Heart transplantation has emerged as a viable therapeutic strategy for select patients with end-stage heart disease, offering extended survival and improved quality of life. Patients with severe heart failure have a 1- to 2-year mortality rate approaching 50%, despite advanced medical treatment. The first heart transplant in human beings was done in South Africa in 1967 by Dr. Christian Barnard; the patient lived for 18 days. Approximately 4000 heart transplantation procedures are performed annually worldwide. Long-term outcomes after transplantation have improved with the advances made in transplant candidate selection, surgical techniques, immunosuppressive regimens, and postoperative care. One year survival averages about 85%-90% and the 12 yr survival rate is approximately 50% by the International Society for Heart and Lung Transplantation (ISHLT) registry.
How is a heart transplantation done?
Heart transplantation consists of three operations.
The first operation is harvesting the heart from the donor. The donor is usually an unfortunate person who has suffered irreversible brain injury called "brain death". Very often these are patients who have had major trauma to the head, for example, in an automobile accident. The victim's organs, other than the brain, are working well with the help of medications and other "life support" that may include a respirator or other devices. A team of physicians, nurses, and technicians goes to the hospital of the donor to remove donated organs once brain death of the donor has been determined. The removed organs are transported on ice to keep them alive until they can be implanted. For the heart, this is optimally less than four hours.
The second operation is removing the recipient's damaged heart. Removing the damaged heart may be very easy or very difficult, depending on whether the recipient has had previous heart surgery (as is often the case). If there has been previous surgery, cutting through the scar tissue may prolong and complicate removal of the heart.
The third operation is the implantation of the donor heart. This operation basically involves the creation of only five lines of stitches, or "anastomoses". These suture lines connect the large blood vessels entering and leaving the heart. Remarkably, if there are no complications, most patients who have had a heart transplant are home about one week after the surgery.
Our immune system attacks transplanted organs. This is what happens when organs are rejected; they are recognized as foreign by the body. Rejection are controlled with powerful "immunosuppressive" medications. If there is not enough immunosuppression the organ can reject acutely. Even when it seems that there is no active rejection, there may be more subtle chronic rejection that consists of a growth of tissue, something like scar tissue, which causes blockage of the blood vessels of the heart. The blockage of the vessels is the process that ultimately causes the transplanted heart to fail. It is this chronic rejection that is the major limiting factor for the long-term success of heart transplantation.. While immune suppression blocks rejection, because it suppresses the immune system, transplant patients are more susceptible to infection and cancers of various types.