The treatment of heart failure has improved in recent years and the number of patients waiting for heart transplant has consequently declined. In the past, the upper age limit for recipients was restricted in response to the shortage of available donor hearts but now these restrictions have been removed and biological age rather than chronological age is the criterion. Since the number of donors is declining (Fig 1), this means there is still a shortage of organs for transplantation.
This shortage has led to a reassessment of the suitability of potential donors. El Oakley et al (1996) suggest increasing the acceptable donor age to 55 years, and Young (1999) discusses the use of 'marginal' older donors for transplantation into patients whose morbidity and mortality would be high without transplant.
Last year, the Cardiothoracic Advisory Group at UK Transplant (2001) agreed to increase the maximum age for cardiothoracic donors to 65 years. The majority of hearts from older donors, however, have been found to be unsuitable on retrieval.
Assessing suitability for transplant
Donor hearts are a scarce resource, and we have a duty to donor families to ensure that they are transplanted into recipients who will gain the most benefit. Prospective recipients are, therefore, carefully assessed before being accepted on the waiting list.
Patients are referred for assessment by their own cardiologist. It is essential to ensure that they are not only fit to undergo major surgery but that they also have no underlying medical problems that could restrict the use of long-term immunosuppression. It is also important to establish that no further medical treatment is possible.
Patients are usually admitted for three or four days to undergo investigations. These include right-heart catheterisation to exclude high pulmonary artery pressure or pulmonary vascular resistance, as these are contraindications to heart transplant.
It is essential that patients have ceased smoking before being accepted on the waiting list. Coronary artery disease in the transplanted heart develops more rapidly with immunosuppression, and smoking accelerates this process. It is important that patients comply with medical treatment and advice at this stage because transplant is a lifelong commitment and requires motivation.
Further tests that patients need to undergo include:
- Cardiopulmonary exercise test;
- Lung function tests;
- Abdominal ultrasound;
- Dental assessment;
- 24-hour urine collection for creatinine clearance;
- Blood for biochemistry, haematology, immunology and tissue typing;
- Microbiology screening;
- Virology screening.
Patients are seen by the transplant physiotherapist, social worker and coordinator. They are given verbal and written information and have the opportunity to ask questions. If the test results indicate that they may be suitable, they are seen by a consultant transplant surgeon. Individual cases are discussed by the multidisciplinary team before the patient is placed on the transplant waiting list. Ideally, there should be continuity of care for each patient via a heart failure clinic while they are waiting (Stevenson, 1996).
Once accepted on the waiting list patients are registered with UK Transplant and their details are put on the national database. UK Transplant is a special health authority whose key role is to ensure that donated organs are matched and allocated in a fair and unbiased way (UK Transplant Support Service Authority, 1999).
Psychological effects of waiting for a transplant
The time patients wait for a heart depends on finding a suitable donor. Some may only wait a few hours or days, while others may have to wait months or years. Because there are not enough donor organs to meet demand, many patients die before a suitable heart becomes available.
Patients, understandably, find this extremely stressful. Their initial relief from the anxiety of wondering whether they will be accepted on the waiting list is replaced by the agony of wondering whether they will be called. All patients are issued with a pager so the transplant coordinator can contact them at any time, but they also know that every phone call could be a summons to the transplant unit.
With all solid organ transplants there is a critical period known as the ischaemic time. This is the time the organ can survive without a blood supply. A heart has a maximum ischaemic time of four hours, so it must be retrieved, packaged, transported (sometimes hundreds of miles), unpacked and transplanted within this time. This means the recipient has to be brought to the transplant unit and prepared for theatre before the retrieving surgeon has examined the heart. If the surgeon is unhappy with the condition of the heart, the transplant is called off and the patient must go home and wait for the next call.
Aborted transplants can be traumatic and happen to around half the patients waiting for hearts. All cardiothoracic transplant units run support groups for people on the waiting list, where they can meet those in a similar situation, and receive support and counselling.
Matching donor and recipient
In cardiac transplantation there is usually insufficient time to perform a prospective tissue-typing crossmatch. This is done only if there is evidence that the recipient has antibodies that may aggressively attack the donor organ. In most cases, the decision is made by matching blood group and assessing the size by comparing the height and weight of the donor and the recipient. Donor and recipient can be of both different ethnic origin and gender, provided the organ is of a suitable size.
Sometimes a heart may be donated from a person who has received a heart/lung transplant but who has a healthy heart. The healthy heart is then transplanted into another recipient. This process is known as a domino transplant.
The vast majority of transplanted hearts come from heart-beating cadaveric donors. This means the donor has been diagnosed as brain-stem dead but is maintained on a ventilator, usually in an intensive care unit. Only a small percentage of people die this way: this may be following head trauma, a road traffic accident or fall, or a catastrophic cerebral insult such as haemorrhage or infarct.
