Heart transplantation can be utilized in patients with end-stage heart failure that is refractory to medical and surgical management.
Common indications for transplant:
Cardiomyopathy requiring IV inotropes or mechanical respiratory or circulatory support
Palliated congenital heart disease with heart failure requiring IV inotropes or prostaglandin E (PGE) and/or mechanical support
Patients with heart failure due to cardiomyopathy or congenital heart disease that leads to severe limitation of exercise/activity or growth
Patients with life-threatening arrhythmias untreatable with medications or an implantable defibrillator
Relative contraindications to transplant:
Severe multiorgan system disease
Severe pulmonary hypertension that is refractory to medical management
History of another medical condition that limits life expectancy in such a way that it would shorten graft survival
Severe psychosocial issues that may limit family’s ability to care for the patient postoperatively
In order to evaluate candidacy, a multidisciplinary team must assess the medical condition of the patient, but also the psychosocial functioning and resources of the entire family. Comorbidities must be taken into account.
Cardiac evaluation
Fully evaluate past medical and surgical cardiac history.
Outline cardiac condition and degree of heart failure. In patients where there is concern for specific anatomic issues or pulmonary hypertension, a cardiac catheterization may be necessary.
Confirm that alternative medical and surgical treatment options have been exhausted.
Immunologic evaluation
Vaccination history
Human leukocyte antigen (HLA) and blood typing for appropriate donor–recipient matching
Infectious evaluation
Testing for human immunodeficiency virus (HIV), hepatitis C virus (HCV), cytomegalovirus (CMV), Epstein-Barr virus (EBV)
Evaluation of dental health
General medical
Evaluation of brain, renal, intestinal, and hepatic systems, all of which can be affected by chronic heart failure or by underlying diagnosis
Psychosocial
Psychological evaluation of patient and family
Social work evaluation of patient and family support systems, financial resources, insurance
Formal family meeting to complete informed consent after outlining specific details of transplant and necessary lifelong changes to lifestyle
Once the team makes the decision to complete listing for transplant, the patient will be assigned a wait list category through the United Network for Organ Sharing (UNOS).
UNOS Categories: Assigned based on clinical severity. Patients with severe disease that would otherwise be listed Status 2 can apply for an “exception” allowing them to be listed as Status 1A or 1B after review by a multicenter board.
Status 1A – Requiring mechanical ventilatory or circulatory (ECMO or VAD) support or congenital heart patients requiring inotropic support or with ductal dependent systemic or pulmonary blood flow who require a stent or PGE to maintain ductal patency. Patients remain hospitalized (VAD patients are exception).
Status 1B – Requiring inotropes but does not meet criteria for 1a or infants with restrictive or hypertrophic cardiomyopathy.
Status 2 – Does not meet criteria for 1A or 1B.
Status 7 – Temporary inactive status.
Transplant Waiting List: Approximately 500 children are added to the heart transplant waiting list annually. Wait list mortality is nearly 20% per year waiting, but has improved over the past 2 decades.
In 2012, over 70% of patients were listed Status 1A (or assigned 1A via exception). This results in a waiting system that is largely based on time on the list.
Patients with weight <10 kg, congenital heart disease, blood type O, ECMO, mechanical ventilation, and renal dysfunction had increased waiting list mortality.
VAD implantation increases likelihood of survival to transplant.
Attempts made to decrease wait time by accepting hearts previously thought to be “marginal.” According to UNOS, up to 40% of available pediatric donor hearts go unused. An evaluation of the Pediatric Heart Transplant Study Database failed to show an impact of traditional donor risk factors (high donor inotropes, donor CPR, mechanism of donor death) on recipient post-transplant survival. Ischemic time and older donor age may be risk factors for poor outcome in patients ≥10 years of age.