All About Heart Transplantation

(LifeWire) - When Is a Heart Transplant Needed?

A heart transplant is a major operation during which a recipient's heart is removed and replaced with a donor heart.

Heart transplants are performed when severe heart failure isn't improving with other treatments. Heart failure occurs when the heart muscle becomes progressively weaker, reducing its ability to effectively pump blood throughout the body. Since blood carries oxygen, and all of the body's organs and tissues require oxygen to function properly, the condition can become life-threatening.

Any medical condition that causes the heart muscle to grow weak can result in heart failure, including repeated heart attacks, high blood pressure, diseases that affect the heart's valves, infections, damage to the heart muscle (from alcohol or drug use) and congenital heart defects (structural abnormalities that babies are born with).

 How Are Donor Hearts Allocated?

Unfortunately, there are many more patients who could benefit from a heart transplant than there are available hearts. About 2,660 people are on the heart transplant list; just more than 2,100 heart transplants are performed yearly.

Since there are more people who need heart transplants than the number of available donor hearts, a careful process is used to determine whether someone should be put on the waiting list for a heart. This process is carried out by a transplant team, which generally includes a heart doctor (cardiologist), heart surgeon, transplant coordinator, social worker, dietitian and psychiatrist. These professionals evaluate potential heart transplant candidates through as series of interviews and medical testing to see that that they meet a number of strict criteria:

• Their heart disease needs to be advanced enough to be truly life-threatening (most transplant candidates are considered to be at risk of dying within the next one to two years).
• Other treatment possibilities have been exhausted.
• They must be physically healthy enough (with the exception of their weak heart) to endure the operation.
• They must be psychologically strong enough to handle the stress associated with a heart transplant and the kinds of lifestyle demands that are required after heart transplantation.

Certain conditions prevent an individual from being placed on the waiting list for a heart, including:

• Age older than 70
• Problems with blood circulation
• Severe kidney, lung or liver disease
• Untreatable high blood pressure in the lungs (pulmonary arterial hypertension)
• Cancer
• Psychological or emotional problems that would interfere with the individual adhering to the lifestyle changes required after a heart transplant, including lifelong use of medication
• Certain infections

Once the transplant team has approved placing an individual on the transplant list, their information is entered in to a national registry called "United Network for Organ Sharing (UNOS)." This organization maintains a waiting list of transplant candidates for all types of organs. When an organ becomes available, anywhere in the nation, strict guidelines determine which candidate on the list will receive that organ -- UNOS has a mandate to avoid any bias because of a potential candidate's financial situation, social standing, gender, race, religion or other personal, nonmedically relevant status.

How Long Is the Wait for a Heart Transplant?

Awaiting an appropriate heart can take several months to several years. Unfortunately, some people don't survive the wait. Others are removed from the list when they develop a condition that excludes them from receiving a heart transplant (such as a severe infection, cancer or a stroke). Once they have made a sufficient recovery, they may be able to be put back on the list.

Hearts become available when another individual has been declared brain dead, perhaps because of a head injury after a car accident, gunshot wound or brain bleed. In these kinds of situations, the donor's brain injury may be severe enough to cause death, but the heart may be perfectly healthy. A donor is identified when he or she has previously signed a wallet card or driver's license sticker expressing a desire to donate organs in the event of death, or when family members request that their loved one's organs be used for transplantation.

What Happens When a Heart Becomes Available?

Patients who are on the transplant list carry a pager with them at all times, so they are available at a moment's notice to report to the transplant center. When a donor heart becomes available, time is of the essence; UNOS is notified of the availability of a donor heart, and the waiting list is evaluated. The ultimate recipient is identified by

• A tissue match - To make sure that the recipient's body doesn't identify the organ as foreign and attack and destroy it, certain chemical markers in the donor's and recipient's blood and tissues must be compatible.
• How critically ill the potential recipient is - UNOS tries to get the organ to the sickest patient first.
• Size - The donor and the potential recipient must be of reasonably similar height and weight.

The heart transplant operation takes about four hours. A bypass machine is used to keep the recipient's blood oxygenated while his or her original heart is removed and the donor heart is sewn in to place. Recovery from the operation can take some time. Most heart recipients have been quite ill for some time before the surgery, so they need to recuperate and rehabilitate from their lengthy illnesses, as well as from the surgery itself. They also need to learn about the medications that they'll be taking to prevent their body from rejecting the new heart.

According to the National Institutes of Health, about 88% of heart transplant patients are still living one year after surgery, 72% are alive 5 years after surgery, about 50% are alive after 10 years and 16% are alive 20 years after a heart transplant.

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