Risks of a heart transplant 

A heart transplant is a major operation and there is a risk of several complications.

Risks of a heart transplant include:

  • rejection of the donor heart
  • infection
  • failure of the transplanted heart to pump properly (primary graft dysfunction)
  • narrowing of arteries connected to the new heart

These complications are explained in more depth below.

After a heart transplant you will need to take immunosuppressants and other medications, which may lead to side effects such as:


One of the most common complications of a heart transplant is rejection of the donor heart. Rejection occurs when the immune system – the body’s defence against infection – mistakes the transplanted heart for a foreign body and begins to attack it.

This can often occur even if you are being treated with medication to suppress your immune system (immunosuppressants)

There are two types of rejection:

  • acute rejection  where rejection occurs just after surgery
  • chronic rejection  where rejection occurs many months or years after surgery

Signs that your body may be rejecting your heart include:

If you have any of these symptoms, contact your GP or your transplant centre as soon as possible. Rejection can usually be treated by increasing your dose of immunosuppressant medication.


Immunosuppressant medication will weaken your immune system and make you more vulnerable to infection. The three most common types of infection that affect people who have had heart transplants are:

CMV is a common virus that is part of the herpes family of viruses.

Bacterial infection

A bacterial infection of the lungs (pneumonia) is common in the first few weeks after a transplant.

Symptoms of pneumonia include:

  • breathing difficulties
  • coughing up phlegm (thick mucus) that may be yellow, green, brown or blood-stained
  • wheezing
  • a rapid heartbeat (tachycardia)
  • a high temperature (fever) of 38°C (100.4°F) or above
  • pain in your chest

If you think you may have pneumonia, contact your GP or transplant team. The condition will need to be treated with antibiotics.

To help prevent infection, you may also be given antibiotics to take for the first few weeks after your transplant.

Read more about treating pneumonia.

Fungal infections

Fungal infections are not as common as bacterial infections, but they can also sometimes develop in the first few weeks after having a transplant.

Less serious fungal infections can develop in the skin, nails, mouth, feet and, in women, the vagina.

Symptoms of these fungal infections will depend on what part of your body is affected, although shared symptoms include:

  • scaling and redness of the skin
  • itchiness
  • discharge of a thick white fluid from the vagina (in cases of vaginal infection)

More serious fungal infections can develop inside the body (invasive fungal infections), such as in the lungs (fungal pneumonia) or blood stream.

Symptoms of an invasive fungal infection include:

  • a high temperature (fever) of 38°C (100.4°F) or above
  • shortness of breath
  • dizziness
  • chest pain
  • a change in mental behaviour, such as confusion or disorientation

You should contact your GP or transplant centre as soon as possible if you think you may have an invasive fungal infection.

Fungal infections can be treated using antifungal medicines. As a precaution, you may be given a course of anti-fungal medication to take for several months after your transplant.

Cytomegalovirus infection

Cytomegalovirus (CMV) infections are common during the second month after a transplant.

Symptoms of a CMV infection include:

  • a high temperature (fever) of 38°C (100.4°F) or above
  • shortness of breath
  • the appearance of large, painful mouth ulcers; visual disturbances, such as blind spots; blurring; and floaters (tiny black or shadowy dots or lines that appear to be floating in your field of vision)

If you think you have a CMV infection, you should contact your GP or transplant centre as soon as possible.

CMV infections can be treated with antiviral medication. As a precaution against CMV, you may be given a course of antiviral medication to take for several months after your transplant.

Read more about treating cytomegalovirus infections.

Preventing long-term infection

After having a heart-lung transplant, you will probably need immunosuppressants for the rest of your life, because you will be more vulnerable to infection. This means you will have to take more precautions than most people. These include:

  • avoiding crowds (if this is unavoidable, you should wear a face mask, particularly during the first year after your transplant)
  • avoiding close contact with anyone known to have an infection
  • avoiding anything that could damage your lungs and make them more vulnerable to infection, such as smoke, chemical sprays or chemical fumes
  • keeping your house very clean to prevent the spread of infection

Read more about how to prevent germs spreading.

Primary graft dysfunction

One of the most serious complications that can occur after a heart transplant is that the donated heart fails to work and does not start beating, or stops beating soon after the surgery is completed.

This is known as primary graft dysfunction. It is the leading cause of death in the first 30 days after surgery, and occurs in around 1 in 32 cases.

Primary graft dysfunction can occur for a number of reasons, such as:

  • damage to the donor heart (as soon as the brain dies, the heart will become progressively damaged, even though it is being kept pumping with a ventilator)
  • underlying problems with blood vessels connected to the donor heart

Treatment options for primary graft dysfunction include:

  • using medications to support the new heart
  • continuing to use a ventilator to help oxygen reach the blood
  • a bypass circuit (extracorpopreal cardiopulmonary membrane oxygenator)  to keep your circulation working until the new heart improves

If treatment can be provided as soon as the heart begins to fail, then the outlook is often favourable. One specialist unit reported being able to save around four out of every five lives in patients who developed primary graft dysfunction.

Narrowing of the arteries

Narrowing and hardening of the small and medium-sized blood vessels connected to the donor heart is a common long-term complication of a heart transplant.

The medical term for this complication is cardiac allograft vasculopathy (CAV).

CAV is thought to develop in:

  • 1 in 12 heart transplant patients during the first year after surgery
  • 1 in 3 patients during the first 5 years after surgery
  • just under half of all patients (43%) during the first 8 years after surgery

Known risk factors for CAV include:

  • experiencing acute rejection shortly after the transplant
  • developing an infection shortly after the transplant
  • receiving a donation from someone with high blood pressure

CAV is potentially serious as it can restrict the supply of blood to the heart, which can sometimes trigger a heart attack or lead to a recurrence of heart failure.

Because of this risk, it is usually recommended that you have regular coronary angiographies (a special type of X-ray used to study the inside of your heart) to check the heart is receiving enough blood

Treatment options for CAV include:

  • statins – a medication that can reduce blood cholesterol levels, which in turn can improve blood supply to the heart
  • calcium channel blockers – which can help widen blood vessels, thereby increasing blood flow to the heart

Page last reviewed: 23/06/2014

Next review due: 23/06/2016