Understanding heart health and cancer

Cancer and heart disease have some of the same risk factors. These shared risk factors include:

• older age
• your sex
• smoking
• diabetes
• physical inactivity
• drinking too much alcohol
• unhealthy diet
• high blood pressure (called hypertension)
• overweight and obesity
• high cholesterol (a type of fat in the blood)
• other chronic inflammatory conditions (e.g. chronic kidney disease).

Making some changes in your day-to-day life can help to lower the risk of heart-related side effects from cancer treatment. Some changes can also reduce the risk of certain cancers. Visit our prevention pages for tips about lifestyle changes. Heart Foundation also has information about looking after your heart.

Some types of cancer treatment can affect how the heart and cardiovascular system work.  This is called cardiotoxicity or cardiovascular toxicity.

When working out the best treatment for you, your doctors will try to find a therapy that is effective in treating the cancer while causing the least amount of damage to the heart and blood vessels. You may also be advised to do more physical activity and eat a healthy diet.

Cancer treatments that may be cardiotoxic include:

• certain chemotherapy drugs, particularly anthracyclines (e.g. doxorubicin, daunorubicin,
  epirubicin) and thymidylate synthase inhibitors (e.g. fluorouracil or 5-FU)
• some targeted therapy drugs (e.g. trastuzumab, bevacizumab, ribociclib, cabozantinib)
• some immunotherapy drugs (e.g. pembrolizumab, nivolumab, CAR T-cell therapy)
• radiation therapy to the chest for some types of cancer (e.g. breast, lung cancers or lymphoma).

These treatments can affect cardiovascular health in different ways.

Some treatments don’t directly affect the heart but can still impact cardiovascular health. For example, certain hormone therapies, such as aromatase inhibitors and androgen deprivation therapy, can increase the risk of high blood pressure, high cholesterol and high blood sugars.

As cancer and heart disease often share risk factors, some people already have heart problems when they are diagnosed with cancer. In these cases, cancer treatments that are potentially cardiotoxic may not be safe. Your doctor may suggest other treatments.

If you’re taking heart medicine, it’s important to keep taking it until you discuss this with your cancer treatment team, cardiologist or cardio-oncologist. Also, let your cancer treatment team know if you have a pacemaker, so they can consider this when planning treatment.

"I had heart issues before being diagnosed with cancer (first primary breast cancer then, 9 years later, primary uterine sarcoma). Before starting chemotherapy for uterine sarcoma, my cardiologist and medical oncologist had a big discussion. They decided the planned chemo protocol would be okay.” Cynthia

Angina and heart attack

What it means – When fats or other substances build up in the blood, blood vessels can become blocked (atherosclerosis). This can reduce the amount of blood flowing through the heart. It may cause:

• angina – pain or tightness in the chest when not enough blood is flowing to the heart. This needs to be checked because it may also be a symptom of a heart attack
• heart attack – pain in the chest due to permanent damage to the heart. This needs emergency treatment.

Risk may increase with some types of:

• chemotherapy
• immunotherapy
• radiation therapy to the chest for certain cancers

Blood clots

What it means – Blood clots are clumps of blood that can block blood vessels. They may cause serious conditions including:

• stroke – when the blocked blood vessel restricts blood flow to the brain (called an ischaemic stroke). Strokes can also be caused by bleeding in the brain if an artery leaks or splits (called a haemorrhagic stroke)
• pulmonary embolism (PE) – when a blood clot blocks the supply of blood to the lungs; this can be life-threatening
• deep vein thrombosis (DVT) – when a blood clot forms in a deep vein, often in the leg; can lead to pulmonary embolism.

Risk may increase with some types of:

• cancer
• chemotherapy
• hormone therapy
• immunotherapy
• ports, etc.
• radiation therapy to the chest for certain cancers (may increase stroke risk, not PE or DVT)
• surgery
• targeted therapy

Heart failure

What it means – Damage or weakening of the heart muscle (cardiomyopathy) may mean the heart becomes too weak to pump blood around the body properly. This can cause shortness of breath and fatigue. Cardiomyopathy must be treated quickly to prevent it becoming permanent.

