Heart problems caused by cancer treatment

Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. Some types of chemotherapy may cause heart problems. The risk can be higher if you are:

• taking several chemotherapy drugs together
• having chemotherapy with chest radiotherapy
• also having some types of targeted therapies.

Your age when you have chemotherapy may also increase the risk of heart problems. With some types of chemotherapy the risk of a heart problem is increased in:

• young children
• people over 65 years old.

Your cancer doctor will explain any risks before you start chemotherapy. Different drugs can cause different problems:

• Some drugs are only likely to cause heart problems if you have a high dose. Your cancer doctor will plan your treatment carefully and record the doses you are given.
• Some drugs may cause heart changes during or shortly after you have treatment.
• Some drugs can cause heart problems many years later – these are known as late effects.

Some chemotherapy drugs are given into a vein (intravenously) with large amounts of fluid. If you already have a heart condition, this can put pressure on your heart and may cause problems. Your nurse will monitor you for any signs of problems while you have these treatments.

Heart tests and chemotherapy

Before treatment, you may have blood tests and a scan to monitor how your heart is working. For some types of chemotherapy, you will have these tests again during and after your treatment. These tests look for early signs of heart muscle damage and monitor your heart function. You may not have any symptoms, but it is important to treat early signs to stop further damage.

Heart symptoms during chemotherapy

Sometimes chemotherapy causes symptoms that need urgent treatment to prevent serious problems. You should tell your doctor or nurse straight away if you:

• have chest tightness, pain or discomfort
• have pain that spreads to your shoulders, neck, back, jaw or arms
• feel unwell, sick or sweaty
• have shortness of breath or are wheezing
• black out (faint)
• feel dizzy or light-headed can feel your heart beating (palpitations).

If you get any of these symptoms during treatment, your doctors will stop the chemotherapy drug and check your heart. They may change the type of chemotherapy to one that does not cause heart problems.

Anthracyclines

Anthracyclines are a group of chemotherapy drugs that most commonly affect the heart. They are used to treat many different types of cancer.

This type of chemotherapy includes the drugs:

• doxorubicin, which is also called Adriamycin®
• epirubicin
• daunorubicin
• idarubicin
• mitoxantrone.

Many people who have these drugs do not develop any heart problems. But sometimes they can cause heart muscle damage. This can cause symptoms during, shortly after or years after treatment (late effects).

To help reduce the risk of heart problems, doxorubicin can be wrapped in a fatty covering called a liposome. The liposome helps prevent the drug from reaching areas with small blood vessels, such as the heart. This treatment is called pegylated liposomal doxorubicin (Caelyx®). Your cancer doctor can tell you if it is suitable for you.

Other chemotherapy drugs

Sometimes other types of chemotherapy drugs can affect the heart. A small number of people may develop heart problems. These may develop within hours or up to a few days after having these treatments.

Alkylating agents

Alkylating agents are used to treat many different types of cancer. Commonly used alkylating agents include:

• cyclophosphamide
• carmustine
• ifosfamide.

Taxanes

These are used to treat different types of cancer including ovary, breast, prostate and lung cancer. The 2 main taxanes are:

• paclitaxel 
• docetaxel.

Fluoropyrimidines

These chemotherapy drugs are used to treat different cancers, such as bowel and breast cancer. Commonly used fluoropyrimidines include:

• fluorouracil (5FU)
• capecitabine.

Other chemotherapy drugs

Other commonly used chemotherapy drugs can also affect the heart. But the risk of heart problems with these drugs issmall. They include:

• bleomycin
• cisplatin
• fludarabine
• gemcitabine
• mitomycin.

Radiotherapy uses high-energy rays, such as x-rays, to treat cancer. Most people who have radiotherapy do not develop heart problems after treatment.

Radiotherapy is only likely to cause heart problems if the heart is in the area being treated. For example, this could be if you have radiotherapy for breast cancer in the left breast. If you have radiotherapy to another part of your body, away from the heart, it is unlikely to damage the heart.

Radiotherapy techniques are very accurate. Treatment can usually be planned to avoid affecting the heart. This means heart problems after radiotherapy have become rare.

Radiotherapy to the heart can:

• affect the coronary arteries, which can lead to coronary heart disease
• cause inflammation of the layers that cover of the heart (pericarditis)
• cause a build-up of fluid between the layers that cover the heart (pericardial effusion)
• damage the heart muscle
• damage the heart valves
• affect the heart’s electrical system and cause an abnormal rhythm.

The risk of damage to the heart depends on:

• the total dose of radiotherapy given
• how much of the heart is in the treatment area.

The higher the overall dose of radiotherapy and the amount of the heart exposed, the greater the risk of damage. But the risk is still very small.

The risk of heart damage is also increased if:

• you are having chemotherapy at the same time
• you already have a heart condition.

After radiotherapy

Heart problems can sometimes happen during treatment. Or they may develop months or years later (late effects).

If you were told the radiotherapy may affect your heart, you can reduce the risk by making healthy lifestyle choices.,

Your GP may arrange regular appointments after cancer treatment to check for signs of heart problems. At the appointments, you may have heart tests such as:

• your blood pressure checked
• a blood test to check your cholesterol levels
• scans to check how your heart is working.

Heart symptoms after radiotherapy

If you have any warning signs of heart problems, it is important to let your doctor know straight away.

Early treatment for a heart problem can prevent further problems.

Sometimes the symptoms of heart problems are like the symptoms of other conditions. But it is important to get any new symptom checked by your doctor. Always tell your doctor if you:

• have chest discomfort, pain or tightness
• have pain that spreads to your arm, neck, jaw, stomach or back
• feel short of breath
• feel unusually tired or weak (fatigue)
• have swelling in your feet, ankles, tummy or lower back
• have palpitations, which might feel like a thumping or fluttering in your chest have blackouts (fainting)
• feel dizzy or light-headed.

A heart attack is life-threatening. If you think you or someone else is having a heart attack, phone 999 for an ambulance straight away.

Surgery is one of the main treatments for cancer. Sometimes surgery can put the heart under stress and cause heart problems. Having drugs to keep you asleep during surgery (general anaesthetic) may also cause heart problems for some people.

If you have a healthy heart, surgery is not usually a problem. But there may be a higher risk of damage to the heart for people who:

• had heart problems before surgery
• have diabetes
• are over 70 years old
• have high blood pressure
• smoke
• are overweight.

If you have minor surgery and only need to be asleep (anaesthetised) for a short time, the risk may be small. If you have major surgery and need to be asleep for several hours, the risk can be greater.

Your doctor will talk to you about the possible risks of your surgery. Before you have a general anaesthetic, you will have some tests. These are to check your heart and make sure you are fit enough for surgery. If you have a high risk of serious heart problems, your doctors may suggest other cancer treatments you can have.