Objective: Monitoring of acute and chronic cardiotoxicity of anthracyclines with biochemical markers – N-terminal pro brain natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT) and myocardial izoenzyme of creatine kinase (CK-MB mass). Setting: University of Defence in Brno, Faculty of Military Health Sciences in Hradec Králové, Department of Field Internal Medicine, Charles University in Prague, Medical Faculty in Hradec Králové and Faculty Hospital Hradec Králové, Department of Internal Medicine II – Clinical Hematology, Department of Internal Medicine I, Institute of Clinical Biochemistry and Diagnostics, Department of Gerontology and Metabolic Care. Patients and Methods: Twenty six consecutive patients treated for newly diagnosed acute leukemia were studied. The patients consisted of 15 males and 11 females with the mean age of 46.2 ± 12.4 years. The patients were given 2–6 cycles of chemotherapy (CT) containing anthracyclines in the total cumulative dose of 464.3 ± 117.5 mg/m2. Evaluation of biochemical markers and echocardiography were performed at the baseline, after first CT with anthracyclines, after last CT with anthracyclines and circa 6 months after completion of the treatment. Results: Mean baseline NT-proBNP concentration was 117.7 ± 46.4 ng/l, values were slightly elevated in 3 patients (above 100 ng/l for male, above 150 ng/l for female). After the administration of the first CT with anthracyclines, NTproBNP elevation to 299.7 ± 176.2 ng/l was observed. After last CT with anthracyclines, NT-proBNP concentration was 287.1 ± 147.4 ng/l. Six months after completion of the treatment, NT-proBNP concentration was 362.5 ± 304.9 ng/l, values were elevated in 16 patients. Changes in NT-proBNP were statistically significant in comparison with the baseline value (p < 0.001). We found correlation between NT-proBNP and systolic and diastolic left ventricular (LV) dysfunction on echocardiography. CTnT concentrations were negative (bellow 0.01 µg/l) during the treatment in all patients. Six months after the treatment, cTnT became positive in 3 patients. CK-MB mass concentrations remained negative (bellow 4.94 µg/l) in all patients during the treatment and the follow-up. Conclusion: Our results show that oncology treatment containing anthracyclines has a toxic effect on the heart, which becomes manifest both during the treatment (acute cardiotoxicity) and during the follow-up (chronic cardiotoxicity). We found changes in biochemical markers of functional myocardial damage (NT-proBNP elevations showing acute and chronic neurohumoral activation) and deterioration of diastolic and systolic LV function on echocardiography. In asymptomatic patients, these changes are regarded as subclinical cardiotoxicity. These findings represent the risk for manifestation of cardiotoxicity in terms of heart failure in the future and require further follow-up. According to our results, anthracycline treatment – even in higher cumulative doses – does not lead to acute damage of cardiomyocyte structure.

        Key words: biochemical markers, NT-proBNP, cardiotoxicity, anthracyclines.