A heart transplant is an open-heart surgery in which a severely diseased or damaged heart is replaced with a healthy heart from a recently deceased person. It may be a treatment option for heart failure due to conditions such as coronary artery disease, cardiomyopathy, congenital heart disease or valve disease.
Heart transplantation has made great strides over the years. Today, more than 85 percent of heart recipients will live at least an additional year and more than 70 percent will live five more years. However, patients continue to face a lengthy waiting list to receive a donor heart.
Researchers are working to develop equipment to improve the health and comfort for patients waiting for a donor heart and, ideally, to develop a mechanical heart that could permanently solve the shortage problem.
People who receive a heart transplant can expect to spend 10 days to two weeks in the hospital. The medical team will join them in the fight to keep the new heart free from infection or rejection by the body.
After being discharged from the hospital, patients must continue to take their medications and keep follow-up appointments. There are many changes that come with having a new heart, and depression is not uncommon. The support of family and friends during this difficult time is an important part of recovery.
About heart transplants
A heart transplant is an open-heart surgery in which a severely diseased or damaged heart is replaced with a healthy heart from a recently deceased person. Heart transplants have been successfully performed since 1967.
Unfortunately, the number of people waiting for a heart transplant is higher than the number of available organs. About 2,657 patients were waiting for a heart transplant in the United States as of July 2008, according to the United Network for Organ Sharing (UNOS), and 2,210 people received donated hearts in 2007.
A patient generally becomes eligible for a heart transplant when diagnosed as having end-stage heart disease, all other medical interventions have failed and the patient is stable enough to sustain a major surgery.
Coronary artery disease and cardiomyopathy are the most common heart conditions that may lead to a heart transplant. Other diseases include congenital heart disease (the most common reason for heart transplant in children), failure of a previous bypass or heart transplant and valvular heart disease. These conditions can lead to heart failure, in which the heart is unable to meet the body's demand for blood.
Most heart transplant patients are white males, according to the American Heart Association. More than half are between the ages of 50 and 64, and about 20 percent are between the ages of 35 and 49.
Heart transplants are sometimes performed along with lung transplants for individuals with end-stage lung disease due to conditions including:
Primary pulmonary hypertension. High blood pressure in the blood vessels of the lungs. This is considered a contraindication for a straight heart transplant, making a lung transplant necessary.
Eisenmenger syndrome. Any type of congenital heart disease that involves severe pulmonary hypertension. The condition accounts for nearly half of all heart-lung transplants.
Cystic fibrosis. A genetic disease that causes thick mucus to build up in the lungs.
Bronchiectasis. Destruction and widening of the lungs' large airways.
While waiting for a heart transplant
The first step to a heart transplant is being added to the list of people waiting for an organ donor. As part of this process, patients undergo a complete evaluation and maintain routine office visits with their physician. The patient and physician must keep the United Network for Organ Sharing (UNOS) aware of any changes that may affect the patient’s transplant status. Preliminary tests will include:
Blood tests. Tests that determine the amount of any given substance in the blood and identify abnormally high or low levels that may affect normal body functions.
Chest x-ray. An image of the chest on film or fluorescent screens. It is produced by using low doses of radiation and shows the general size, shape and structure of the heart and lungs.
Electrocardiogram (EKG). A recording of the heart's electrical activity as a graph on a moving strip of paper or video monitor. The highly sensitive electrocardiograph machine helps detect heart irregularities, disease and damage by measuring the heart's rhythms and electrical impulses.
Cardiac catheterization. A minimally invasive test that offers clear, accurate information about the heart chambers, the coronary arteries located on the surface of the heart and (depending on whether another test is done) the aorta.
Echocardiogram. This ultrasound technique allows comprehensive evaluation of the structure and function of the heart muscle and valves. Patients who are candidates for heart transplantation usually have severely depressed pumping function. The technique can also detect some reversible causes of heart failure such as valvular heart disease that can be surgically corrected.
Noninvasive evaluation of myocardial viability. Coronary artery disease is the underlying source of heart dysfunction in the majority of patients who require heart transplantation. Coronary artery disease impairs heart function by inducing scarring of the heart tissues due to shortage of oxygen-rich blood in the heart muscles. However, in some patients heart dysfunction may be reversible in the presence of viable tissues. Techniques such as dobutamine stress echocardiography and positron emission tomography (PET) can differentiate a scar from viable tissue. These tests can identify patients who may benefit from the restoration of blood supply to the heart through coronary artery bypass or angioplasty (revascularization procedures). Patients with mostly scar tissues are considered for transplant whereas those who may improve with revascularization may not require transplantation.
Other tests may be conducted depending on the conditions or symptoms present, and tests may be repeated periodically. Patients who have life-threatening illnesses unrelated to the heart (e.g., kidney failure, liver failure) are generally not candidates for a heart transplant.
