Introduction
In the three decades since the performance of the first human heart
transplant in December 1967, the procedure has changed from an experimental
operation to an established treatment for advanced heart disease. Approximately
2,300 heart transplants are performed each year in the United States.
In 1981, combined heart and lung transplants began to be used to treat
patients with conditions that severely damage both these organs. As of 1995,
about 500 people in the United States and 2,000 worldwide have received
heart-lung transplants.
There have been two main barriers to increasing the number of successful
operations. In 1983, the first barrier to successful transplantations--rejection
of the donor organ by the patient--was overcome. The drug cyclosporine was
introduced to suppress rejection of a donor heart or heart-lung by the patient's
body. Cyclosporine and other medications to control rejection have significantly
improved the survival of transplant patients. About 80 percent of heart
transplant patients survive 1 year or more. About 60 percent of heart-lung
transplants live at least 1 year after surgery. Research is under way to develop
even better ways to control transplant rejection and improve survival.
Organ availability is the second barrier to increasing the number of
successful transplantations. Hospitals and organizations nationwide are trying
to increase public awareness of this problem and improve organ distribution.
What happens during a heart or heart-lung transplant?A transplant
is the replacement of a patient's diseased heart or heart and lungs with a
normal organ(s) from someone--called a donor--who has died. The donor's organ(s)
is completely removed and quickly transported to the patient, who may be located
across the country. Organs are cooled and kept in a special solution while being
taken to the patient.
During the operation, the patient is placed on a heart-lung machine. This
machine allows surgeons to bypass the blood flow to the heart and lungs. The
machine pumps the blood throughout the rest of the body, removing carbon dioxide
(a waste product) and replacing it with oxygen needed by body tissues. Doctors
remove the patient's heart except for the back walls of the atria, the heart's
upper chambers. The backs of the atria on the new heart are opened and the heart
is sewn into place. A similar process is followed in heart-lung transplants,
except doctors remove the heart and lungs as a unit from the donor; the new
lungs are attached first, followed by the heart.
Surgeons then connect the blood vessels and allow blood to flow through the
heart and lungs. As the heart warms up, it begins beating. Sometimes, surgeons
must start the heart with an electrical shock. Surgeons check all the connected
blood vessels and heart chambers for leaks before removing the patient from the
heart-lung machine.
Patients are usually up and around a few days after surgery, and if there are
no signs of the body immediately rejecting the organ(s), patients are allowed to
go home within 2 weeks.
Why are transplants done?A transplant is considered when the heart
is failing and does not respond to all other therapies, but health is otherwise
good. The leading reasons why people receive heart transplants are:
- Cardiomyopathy--a weakening of the heart muscle.
- Severe coronary artery disease--in which the heart's blood vessels become
blocked and the heart muscle is damaged.
- Birth defects of the heart.
Heart-lung transplants are performed
on patients who will die from end-stage lung disease that also involves the
heart. Alternative therapies for these patients have been tried or considered.
Leading reasons people receive heart-lung transplants are:
- Severe pulmonary hypertension--a large increase in blood pressure in the
vessels of the lungs that limits blood flow and delivery of oxygen to the rest
of the body.
- A birth defect of the heart that results in Eisenmenger's complex--another
name for acquired pulmonary hypertension.
Who can have a transplant?Patients under age 60 are the most likely
heart transplant candidates. Patients under age 45 are generally accepted for
heart-lung transplants. In both cases, patients must be suffering from end-stage
disease and be in good health otherwise. The doctor, patient, and family must
address the following four basic questions to determine whether a transplant
should be considered:
- Have all other therapies been tried or excluded?
- Is the patient likely to die without the transplant?
- Is the person in generally good health other than the heart or heart and
lung disease?
- Can the patient adhere to the lifestyle changes--including complex drug
treatments and frequent examinations--required after a transplant?
Patients who do not meet the above considerations or who have
additional problems--other severe diseases, active infections, or severe
obesity--are not good candidates for a transplant.
How are donors found?Donors are individuals who are brain dead,
meaning that the brain shows no signs of life while the person's body is being
kept alive by a machine. Donors have often died as a result of an automobile
accident, a stroke, a gunshot wound, suicide, or a severe head injury. Most
hearts come from those who die before age 45. Donor organs are located through
the United Network for Organ Sharing (UNOS).
Not enough organs are available for transplant. At any given time, almost
3,500 to 4,000 patients are waiting for a heart or heart-lung transplant. A
patient may wait months for a transplant. More than 25 percent do not live long
enough. Yet, only a fraction of those who could donate organs actually do.
