Clinical outcomes after a biopsy diagnosis of antibody-mediated rejection in pediatric heart transplant recipients.

Background: Extending survival after heart transplant (HT) is of paramount importance for childhood recipients of HT. Acute rejection is a significant event, and biopsy remains the most specific means for distinguishing between cellular (ACR) and antibody-mediated rejection (AMR).

Methods: All children in the Pediatric Heart Transplant Society Registry who underwent HT between January 2015 and June 2022 and had ≥1 rejection episode were included.

Elimination of 15N-thymidine after oral administration in human infants.

Background: We have developed a new clinical research approach for the quantification of cellular proliferation in human infants to address unanswered questions about tissue renewal and regeneration. The approach consists of oral 15N-thymidine administration to label cells in S-phase, followed by Multi-isotope Imaging Mass Spectrometry for detection of the incorporated label in cell nuclei. To establish the approach, we performed an observational study to examine uptake and elimination of 15N-thymidine.

Expanding use of the HeartMate 3 ventricular assist device in pediatric and adult patients within the Advanced Cardiac Therapies Improving Outcomes Network (ACTION).

Background: We report current outcomes in patients supported with the HeartMate 3 (HM3) ventricular assist device in a multicenter learning network.

Methods: The Advanced Cardiac Therapies Improving Outcomes Network database was queried for HM3 implants between 12/2017 and 5/2022. Clinical characteristics, postimplant course, and adverse events were collected.

Identification of Two Homozygous Variants in and Genes Associated with Severe Infantile Cardiomyopathy.

Mutations in cardiac genes are one of the primary causes of infantile cardiomyopathy. In this study, we report the genetic findings of two siblings carrying variations in the and genes. The first patient is a female proband exhibiting hypertrophic cardiomyopathy (HCM) and biventricular heart failure carrying a truncating homozygous variant c.

Short-term clinical outcomes and predicted cost savings of dd-cfDNA-led surveillance after pediatric heart transplantation.

Background: Endomyocardial biopsy (EMB)-led surveillance is common after pediatric heart transplantation (HT), with some centers performing periodic surveillance EMBs indefinitely after HT. Donor derived cell-free DNA (dd-cfDNA)-led surveillance offers an alternative, but knowledge about its clinical and economic outcomes, both key drivers of potential utilization, are lacking.

Methods: Using single-center recipient and center-level data, we describe clinical outcomes prior to and since transition from EMB-led surveillance to dd-cfDNA-led surveillance of pediatric and young adult HT recipients.

Responsiveness to second and third dose of mRNA COVID-19 vaccination in adolescent and young adult heart transplant recipients.

Background: Third-dose mRNA COVID-19 vaccine is currently recommended in the United States for SOT recipients based in part on data showing diminished immune response, including Ab production, after a two-dose regimen. Data on vaccine response in adolescent and young adult SOT recipients are limited, including no data reported on third-dose responsiveness.

Methods: Results of serologic testing in a convenience sample of 28 vaccinated adolescent and young adult HT recipients at a single institution were collected from the medical record and summarized.

Early findings after integration of donor-derived cell-free DNA into clinical care following pediatric heart transplantation.

Background: Endomyocardial biopsy (EMB) is costly and discomforting yet remains a key component of surveillance after pediatric heart transplantation (HT). Donor-derived cell-free DNA (dd-cfDNA) has been histologically validated with high negative predictive value, offering an alternative to surveillance EMB (sEMB).

Methods: We implemented an alternative surveillance protocol using commercially available dd-cfDNA assays in place of sEMB after pediatric HT.

Resource utilization in children with paracorporeal continuous-flow ventricular assist devices.

Background: Paracorporeal continuous-flow ventricular assist devices (PCF VAD) are increasingly used in pediatrics, yet PCF VAD resource utilization has not been reported to date.

Methods: Pediatric Interagency Registry for Mechanically Assisted Circulatory Support (PediMACS), a national registry of VADs in children, and Pediatric Health Information System (PHIS), an administrative database of children's hospitals, were merged to assess VAD implants from 19 centers between 2012 and 2016. Resource utilization, including hospital and intensive care unit length of stay (LOS), and costs are analyzed for PCF VAD, durable VAD (DVAD), and combined PCF-DVAD support.