The waiting period during which a patient is registered and awaiting delivery of a heart may be the most difficult part of the transplant process. The median wait time for a new heart is currently more than 200 days and is dependent on factors such as blood type, weight and health status.
Support groups and therapy are available to help people cope with the process. Most heart transplant teams have a social worker and/or a mental health professional available to help patients work through the emotional, medical and lifestyle changes that will likely accompany the procedure. In the meantime, the physician will continue medical therapies that can provide short-term relief of the heart condition.
In some cases, a ventricular assist device (VAD) or left ventricular assist device (LVAD) may be used to as a "bridge to transplant." A VAD helps one of the lower chambers of the heart (the ventricles) pump blood. The device may also be used after the transplant while the patient recovers from surgery. Some researchers hope that either the ventricular assist device or the total artificial heart will one day be used as a permanent solution to the problem of severe heart disease.
Heart transplant teams will do everything they can to help, but patients have the responsibility to make lifestyle changes that improve their situation in the short-term, including:
Quitting smoking. Many heart conditions are caused or aggravated by smoking. To prepare for a heart transplant, the use of all tobacco products must be stopped at least six months before the procedure. Use of such products not only continues a health risk for those awaiting a heart, it also endangers any chance of receiving a donated organ. Traces of tobacco products during random testing by the physician can lead to removal of a patient from the transplant registry.
Avoiding the use of alcohol and other controlled substances. These are forbidden for people who are on the waiting list. If an organ suddenly becomes available, these substances cannot be present in the patient’s system. This is because many of the drugs taken after the transplant are broken down (metabolized) in the liver. It is therefore important that the liver not be involved in metabolizing other substances, such as alcohol. Alcohol is not only broken down in the liver, but can cause liver damage. As a result, potential benefits of medications will be lost.
Eating a heart-healthy diet. It is important to adopt healthy dietary habits as soon as possible that will remain with the patient after a new heart has been received. For example, too much sodium in the diet can cause fluid buildup in the body, which, in turn, can make the heart work harder. Fluid retention can also be caused by medication. Transplant patients should also be aware that some of their medications can increase the appetite and raise glucose (blood sugar) levels. Just as excess fluid strains the heart, so does being overweight. Nutritionists typically are part of the transplant team, and will work with patients regarding a proper balance of foods as well as what foods to limit or avoid.
Getting regular exercise, under the direction of one’s physician. The patient needs to maintain strength for the surgery or will be removed from the waiting list.
Controlling diabetes and high blood pressure (hypertension). These conditions must be under control to reduce the risk of serious complications during surgery.
Before the heart transplant procedure
Patients waiting for a donor heart will generally carry a pager and be “on call.” When a suitable donor heart becomes available, the patient will be paged and told to come to the hospital immediately.
If the donor heart is in the same hospital as the recipient, then the surgery will be done as soon as all preparations have been made. If the donor heart is being transported by ambulance or by air, then the surgical team responsible for the transfer will keep the hospital team informed of its progress.
The hospital team will require about 20 minutes to prepare the donor for removal of the heart. Time is critical, because the donor heart can survive for only four to six hours outside the body.
After arriving at the hospital, the patient will be given specific preoperative medications and prepped for surgery. First, the chest area is shaved (if necessary). Next, the surgical team creates a sterile environment by swabbing the patient's chest with an antiseptic solution and covering the area in sterile surgical drapes. An intravenous (IV) line will be started, usually in the forearm or back of the hand.
When the time is right, the patient is given general anesthesia through the IV line. The patient will continue to breathe a mixture of oxygen and anesthetic gas to remain asleep throughout the surgery.
During the heart transplant procedure
After the patient is asleep, a device called the Swan-Ganz catheter may be inserted into the jugular vein in the neck. It is then threaded to the pulmonary artery, which transports blood from the heart to the lungs. The catheter measures heart function, pressures within the heart and lungs and oxygen levels within the blood. Medication is also delivered through the Swan-Ganz catheter. A breathing tube (endotracheal tube) will be inserted into the mouth and down the windpipe (trachea) to maintain an airway.
An incision is made through the chest and breastbone (sternum), and the ribs are separated. A heart-lung machine takes over the functions of the heart and lungs, freeing the heart from its normal function so that it can be removed. Some heart muscle is reserved during extraction to act as a support for the new heart as it is sewn into place.
When the new heart is positioned and the blood vessels are reattached, the heart incision is closed, the heart is restarted and blood circulation and oxygen are restored. The warmth of the blood should “wake up” the heart and stimulate it to start beating. If this does not occur, it may be necessary to start the heart using an electric shock (defibrillation). Once the blood is flowing through the new heart normally and without any leaks, the heart-lung machine is disconnected and the chest incision is closed.
