Cardiooncology. Basic principles of prevention and treatment of cardiotoxicity in cancer patients

Approaches to early diagnosis and prevention of cardiovascular toxicity induced by targeted drugs and immune checkpoint inhibitors in oncohematology: a literature review

The development of targeted drugs and immune checkpoint inhibitors (ICIs), as well as their implementation into clinical practice has allowed increasing the overall and event-free survival of oncohematological patients. Currently, assessment of the efficacy of a therapeutic strategy in each specific case includes the evaluation of an acceptable tolerability profile. The subject of discussion includes cardiovascular complications induced by target drugs and ICIs. The review mainly presents the issues of cardiovascular toxicity (CVT) in certain groups of oncohematological patients (with chronic lymphocytic leukemia, chronic myeloid leukemia, multiple myeloma). The spectrum of cardiovascular adverse effects associated with targeted and ICI therapy in oncohematological practice is quite wide — coronary artery disease, peripheral arterial disease, myocarditis, heart failure, arrhythmias, hypertension. The high importance of the problem of using targeted and immunosuppressive therapy dictates the need to predict adverse effects. The diagnosis of heart failure (one of CVT manifestations) is based on determining the decreased left ventricular ejection fraction during echocardiography, less often — during cardiac magnetic resonance imaging; global longitudinal myocardial strain is a significant parameter of preclinical heart failure, which is determined using the speckle tracking technique. To determine vascular toxicity, a special attention is paid to the vascular wall structure and microcirculation parameters — capillary density at rest, percentage of capillary recovery and perfused capillaries, stiffness index for large blood vessels, reflection index for small arteries, laboratory markers of inflammation and endothelial dysfunction (C-reactive protein, fibrinogen, homocysteine, endothelin 1, vascular endothelial growth factor). CVT prevention presumes the determination of the risk group, correction of risk factors, and administration of protective therapy to very high and high-risk patients. One of the promising directions for preventing vascular toxicity is the use of sodium-glucose linked transporter-2 inhibitors.

Modeling Doxorubicin-Induced Cardiomyopathy With Fibrotic Myocardial Damage in Wistar Rats

Background

Cardiovascular complications, arising after anthracycline chemotherapy, cause a significant deterioration in the life quality and expectancy of those patients who were previously successfully treated for malignant neoplasms. A number of clinical studies have demonstrated that patients with cardiotoxicity manifested during anthracyclines therapy also have extensive fibrotic changes in the cardiac muscle in the long term. Given the lack of an unambiguous understanding of the mechanisms of fibrotic changes formation under doxorubicin treatment in the myocardium, there is the obvious necessity to create a relevant experimental model of chronic doxorubicin-induced cardiomyopathy with fibrotic myocardial lesions and delayed development of diastolic dysfunction.

Methods

The study was divided into two stages: first stage (creation of acute doxorubicin cardiomyopathy) - 35 male Wistar rats; second stage (creation of chronic doxorubicin cardiomyopathy) - 40 male Wistar rats. The animals were split into eight groups (two control ones and six experimental ones), which determined the doxorubicin dose (first stage: 25, 20.4, 15 mg/kg; second stage: 5, 10, 15 mg/kg, intraperitoneally) and the frequency of injection. Echocardiographic, hematological, histological, and molecular methods were used to confirm the successful modeling of acute and chronic doxorubicin-induced cardiomyopathy with fibrotic lesions.

Results

A model of administration six times every other day with a cumulative dose of doxorubicin 20 mg/kg is suitable for evaluation of acute cardiotoxicity. The 15 mg/kg doxorubicin dose is highly cardiotoxic; what's more, it correlates with progressive deterioration of the clinical condition of the animals after 2 months. The optimal cumulative dose of doxorubicin leads to clinical manifestations confirmed by echocardiographic, histological, molecular changes associated with the development of chronic doxorubicin-induced cardiomyopathy with fibrotic lesions of the left ventricular of the cardiac muscle and ensure long-term survival of animals is 10 mg/kg doxorubicin. A dose of 5 mg/kg of the doxorubicin does not ensure the development of fibrous changes formation.

Conclusion

We assume that cumulative dose of 10 mg/kg with a frequency of administration of six times in 2 days can be used to study the mechanisms of anthracycline cardiomyopathy development.