed with the decision made by the presenting center only 49% of the time. Post-presentation discussion resulted in 25% of participants changing their original decision. Survey conducted reported that 50% respondents changed their donor acceptance practices. CONCLUSION: DDDF identified significant variation in pediatric donor decision-making among centers. DDDF may be an effective format to reduce practice variation, provide education to decision-makers, and ultimately increase donor utilization.

Survival does not differ by annual center transplant volume-A Pediatric Heart Transplant Society Registry study.

BACKGROUND: There are conflicting data regarding the relationship between center volume and outcomes in pediatric heart transplantation. Previous studies have not fully accounted for differences in case mix, particularly in high-risk congenital heart disease (CHD) groups. We aimed to evaluate the relationship between center volume and outcomes using the Pediatric Heart Transplant Society (PHTS) Registry and explore how case mix may affect outcomes. METHODS: A retrospective cohort study of all pediatric patients in the PHTS Registry who received a heart transplant from 2009 to 2018 was performed. Centers were divided into 5 groups based on average yearly transplant volume. The primary outcome was time to death or graft loss and outcomes were compared using Kaplan-Meier analysis. RESULTS: There were 4583 cases among 55 centers included. There was no difference in time to death or graft loss by center volume in the entire cohort (p = .75), in patients with CHD (p = .79) or in patients with cardiomyopathy (p = .23). There was also no difference in time to death or graft loss by center size in patients undergoing transplant after Norwood, Glenn or Fontan (log rank p = .17, p = .31, and p = .10 respectively). There was a statistically significant difference in outcomes by center size in the positive crossmatch group (p < .0001), though no discernible pattern related to high or low center volume. CONCLUSIONS: Outcomes are similar among transplant centers of all sizes, including for high-risk patient groups with CHD. Future work is needed to understand how patient-specific risk factors may vary among centers of various sizes and whether this influences patient outcomes.

An integrated program to expand donor utilization in pediatric heart transplantation: Case report of successful transplant with multiple donor risk factors.

BACKGROUND: Pediatric heart transplantation (HT) continues to be limited by the shortage of donor organs, distance constraints, and the number of potential donor offers that are declined due to the presence of multiple risk factors. METHODS: We report a case of successful pediatric HT in which multiple risk factors were mitigated through a combination of innovative donor utilization improvement strategies. RESULTS: An 11-year-old, 25-kilogram child with cardiomyopathy and pulmonary hypertension, on chronic milrinone therapy and anticoagulated with apixaban, was transplanted with a heart from a Hepatitis C virus positive donor and an increased donor-to-recipient weight ratio. Due to extended geographic distance, an extracorporeal heart preservation system (TransMedics™ OCS Heart) was used for procurement. No significant bleeding was observed post-operatively, and she was discharged by post-operative day 15 with normal biventricular systolic function. Post-transplant Hepatitis C virus seroconversion was successfully treated. CONCLUSIONS: Heart transplantation in donors with multiple risk factor can be achieved with an integrative team approach and should be taken into consideration when evaluating marginal donors in order to expand the current limited donor pool in pediatric patients.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients.

BACKGROUND: Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown. METHODS: We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support. RESULTS: We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD. CONCLUSIONS: In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Trajectories in Intensity of Medical Interventions at the End of Life: Clustering Analysis in a Pediatric, Single-Center Retrospective Cohort, 2013-2021.

