Success Of Transplants In Treating Heart Conditions Biology Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Heart transplants save the lives of thousands of people every year. But many more patients are waiting for a new heart to become available and hundreds will die without ever getting a second chance. Some people do not require a transplant, but suffer from heart problems which affect a big part of their lives. Most heart transplants are carried out on people who have severe heart failure. This is when the heart becomes less efficient at pumping blood around the body. Transplants are also carried out on people who have cardiovascular disease (CVD). CVD is all the diseases of the heart, such as coronary heart disease (atherosclerosis, angina and myocardial infarction).

Coronary heart disease is caused by a build up of fatty deposits on the walls of coronary arteries. This causes the artery to narrow, and makes it harder for the artery to supply the heart muscle with blood and oxygen. The medical term for this condition is atherosclerosis and the fatty material is known as atheroma. Over time, the artery may become so narrow that it cannot deliver enough blood oxygen to your heart, especially when you're exerting yourself. This can lead to angina - a pain or discomfort in your chest.

Congenital heart disease is an abnormality of the heart that a person has had since birth. The word congenital means 'present from birth', and conditions vary from simple problems with minor consequences to complex abnormalities with a more serious outcome. The heart or its vessels or valves may not be properly formed or there could be holes between the chambers of the heart. Some defects do not require any treatment initially but many may need medical treatment or surgery shortly after birth or later on in life.

A diseased or damaged valve can affect the flow of blood in two ways. If the valve does not open fully, it will obstruct the flow of blood. This is called valve stenosis. If the valve does not close properly, it will allow blood to leak backwards. This is called valve incompetence or regurgitation. Many people who suffer from heart valve problems after a transplant have a higher chance of getting endocarditis, which is an infection of the heart's valves or its inner lining. It is most common in people who have a damaged, diseased, or artificial heart valve.

However, not everyone who has these problems is suitable for a transplant. The number of transplants is still limited by the lack of available donors. A heart transplant itself sometimes may not be the answer to a heart problem, as tissue can be rejected by the patient's immune system resulting in a higher chance of getting endocarditis. Medications that suppress the immune response are used to reduce the risk of rejection. Sometimes doses of these medications need to be adjusted. Dose adjustments are needed if symptoms of rejection appear or if side effects are intolerable. Side effects of these medications can be serious. These include risk of infection, diabetes, osteoporosis (thinning of the bones), high blood pressure, kidney disease, and cancer - especially lymphoma and skin cancer. During the first year after a heart transplant, people often rapidly lose bone from their spine and hips. About 35 percent of people who receive heart transplants will suffer broken bones during the first year after transplantation [1].


Heart transplantation has a high early mortality. 15-20% of recipients die within a year of the operation in the UK. Thereafter the death rate is constant, at about 4% a year for the next 18 years, so that 50% of patients can expect to be alive after 10 years and 15% after 20 years [2].

"As of May 30, 2008, the one-year survival rate in the US was 87.5 percent for males and 85.5 percent for females; the three-year survival rate was about 78.8 percent for males and 76.0 percent for females. The five-year survival rate was 72.3 percent for males and 67.4 percent for females," says the American Heart Association [3].

Figure 2: Patient survival rate [4]

Long-term patient survival for adult (≥16 years) recipients after first heart only transplants in the UK is shown above (figure 2). The graph shows that the patient survival rate is declining rapidly. However, the survival rate between the years 2000 - 2002 did increase compared to 1997 - 1999. However, between the years of 2003 and 2006 the survival rate dropped significantly, which is putting constant pressure on the NHS to come up with an alternative solution to change this trend.

Possible solutions

1) Organ Care System (OCS) - The OCS keeps donor hearts functioning while they are transported in a sterile chamber to recipients. The heart is connected at the aorta, the pulmonary artery and the left atrium, allowing it to be fed with oxygenated and nutrient-rich blood from the donor kept at body temperature.

Currently donated hearts are cooled with ice in conditions in which they deteriorate rapidly, giving surgeons only around four hours between their removal from donors and their implantation in recipients.

Figure 3: OCS [6]The technology, developed by US company TransMedics, could save health care systems millions of pounds by cutting the length of time patients wait for donor organs, speeding up recovery, shortening hospital stays and reducing the need to treat complications [6].

