Plasma concentrations of NT-pro-BNP and cardiac troponin-I in relation to doxorubicin-induced cardiomyopathy and cardiac function in childhood malignancy

OBJECTIVE: Anthracyclines are well established as highly efficacious antineoplastic agents for childhood malignancy, but they frequently cause dose-related cardiotoxicity. For this reason, children who have received anthracyclines need periodical cardiac evaluation. The plasma levels of B-type natriuretic peptide (BNP) have been shown to increase in proportion to severity of cardiac dysfunction. N-terminal BNP (NT-pro-BNP) is secreted from the cardiac ventricles in response to volume expansion and pressure overload. The aim of our study was to investigate whether plasma levels of NT-pro-BNP and cardiac troponin I (cTnI) can be used as specific markers for doxorubicin-induced cardiotoxicity in children with malignancy. METHODS: We performed the study in Dicle University Hospital, Pediatric Hematology and Oncology clinic. Were measured plasma NT-pro-BNP and cTnI in 31 patients (14 boys and 17 girls) who received doxorubicin-containing chemotherapy for their malignancy at cumulative doses of 30-600 mg/m2, between October 2000 and December 2004. Cardiac evaluation of the patients included recording of electrocardiography and assessment of systolic and diastolic functions of the heart by echocardiography. RESULTS: Of the 31 patients, 4 (12.9%) had left ventricular dysfunction as assessed by echocardiography. Plasma NT-pro-BNP levels in these patients were significantly elevated in comparison with healthy controls (p<0.001). Plasma NT-pro-BNP levels were significantly elevated in patients with cardiac dysfunction when compared with normal cardiac function (p<0.008). The cTnI levels were found under normal value in all patients. CONCLUSION: Measurement of NT-pro-BNP level may be an easy and practical tool, and during treatment may allow earlier-identification of individuals at risk for monitoring cardiac damage. Plasma NT-pro-BNP concentration may be a useful and sensitive indicator of cardiac dysfunction in children receiving doxorubicin therapy.