OBJECTIVE: Pediatric deaths often occur within hospitals and involve balancing aggressive treatment with minimization of suffering. This study first investigated associations between clinical/demographic features and the level of intensity of various therapies these patients undergo at the end of life (EOL). Second, the work used these data to develop a new, broader spectrum for classifying pediatric EOL trajectories. DESIGN: Retrospective, single-center study, 2013-2021. SETTING: Four hundred sixty-one bed tertiary, stand-alone children's hospital with 112 ICU beds. PATIENTS: Patients of age 0-26 years old at the time of death. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 1111 included patients, 85.7% died in-hospital. Patients who died outside the hospital were older. Among the 952 in-hospital deaths, most occurred in ICUs (89.5%). Clustering analysis was used to distinguish EOL trajectories based on the presence of intensive therapies and/or an active resuscitation attempt at the EOL. We identified five simplified categories: 1) death during active resuscitation, 2) controlled withdrawal of life-sustaining technology, 3) natural progression to death despite maximal therapy, 4) discontinuation of nonsustaining therapies, and 5) withholding/noninitiation of future therapies. Patients with recent surgical procedures, a history of organ transplantation, or admission to the Cardiovascular ICU had more intense therapies at EOL than those who received palliative care consultations, had known genetic conditions, or were of older age. CONCLUSIONS: In this retrospective study of pediatric EOL trajectories based on the intensity of technology and/or resuscitation discontinued at the EOL, we have identified associations between these trajectories and patient characteristics. Further research is needed to investigate the impact of these trajectories on families, patients, and healthcare providers.

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.

A novel acute kidney injury scoring system for renal and clinical outcomes in pediatric heart transplant patients.

BACKGROUND: The development of acute kidney injury (AKI) has been associated with worse outcomes in children after heart transplantation. Our study compares the application of a cumulative six-point Kidney Diseases Improving Global Outcomes (KDIGO) AKI scoring system, utilizing both creatinine and urine output criteria that we term as the AKI-6 criteria, to traditional AKI staging as a predictor for clinical and renal outcomes in the pediatric heart transplant recipients. METHODS: We conducted a retrospective single-center chart review on 155 pediatric patients who underwent heart transplantation from May 2014 to December 2021. The primary independent variable was the presence of severe AKI. Severe AKI by KDIGO was defined as Stage ≥2, whereas severe AKI by AKI-6 was defined as cumulative scores ≥4 or Stage 3 AKI based on either KDIGO criterion alone. Primary outcomes included actuarial survival and renal dysfunction by 1-year post-transplant, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 . RESULTS: In total, 140 (90%) patients developed AKI; 98 (63%) patients developed severe AKI by KDIGO, and 60 (39%) by AKI-6. Severe AKI by AKI-6 was associated with worse actuarial survival following heart transplantation compared with KDIGO (p = 0.01). Of the 143 patients with 1-year creatinine data, 6 (11%) patients out of 54 with severe AKI by AKI-6 had evidence of renal dysfunction (p = 0.01), compared with 6 (7%) patients out of 88 by KDIGO (p = 0.3). CONCLUSIONS: AKI-6 scoring provides greater prognostic utility for actuarial survival and renal dysfunction by 1-year post-heart transplantation in pediatric patients than traditional KDIGO staging.

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.

International practice heterogeneity in pre-transplant management of pulmonary hypertension related to pediatric left heart disease.

BACKGROUND: Elevated pulmonary vascular resistance (PVR) in the setting of left heart failure may contribute to poor outcomes after pediatric heart transplant (HTx), but peri-transplant management is variable. METHODS: We sought to characterize international practice by surveying physicians at pediatric HTx centers. RESULTS: We received 49 complete responses from 39 centers in 16 countries. Most respondents are pediatric cardiologists (90%), practice at centers offering heart (86%) and lung (55%) transplant, and perform pre-HTx acute vasoreactivity testing (AVT, 88%) in patients with elevated PVR. Half (51%) reported defining a PVR cutoff for HTx eligibility as ≤6 WU m2 (56%) post-AVT (84%). The highest post-AVT PVR ever accepted for HTx ranged from 3-14.4 (median 6) WU m2 . To treat elevated pre-transplant PVR, phosphodiesterase type 5 inhibitors are most common (65%) followed by oxygen (31%), nitric oxide (14%), endothelin receptor antagonists (11%), and prostacyclins (6%). Nearly a third (31%) do not routinely use pulmonary vasodilators without implantation of a left ventricular assist device (LVAD). Case scenarios highlight treatment variability: in a restrictive cardiomyopathy scenario, HTx listing with post-transplant vasodilator therapy was favored, whereas in a Shone's complex patient with fixed PVR, LVAD ± pulmonary vasodilators followed by repeat catheterization was most common. Management of dilated cardiomyopathy with reactive PVR was variable. Most continue vasodilator therapy until HTx (16%), PVR normalizes (16%) or ≤6 months. CONCLUSIONS: Management of elevated PVR in children awaiting HTx is heterogenous. Evidence-based guidelines are needed to allow for longitudinal determination of optimal outcomes and standardized care.

