Heart transplantation is an end-stage procedure which is carried out as a last resort only if the patient’s heart condition continues to deteriorate despite other forms of treatment to such an extent that his chances of survival drop to less than 50%.
This procedure involves replacing the patient’s diseased heart with a healthy heart from a donor, typically a person who has been medically certified to be brain-dead. The donor’s heart is completely removed and transported to the patient, who in turn has his diseased heart removed, leaving only the back walls of his upper chambers (the left and right atria). The back part of the atria of the donor’s heart is then opened up and that heart sewn into place by suturing its upper chambers to the recipient-patient’s atria. Next, the blood vessels are connected and blood flow through the heart and lungs is resumed. As the patient’s new transplanted heart warms up, it begins beating. Throughout the operation, the patient is kept alive by a heart-lung machine which pumps blood to the rest of his body.
Not every cardiac patient suffering from end-stage heart disease is a suitable candidate for a transplant. In general, the patient must
have exhausted all other alternative forms of treatment;
be likely to die if he does not have a heart transplant;
be in good health generally apart from his cardiac condition; and
be able to tolerate the many lifestyle changes (for instance, following a regime of complex medications and frequent medical examinations) required after a transplant.
Patients who do not meet these criteria – in particular, patients with other existing medical problems such as insulin-dependent diabetes or impaired kidney function – are not good candidates for a heart transplant.
As for heart donors, they are drawn from the pool of those who have been declared by doctors to be brain-dead, meaning: individuals whose brains show no signs of activity even though they are being kept physically alive by a ventilator. Donors tend to be people who have died as a result of a road traffic accident, severe head injury, or stroke. The ideal donor is one who
is under the age of 45;
does not suffer from any significant heart disease; and
does not have risk factors for cardiovascular disease, cancer, or other acute or chronic illnesses.
The blood group and weight of the donor must also match those of the intended recipient.
In the immediate aftermath of a heart transplant, the patient is closely monitored in an intensive care unit and remains on a ventilator for several hours until his condition stabilises. Thereafter, the patient will generally be up and about within a few days. In the ensuing weeks, the risk of rejection of the newly-transplanted heart is high as the patient’s body will treat that heart as a foreign object. To tide the patient over this period, immunosuppressants will be prescribed even though they will reduce his body’s natural defences against infections. Organ rejection and infection are most likely during the critical 1-month period following a heart transplant. Thereafter, if the patient’s condition is relatively stable, he may be discharged from hospital.
In general, a successful heart transplant will lead to the patient’s quality of life being dramatically improved. The patient will be able to lead a more active live, including returning to work. He is, however, likely to have to take immunosuppressants for the rest of his life so as to prevent his body from rejecting the transplanted heart. The survival rate of heart transplant patients varies significantly depending on factors such as age. On average, 80% of these patients survive for at least one year after the transplant; a further 70% of this group of survivors live for more than five years.