A heart transplant is surgery in which a patient with a life-threatening heart problem receives a new, healthy heart from a person who has died. In a heart transplant, the patient who receives the new heart (the recipient) is someone who has a 30 percent or greater risk of dying within 1 year without a new heart. Although there is no absolute age limit, most transplants are performed on patients younger than 70 years old.
The person who provides the healthy heart (the donor) is usually someone who has been declared brain dead and is still on life-support machinery. Heart donors are usually younger than 50, have no history of heart problems, and do not have any infectious diseases.
The recipient and donor must be a good match, meaning that certain proteins on their cells (called antigens) are similar. A good match will reduce the risk that the recipient's immune system will see the donor heart as a foreign object and attack it in a process called organ rejection.
Surgeons perform about 2,200 heart transplants each year in the United States. More than 3,000 people remain on the national waiting list for a donor heart. At these rates, up to 15 percent of patients on the waiting list will die before a suitable heart is found.