Variation in Cardiac Rehabilitation for Pediatric Ventricular Assist Device Recipients Across North America.

Despite increasing utilization of continuous-flow pediatric ventricular assist devices (VAD) in children, data on exercise testing and cardiac rehabilitation (CR) are unknown. We described variation in CR practices and identified barriers to exercise testing and CR. A survey was performed through the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) representing pediatric VAD centers across North America.

Bartonella henselae infection in the pediatric solid organ transplant recipient.

Bartonella henselae infection can cause a wide spectrum of diseases in both the immunocompetent and immunocompromised host with BA a severe form relegated to immunocompromised hosts, including solid organ transplant population. There are established criteria for diagnosis of Bartonella infection based on clinical presentation, serologic testing, imaging studies and, when indicated, tissue sampling for histopathological evaluation, particularly for BA. However, treatment recommendations for BA are inconclusive.

Anti-hypertensive treatment in the immediate post-operative period and 1 year after pediatric heart transplantation.

Hypertension is a known complication of pediatric heart transplantation. We sought to identify factors associated with anti-hypertensive use in pediatric heart transplant recipients immediately post-transplant and oral anti-hypertensive use at discharge and 1-year post-transplant. Retrospective chart review was conducted of patients ≤18 years who underwent heart transplantation at two major heart transplant centers between August 1, 2009 and December 31, 2017 with ≥1-year follow-up.

Early experience with the HeartMate 3 continuous-flow ventricular assist device in pediatric patients and patients with congenital heart disease: A multicenter registry analysis.

Background: The HeartMate 3 ventricular assist device (VAD) is a newer centrifugal continuous-flow VAD used for bridge-to-transplant and destination therapy in adults. However, there is limited experience regarding its use in children and adults with complex congenital heart disease (CHD).

Methods: The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) is a multicenter learning network comprised of pediatric hospitals implanting VADs in children and adults with complex CHD.

Impact of the 2016 revision of US Pediatric Heart Allocation Policy on waitlist characteristics and outcomes.

US Pediatric Heart Allocation Policy was recently revised, deprioritizing candidates with cardiomyopathy while maintaining status 1A eligibility for congenital heart disease (CHD) candidates on "high-dose" inotropes. We compared waitlist characteristics and mortality around this change. Status 1A listings decreased (70% to 56%, P < .

Heart Transplantation from Biventricular Support in Infant with Novel SMYD1 Mutation.

SET and MYND domain-containing protein 1 (SMYD1) has been shown to be responsible for the development of fast twitch and cardiac muscle. Mutations in SMYD1 have been shown to be uniformly fatal in laboratory studies, and not previously described in living humans. We describe here the care of an infant suffering from cardiac failure due to an SMYD1 mutation requiring biventricular assist devices as a bridge to successful heart transplantation.

Impact of routine surveillance biopsy intensity on the diagnosis of moderate to severe cellular rejection and survival after pediatric heart transplantation.

Data are lacking on RSB intensity and outcomes after pediatric heart transplantation. PHTS centers received a survey on RSB practices from 2005 to present. PHTS data were obtained for 2010-2013 and integrated with center-matched survey responses for analysis.

Impact of age on incidence and prevalence of moderate-to-severe cellular rejection detected by routine surveillance biopsy in pediatric heart transplantation.

Background: The effect of age at transplant on rejection detected by routine surveillance biopsy (RSB) in pediatric heart transplant (HT) recipients is unknown. We hypothesized there would be low diagnostic yield and decreased prevalence of rejection detected on RSB in infants (age <1 year) when compared with children (age 1 to 9 years) and adolescents (age 10 to 18 years).

Methods: We utilized Pediatric Heart Transplant Study (PHTS) data from 2010 to 2013 to analyze moderate-to-severe (ISHLT Grade 2R/3R) cellular rejection (MSR) detected only on RSB (RSBMSR).

Bortezomib use in a pediatric cardiac transplant center.

Data are limited on the efficacy and safety of bortezomib for the treatment of AMR following OHT for pediatric acquired or CHD. Retrospective chart review identified patients who received bortezomib for acute (n = 3, within two wk of diagnosis) and chronic (n = 1, three months after diagnosis) AMR or as part of a desensitization regimen (n = 1). Bortezomib was associated with a 3-66% reduction in class I DSA and a 7-82% reduction in class II DSA.