Heart Transplantation
A heart transplant replaces the patient's heart with a donor heart. Doctors remove the patient's heart by transecting the aorta, the main pulmonary artery, and the superior and inferior vena cavae. They then divide the left atrium, leaving the back wall of the left atrium with the pulmonary vein openings in place. The surgeon connects the donor heart by sewing together the recipient and donor vena cavae, aorta, pulmonary artery and left atrium. In patients with congenital heart disease, the surgeon may simultaneous transplant the lungs and the heart (Association, 2017). Although heart transplant surgery is a life-saving measure, it has many risks. Careful monitoring, treatment, and regular medical care can prevent or help manage some of these risks.
Most heart transplants involve replacing the patient's heart with the heart from a cadaveric donor. In certain situations, the patient's native heart is not removed; this is known as a heterotopic transplant. There have also been a few transplants in the U.S. involving a living heart donor. This may occur if one patient receives a heart-lung combination transplant but their heart is in good condition. This patient's heart may then be subsequently transplanted into another recipient. This is known as a "domino" heart transplant. (US Department of Health and Human Services, n.d.)
There are many reasons that are deemed necessary for a heart transplant. The most common reason is that one or both ventricles have not been functioning properly and severe heart failure is present. Ventricular failure can happen in many forms of congenital heart disease, but is more common in congenital defects with a single ventricle or if long-standing valve obstruction or leakage has led to irreversible heart failure. (Association, 2017).
As of June 4, 2018, the total waiting list of people who are in need of a heart transplant is 4,020 people. It is more prevalent for people between the age brackets of 50-64 years of age to receive a transplant of any organ than anyone else. There have been 69,987 total heart transplants since January 1, 1998 up until April 30, 2018. More than 7,000 candidates died in 2016 while on the wait list, or within 30 days of leaving the list for personal or medical reasons, without receiving an organ transplant (Sharing, 2018).
The history of heart transplant dates back to earlier than 1967 when there were more and more human anatomy and physiology being discovered. In 1967, the first successful heart transplant was done by a South African surgeon named Dr. Christiaan Barnard in Cape Town. In early December, Dr. Barnard's surgical team removed the heart of a 25-year-old woman who had died following an auto accident and placed it in the chest of Louis Washkansky, a 55-year-old man dying of heart damage. The patient survived for 18 days. Dr. Barnard had learned much of his technique from studying with the Stanford group. This first clinical heart transplantation experience stimulated world-wide notoriety, and many surgeons quickly co-opted the procedure. However, because many patients were dying soon after, the number of heart transplants dropped from 100 in 1968, to just 18 in 1970. It was recognized that the major problem was the body's natural tendency to reject the new tissues (Surgeons).
Over the next 20 years, important advances in tissue typing and immunosuppressant drugs allowed more transplant operations to take place and increased patients' survival rates. The most notable development in this area was Jean Borel's discovery of cyclosporine, an immunosuppressant drug derived from soil fungus, in the mid 1970s (Sharing, 2018).
Heart transplants are reserved for patients with severe heart failure like congenital heart disease. Congenital heart disease refers to disorders of the heart that are present at birth and that can affect adult patients in many ways. This term encompasses a range of cardiac defects, including atrial septal defect, which is a miscommunication between the right and left atrium, ventricular septal defect, described as a hole in the muscle which separates the right and left ventricles, and pulmonary stenosis, a narrowing of the valve between the right ventricle and the pulmonary artery.
Cardiomyopathy or heart muscle disease affects approximately 500,000 new patients per year in the United States. This group of disorders directly damages the muscle, impairing its ability to pump blood to other parts of the body. “In recent years, the definition of cardiomyopathy has been restricted to the idiopathic forms of myocardial disease and has been grouped into three general categories: (1) congestive or dilated cardiomyopathy, (2) hypertrophic cardiomyopathy, and (3) restrictive cardiomyopathy†(Tajik & Seward, 1980).
Congestive Heart Failure occurs when the heart is unable to maintain adequate circulation of blood in the tissues of the body or to pump out the venous blood returned to it. This weakening of the heart prevents it from circulating a sufficient quantity of oxygen to the body's tissues. Common symptoms associated with heart failure are fatigue, shortness of breath, joint swelling and weight gain.
Coronary Artery Disease is the number-one killer of men and women in the United States. Also known as coronary heart disease, this disorder involves the progressive narrowing of the arteries that nourish the heart muscle. Often this disease is asymptomatic, but if one or more of these arteries become severely narrowed angina may develop during exercise, stress, or other times when the heart muscle is not getting enough blood.