Once brain-stem death has been confirmed the family must declare their lack of objection to organ donation. If they are unhappy with this, their views are respected - this occurs in about 26% of cases (UK Transplant Coordinators Association, 1995). If the family agrees, the donor transplant coordinator will explain the procedure and discuss issues such as the need to continue ventilatory support during surgery and timing of surgery (Buckley, 2000).
How the transplant is coordinated
After discussion with the family, the donor transplant coordinator assesses the donor in ICU, giving staff both practical and psychological support and advice. If the death was reported to the coroner, his or her consent may also be required (for example, in cases of industrial disease, sudden or unexplained death, or if death occurred during surgery). Information is collated from the donor's notes and family or GP, to ensure no medical or social contraindications to donation. Blood samples are obtained for virology screening to ensure minimal risk of transference of disease. The donor is then registered with UK Transplant.
The recipient transplant coordinator from the local cardiothoracic transplant unit is contacted and given information about the donor. If the local unit does not have a suitable recipient, UK Transplant will offer the heart to other units in turn. Good management of the donor is crucial at this stage to avoid deterioration in the condition of the heart.
Once a unit has accepted the heart, a suitable recipient is called in. The retrieval team from the transplant unit travel to the donor hospital where the donor is transferred to the operating theatre. In multi-organ donation there are usually three retrieval teams: a liver team, a kidney/pancreas team and a cardiothoracic team.
The organs are mobilised, dissected and cannulas placed in the large vessels. The cross-clamp is applied to the aorta and cardioplegia is perfused under pressure into the heart to paralyse and preserve it. (The other organs are also perfused simultaneously.) The heart is cooled with ice-cold saline.
Once removed from the body, the heart is placed in three layers of sterile bags containing more ice-cold saline and transported in a cool box filled with crushed ice. The retrieval team communicates with the transplant unit continually during the retrieval process to ensure that the recipient's operation is timed to minimise the ischaemic time. The cardiothoracic retrieval team needs to leave immediately, and the liver team will close the wound after the operation. The donor transplant coordinator will assist staff at the donor hospital with last offices.
Donors' families are, as a rule, followed up two to three weeks later to offer further support and give them information about the recipient. Only limited information, such as the recipient's age, sex and area of residence, is given owing to patient confidentiality. Recipients are also offered the same limited information about their donor, and many want to write an anonymous thank-you letter to the donor's family. They can be offered help and support to do this if they wish. Donor families always find it comforting to receive thanks from a recipient at a time of grief.
The need to increase organ donation
Part of the extended remit of UK Transplant is to increase the number of organ donors. Extra funding of £4m has meant that more donor transplant coordinators could be employed across the country. A transplant coordinators advisory group was set up at UK Transplant and task groups have examined all aspects of transplant coordination such as standards, education, research and job descriptions.
Even if people are on the organ donor register or carry a donor card, they do not become organ donors unless their family gives consent at the stage of brain-stem death testing. We believe every family of a brain-stem dead patient should have the chance to consider organ donation. Many potential donors slip through the net because staff either feel it is inappropriate to ask, may not feel qualified to answer any questions the family may have, or because of pressure on ICU beds; in addition, many suitable patients in A&E are not considered as potential donors.
One initiative aimed at reducing the number of suitable donors lost to the transplant system has been the creation of a new role - that of the donor liaison sister/charge nurse. Several such nurses are already in post in ICUs, with plans to increase this to a total of 21. One of their first roles is to audit all deaths in ICU: the aim is to find out whether families are being approached to consider organ donation following brain stem-death testing and to explore answers to the following questions:
- If not, why not?
- If consent is given, does donation proceed?
- If not, why not?
- If consent is refused, what reason is given?
These audits have already begun in a few hospitals. The donor liaison sisters'/charge nurses' main role is to educate staff in ICUs and encourage a change in attitudes toward organ donation and approaching potential donors' families. They will also forge links with areas such as A&E and the wards, and promote awareness of tissue as well as organ donation. The results will be analysed to establish what more can be done to increase organ donation, for example through better education of the public, better publicity campaigns, more resources (ICU beds, staff), better education of health care professionals and so on.
Other organs may be transplanted from different kinds of donors, for example:
- Live related donors: kidneys, liver lobe, lung lobe, small bowel;
- Live unrelated donors: kidneys;
- Non heart-beating donors: kidneys, liver.
In future, lungs may be transplanted from non heart-beating donors: trials are currently under way in the USA although not, as yet, in the UK.
The donor liaison sister/charge nurse can also educate staff about these issues. The new role is an exciting development and the transplant community is optimistic that it will lead to an increase in the number of donors, thus reducing the transplant waiting lists.