What is cardiotoxicity?
Cardiotoxicity occurs when life-saving treatments designed to fight cancer inadvertently affect the heart. While these therapies are remarkably effective against cancer cells, they can sometimes impact healthy heart tissue.
How does cardiotoxicity affect the heart?
The heart is a muscle that pumps blood around the body, providing oxygen and nutrients to every organ. Cardiotoxicity occurs when something interferes with the heart’s ability to do its job. This can lead to conditions like heart failure, where the heart doesn’t pump blood as efficiently as it should, or arrhythmias, which are irregular heartbeats. It can also affect blood vessels, causing atherosclerosis and coronary artery disease.
Certain treatments, including chemotherapy drugs used to fight cancer, can sometimes cause direct and indirect harm to the heart. While these drugs are effective at killing cancer cells, they can also impact healthy heart cells.
How common is cardiotoxicity?
Around one in five adults treated for cancer may develop some form of heart damage. This risk varies depending on treatment type, dosage and personal health history.
However, cardiotoxicity is not only linked to cancer treatments. Some other medications used to treat diseases like HIV and autoimmune conditions have also been linked to heart issues. Even environmental toxins like alcohol, smoking, or exposure to heavy metals can be cardiotoxic.
Who does cardiotoxicity impact?
People undergoing cancer treatment, particularly with chemotherapy drugs, including anthracyclines or targeted therapies, and those who have radiation therapy to the chest, are at the highest risk for cardiotoxicity. While it’s difficult to determine the exact rate of cardiotoxicity in adults who had cancer treatment as an adult, it is estimated that up to 20 per cent of this population may develop heart problems, with between 7 per cent and 10 per cent having cardiomyopathy or heart failure in subsequent years. Adults treated with chemotherapy as children are at a greater risk of premature development of heart failure.
How can cardiotoxicity be prevented?
Preventing cardiotoxicity starts with awareness. Doctors carefully monitor people who are undergoing treatments known to cause heart problems. They may use tests like echocardiograms, which show how well the heart is functioning, cardiac magnetic resonance imaging, cardiac stress tests, or blood tests to check for signs of stress on the heart.
If there are signs of cardiotoxicity or a patient has a higher risk, doctors may prescribe medications to help protect the heart, such as beta-blockers or ACE inhibitors, which can lower blood pressure and reduce the heart's workload. There are options to adjust the dosage of the medication or switch to a different treatment that is less likely to harm the heart, but fortunately, these are rarely needed.
Exercise has been shown to be cardioprotective. For those with a higher risk of cardiovascular disease, adopting a healthy lifestyle could also mitigate cardiotoxic risk. If someone does develop heart damage, there are treatments available to manage symptoms and improve heart function.