Definition & Overview
Heart transplant is an invasive surgical procedure performed to replace a diseased heart with a healthy donor heart to prolong the life of patients suffering from heart failure, which could be due to coronary artery disease, valvular heart disease, congenital heart defect, and cardiomyopathy, among others.
Prior to the surgery, potential candidates are subjected to a thorough evaluation and assessment to determine if they are physically fit and mentally prepared to endure the transplant surgery. Factors such as the patient's age and overall health condition will be seriously considered in weighing the procedure's pros and cons. Suitable candidates are placed on a waiting list for a heart donor while those who do not qualify will be presented with other less invasive treatment options that best suit their unique circumstances.
Who should undergo and expected results
A heart transplant is typically considered when all other options have been tried, but failed to completely improve the patient's condition. This is typically recommended for people who are suffering from heart failure, which can be caused by the following heart conditions:
- Coronary artery disease
- Valvular heart disease
- Congenital heart defect
- Failure of a previous heart transplant
Heart failure can affect anybody of any age. In children, the two common causes are congenital heart defect and cardiomyopathy. Meanwhile, adult patients who have had the Fontan procedure as a child may also be in need of a heart transplant later on in life. For these patients, the veins typically become congested, seriously affecting the blood flow.
However, not everyone can undergo heart transplant surgery. A patient is deemed ineligible for the procedure if he or she:
- is aged 65 or older
- has another disease that may affect his or her chances of survival regardless of a heart transplant
- has a personal medical history that involves cancer
- has risky blockages in the arteries in the arms and legs
- smokes and drinks alcohol regularly
- is malnourished
- has HIV infection
- has hepatitis
- has insulin-dependent diabetes
- has a disease involving the nerve, lung, kidney, or liver
- experiences pulmonary hypertension or the thickening of blood vessels in the lungs
The expected outcome of a successful heart transplant is that it will prolong the life of the patient. About 80% of people who had the procedure are still alive and healthy two years after the operation, and about 70% continue to live after five years. The worst possible outcome is if the patient's body rejects the new heart.
How the procedure works
With heart transplant being a major invasive surgery, patients usually start preparing for it weeks or months prior to the operation. Once the doctor recommends the procedure, the patient is immediately referred to a heart transplant centre for an evaluation to see whether he or she is eligible for the surgery. The evaluation procedure is designed to assess if the transplant is really the best treatment option and if the patient is physically, emotionally, and mentally prepared for whatever the operation entails.
The next step for patients who are deemed suitable for the procedure is to wait for a donor heart to become available. As soon as a patient has been qualified for a transplant, he or she will be placed on a waiting list and his or her condition will be continuously monitored. A patient may be temporarily removed from the waiting list if something happens that affects his or her capability to accept the transplant. While waiting for a donor, devices such as ventricular assist devices (VADs) will be used to strengthen the heart and temporarily support the patient's life.
Once a donor heart becomes available, a donor-recipient match will be made based on the following factors:
- Blood type
- Size of the donor heart
- Medical needs of the potential recipient
- Antibodies of the recipient
- Time spent by the recipient on the waiting list
A donor heart can only be used for a transplant within four hours after it has been harvested from a recently deceased patient. Thus, it is usually taken to a transplant centre that is near the hospital where it came from. The patient on the waiting list will be notified via a mobile phone or a pager provided by the transplant centre.
The heart transplant surgery involves removing the patient's original heart by transecting the main pulmonary artery, aorta, and the superior and inferior vena cavae. The left atrium is then divided, while the back wall of the left atrium is left in place with the pulmonary vein openings. After removing the diseased heart, the cardiologist connects the donor heart to the body by sewing its vena cavae, aorta, pulmonary artery, and left atrium.
Possible risks and complications
A heart transplant is a major surgery and comes with its fair share of possible complications and risks, which include those that come with the use of any kind of anaesthesia, such as:
- Negative reactions to the medication
- Breathing problems
The possible complications and risks that may happen during the whole surgery and transplant procedure are the following:
- Blood clots
- Wound infection
- Damage to the kidney or liver
- Cancer due to the drugs used to prevent the rejection of organ
- Heart attack or stroke
- Problems in heart rhythm
- High cholesterol levels, diabetes, and bone thinning
- Coronary artery disease
- Rejection of the heart
Although a heart transplant is done to prolong a person's life, it is a risky procedure. The major risk is if the body rejects the donor heart, which occurs because the body's immune system may consider it as a foreign object that does not belong to the body, therefore fighting it off. To prevent rejection, patients are required to take immunosuppressant drugs. About 25% of heart transplant patients still live with signs of rejection even after a year after the surgery.
Biopsies are usually performed to observe whether the body is rejecting the donor heart or not. Signs that may indicate that the body is rejecting its new heart include the following:
- Shortness of breath
- Weight gain
- Urine problems
Bernstein D. Pediatric heart and heart-lung transplantation. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 437.
Acker MA, Jessup M. Surgical management of heart failure. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 31.
Costanzo MR, Dipchand A, Starling R, Anderson A, Chan M, Desai S, et al. International Society of Heart and Lung Transplantation Guidelines. The International Society of Heart and Lung Transplantation Guidelines for the care of heart transplant recipients. J Heart Lung Transplant. 2010;29(8):914-956.
Jessup M, Abraham WT, Casey DE, Feldman AM, Francis GS, Ganiats TG, et al. 2009 focused update: ACCF/AHA Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation. 2009; 119(14):1977-2016.