Increased risk of infections in pediatric Fontan patients after heart transplantation.

BACKGROUND: Infectious complications are a major cause of morbidity and mortality after HT. Fontan patients may be more susceptible to post-HT infections. METHODS: This was a single-center, retrospective cohort analysis of pediatric patients undergoing HT for FF physiology or DCM, who underwent induction with ATG. The primary endpoint was an infection in the first 180 days post-HT, defined as positive (1) blood/urine/respiratory culture; (2) viral PCR; (3) skin or wound infection; and/or (4) culture-negative infection if ≥5 days of antibiotics were completed. Secondary endpoints included (1) cell counts after ATG; (2) PTLD; and (3) rejection (≥Grade 2R ACR or pAMR2) in the first 180 days post-HT. RESULTS: A total of 59 patients (26 FF, 33 DCM) underwent HT at 14.7 (IQR 10.6, 19.5) and 11.7 (IQR 1.4, 13.6) years of age, respectively. The median total ATG received was 7.4 (IQR 4.9, 7.7) vs 7.5 (IQR 7.3, 7.6) mg/kg (p = NS) for FF and DCM patients, respectively. Twenty-three patients (39%) developed an infection 180 days post-HT, with a higher rate of infection in FF patients (54% vs 27%, p = .03). Adjusted for pre-transplant absolute lymphocyte count, FF patients had a higher risk of infection at 30 days post-HT (OR 7.62, 95% CI 1.13-51.48, p = .04). There was no difference in the incidence of PTLD (12% vs 0%; p = .08) or rejection (12% vs 21%; p = .49). CONCLUSION: Compared to DCM patients, FF patients have a higher risk of infection. Modifications to induction therapy for FF patients should be considered.

End-of-Life in Pediatric Patients Supported by Ventricular Assist Devices: A Network Database Cohort Study.

OBJECTIVES: Most pediatric patients on ventricular assist device (VAD) survive to transplantation. Approximately 15% will die on VAD support, and the circumstances at the end-of-life are not well understood. We, therefore, sought to characterize patient location and invasive interventions used at the time of death. DESIGN: Retrospective database study of a cohort meeting inclusion criteria. SETTING: Thirty-six centers participating in the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Registry. PATIENTS: Children who died on VAD therapy in the period March 2012 to September 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 117 of 721 patients (16%) who died on VAD, the median (interquartile range) age was 5 years (1-16 yr) at 43 days (17-91 d) postimplant. Initial goals of therapy were bridge to consideration for candidacy for transplantation in 60 of 117 (51%), bridge to transplantation in 44 of 117 (38%), bridge to recovery 11 of 117 (9%), or destination therapy (i.e., VAD as the endpoint) in two of 117 (2%). The most common cause of death was multiple organ failure in 35 of 117 (30%), followed by infection in 12 of 117 (10%). Eighty-five of 92 (92%) died with a functioning device in place. Most patients were receiving invasive interventions (mechanical ventilation, vasoactive infusions, etc.) at the end of life. Twelve patients (10%) died at home. CONCLUSIONS: One-in-six pediatric VAD patients die while receiving device support, with death occurring soon after implant and usually from noncardiac causes. Aggressive interventions are common at the end-of-life. The ACTION Registry data should inform future practices to promote informed patient/family and clinician decision-making to hopefully reduce suffering at the end-of-life.

Risk factors and outcomes of sudden cardiac arrest in pediatric heart transplant recipients.