Does a person lead a normal life after a transplant? After a heart
or heart-lung transplant, patients must take several medications. The most
important are those to keep the body from rejecting the transplant. These
medications, which must be taken for life, can cause significant side effects,
including hypertension, fluid retention, tremors, excessive hair growth, and
possible kidney damage. To combat these problems, additional drugs are often
prescribed.
A transplanted heart functions differently from the old one. Because the
nerves leading to the heart are cut during the operation, the transplanted heart
beats faster (about 100 to 110 beats per minute) than the normal heart (70 beats
per minute). The new heart also responds more slowly to exercise and doesn't
increase its rate as quickly as before.
A patient's prognosis depends on many factors, including age, general health,
and response to the transplant. Recent figures show that 73 percent of heart
transplant patients live at least 3 years after surgery. Nearly 85 percent of
patients return to work or other activities they like. Many patients enjoy
swimming, cycling, running, or other sports.
As noted, 60 percent of patients who receive combined heart-lung transplants
survive at least 1 year. Fifty percent live at least 3 years.
What are the risks from transplants?The most common causes of death
following a transplant are infection or rejection of the heart. Patients on
drugs to prevent transplant rejection are at risk for developing kidney damage,
high blood pressure, osteoporosis (a severe thinning of the bones, which can
cause fractures), and lymphoma (a type of cancer that affects cells of the
immune system).
Coronary artery disease (atherosclerosis) is a problem that develops in
almost half the patients who receive transplants. Normally, patients with this
disease experience chest pain and/or other symptoms when their hearts are under
stress. This is called angina and is an early warning sign of a blocked heart
artery. However, transplant patients may have no early pain symptoms of a
blockage building up because they have no sensations in their new hearts.
Thirty to fifty percent of patients who receive a heart-lung transplant
develop bronchiolitis obliterans, in which there are obstructive changes in the
airways of the lungs.
What does rejection mean? The body's immune system protects the
body from infection. Cells of the immune system move throughout the body,
checking for anything that looks foreign or different from the body's own cells.
Immune cells recognize the transplanted organ(s) as different from the rest of
the body and attempt to destroy it--this is called rejection. If left alone, the
immune system would damage the cells of a new heart and eventually destroy it.
In a heart-lung transplant, immune cells may also destroy healthy lung tissue.
To prevent rejection, patients receive immunosuppressants, drugs that
suppress the immune system so that the new organ(s) is not damaged. Because
rejection can occur anytime after a transplant, immunosuppressive drugs are
given to patients the day before their transplant and thereafter for the rest of
their lives. To avoid complications, patients must strictly adhere to their drug
regimen. The three main drugs now being used are cyclosporine, azathioprine, and
prednisone. Researchers are working on safer, more effective immunosuppressants
for future testing. Some of the more promising drugs are FK-506 and
mycophenolate mofetil.
Doctors must balance the dose of immunosuppressive drugs so that a patient's
transplanted organ(s) is protected, but his or her immune system is not
completely shut down. Without an active enough immune system, a patient can
easily develop severe infections. For this reason, medications are also
prescribed to fight any infections.
To carefully monitor transplant patients for signs of heart rejection, small
pieces of the transplanted organ are removed for inspection under a microscope.
Called a biopsy, this procedure involves advancing a thin tube called a catheter
through a vein to the heart. At the end of the catheter is a bioptome, a tiny
instrument used to snip off a piece of tissue. If the biopsy shows damaged
cells, the dose and kind of immunosuppressive drug may be changed. Biopsies of
the heart muscle are usually performed weekly for the first 3 to 6 weeks after
surgery, then every 3 months for the first year, and then yearly thereafter.
How much do transplants cost?According to the UNOS, the estimated
first year charges for a heart transplant is $209,100, and annual followup
charges are $15,000. In most cases these costs are paid by private insurance
companies. More than 80 percent of commercial insurers and 97 percent of Blue
Cross/Blue Shield plans offer coverage for heart transplants. Medicaid programs
in 33 states and the District of Columbia also reimburse for transplants. Heart
transplants are covered by Medicare for Medicare-eligible patients if the
operation is performed at an approved center.
Approximately 70 percent of commercial insurance companies and 92 percent of
Blue Cross/Blue Shield plans cover heart-lung transplants. Medicaid coverage for
heart-lung transplants is available in 20 states. According to the UNOS,
estimated first year charges for a heart-lung transplant is $246,000, and annual
followup charges are $18,400.
What will transplants be like in 5 to 10 years? Hospitals
nationwide are trying to set up a better system for distributing organs to
patients in need. Researchers are looking for easier methods to monitor
rejection to replace the regular biopsies that are needed now. Work is
progressing to make immunosuppressive drugs with fewer long-term side effects so
that coronary artery disease development and lung destruction may by prevented.
Keeping on Top of Your Condition
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