Risk may increase with some types of:

• chemotherapy
• immunotherapy
• radiation therapy to the chest for certain cancers
• targeted therapy

Heart inflammation (myocarditis)

What it means – When the heart muscle (myocardium) becomes inflamed (swollen or irritated) it can affect the heart’s ability to pump blood. This may cause chest pain, shortness of breath and rapid or irregular heartbeats, and can be life-threatening if not treated early.

Risk may increase with some types of:

• immunotherapy
• radiation therapy to the chest for certain cancers

Irregular heartbeats (arrhythmia)

What it means – The heart has an electrical system that tells it to beat. If this system is not working properly, it can lead to a heartbeat that is irregular (beating too fast or too slow). This is called arrhythmia. For example, atrial fibrillation (AF) is an irregular heartbeat that is often faster than usual. Arrhythmia can cause you to be light-headed or dizzy and, in some cases, to faint. It may also be a sign of heart attack, heart failure or heart inflammation (myocarditis).

Risk may increase with some types of:

• chemotherapy
• immunotherapy
• radiation therapy to the chest for certain cancers
• targeted therapy

Other cardiovascular concerns

What it means – Cancer treatments may also affect the heart by causing:

• high blood pressure (hypertension) – when the force of the blood pushing against the artery walls is too high for a long time or the arteries become stiff, the heart has to work harder to pump blood. This increases the risk of heart attack and stroke
• high cholesterol (hyperlipidaemia) – a build-up of fats (lipids) in the blood. This increases the risk of heart attack, stroke and kidney damage
• high blood sugars (hyperglycaemia) – when there is too much glucose (sugar) in your blood. This increases the risk of heart attack, angina and stroke.

See your GP for regular check-ups for these issues.

Risk may increase with some types of:

• chemotherapy
• hormone therapy (e.g. androgen deprivation therapy)
• immunotherapy
• targeted therapy

Watch for early signs that something may be wrong with your cardiovascular system. Some symptoms may not be related to the cancer or its treatment; your doctor will consider other possible causes.

Chest pain or tightness – This may feel like heavy, crushing pain or pressure in your chest, back, neck or jaw. It may also feel like sharp, stabbing pain.

Shortness of breath – This is when you feel that you cannot get enough air into your lungs. It’s normal to feel this way after exercise or physical work, but if it feels worse than usual or happens for no reason, this may be a sign of heart problems.

Swelling in the legs – If your heart is not pumping blood around the body as well as it should, blood and other fluids can build up in your legs, ankles and feet. This is called oedema. It can also be a side effect of some cancer treatments.

Fatigue – This is extreme tiredness and lack of energy that usually does not go away with rest.

Feeling faint or dizzy – You may feel light-headed, unsteady on your feet, or notice changes in your vision.

Abnormal heartbeat – Your heart may beat faster than usual (heart palpitations) or in an abnormal way (irregular heartbeat). This may happen when the heart’s electrical signals aren’t working properly.

Other symptoms – These may include: pain in the arms or shoulders; indigestion; unexplained
perspiration (feeling sweaty); or unexplained nausea (feeling sick) and vomiting. These symptoms are more common in women, but can also affect men. For more information about heart health for women, visit Her Heart.

If symptoms are severe or come on suddenly, call Triple Zero (000) or go to your nearest emergency department. Be sure to tell the emergency doctors about your cancer treatment.

Looking after your cardiovascular health during and after cancer treatment is important. If you have existing heart problems or have any risk factors, you may need support in making lifestyle changes. You may see a:

• general practitioner (GP) – a doctor who supports your general health, including your cardiovascular health, before and after cancer treatment. Depending on where you are having your treatment, your GP may also be involved in your care during cancer treatment. If you don’t have a regular GP, it’s a good idea to find one and start building a relationship
• exercise physiologist, physiotherapist – prescribe safe and effective exercise to help restore or improve people’s overall health, fitness, strength and energy levels
• dietitian – helps with nutrition concerns and may recommend changes to your diet during treatment and recovery.