BACKGROUND: Sudden cardiac arrest (SCA) is a prevailing cause of mortality after pediatric heart transplant (HT) but remains understudied. We analyzed the incidence, outcomes, and risk factors for SCA at our center. METHODS: Retrospective review of all pediatric HT patients at our center from January 1, 2009 to January 1, 2021. SCA was defined as an abrupt loss of cardiac function requiring cardiopulmonary resuscitation and/or mechanical circulatory support (MCS). Events that occurred in the setting of limited resuscitative wishes, or while on MCS were excluded. Patient characteristics and risk factors were analyzed. RESULTS: Fourteen of 254 (6%) experienced SCA at a median of 3 (1, 4) years post-HT. Seven (50%) events occurred out-of-hospital. Eleven (79%) died from their initial event, 2 (18%) after failure to separate from extracorporeal membrane (ECMO). In univariate analysis, black race, younger donor age, prior acute cellular rejection (ACR) episode, pacemaker and/or ICD in place, and pre-mortem diagnosis of allograft vasculopathy were associated with SCA (P = .003-0.02). In multivariable analysis, history of ACR, younger donor age, and black race retained significance. [OR = 6.3, 95% CI: 1.6-25.4, P = .01], [OR = 0.9, 95% CI: 0.8-1, P = .04], and [OR = 7.3, 95% CI: 1.1-49.9, P = .04], respectively. SCA occurred in 3 patients with a functioning ICD or pacemaker, which failed to restore a perfusing rhythm. CONCLUSIONS: SCA occurs relatively early after pediatric HT and is usually fatal. Half of events happen at home. Those who received younger donors, have a history of ACR, or are of black race are at increased risk. ICDs/pacemakers may offer limited protection.

Circumstances surrounding end-of-life in pediatric patients pre- and post-heart transplant: a report from the Pediatric Heart Transplant Society.

BACKGROUND: Although mortality has decreased considerably in pediatric heart transplantation, waitlist and post-transplant death rates remain notable. End-of-life focused research in this population, however, is very limited. This Pediatric Heart Transplant Society study aimed to describe the circumstances surrounding death of pediatric heart transplant patients. METHODS: A retrospective analysis of the multi-institutional, international, Pediatric Heart Transplant Society registry was conducted. Descriptive statistics and univariate analyses were performed to 1) describe end-of-life in pediatric pre- and post-heart transplant patients and 2) examine associations between location of death and technological interventions at end-of-life with demographic and disease factors. RESULTS: Of 9217 patients (0-18 years) enrolled in the registry between 1993 and 2018, 2804 (30%) deaths occurred; 1310 while awaiting heart transplant and 1494 post-heart transplant. The majority of waitlist deaths (89%) occurred in the hospital, primarily in ICU (74%) with most receiving mechanical ventilation (77%). Fewer post-transplant deaths occurred in the hospital (22%). Out-of-hospital death was associated with older patient age (p < .01). CONCLUSIONS: ICU deaths with high use of technological interventions at end-of-life were common, particularly in patients awaiting heart transplant. In this high mortality population, findings raise challenging considerations for clinicians, families, and policy makers on how to balance quality of life amidst high risk for hospital-based death.

Fatal nocardiosis infection in a pediatric patient with an immunodeficiency after heart re-transplantation.

