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Frequently asked questions

Why do I need a heart transplant?

References:
M. Yeatman, J.A. Smith, J.J. Dunning, S.R. Large and J. Wallwork. Cardiovascular Surgery vol 3, No 1, pp. 1-14. 1995.
Baily and Love's Short Practice of Surgery 22nd edition, edited by Charles V. Mann, R.C.G. Russell and Norman S. Williams.

Candidates for heart transplantation should have terminal heart failure, and a life expectancy of less than 12 months.

Sometimes the heart is irreversibly damaged by long-lasting heart disease or viral infection. In general, indications for heart transplantation are:

  1. Cardiomyopathy (acute or chronic disease of the heart muscle)
  2. Coronary artery disease
  3. Valvuler heart disease
  4. Re-transplantation
  5. Complex forms of congenital heart defects

Can anybody go through heart transplantation?

No. The criteria for recipient selection according to Papworth Hospital in Cambridge is as following:

  1. End-stage heart disease with life expectancy limited to 6-12 months.
  2. Age of less than 55 years for coronary arteries disease; less than 60 years for cardiomyopathy
  3. Absence of irreversible hepatic or renal failure
  4. Absence of active infection
  5. Absence of recent pulmonary infection
  6. Psychosocial stability
  7. There is no lower age limit to heart transplantation

When can't you do a heart transplant?

There are absolute and relative contraindications to heart transplantation.

  1. Absolute contraindications:
    • active infection
    • untreated malignancy
    • coexisting systemic illness likely to limit survival
    • severe and irreversible major organ dysfunction
    • fixed elevated pulmonary vascular resistance
  2. Relative contraindications:
    • advanced age
    • recent or unresolved pulmonary infection
    • active peptic ulceration
    • marked peripheral or cerebrovascular disease
    • mental illness

How long can I expect to live after heart transplantation?

The longest survival after heart transplantation is 24 years. The survival rate has improved dramatically during the last 10 years.

Heart transplants performed with 1, 5, and 10 year survival figures are now approaching 90%, 70%, and 50%, respectively.

What are the criteria in donor selection?

Donor selection is critically important if early postoperative problems are to be avoided.

Potential donors will be certified as brain dead if two separate brain stem function tests show no activity. Most donors have had head injuries or an intra cerebral bleeding, gunshot wound, brain tumour, or liver failure.

Ideal criteria for the donor include the following:

  • age (<45 years for male, <50 years for females)
  • weight (within 25 per cent of the recipient's weight)
  • ABO compatibility
  • no evidence of heart injury (normal ECG, normal chest X-ray)
  • no evidence of active infection (HIV, hepatitis B, or bacterial)
  • no malignancy apart from brain tumours.

What are the most common complications expected after heart transplantation?

There are many complications associated with heart surgery in general, but the most important complications in heart transplantation are divided into two groups:

  • Early complications:
    1. donor organ dysfunction
    2. acute rejection
    3. renal failure
    4. arrhythmia (abnormal heart beat)
    5. bleeding
    6. infection
  • Late complications:
    1. infection
    2. accelerated coronary athrosclerosis (coronary disease)
    3. chronic rejection
    4. hypertension (high blood pressure)
    5. malignancy (cancer)

What are the causes of donor heart dysfunction?

Ventricular dysfunction is often present as a result of the adverse effects of brain death on the heart; and the ischemic period during storage and transplant.

Right ventricular failure may occur because the unprepared right ventricle of the donor has to perform work against the recipient's pulmonary vascular resistance which may be elevated. Lack of reflex sympathetic enervation may diminish the heart ability to compensate for any reduction in function.

What are the causes of renal failure after heart transplantation?

Renal failure usually is caused by:

  1. effects of Cardiopulmonary bypass "CPB", which is a technique by which the pumping action of the heart and the gas exchange action of the lung, are replaced temporarily by a mechanical device during the heart operation.
  2. secondary to chronic heart failure before heart transplantation.
  3. nephrotoxic agents, particularly Cyclosporin drug.

Why do some patients suffer from skin cancer after transplantation?

Malignancy may be developed due to chronic use of immunosuppression drugs and rarely from receiving transmitted malignant cells with the donor organ.

The malignancies are Lymphoproliferative of the Epstein-Barr virus type or B-Cell hyperplasias.

Cancers are an unfortunate consequence of chronic immunosuppression. In general, transplant recipients have a threefold increase in the incidence in various cancers when compared with age-matched controls. Some specific cancers are more than 100 times more frequent in immunosuppressed patients than in the general population.

For all tumours, the average time of appearance of the cancer after transplantation is 58 months. The most common tumours among transplant patients are those of the skin and lips, non-Hodgkin lymphomas, Kaposi sarcomas, and uterine, cervical, vulval, and perineal cancers.

What is rejection, and how many kinds are there?

References:
Basic Pathology edited by V. Kumar, R. Cotran, S.L. Robbins; with illustration by James A Pertine, 6th ed.

Rejection of organ transplants is a complex immunologic phenomenon that involves cell-mediated and antibody-mediated responses, both of which are targeted on the human lymphocytes antigens in the graft.

The basis of morphology and the mechanisms involved in rejection have been classified as hyper acute, acute, and chronic.