If you have a higher risk of heart-related side effects, you may also see a:

• cardiologist – a doctor who specialises in the treatment of heart disease
• cardio-oncologist – a cardiologist with special training in managing the effects of cancer and cancer treatments on the cardiovascular system; they help to reduce cardiovascular risks and manage cardiovascular problems that may occur
• cardiac nurse – a nurse who specialises in cardiovascular health; may be involved in some heart tests.

After your cancer treatment is finished, your heart health may continue to be monitored by your GP, a cardiologist or cardio-oncologist.

There are also many things that you can do to look after your own cardiovascular health and reduce your risk of any future problems.

Changing some daily habits can help to improve your heart health.

Starting healthier habits before cancer treatment (prehabilitation) and continuing them during and after treatment (rehabilitation), may help your recovery. Some changes can also help to prevent the cancer coming back. If your general practitioner (GP) refers you to see an allied health professional (e.g. exercise physiologist, dietitian), you may be eligible for Medicare rebates for some visits.

Sit less and be physically active

Spending too much time sitting can increase your risk of heart problems. Including regular movement and exercise in your daily or weekly routine is one of the most important changes you can make to lower your heart disease risk. It can also reduce cancer risk. It’s recommended that people with cancer work towards, then maintain, at least 150 minutes (2½ hours) of moderate-intensity aerobic exercise or 75 minutes (1¼ hours) of vigorous-intensity aerobic exercise every week. Aerobic exercise includes activities such as brisk walking or bike riding. Also, doing 2–3 strength-training (resistance exercise) sessions a week can build muscle strength. Even small increases in your activity levels can be good for your health.

Download our booklet ‘Exercise for People Living with Cancer’

Quit smoking and vaping

If you smoke or vape, it’s important to quit. Exposure to tobacco smoke can cause your blood vessels to become stiff and more likely to split. This can lead to angina, heart attack or stroke. Smoking also increases the risk of developing many types of cancer. It’s also important to avoid second-hand smoke and to stop vaping (e-cigarettes), which can harm your heart as well. For support, visit Quit, call the Quitline on 13 7848 or talk to your GP.

Maintain a healthy body weight

Carrying extra body weight can cause fatty material to build up in your blood vessels (atherosclerosis). This increases the risk of heart problems and stroke. While some people lose weight during cancer treatment, others gain weight due to side effects of some medicines. Talk to your cancer treatment team or GP about healthy eating and staying active to help manage your weight.

Drink less alcohol

Alcohol does not protect the heart, and drinking alcohol increases the risk of cancer. It’s important not to drink too much alcohol both for your heart health and to reduce the risk of some cancers (including breast, bowel, liver, mouth and stomach cancers). If you choose to drink, follow the Australian Government’s alcohol guidelines and limit alcohol use. If you do not drink alcohol, you should not start.

Eat a healthy diet

Eat a balanced diet from the 5 food groups – vegetables, fruit and legumes, breads and cereals, meat (and alternatives) and dairy (and alternatives). Limit foods containing saturated fat, added salt and added sugars, and avoid sugary drinks. Your doctor may suggest you see a dietitian to help you with your diet.

Download our booklet ‘Nutrition for People Living with Cancer’

Take your medicine

If you take heart medicines (for blood pressure or cholesterol) or diabetes medicines, keep taking them during and after cancer treatment, unless your doctors tell you to stop. If you have questions, talk to your doctor.

See your GP for heart checks

It’s important to get your blood pressure, blood sugar and cholesterol checked regularly,
including before, during and after cancer treatment. Talk to your GP about these tests.

Depending on the type of cancer you have and your cardiovascular risk factors, you may have one or more of the following tests before starting cancer treatment.

Blood tests

What does it check for? If your heart has existing damage or is under strain, the cells may release particular proteins (called biomarkers) into the blood.

How it is done – A sample of your blood will be collected with a needle from a vein in your arm. It will be sent to a laboratory where a pathologist will check your blood for certain biomarkers.

Electrocardiogram (ECG)

What does it check for? This shows how fast or slow your heart is beating and checks for irregular heartbeats (called arrhythmias). It can also show if you have had a heart attack.

