Review of the impact of donor characteristics on pediatric heart transplant outcomes

Donor Characteristics and Outcomes of Pediatric Heart Transplantation in South Korea

BACKGROUND

Heart transplantation is often limited by the availability of transplantable donor heart and understanding of donor aspects that would influence transplant outcomes becomes important. In this study, donor characteristics and their impact on the outcomes of pediatric heart transplantations performed in South Korea were investigated.

METHODS

We reviewed the medical records of patients less than 18 years old who received heart transplantation between 2002 and 2022 in three tertiary hospitals located in South Korea.

RESULTS

A total of 139 cases were enrolled. One-year mortality was 10.4% and total mortality was 33.8%. Forty-nine recipients (35.3%) showed biopsy-proven rejections and 20 (14.4%) showed cardiac allograft vasculopathy during mean follow-up of 6.4 ± 4.9 years. Six recipients (4.5%) showed left ventricle ejection fraction of less than 55% post-transplantation. The mean age of the donors was 23.0 ± 15.4 years. The most common cause of death of the donors was unspecified illness (46.4%). Donors with a history of diabetes, hypertension, smoking, and alcohol consumption were 0%, 3.1%, 32.1%, and 34.4%, respectively. Mean total ischemic time was 191.6 ± 72.7 min, while total ischemic time was over 4 h in 37 patients (26.6%). There were no significant relationship between donor factors and survival. However, donor's history of drinking or cardiopulmonary resuscitation was significantly associated with acute rejection and donor's age with cardiac allograft vasculopathy.

CONCLUSION

Donor factors did not show significant impact on post-transplant survival but some factors were predictive of post-transplant rejection and cardiac allograft vasculopathy.

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Pediatric heart transplantation: Looking forward after five decades of learning

Heart transplantation has become the standard of care for pediatric patients with end-stage heart disease throughout the world. Since the first transplant was performed in 1967, the number of transplants has grown dramatically with 13 449 pediatric heart transplants being reported to The International Society of Heart and Lung Transplant (ISHLT) between January 1992 and June 30, 2018. Outcomes have consistently improved over the last few decades, specifically short-term outcomes. Most recent survival data demonstrate that recipients who survive to 1-year post-transplant have excellent long-term survival with more than 60% of those who were transplanted as infants being alive 25 years later. Nonetheless, the rates of graft loss beyond the first year have remained relatively constant over time; driven primarily by our poor understanding and lack of treatments for chronic allograft vasculopathy (CAV). Acute rejection, CAV, graft failure, and infection continue to be the major causes of death within the first 5 years post-transplant. In addition, renal dysfunction, malignancy, and the need for re-transplantation remain as significant issues that require close follow-up. Looking forward, key challenges include improving donor utilization rates (including donation after cardiac death (DCD) and the use of ex vivo perfusion devices), the development of non-invasive biomarkers for rejection, efforts to mitigate the long-term effects of immunosuppression, and prevention of CAV. It is not possible to cover the entire evolution of pediatric heart transplantation over the last five decades, but in this review, we hope to touch on key observations, lessons learned, and practice changes that have advanced the field, as well as glance ahead to the next decade.

A coordinated approach to improving pediatric heart transplant waitlist outcomes: A summary of the ACTION November 2019 waitlist outcomes committee meeting

The number of children needing heart transplantation continues to rise. Although improvements in heart failure therapy, particularly durable mechanical support, have reduced waitlist mortality, the number of children who die while waiting for a suitable donor organ remains unacceptably high. Roughly, 13% of children and 25% of infants on the heart transplant waitlist will not survive to transplantation. With this in mind, the Advanced Cardiac Therapies Improving Outcomes Collaborative Learning Network (ACTION), through its Waitlist Outcomes Committee, convened a 2-day symposium in Ann Arbor, Michigan, from 2-3 November 2019, to better understand the factors that contribute to pediatric heart transplant waitlist mortality and to focus future efforts on improving the organ allocation rates for children needing heart transplantation. Using improvement science methodology, the heart failure-transplant trajectory was broken down into six key steps, after which modes of failure and opportunities for improvement at each step were discussed. As a result, several projects aimed at reducing waitlist mortality were initiated.

A comprehensive strategy in donor acceptance: Impact on pediatric waitlist and heart transplant outcomes

Significant inter- and intra-center practice variability is present in pediatric donor heart acceptability. This may contribute to variation in the donor refusal rate and may impact waitlist time, morbidity, mortality, and transplant rates. In order to reduce practice variability, our center developed and implemented a comprehensive strategy regarding donor acceptance in September 2017. The aim of this study was to assess the impact of this strategy on waitlist time and outcomes as well as early post-transplant outcomes. We performed a single-center, retrospective analysis of all pediatric (<18 years) patients listed for single-organ heart transplant at our center from September 2015 to September 2018. Patients were divided into those listed before (Group 1) and after implementation of the comprehensive strategy (Group 2). The primary end-point was waitlist time. Secondary end-points included waitlist removal due to death or clinical deterioration, donor refusals per listed patient, early post-transplant outcomes (graft failure, mechanical ventilation time, inotropic support, length of hospital stay) and 1-year post-transplant survival. Of 78 listed patients, 54 were transplanted (29 in Group 1), 9 were removed due to death or clinical deterioration (7 in Group 1) and 15 were removed due to clinical improvement (12 in Group 1). The waitlist time was significantly shorter in Group 2 (17 days, IQR 7-53) vs Group 1 (90 days, IQR 14-162); P = .006. The number of donor refusals was lower in Group 2 (1, IQR 0-2.2) vs Group 1 (4, IQR 2-19); P < .001. The percentage of refused donors with normal function (Left ventricular ejection fraction > 50%) was lower in Group 2 vs Group 1 (53% vs 84%; P < .001). Difference in removal from the waitlist for death or deterioration in Group 2 vs Group 1 (n = 2, 7% vs n = 7, 20%, P = .18) did not reach statistical significance. There was no difference in post-transplant outcomes between groups. The waitlist time and donor refusals significantly decreased after implementation of a comprehensive donor acceptance strategy without impacting transplant outcomes. This analysis supports the need for a comprehensive approach to donor organ acceptance within a pediatric transplant center.