Heart Transplant Rejection

The human heart beats around 100,000 times in a day and pumps about 5,000 gallons of blood through our body every day. Heart transplant surgery is reserved for those patients who did not respond to any other treatment or surgery. Heart transplant rejection occurs due to our defense mechanism which deals with the transplanted heart just like it opposes any virus or bacteria. The rejection can be handled with immunosuppressive medication, which one has to take lifelong. The dosage will be altered by the doctor as and when required. One should be aware of the signs of organ rejection in a heart transplant, to enable early management.

What is heart transplant and why do you need a heart transplant?

A heart transplant is a major surgery in which a failing or diseased heart is replaced with a healthy donor’s heart. In a heart transplant, the donor’s heart is procured from a person who is dead or declared brain dead. A patient is recommended for a heart transplant due to heart failure which is not responding to any other treatment options.

Causes of heart failure in adults are due to:

• Cardiomyopathy, in which the heart muscles become weak, further leading to heart failure.
• Coronary Artery Disease (CAD), narrowing or blockage of coronary arteries due to build-up of fatty deposits or cholesterol.
• Heart valve not working properly.
• Abnormal heartbeats, which is not getting cured with any other treatment.
• Congenital heart defect (birth defect)
• Previous heart transplant failure.

Causes of heart failure in children are due to: 

• Congenital heart defect (birth defect)
• Cardiomyopathy

What is heart transplant rejection? What are the types of heart rejection?

The immune system of the human body seeks and destroys bacteria and viruses to keep us healthy. Unfortunately, the immune system considers the donor’s heart as a foreign substance and tries to attack it, which is known as heart transplant rejection. The first year of transplant is considered very critical from an organ rejection point of view.

Post-transplant your doctor will prescribe medicines, which help prevent heart rejection and you will be continuously monitored for any rejection symptoms. 

Types of heart rejection:

• Acute Cellular Rejection: Acute Cellular Rejection is the most common form of heart transplant rejection which usually occurs in the first 3 to 6 months of a heart transplant. It is caused due to T-cells (which is part of our immune system) attacking the cells of a donor’s heart.

• Humoral Rejection: Humoral Rejection is generally seen after several months or years of a heart transplant, however, there are chances of its occurrence during the first month of the transplant. In this type of rejection, the antibodies damage the blood vessels in our body and in some cases coronary arteries are also damaged, hence affecting the blood flow to the heart. It is also known as acute antibody rejection.

• Coronary Artery Vasculopathy: This form of heart rejection affects the coronary arteries by thickening of the inner lining of blood vessels which will further reduce the blood flow to the heart. Coronary artery vasculopathy occurs in the long-term.

Heart transplant rejection generally happens due to the attack of the immune system or not taking the prescribed medications properly. However, there are other factors involved too like a genetic mismatch between the donor and recipient, previous heart transplant failure etc. After a heart transplant, your doctor will put you on a medication plan, which includes immunosuppressive medications to prevent heart rejection. The dosage of medicines will be changed, as the time progress and based on the health of your heart. It is very important that you don’t miss your medicines, but many people who take their prescribed medicines on time still face heart transplant rejection and reasons for such rejection are not know yet.

Heart transplant rejection can be acute or chronic. Acute rejection usually happens within the first year of the transplant, which is quite common. Chronic rejection is narrowing of coronary arteries and usually occur after months or years of transplant.

Signs and Symptoms of heart transplant rejection:

• Pain in the chest
• Fast or abnormal heartbeats
• Swelling in hands, feet or ankles
• Decreased urine output
• Loss of appetite
• Shortness of breath
• Sudden weight gain
• Fever
• Flu-like symptoms (fatigue, chills, nausea etc.)

If you come across any of the above symptoms, please contact your doctor immediately. However, in some cases, heart transplant rejection has occurred without any symptoms. Heart rejection can be treated, but if ignored,  can lead to death.

Factors affecting the chances of acute heart transplant rejections are:

• The chances of heart transplant rejection are more during the initial period (weeks or months) after the surgery, later the risk gradually decreases.
• Female heart recipient or female heart donor is more at risk of rejection.
• African-American heart recipient is more at risk.

Factors affecting the chances of chronic heart transplant rejections are:                 

• Recipient is of young age
• Male donor or elderly heart donor
• Recipient has high cholesterol
• Recipient has the history of acute heart rejection
• Donor or recipient has coronary heart disease
• Insulin resistance
• Infection due to cytomegalovirus

The only way to diagnose heart transplant rejection is through cardiac biopsy and blood test. Initially, after transplant surgery, the patient undergoes multiple routine biopsies. This helps the doctor to monitor rejection symptoms. Often even before you feel the first sign, the biopsy report reveals heart rejection.

In some cases, blood test results reveal acute rejection. Coronary angiography, Intravascular ultrasound, cardiac stress testing etc. are also suggested to have a better look at the blood vessels and to check for chronic rejection.

Other tests like ECG, are also recommended to check the functioning of a transplanted heart.

Heart or cardiac rejection doesn’t mean that the patient is losing the heart. It means that we have to treat the rejection. Treatment depends on various factors like severity of rejection, symptoms, current prescribed medications and type of rejection occurring.

Treatment for acute rejection may include :

• Anti-rejection dosage is either increased or increase in how often you have to take it.
• Different anti-rejection medicine is prescribed.
• New medicine to suppress the immune system is included

Treatment for humoral rejection may include :

• Plasmapheresis, as a rescue therapy to treat humoral rejection by filtering the blood and removing the harmful antibodies.
• In some cases, light therapy is used to treat the white cells in the extracted blood, this process is known as Photophoresis. The treated blood is then returned to the recipient’s body.

Treatment of chronic rejection:

• Anti-rejection dosage is increased
• In case, of severe damage to coronary arteries, angioplasty or open-heart surgery is recommended which ensures better blood flow.

Chronic rejection usually does not require another heart transplant, but leading a healthy lifestyle will definitely reduce the risk due to chronic rejection.

The chances of heart transplant rejection can be reduced by:

• Regular visit to your doctor
• Keep a track of your weight, blood pressure and temperature.
• Taking medicines on time.
• Undergoing tests as and when prescribed by your doctor
• Living a healthy heart lifestyle
• Abstaining from alcohol and cigarette use.

Conclusion

Rejection of a transplanted heart is not a disease but a natural defense by our immune system to protect our body from the foreign object. The immunosuppressant treatment has significantly reduced the rate of heart transplant rejection and these medicines have to be taken for the rest of the life of the patient. However, one has to ensure regular visits to the doctor, self-monitor the signs of rejection, lead a  healthy lifestyle and so on.