BACKGROUND: Nocardia infections are rare opportunistic infections in SOT recipients, with few reported pediatric cases. Pediatric patients with single ventricle congenital heart defects requiring HT may be more susceptible to opportunistic infections due to a decreased T-cell repertoire from early thymectomy and potential immunodeficiencies related to their congenital heart disease. Other risk factors in SOT recipients include the use of immunosuppressive medications and the development of persistent lymphopenia, delayed count recovery and/or lymphocyte dysfunction. METHODS: We report the case of a patient with hypoplastic left heart syndrome who underwent neonatal congenital heart surgery (with thymectomy) prior to palliative surgery and 2 HTs. RESULTS: After developing respiratory and neurological symptoms, the patient was found to be positive for Nocardia farcinica by BAL culture and cerebrospinal fluid PCR. Immune cell phenotyping demonstrated an attenuated T and B-cell repertoire. Despite antibiotic and immunoglobulin therapy, his symptoms worsened and he was subsequently discharged with hospice care. CONCLUSION: Pediatric patients with a history of congenital heart defects who undergo neonatal thymectomy prior to heart transplantation and a long-term history of immunosuppression should undergo routine immune system profiling to evaluate for T- and B-cell deficiency as risk factors for opportunistic infection. Such patients could benefit from long-term therapy with TMP/SMX for optimal antimicrobial prophylaxis, with desensitization as needed for allergies. Disseminated nocardiosis should be considered when evaluating acutely ill SOT recipients, especially those with persistent lymphopenia and known or suspected secondary immunodeficiencies.

Impact of a clinical pathway on acute kidney injury in patients undergoing heart transplant.

BACKGROUND: To evaluate the impact of a clinical pathway on the incidence and severity of acute kidney injury in patients undergoing heart transplant. METHODS: This was a 2.5-year retrospective evaluation using 3 years of historical controls within a cardiac intensive care unit in an academic children's hospital. Patients undergoing heart transplant between May 27, 2014, and April 5, 2017 (pre-pathway) and May 1, 2017, and November 30, 2019 (pathway) were included. The clinical pathway focused on supporting renal perfusion through hemodynamic management, avoiding or delaying nephrotoxic medications, and providing pharmacoprophylaxis against AKI. RESULTS: There were 57 consecutive patients included. There was an unadjusted 20% reduction in incidence of any acute kidney injury (p = .05) and a 17% reduction in Stage 2/3 acute kidney injury (p = .09). In multivariable adjusted analysis, avoidance of Stage 2/3 acute kidney injury was independently associated with the clinical pathway era (AOR -1.3 [95% CI -2.5 to -0.2]; p = .03), achieving a central venous pressure of or less than 12 mmHg (AOR -1.3 [95% CI -2.4 to -0.2]; p = .03) and mean arterial pressure above 60 mmHg (AOR -1.6 [95% CI -3.1 to -0.01]; p = .05) in the first 48 h post-transplant, and older age at transplant (AOR - 0.2 [95% CI -0.2 to -0.06]; p = .002). CONCLUSIONS: This report describes a renal protection clinical pathway associated with a reduction in perioperative acute kidney injury in patients undergoing heart transplant and highlights the importance of normalizing perioperative central venous pressure and mean arterial blood pressure to support optimal renal perfusion.

Bereaved Caregiver Perspectives on the End of Life in Pediatric Patients With Ventricular Assist Devices.

OBJECTIVES: Ventricular assist devices (VADs) are increasingly used in pediatric heart failure as bridges to heart transplantation, although 25% will die with VADs. Family experiences in this population are not well-described. The objective is to understand bereaved families' perspectives on VAD and end-of-life decision-making. DESIGN: Semistructured interviews with bereaved caregivers of pediatric VAD patients. SETTING: Tertiary children's hospital. PATIENTS: Families of six pediatric VAD patients who died from 2014 to 2020. INTERVENTIONS: Not available. MEASUREMENTS AND MAIN RESULTS: Applying a grounded theory framework, interviews were coded by two independent readers using qualitative software. Themes were discussed in iterative multidisciplinary meetings. Participants were interviewed at a median 2.4 years after their child died. Three major themes emerged: 1) "lack of regret" for VAD implantation despite the outcome; 2) "caregiver-child accord" (via patient's verbal assent or physical cues) at implantation and end-of-life was important in family decision-making; and 3) development of a "local surrogate family" (medical team and peer families) provided powerful support. CONCLUSIONS: Bereaved families' perspectives provide insight into quality decision-making for major interventions and end-of-life care in pediatric patients with chronic illness who face decisions regarding technology dependence.

Comprehensive Genetic Testing for Pediatric Hypertrophic Cardiomyopathy Reveals Clinical Management Opportunities and Syndromic Conditions.

