Article made by our primary cardiologist Dr. Maria Florescu.
The oncological treatment (chemotherapy, radiotherapy and surgery) has led to a significant improvement in the survival of patients with neoplasms, but with the risk of adverse reactions. Currently, the most severe adverse effects of oncology therapy are cardiovascular, potentially irreversible and fatal complications. Thus, their incidence can reach up to 20-30%, now becoming the main cause of mortality of oncological patients (exceeding the mortality intrinsically determined by neoplasms). In the United States, there is already a new specialty, cardio-oncology, both cardiologists and oncologists, performing training courses to treat this heart disease in cancer patients.
Cardio-oncological examination is essential and is a necessity for monitoring the potential adverse effects of oncological treatment on the heart, for early identification and rapid therapeutic intervention to reduce the morbidity and mortality of these patients.
Cardio-vascular adverse effects of oncological therapy
- Cardiotoxicity or myocardial dysfunction – impairment of the systolic and / or diastolic function of the heart, defined as the decrease of the ejection fraction of the left ventricle below 50% and by more than 10% of the baseline value, may appear acute (in the first hours after treatment), subacute (within the first two weeks after treatment) or chronically (early – in the first year after therapy or late – after the first year). This is determined by the direct toxic mechanism of the chemotherapies on the heart muscle or by the acceleration of the myocardial ischemia. The risk of occurrence and the potential for progression to heart failure depends on the risk profile of the patients, the association of the mediastinal radiotherapy, as well as the type of chemotherapy administered.
Thus, the administration of Anthracyclines ( doxorubicin, epirubicin, daunorubicin), commonly used in almost all solid neoplasms, but also lymphomas and leukemias, causes myocardial damage in up to 48% of dose dependent cases with potential for progression to refractory heart failure and death up to 16% of cases (mortality of this form of heart failure is very high – 60% at 2 years). Administration of monoclonal antibodies (trastuzmab), commonly used in breast cancer, causes myocardial damage in 4% of patients or 27% of patients if it is associated with treatment and taxanes (another type of chemotherapy) or radiotherapy. This form of myocardial impairment is frequently reversible upon discontinuation of therapy and does not depend on the administered dose.
- Myocardial ischemia may rarely occur after the administration of taxanes, 5-fluorouracil, Capecitabine, vincristine, rituximab, or sorafenib for breast, colorectal, lymphoma, leukemia, or hepatic or thyroid cancers or high doses of radiotherapy.
- Aggravation or induction of valvular impairment occurs especially after the combination of high-dose mediastinal radiotherapy.
- Rhythm and driving disorders , can appear up to 16-36% and can be life-threatening.
- Hypertension may occur up to 47%, especially after administration of bevacizumab or sorafenib / sunitinib in colorectal, lung or renal cancers.
- Impaired blood coagulation, especially in metastatic cancers after administration of Talidomide, cisplatin, bevacizumab, sunitinib, with an incidence of venous thrombembolism of up to 20%.
- Risk of occurrence or worsening of peripheral or cerebral arterial disease up to 30%, especially in the case of mediastinal radiotherapy associated with an increased risk of stroke.
- Pericardial impairment or the onset of pulmonary hypertension in the administration of cyclophosphamide, bleomycin or combination radiotherapy.
Diagnosis of cardiovascular complications induced by oncological therapy
- Electrocardiogram for identifying rhythm and leading disorders.
- Conventional echocardiography (2D and Doppler) for the evaluation of systemic and diastolic function and necessary cavity structures of the heart, valves and pericardium. The ventricular execution fraction is calculated and used for the cardiotoxic definition of information and is a parameter that must be measured mandatory for the monitoring of oncological therapy.
- 3D echocardiography for the ejection fraction calculus of the left ventricle is recommended by guidelines for monitoring oncology therapy, when available, having advantages over conventional ultrasound.
- Tissue Doppler echocardiography
- Myocardial deformation echocardiography (Speckle Tracking eco) with measuring myocardial deformation parameters – strain, strain rate, torsion of the left ventricle, of which periodic measurement of the longitudinal strain of the left ventricle is recommended by guides for monitoring oncological therapy. It has the advantage of early detection of myocardial damage induced by chemo or radiotherapy (before the left ventricular ejection fraction is affected).
Other investigations that can be done to the oncological patients, depending on the signs and symptoms of the disease or the suspicion of the disease, at the cardiologist’s recommendation may be: Effort ECG, Holter TA or ECG monitoring, contrast stress echocardiography, cardiac magnetic resonance imaging (Cardio-MR) or cardiac computed tomography, as well as laboratory investigations (specifically troponin hs).
Algorithm for monitoring oncological patients
(recommended by the 2014 and 2016 guides, specifying that it can be modified by the cardiologist, individually, depending on the patient’s risk profile, the oncological therapy used, as well as the appearance of signs or symptoms of cardiovascular disease).
- In oncological patients without signs / symptoms of cardiovascular disease initially or during oncology therapy: ECG, conventional / 3D echocardiography (where it is available), Speckle tracking ultrasound (longitudinal strain), eventually troponin hs.
- In patients treated with mediastinal radiotherapy – evaluation by conventional / 3D echocardiography, speckle tracking echocardiography and after 10 years from radiotherapy and then from 5 to 5 years (risk of valvular or or Doppler ultrasound of cervical or upper limbs for 5 to 5 years (risk of cervical or upper limb stenosis).
- Individualized, at any time, at the indication of the cardiologist, if the patient’s evolution requires it.