Twenty patients received donor hearts that were maintained by the OCS in a beating state for an average time of 4 hours. The study lasted 30 days and resulted in a survival rate of 100%. Results showed that the patients recovered more quickly in terms of the average time spent by a patient on a ventilator and in the ICU, which were 10.7 hours and 24.3 hours, respectively [7].

So far the OCS looks to be the most appropriate solution to increase the survival rate of heart transplants. It seems that the OCS will be used by the NHS more frequently as Royal Brompton & Harefield NHS Trust surgeons successfully carried out their first transplant in 2007 on a 61-year-old patient.

"By allowing organs to be transported further, the OCS has the potential to increase the number of useable transplant organs and therefore also increase the total number successful transplant operations."

Consultant cardiac and transplant surgeon at Royal Brompton & Harefield NHS Trust, Mr Mario Petrou.

The OCS looks promising for patients waiting for a heart transplant, but also for those waiting for a donated organ [15].

The trial sites participating in the study included the Clinic for Thoracic & Cardiovascular Medicine, Bad Oeynhausen, the German Heart Institute in Berlin, Germany, Papworth Hospital in Cambridge and Harefield Hospital in Middlesex.

Figure 4: An artificial heart displayed at the London science museum2) Artificial heart - Artificial hearts beat almost like a real heart. The device uses electronic sensors to regulate the heart rate and blood flow and may offer hope to heart disease sufferers unable to receive a transplant [14].

The SynCardia temporary CardioWest artificial heart is currently approved for patients dying who were not able to receive a donor heart. The artificial heart is temporary and is implanted until a heart is available for transplant.

There have already been more than 800 implants. During the 10-year pivotal clinical study, 79% of patients receiving the Total Artificial Heart survived until donor hearts were available for transplant [8].

Figure 5 [8]Last year, over 400 people died waiting for a donor heart.The artificial heart may not be as successful as the OCS, but is very promising as people who were not able to receive a donor heart can be kept alive a little while longer until a heart is available [15].

Ethical and social issues

Around 40,000 patients are on EU waiting lists for a transplant, and it is thought ten people a day die waiting in vain for a donor organ [9]. Some members of the public in the UK carry Donor Cards in their wallets, which state that the person wishes to be a donor in the event of their death. However, in some cases when a person dies the family has to give consent and they may reject the idea of organ donation.

Some people are made to wait on a waiting list for many years and end up not getting hold of a donor heart. People can choose to go for an alternative solution, such as seeing a private doctor or using one of the possible solutions mentioned earlier. Most working class people will not be able to afford an alternative solution, whereas middle or upper class people are more likely to have the money to see a private doctor.

Few groups do not favour organ donation or transplantation; these include Shinto and those who follow the folk customs of the Gypsies. While demand for donor organs is increasing, more than half of all hearts for which consent for donation has been given go unused, partly because of the limits of cold preservation methods.

Not everyone has the chance for a second life and it could mean that a person might die or he/she may have to live their life with a bad heart and will not get the benefits from life that he/she should.

There is a controversial issue regarding how organs are allocated between patients. For example, some believe that livers should not be given to alcoholics in danger of reversion, while others view alcoholism as a medical condition like diabetes.


The benefits of a heart transplant are life changing. It can restore mobility, energy, and life. It offers people the chance of a second life.

Using donor cards can increase the supply of hearts for transplant. People will no longer have to wait in a queue for months. All major religions accept organ donation, they recognise it as the ultimate gift. Most religions like the Roman Catholic Church are in favour of organ donation as acts of charity and as a means of saving a life. Some impose certain restrictions. For example, Jehovah's Witnesses require that organs be drained of any blood, and Muslims require that the donor have provided written consent in advance.

If the number of donor hearts increases, this will help the SynCardia temporary CardioWest artificial heart (figure 4) to succeed. This artificial heart is only temporary and the quicker it is replaced with a donor heart, the higher the chance of survival.

The organ care system has the potential to increase the number of donor organs which can be used for an organ transplant. So far more than 14 million people have joined the NHS Organ Donor Register [15]. This means if the OCS (Figure 3) is used by the NHS throughout the UK then fewer hearts will go to waste, thus increasing the survival rate.


Heart transplantation can save the lives of many people, however it has many risks. Risks of heart transplants are huge. Tissue can be rejected by the patient's immune system which can result. People often rapidly lose bone from their spine and hips. Side effects of these medications can be serious.

