A heart transplant consists of replacing a diseased heart with a healthy donor heart. Transplantation is used for patients with refractory end-stage cardiac disease.
Heart failure may be the consequence of a number of differing etiologies, including ischemic heart disease, cardiomyopathy, or congenital heart defects. The reduction of cardiac output is considered to be severe when systemic circulation cannot meet the body’s needs under minimal exertion. Heart transplantation can potentially improve both survival and quality of life. According to the Organ Procurement and Transplant Network (OPTN), patient survival rate at 1 year is 87.5% in males and 85.6% in females and at 5 years is 72.4% in males and 67.4% in females. (1)
The shortage of donor hearts has led to the use of transplantation in those most likely to derive benefit. At the same time, advances in medical and device therapy for patients with advanced heart failure has improved the survival of patients awaiting heart transplantation. Due to the variable natural history of heart failure, functional and hemodynamic parameters have been utilized to estimate prognosis.
In 2011, 2,322 heart transplants were performed in the U.S. There were 3,329 patients on the waiting list at the end of September 2012. (1)
Potential contraindications subject to the judgment of the transplant center:
- Known current malignancy, including metastatic cancer;
- Recent malignancy with high risk of recurrence;
- Untreated systemic infection making immunosuppression unsafe, including chronic infection;
- Other irreversible end-stage disease not attributed to heart or lung disease;
- History of cancer with a moderate risk of recurrence;
- Systemic disease that could be exacerbated by immunosuppression;
- Psychosocial conditions or chemical dependency affecting ability to adhere to therapy.
Patients must meet the United Network for Organ Sharing (UNOS) guidelines for 1A, 1B, or 2 Status and not currently be Status 7.
The United Network for Organ Sharing (UNOS) prioritizes donor thoracic organs according to the severity of illness, with those patients who are most severely ill (Status 1A) given highest priority in allocation of the available organ as follows (2):
Adult patients (18 years of age or older)
A patient is admitted to the listing transplant center hospital and has at least one of the following devices or therapies in place:
- Mechanical circulatory support for acute hemodynamic decompensation that includes at least one of the following:
- Left and/or right ventricular assist device implanted;
- Total artificial heart;
- Intra-aortic balloon pump; or
- Extracorporeal membrane oxygenator (ECMO);
- Mechanical circulatory support;
- Mechanical ventilation;
- Continuous infusion of inotropes and continuous monitoring of left ventricular filling pressures;
- If criteria a, b, c, and d are not met, such status can be obtained by application to the applicable Regional Review Board.
A patient has at least one of the following devices or therapies in place:
- Left and/or right ventricular device implanted, or
- Continuous infusion of intravenous inotropes.
A patient who does not meet Status 1A or 1B is listed as Status 2.
A candidate listed as Status 1A meets at least one of the following criteria:
- Requires assistance with a ventilator;
- Requires assistance with a mechanical assist device (e.g., ECMO);
- Requires assistance with a balloon pump;
- A candidate younger than 6 months-old with congenital or acquired heart disease exhibiting reactive pulmonary hypertension at greater than 50% of systemic level. Such a candidate may be treated with prostaglandin E (PGE) to maintain patency of the ductus arteriosus;
- Requires infusion of high dose (e.g., dobutamine >7.5 mcg/kg/min or milrinone >0.5 mcg/kg/min) or multiple inotropes (e.g., addition of dopamine at >5.0 mcg/kg/min); or
- A candidate who does not meet the criteria specified in a, b, c, d, or e may be listed as Status 1A if the candidate has a life expectancy without a heart transplant of less than 14 days, such as due to refractory arrhythmia.
A candidate listed as Status 1B meets at least one of the following criteria:
- Requires infusion of low-dose single inotropes (e.g., dobutamine or dopamine <7.5 mcg/kg/min);
- Younger than 6 months-old and does not meet the criteria for Status 1A; or
- Growth failure, i.e., greater than 5th percentile for weight and/or height, or loss of 1.5 standard deviations of expected growth (height or weight) based on the National Center for Health Statistics for pediatric growth curves.
A candidate who does not meet the criteria for Status 1A or 1B is listed as Status 2.
Note: Pediatric heart transplant candidates who remain on the waiting list at the time of their 18th birthday without receiving a transplant continue to qualify for medical urgency status based upon the pediatric criteria.
Status 7 patients are considered temporarily unsuitable to receive a thoracic organ transplant.