After the heart transplant procedure
Continuous monitoring will follow the surgery. During this critical time, the cardiac surgeon, cardiologist and other members of the hospital staff will watch closely for any signs of heart rejection or infection. These are the two leading causes of death immediately after a heart transplant. Medications that suppress the body's natural immune system will be administered to counter the body's tendency to reject the new heart. These medications have dramatically reduced the number of rejections.
Patients are unlikely to be very active in the next couple of days, but should be able to walk around in just three or four days. The total length of a hospital stay after a heart transplant is about 10 days to two weeks. Once patients are discharged from the hospital, the cardiologist and primary physician will provide regular medical support, including biopsies and other diagnostic tests several times a year.
The new heart will beat significantly faster than the original heart and will not respond as promptly to increased physical stress (e.g., when exercising). This is because the new heart lacks the nerve connections that help a normal heart respond to changes in activity.
There are many unexpected adjustments that may face heart transplant patients. Depression is not uncommon during this time, and the support of families and friends is very important. Most transplant centers have social workers and/or psychiatrists who can provide some assistance for heart transplant patients and their families.
Benefits and risks of heart transplants
Even considering that patients are in a life-threatening situation at the time of transplant, about 87 percent of those who receive heart transplants survive for more than one year, according to the United Network for Organ Sharing (UNOS). Additionally, 73 percent live at least five years after the procedure.
Today's heart transplant recipients live longer after surgery than those who received heart transplants just 10 years ago. Many transplant recipients return to work and many participate in moderately strenuous activities, such as walking, swimming and even running. Studies have shown that exercise is a valuable tool for recovery during the healing period and beyond.
The improved life expectancy of patients after a heart transplant is largely due to immunosuppressive drugs, which reduce the body's tendency to reject the new organ. Rejection is a major risk associated with transplant surgery. When it occurs, the immune system sends out antibodies to destroy the new heart, which is perceived as foreign or "invading" tissues. Left unchecked, this rejection can result in extensive damage to, and imminent failure of, the transplanted heart.
The many possible side effects of immunosuppressants include trembling, elevated cholesterol levels and elevated blood pressure (hypertension). Patients taking some immunupressants are cautioned to avoid grapefruit juice and grapefruit. This combination increases blood levels of the drug and can cause nausea, lightheadedness and abdominal pain.
Certain tests can help predict whether the heart is likely to be rejected. These tests include:
Biopsies to monitor the body's response to the transplanted heart tissue. This involves using a thin tube to remove a small piece of heart tissue. The tube is inserted through a vein either in the groin or side of the neck. Biopsies are outpatient procedures that can be performed in less than an hour. They are performed often in the first four months after transplantation and less frequently in the months and years after that.
Blood tests (e.g., an enzyme test). Studies have found that the risk of transplant failure is three times greater among recipients with high levels of troponin I than those with normal levels of this enzyme.
Patients can do much to monitor themselves, as some symptoms may signal rejection. They include:
Dizziness, nausea or vomiting
Chest pain
Shortness of breath
Flu-like symptoms (e.g., chills, sore throat)
Fever over 100 degrees F
Rejection, however, is not necessarily an irreversible event. In fact, cardiac transplant patients experience an average of two to three episodes of rejection in the first year after transplantation. Up to 80 percent of patients will experience at least one episode of rejection. It could be that a patient needs different doses or timing of medication. This is why it is recommended that patients immediately contact their transplant center or team should any of the above symptoms occur.
The second risk is that of infection. Patients are urged to immediately report to their physician any of the following signs of infection:
Fever
Redness
Swelling
Drainage
When patients receive a new heart, they also receive new coronary arteries on the surface of that heart. Although these new coronary arteries may have less plaque buildup than their original coronary arteries, heart transplant recipients are more likely to develop coronary artery disease (CAD). This disease is thought to be part of the slow rejection process in the transplanted hearts. About 50 percent of heart transplant patients develop CAD. Therefore, patients must undergo a cardiac catheterization test periodically to check for the disease.
Researchers have been investigating ways to lower the risks of CAD in transplant patients. In one study, 40 heart transplant patients were given daily doses of antioxidant vitamins C and E in addition to cholesterol-lowering statins. Results showed only minimal thickening in artery walls compared to greater thickening among patients taking only cholesterol drugs. Further studies involving a larger number of heart transplant patients will need to demonstrate similar outcomes before this treatment can be offered.
Promising early results have also been seen with sirolimus, an immunosuppressive used since 1999 to help prevent kidney transplant rejection. In limited studies of human patients, sirolimus showed significant ability to slow down coronary artery disease.
About organ donations
Organs are obtained from people who give their consent to have certain organs donated. They can also be obtained by permission of next of kin when a suitable donor is considered to be "brain dead." Although almost 40 percent of donated kidneys are surgically removed from living donors, most major organ donations (e.g., the heart, lungs, liver) are pledged while living and removed when the donor dies. Like most organs, the heart can be obtained only from donors who died a "brain death," meaning that the brain died while the body remains on life support.