Rejection of the Donor Heart

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 body" and attacks it.

25% of patients who have undergone a heart transplant have signs of rejection during the first year. 50% of rejections occur within 6 weeks after transplantation, and most in the first 6 months [11].

Side effects from Medicines

Patients are provided with medicines that stop the immune system from attacking the donor heart. These medicines are essential, as the immune system may detect the new heart as a foreign threat.

However these medicines can cause kidney damage. 25% of patients are affected by kidney damage within the first year [11].

Problems that occur after not following a health care plan after transplantation

The chance of heart transplant complications can increase if the health care plan is not followed. Patients are told to follow instructions to avoid any complications:

Control high blood pressure

Reduce cholesterol level

Be physically active

Achieve and maintaining a healthy weight

Control blood glucose if you have diabetes

No smoking

Eat a healthy, balanced diet and only drink moderate amounts of alcohol

Alternative method

1) A malfunctioning heart could be restored to health with the help of stem cells taken from the patient's own body. A stem cell is an undifferentiated cell whose daughter cells may differentiate into other cell types.

Scientists have shown that it is possible to grow cardiac stem cells in the laboratory before transplanting them back into a patient to replace damaged hair tissue. The findings demonstrate the possibility of rebuilding cardiac muscle that had been destroyed during a heart attack, offering an alternative treatment to a complete heart transplant. There are still concerns about possible risks to patients.

These types of stem cells are known as multipotent. These stem cells have already partially differentiated and they continue specialising as they develop. They can be isolated from a person's tissues and then guided to develop into a certain type of cell before being transplanted back into the same patient. This avoids the patient's immune system to reject the new tissue. Another advantage is that the ethical debate involved in extracting foetal stem cells is avoided, because neither foetal tissues nor an aborted embryo are necessary.

An article from The New Zealand Herald newspaper published an article in 2006 about an experiment carried out on pigs. A sample of living heart muscle (biopsy) was taken. Stem cells present in the biopsy was grown in the laboratory and then infused back into the animals heart by accessing the organ through a catheter inserted into an artery in the leg. Early results have been positive and trials on humans will be carried out in the next few years [10].

2) During the first year after a heart transplant, people often rapidly lose bone from their spine and hips. A study compared the safety and effectiveness of the drug alendronate (Fosamax) and the active form of vitamin D (calcitriol) in preventing bone loss at the spine and hip after a heart transplant.

In this study, people who have had a successful heart transplant received either active alendronate and a "dummy pill" instead of calcitriol, or active calcitriol and a dummy pill instead of alendronate for the first year after their transplant, starting within 1 month after transplant surgery. Bone density was measured in the hip and spine at the start of the study and after 6 and 12 months, and checked for broken bones in the spine. Unfortunately, results and further details for this trial are still not available. This source does not seem to be reliable as the trial was completed in April 2002 but the results are still not yet available, which makes this information incomplete and out of date. The trial has been sponsored by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) [1].

Evaluation of sources

Since the NHS was launched 60 years ago, the NHS has grown to become the world's largest publicly funded health service. It collects results annually and publishes it in its annual publication of 'Transplant activity in the UK'. The statistics from figure 2 can be regarded as reliable [3]. The American Heart Association is a national voluntary health agency whose mission is: "Building healthier lives, free of cardiovascular diseases and stroke." It collects data in a similar way to the NHS and is well known in America. The source can also be regarded as reliable as the statistics show a similar trend to other sources [4]. I thought it was necessary to obtain data on heart transplants from two different sources to make sure the trends are similar.

TransMedics is a medical company in the US who are on a mission to enable more patients with end stage organ failure to benefit from the accepted medical standard of care [7]. Clinical trials have been a successful. The results have been peer-reviewed and have gone through all the stages ensuring they are valid. A recent press release issued by the Royal Brompton & Harefield NHS Trust states that surgeons successfully carried out their first beating-heart transplant on a 61 year old patient. A surgeon said "The Transmedics OCS represents a major breakthrough. By keeping the heart beating with nutrient-rich blood, it stays healthier for longer. This gives the transplant team valuable hours to identify the best possible donor/recipient match from a wider geographical area," [15]. The information provided by both sources is similar which means it is reliable.

The New Zealand Herald is a broadsheet newspaper which is a good source for information on the latest news on science. The article was published by a scientist and the results would have been peer-reviewed and can be relied on [10].