Valvular Disease in the heart is caused by a number of conditions including congenital defects, such as rheumatic fever, or rheumatic heart disease. In heart valve disease, problems arise when a valve fails to close properly (mitral valve prolapse) or open properly (valvular stenosis). In either case, the heart has to work harder to pump enough blood to the body, eventually leading to heart muscle damage. Congestive heart failure, syncope (fainting), and arrhythmias are common signs of valve disease (Center).
The risks of having a heart transplant include: failure of the donor heart, complications from medicines, infection, cancer, and problems that arise from not following a lifelong care plan after surgery. Over time, the new heart may fail due to the same reasons that caused the original heart to fail. Failure of the donor heart also can occur if your body rejects the donor heart or if cardiac allograft vasculopathy (CAV) develops. CAV is a blood vessel disease. Patients who have a heart transplant that fails can be considered for another transplant (called a retransplant).
CAV is a chronic (ongoing) disease in which the walls of the coronary arteries in the new heart become thick, hard, and less stretchy. CAV can destroy blood circulation in the new heart and cause serious damage. CAV is a leading cause of donor heart failure and death in the years following transplant surgery. CAV can cause heart attack, heart failure, dangerous arrhythmias, and sudden cardiac arrest. To detect CAV, your doctor may recommend coronary angiography yearly and other tests, such as stress echocardiography or intravascular ultrasound.
The most frequent cause of death in the first 30 days after transplant is primary graft dysfunction. This occurs if the new donor heart fails and isn't able to function. Rejection is one of the leading causes of death in the first year after transplant. The recipient's immune system sees the new heart as a foreign object and attacks it.
During the first year, heart transplant patients have an average of one to three episodes of rejection. Rejection is most likely to occur within 6 months of the transplant surgery. Factors such as shock or trauma to the donor heart or narrow blood vessels in the recipient's lungs can cause primary graft dysfunction. Doctors may prescribe medicines (for example, inhaled nitric oxide and intravenous nitrates) to treat this condition.
Taking daily medicines that stop the immune system from attacking the new heart is crucial, even though the medicines have serious side effects. Cyclosporine and other medicines can cause kidney damage. Kidney damage affects more than 25 percent of patients in the first year after transplant. When the immune system—the body's defense system—is suppressed, the risk of infection increases. Infection is a major cause of hospital admission for heart transplant patients. It also is a leading cause of death in the first year after transplant. Suppressing the immune system leaves patients at risk for cancers and malignancies. Malignancies are a major cause of late death in heart transplant patients. The most common malignancies are tumors of the skin and lips (patients at highest risk are older, male, and fair-skinned) and malignancies in the lymph system, such as non-Hodgkin's lymphoma.
High blood pressure develops in more than 70 percent of heart transplant patients in the first year after transplant and in nearly 95 percent of patients within 5 years. High levels of cholesterol and triglycerides in the blood develop in more than 50 percent of heart transplant patients in the first year after transplant and in 84 percent of patients within 5 years. Osteoporosis can develop or worsen in heart transplant patients. This condition thins and weakens the bones.
Not following a lifelong care plan increases the risk of all heart transplant complications. Heart transplant patients are asked to closely follow their doctors' instructions and check their own health status throughout their lives. Lifelong health care includes taking multiple medicines on a strict schedule, watching for signs and symptoms of complications, going to all medical checkups, and making healthy lifestyle changes, such as quitting smoking (Services, U.S. Department of Health & Human, n.d.).
After your heart transplant, your medical team will monitor you closely for heart rejection, which can happen in the heart muscle cells or in the heart's arteries. They will also watch for side effects of the immunosuppressive medications, which include diabetes, infection, kidney disease, cancer or high blood pressure. If any of these problems arise, your doctor will change the medication type or dose. You and your doctor may also decide to change your immunosuppressive medications as new drugs become available.
You will require regular checkups after your transplant by a transplant cardiologist. At these visits, your cardiologist will do blood tests to check the levels of your immunosuppressive drugs and look for side effects. He or she may also order electrocardiogram, echocardiogram and Holter monitoring to help monitor your heart rhythm and function, or an endomyocardial biopsy, which is a diagnostic procedure that surveys the sufficiency of your immunosuppressive therapy. Your doctor will evaluate your coronary arteries yearly or every other year to monitor for signs of narrowed coronary arteries in your transplanted heart. You should also have routine medical checkups to maintain overall health (Association, 2017).