How it is done – Several leads (electrodes) will be stuck to your chest; any hair on your chest may need to be shaved so the electrodes stick properly. The electrodes are connected to a computer that records your heart beating.

Echocardiogram (echo scan)

What does it check for? This looks at how well your heart muscle and heart valves are working.

How it is done – This is a type of ultrasound scan. The person doing the ultrasound (sonographer) will spread gel on your chest and then move a small device (transducer) over the chest. The transducer sends soundwaves to a computer to create pictures of your heart.

Cardiac magnetic resonance imaging (CMRI)

What does it check for? This scan may be done if an echo scan suggests a more serious cardiovascular problem. A CMRI shows how well the heart is pumping and if the valves are working properly. Most people will not need this test.

How it is done – This scan uses a powerful magnet and radio waves to create detailed cross-sectional pictures of your heart. During the scan, you may be injected with a dye (called contrast) to help make the pictures clearer. You will lie on a table inside a large metal tube that is open at both ends. The scan is noisy but painless.

Computerised tomography (CT) coronary angiogram

What does it check for? This scan checks for any blockages or damage in your heart and surrounding blood vessels. It may be called a CTCA.

How it is done – A small tube (cannula) will be put into a vein in your arm. You will lie on a table that slides into the CT machine. Dye (called contrast) will be injected into the cannula to help show if there is any narrowing or blockage in your heart arteries. You will be asked to hold your breath for about 10 seconds and stay still while the images are taken.

Coronary angiogram

What does it check for? This test is used to check if the arteries around your heart (coronary arteries) have narrowed or are blocked. Most people will not need this test.

How it is done – A thin, flexible tube (catheter) is inserted into the largest artery in your body (the aorta) through your wrist or the groin. It is then threaded up into the coronary arteries. A dye (called contrast) is injected into the catheter, and x-rays are taken to show up any blockages.

Exercise stress test

What does it check for? This measures how well your heart and lungs are working during exercise.

How it is done – Your heart rhythm and lung function will be monitored while you walk on a treadmill or ride a stationary bike. The appointment may take about 90 minutes, but you will only be exercising for 5–15 minutes. An echo scan might be done before and after the stress test. You will be given instructions on what you can eat or drink the day before the test.

Prof Bogda Koczwara, Director, Australian Research Centre for Cancer Survivorship, UNSW, NSW; Prof Aaron Sverdlov, Cardiologist and Co-Director, Newcastle Centre of Excellence in Cardio-Oncology, Hunter New England Health and The University of Newcastle, NSW; Dr Diana Adams, Medical Oncologist, Macarthur Cancer Therapy Centre, NSW; Tamara Casey, Clinical Nurse Consultant, Breast Assessment Unit, Fiona Stanley Hospital, WA; Dr Daniel Chen, Cardiologist and Specialist in Cardio-Oncology, Prince of Wales and St George Hospitals, NSW; A/Prof Eng-Siew Koh, Radiation Oncologist, Liverpool Cancer Therapy Centre, Liverpool Hospital and University of NSW, NSW; Cynthia Leigh, Consumer; Dr David Mizrahi, Senior Research Fellow and Accredited Exercise Physiologist, The Daffodil Centre at Cancer Council NSW and The University of Sydney, NSW; Prof Doan Ngo, Co-Director, Newcastle Centre of Excellence in Cardio-Oncology, The University of Newcastle, Hunter Medical Research Institute, NSW; Peter O’Hearn, Consumer; Prof Nick Pavlakis, Medical Oncologist, Royal North Shore Hospital and Professor of Medicine, The University of Sydney, NSW; Deb Roffe, 13 11 20 Consultant, Cancer Council SA; Dr Lorcan Ruane, Cardiologist, The Prince Charles Hospital, QLD; Margaret Ryan, Nurse Practitioner, Cardio-Oncology Clinic, Prince of Wales Hospital, NSW; Dr Elysia Thornton-Benko, Specialist GP/Primary Care and Cancer Survivorship Physician, NSW; Helen Wardman, Consumer; Dr Trent Williams, Clinical Nurse Consultant, Cardiology, John Hunter Hospital, NSW; Dr Janice Yeh, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC; Megan Yong, Consumer.