Donor hearts needn't always be perfect. For example, five-year results for people given hearts with mild-to-moderate left ventricular hypertrophy (LVH), a thickening of the main pumping chamber, were comparable to those who got hearts with no problems, according to recent research.
Because of the great demand for organ donors, generally healthy people are strongly encouraged to become donors. To become a donor, individuals over the age of 18 can sign a donor card, provide instructions in a legal document or inform relatives that they wish to donate.
Individuals should keep some indication of their willingness to donate on their persons at all times, such as in a wallet or purse, preferably in the form of a signed and witnessed donor card or, in some states, a donor indication on a driver's license.
Recent advances in heart transplants
The future of heart transplants may be brighter for the many people waiting to obtain one of a limited number of natural hearts. Some researchers are trying to find ways of prolonging life until a "match" organ can be found. For example, a biventricular pacemaker helps the heart pump more effectively, lessening the degree of heart failure. Some types of pacemakers also double as defibrillators, which detect and correct abnormal heart rhythms by sending electrical signals to the heart.
Recent research suggests that the drug daclizumab may prove effective at reducing organ rejection among heart transplant patients. A study showed that among the patients who did reject an organ ,it took much longer for those on daclizumab to reach a clinical end point, which was defined as rejection, heart dysfunction or death. Though the initial results appear promising, daclizumab needs to undergo further study before it is cleared for widespread use in heart transplants.
An experimental surgery called ventricular remodeling is also available for patients with end-stage dilated cardiomyopathy. A number of patients who underwent this surgery improved to the point that they were taken off the transplant waiting list. However, patients need immediate assistance from a ventricular assist device if the procedure fails. Cardiomyopathy patients whose bodies are too large for a standard donor organ may also be eligible for a heterotopic transplant or "piggyback" transplant. This is a procedure in which a donor heart is surgically sewn to the blood vessels near the patient's own heart, allowing the two hearts to pump side by side. However, the survival rate of this procedure tends to be lower than that of traditional transplant surgery.
Another experimental option is the use of a heart jacket, or mesh-like net that is wrapped around the failing heart. Early studies have shown that the jacket helps the heart function and stimulated changes in the shape and size of the heart. Studies have shown that patients with severe heart failure who are fitted with a heart jacket are less likely to need a transplant.
In 2006, the U.S. Food and Drug Administration (FDA) approved the first totally implantable artificial heart. The device was approved for patients with advanced heart failure involving both chambers of the heart. It is intended for patients with severe heart failure who are not likely to live longer than one month without intervention. These patients are typically not candidates for heart transplants due to advanced age or medical conditions.
The implantable system is composed of a mechanical heart that is placed in the chest and a controller and battery system that is implanted in the patient's abdomen. The artificial heart can be charged, allowing the patient free movement for up to two hours. Candidates must meet certain criteria to receive the heart and must have adequate room in the chest to accompany the device.
A longer-term goal for some researchers is the genetically engineered heart. The organ is composed of human tissues - perhaps one's own - and is cultured or grown over a period of months to match detailed specifications. Currently, this "heart-in-a-box" project exists only in the halls of a university research facility, but researchers have a goal to have cryogenically stored organs available for transplant in less than a decade.
The outlook for these technologies will depend on many factors, and their success or failure is not guaranteed. However, it does provide those in need of current and future heart transplants with the hope of additional treatment options in the coming years.
The waiting list for heart transplants
To be put on the waiting list for a heart transplant, a form must be completed by a facility that is a participating member of the United Network for Organ Sharing (UNOS). The UNOS member will enter the application (which includes information from the patient and his or her physician) into an online database. When a "match" organ becomes available, the hospital will be contacted by an organ procurement organization (OPO) about scheduling a transplant surgery with the patient.
The registration and selection process is based on urgency of need, size and blood type. A heart may be made available immediately, or patients may be placed on standby for several months or, in the least critical cases, even years. Once a patient has been registered as a transplant candidate, however, the physician will continuously report any change in his or her condition to UNOS.
The entire policy of the waiting list can be read online at www.UNOS.org. Despite the depth of this information, it is common to have specific questions about the list. One Web site that may be helpful is www.TransWeb.org, which presents information from UNOS officials in response to people's questions.
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about heart transplants:
How urgently do I need a heart transplant?
What determines where I am place on the waiting list?
How long can I expect to be on the waiting list for a new heart?
If my condition deteriorates, will I be moved up on the waiting list?
Will I benefit from using an LVAD before I receive a new heart?
Is using an artificial heart an option?
What are the chances that I will reject the new heart?
What is my expected survival time with a new heart?
What medications will I need after a heart transplant?
What can I expect in terms of recovery from the surgery?
What are my restrictions after the surgery?
Can you recommend resources for me regarding the heart transplant procedure?