Hypertrophic cardiomyopathy (HCM) has historically been diagnosed phenotypically. Through genetic testing, identification of a molecular diagnosis (MolDx) is increasingly common but the impact on pediatric patients is unknown. This was a retrospective study of next-generation sequencing data for 602 pediatric patients with a clinician-reported history of HCM. Diagnostic yield was stratified by gene and self-reported race/ethnicity. A MolDx of HCM was identified in 242 (40%) individuals. Sarcomeric genes were the highest yielding, but pathogenic and/or likely pathogenic (P/LP) variants in syndromic genes were found in 36% of individuals with a MolDx, often in patients without documented clinical suspicion for a genetic syndrome. Among all MolDx, 73% were in genes with established clinical management recommendations and 2.9% were in genes that conferred eligibility for clinical trial enrollment. Black patients were the least likely to receive a MolDx. In the current era, genetic testing can impact management of HCM, beyond diagnostics or prognostics, through disease-specific guidelines or clinical trial eligibility. Genetic testing frequently can help identify syndromes in patients for whom syndromes may not be suspected. These findings highlight the importance of pursuing broad genetic testing, independent of suspicion based on phenotype. Lower rates of MolDx in Black patients may contribute to health inequities. Further research is needed evaluating the genetics of HCM in underrepresented/underserved populations. Additionally, research related to the impact of genetic testing on clinical management of other diseases is warranted.

Using kinetic eGFR to identify acute kidney injury risk in children undergoing cardiac transplantation.

BACKGROUND: Acute kidney injury (AKI) is common following pediatric cardiac transplantation. Since no treatments exist, strategies focus on early identification and prevention. Kinetic glomerular filtration rate (kGFR) was developed to assess renal function in the non-steady state. Although used to predict AKI in adults, kGFR has not been explored in children. Our study examines AKI and the ability of kGFR to identify AKI risk in pediatric heart transplant recipients. METHODS: One hundred and seventy-five patients under 21 years who underwent cardiac transplantation at Lucile Packard Children's Hospital between September 2007-December 2017 were included. kGFR1 was calculated using pre-operative and immediate post-operative creatinines; kGFR2 was calculated with the first two post-operative creatinines. The primary outcome was AKI as defined by the Kidney Disease: Improving Global Outcomes criteria. RESULTS: One hundred and thirty-one (75%) and 78 (45%) patients developed AKI and severe AKI, respectively; 5 (2.9%) required dialysis. kGFR was moderately associated with post-operative AKI risk. The adjusted area under the curve (AUC) for kGFR1 was 0.72 (discovery) and 0.65 (validation). The AUC for kGFR2 was 0.72 (discovery) and 0.68 (validation). CONCLUSIONS: AKI is pervasive in children undergoing cardiac transplant, particularly in the 24 h after surgery. kGFR moderately identifies AKI risk and may represent a novel risk stratification technique. IMPACT: Our research suggests that kGFR, a dynamic assessment of renal function that uses readily available laboratory values, can moderately identify AKI risk in children undergoing cardiac transplantation. Current published studies on kGFR are in adult populations; this study represents the first formal study of kGFR in a pediatric population. kGFR may serve as an early AKI indicator, allowing providers to implement preventative strategies sooner in a patient's clinical course.

Impact of institutional routine surveillance endomyocardial biopsy frequency in the first year on rejection and graft survival in pediatric heart transplantation.

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 < 0.001) but no difference in graft survival (HR 1.00, p = 0.970) or CAV (SHR 1.04, p = 0.757) over median follow-up 3.9 years. Center RSB-frequency threshold of ≥2/year was associated with increased unadjusted rates of treated AR, but no association was found at thresholds greater than this. CONCLUSION: Center RSB frequency is positively associated with increased diagnosis of AR at 1 year post-HT. Graft survival and CAV appear similar at medium-term follow-up. We speculate that higher frequency RSB centers may have increased detection of clinically less important AR, though further study of the relationship between center RSB frequency and differences in treated AR is necessary.