Effectiveness of using cardiac biomarkers to detect late anthracycline cardiotoxicity in childhood leukemia survivors.

Abstract

9592 Background: Cardiotoxicity is usually detected only when clinical symptoms or progressive cardiac dysfunction has already occurred. Cardiac biomarkers (troponin T and N-terminal fragment brain natriuretic peptide precursor) have been hypothesized to reflect subclinical anthracycline cardiotoxicity earlier than echocardiography. This study aims to assess the effectiveness of using cTNT and NTproBNP in asymptomatic long-term survivors of childhood leukemia treated with and without antracyclines (ANT). Methods: Sixty-nine childhood leukemia survivors 5 - 25 years after completion of therapy were evaluated with immunochemical analysis of cTnT and NT-proBNP and echocardiography. Patients from group I (n = 36) received combined therapy with anthracyclines (ANT) with total cumulative dose 95-600 (median 221) mg/m2, patients from group II (n = 33) received therapy without anthracyclines (nonANT). Control group consisted from 44 age- and gender-matched apparently healthy subjects. Results: Levels of NTproBNP were significantly higher in ANT group than in controls (median 51,52 vs 17,37 pg/ml; p=0.0026). Patients treated with ANT had significantly increased median values of NTproBNP compared with patients in non ANT group (51,52 vs 12,24 pg/ml; p=0.0002). CTnT levels remained below the diagnostic cut-off levels in all groups. No patient had echocardiographic abnormalities, but significant differences were found in mean values of left ventricular ejection fraction and deceleration time between patients treated with and without ANT. Conclusions: Assessment of plasma NTproBNP concentrations may be an effective tool for detection of late subclinical cardiac damage in survivors of childhood leukemia previously treated with low ANT doses. Higher NTproBNP levels in patients after ANT therapy might reflect an initial stage of cardiotoxicity before the development of echocardiographic abnormalities. This study was supported by a grant from Ministry of Health 2007/42-UK-18, Slovakia.