  1. Hyper acute rejection:
    • May occur within minutes or a few hours in pre-sensitised persons. It is characterised by widespread acute arteritis and arteriolitis, thrombosis of vessels, and ischemic necrosis, all of which result from reaction with pre formed humoral antibodies.
    • As a consequence of the vascular damage, the graft never becomes vascularized and it undergoes ischemic necrosis.
    • It should be noted that with the current practice of cross-matching (testing recipient for the presence of antibodies directed against donors lymphocytes), hyperacute rejection is no longer a significant clinical problem.
  2. Acute rejection:
    • May occur within days of transplantation, or may appear suddenly months or even years later, after immunosuppression has been employed and terminated.
    • Acute graft rejection is a combined process in which both cellular and humoral tissue injuries play parts. In any one patient, one or the other mechanism may predominate. Histologically, humoral rejection is associated with vasculitis, whereas cellular rejection is marked by an interstitial monocular cell infiltrate.
  3. Chronic rejection:
    • In this type of rejection, the endothelial cells are damaged or destroyed, but the time constants of this part of heart rejection are generally much longer. Some researchers believe that the immunologic basis for accelerated coronary artery disease may be similar to rejection.

Why do some patients suffer from infection following transplantation?

References:
John R.Pepper, Asghaz Khagani and Magdi Yacoub Journal of antimicrobial chemotherapy 1995 36 suppl. B, 23-38.
Miller, L.W., Nafted, D.C., Bourge, R.C., Kirklin J.K., Brozena S.C. Infection following cardiac transplantation, Journal of Heart Lung Transplant.
McGiffin, D.C., Bonner, J.R., Kirklin, J.K., Nafted, D.C. Patterns of infection and management in cardiac transplant, in J. Wallwork (ed) Heart and Heart-Lung Transplantation, Philadelphia WB Saunders 1989, pp. 251.

Infection is an unfavourable outcome event, which almost always is related to the immunosuppression therapy.

About 30% of patients experience an infection episode, which most commonly develops within three months of transplantation.

The most common organ infected is the lung, and in one study, when this organ was involved the mortality was 22%.

The organism most frequently causing infection after heart transplantation is the Cytomegalovirus (CMV). Overall, viruses cause about 45% of infection, and bacteria about 45%; fungi and protozoa account for the remainder.

Why do coronary arteries get damaged after heart transplantation?

References:
Michael J. Dunn, Samantha J. Crip, Marlene L. Rose, Patricia M. Taylor, Magdi Yacoub Anti-endothelial antibodies and coronary artery disease after cardiac transplantation, The Lancet vol 339: June 27, 1992.

Accelerated coronary artery disease is the third most common cause of death after heart transplantation, following behind infection and acute rejection. The disease has a multifactorial aetiology, with little agreement about the relative importance of the various risk factors. Some studies provided evidence of immune involvement in this disease, and showed anti-endothelial antibodies in patients with accelerated coronary artery disease.

Why do most patients not feel pain, despite the existence of coronary disease after heart transplant?

Most of the patients with this disease after heart transplantation fail to experience typical angina (chest pain); this may be related to the likelihood that the heart allograft (donor heart) denervated permanently.

What are the common side effects of Cyclosporin drug?

References:
Penn, I. and Brunson, M.E. Cancer after Cyclosporin therapy. Transplant. Proc. 20:85, 1988.

All of the commonly used immunosuppressive drugs increase the risk of infection complications and cancer.

Cyclosporin toxicity may result in renal failure, liver failure, high blood pressure, and neurotoxicity.

Neurotoxic reaction are manifested by a fine tremor, paresthesias and, occasionally, seizures.

Other unusual side effects include the development of Hirsutism (abnormal hairiness), observed in almost all patients who receive Cyclosporin. This effect regresses as the dosage of Cyclosporin is lowered.

What are the techniques for heart transplantation?

There are two main techniques for heart transplantation:

Heterotopic, in which the donor heart is placed parallel to the recipient's heart; and

Orthotopic, in which the patient's heart is replaced with a donor heart.

  1. Heterotopic heart transplant

    References:
    C.N. Barnard and D.K.C. Cooper Third international symposium on substitution Rome, May 17, 1982 c 1984 by Grune & Stratton, Inc.

    Exploration of the possibility of using the donor heart as an accessory pump had been carried out previously in laboratory experiments, most notably by Demikhov.

    Two techniques were developed at the university of Cape Town, the first of which was a means of bypassing or supporting the left ventricle only, and the second a means of biventricular support.

    Advantages and disadvantages of heterotopic as opposed to orthotopic heart transplantation:

    Advantages

    1. The recipient heart acts as a build in heart assist during;
      1. recovery from ischemia of donor heart sustained during transplantation;
      2. sever acute rejection episodes.
    2. Recipient heart may maintain circulation after irreversible rejection while awaiting a second donor.
    3. Heterotopic transplant allows for some possible recovery of the recipient heart.
    4. Can be performed even in the presence of a high pulmonary vascular resistance.

    Disadvantages

    1. Risk of systemic emboli from clots in the poorly contracting recipient left ventricle.
    2. Continuing angina related to recipient ischemic heart muscle.
    3. Risk of infection and thrombus formation in relation to presence of the prosthetic valve in the recipient heart (this is a contraindication to heterotopic transplantation)
  2. Orthotopic heart transplantation

    References:
    Cardiac Surgery second edition. John W. Kirklin, Brian G. Barratt-Boyes.

    The technique of orthotopic heart transplantation has been well established for more than 30 years, based on the first description by Lower, Stofen, and Shamway. Nevertheless anastomosis of donor to recipient atria according to this technique creates atria cavities with abnormal geometry.

    This abnormal geometry has been demonstrated to be responsible for tricuspid and mitral regurgitation and for arrhythmia's resulting from sinus node injury. The risk of atrial septal aneurysms or atrial thrombus formation is certain. Because of these problems, some surgeons proposed a more anatomic surgical technique with complete excision of the recipient atria and direct anastomosis on the left pulmonary veins, right pulmonary veins, inferior vena cava and superior vena cava. But the benefit of this procedure on clinical outcome has not been demonstrated.


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