Cardiotoxicity evaluation in pediatric patients with acute lymphoblastic leukemia - results of prospective study

The chemotherapy protocol for acute lymphoblastic leukemia (ALL) uses low doses of anthracyclines (AC), generally associated with subclinical cardiotoxicity. The aim of our study was to evaluate the serum biomarkers and echocardiography parameters in children with ALL treated with AC in order to determine the most useful element for early detection of cardiotoxicity.

In this prospective study, troponin I (TnI) and heart-type fatty acid binding protein (HFABP) were assessed five times during the first year after the onset of ALL. Serial Tissue Doppler Imaging and conventional cardiac echography were performed by two pediatric cardiologists (intraclass correlation coefficient over 0.85 for all measurements) in three periods during the study protocol.

We evaluated 48 children with ALL. TnI increased during therapy, without returning to baseline values one year after diagnosis. HFABP did not show significant changes during the study protocol. Left ventricle outflow tract time-velocity integral and peak systolic septal mitral annulus velocity decreased during chemotherapy and returned to baseline levels at one year after diagnosis, while peak systolic tricuspid annulus velocity and excursion, maintained a descending tendency. Early filling transmitral flow velocity and E/A ratio were also transiently influenced by chemotherapy.

The study showed signs of transient cardiotoxicity in the left ventricle and diastolic parameters after chemotherapy, compared to right ventricle parameters which maintained low values even one year after diagnosis. TnI proved to be directly proportional to chemotherapy doses but HFABP was not useful in this setting.