As a result of the increased incidence of cancer and the longer survival of patients, the prevention and treatment of cardiovascular diseases in this population have been gaining prominence. Cardiotoxicity is one of the most significant complications of cancer treatment, responsible for considerable morbidity and mortality, that is, not only increasing the risk of death but also of important sequelae for the patient.
Currently, the early identification of cardiovascular risk, the implementation of risk reduction strategies, the correct diagnosis of the cardiovascular problem and the institution of effective therapy are essential for the proper care of patients with cancer. This set of measures aims to reduce the risk of mortality and improve the patient’s quality of life, without interfering, if possible, with the specific treatment of cancer.
What is cardiotoxicity and main symptoms
Cardiotoxicity is the damage caused to the heart by cancer treatment, which may occur as a result of an alteration or damage to the heart muscle, or to the electrical system of the heart, for example. The most worrying injury is heart failure, which occurs when the organ becomes weaker and is not as efficient at pumping, which compromises blood circulation. There are other effects of cancer treatment that affect the patient, such as acute coronary insufficiency (infarction), arterial hypertension, arrhythmias and thromboembolic events.
If the treatment scheme causes thrombosis, which can be in the leg or even pulmonary embolism, the symptoms include:
- Fast breathing, shortness of breath, chest pain and palpitations, in the lung
- Swelling in one of the legs and redness, increased temperature in the area and pain when touched, in the leg
The symptoms of heart failure, which occurs when the heart loses strength, are:
- Swelling in the legs in a symmetrical way
- Shortness of breath in activities that were previously performed normally
- Shortness of breath when lying down, which improves when sitting up
- Easy fatigue
Treatments that can cause cardiotoxicity
Chemotherapy – it is not the only treatment that can lead to heart problems, although it is the most common among the therapeutic approaches adopted in oncology. Toxicity for the cardiovascular system is variable and depends on the therapeutic scheme used. Certain chemotherapy strategies are directly toxic to the organ, causing it to lose strength, causing heart failure. Other protocols can lead to increased blood pressure, or to a higher incidence of thrombosis or change in coronary circulation – which may cause myocardial infarction or ischemia, or cause palpitations and arrhythmias.
Radiotherapy – when performed in the chest region, it can affect the pericardium, which is a membrane that surrounds the heart. That way, it can get thicker and harden. In addition to increasing the risk of atherosclerosis (fat plaque in the vessels) in the long term. It can lead to heart attack.
Immunotherapy – drugs that stimulate the body’s defense system to fight cancer – can lead to myocarditis, an acute inflammation in the heart, and it is possible that the monoclonal antibodies cause heart damage.
The importance of early risk assessment
To prevent heart problems, it is ideal for cancer patients to undergo a complete cardiological evaluation before starting chemotherapy or radiotherapy. In this evaluation, in addition to clinical examinations, the doctor may request specific blood tests to assess cardiovascular health markers such as Troponins and BNP (Natriuretic Peptide). In addition to these, you can also request imaging tests, such as an echocardiogram, for a structural assessment of the heart.
Electrocardiogram – Routinely performed in the evaluation of patients with risk factors for cardiotoxicity. The detection of ventricular and supraventricular arrhythmias, such as atrial fibrillation, alerts the clinician to the presence of structural heart damage.
Cardiospecific biomarkers – It is a useful tool in the early identification of cardiac damage caused by chemotherapy. Blood tests can detect these cardiospecific biomarkers suggesting the potential development of a heart problem.
Imaging Methods – Before starting cardiotoxic chemotherapy, it is necessary to evaluate and quantify ventricular function using imaging methods. This measurement should be performed using Doppler echocardiography. The doctor will be able to discuss with the patient the possible chemotherapy schemes with lower cardiovascular risk. Echocardiography has been the most used option due to its low cost, easy access and non-invasive character.
Healthy routine helps in prevention
It is important that even after the diagnosis of cancer, the patient maintains a routine of physical activity and healthy eating whenever possible. The benefits of this care are well established in terms of improving quality of life and significantly reducing the risk of developing cardiovascular and metabolic diseases. Sedentary lifestyle is associated with a significant increase in the risk of obesity, metabolic syndrome and coronary events.
Current evidence suggests that increased physical activity after cancer diagnosis may reduce the risk of recurrence and mortality. Cancer and its treatment are associated with a series of systemic metabolic alterations that can significantly compromise the patient’s quality of life and life expectancy even after cure.
Which physicians should advise on cardio-oncology
Guidance on the risks of chemotherapeutic agents causing heart problems should be given to the patient initially by his oncologist. The evaluation and, if applicable, the initiation of schemes to prevent heart problems potentiated by the treatment must be carried out by a cardio-oncologist.
Nowadays, there are specific residencies in cardio-oncology, who are training cardiologists but specialists in oncology patients. Large centers specializing in cancer treatment have these professionals on the team that monitors the patient.