The Significance Of Evaluating Cardiotoxicity After Anthracycline Therapy For Acute Leukemia In Children

Objective: Anthracycline antibiotics, predominantly doxorubicin (DOX) anddaunorubicin (DNR), are highly effective in the treatment of childhoodmalignancies, but are potentially cardiotoxicity at all dose ranges and is a knowncomplication of anthracycline therapy. We studied cardiotoxicity byelectrocardiogram(ECG), echocardiography(left ventricular ejection fraction LVEFor myocardial performance index MPI) and biochemical indicators (creatine kinaseCK, creatine kinase–MB CK-MB, cardiac troponin I cTnI), analysisedAnthracycline-related cardiotoxicity in different cumulative dose of childhood withacute leukemia(AL), looked for the sensitive factor indicating early heart injurewhich remind clinical intervention in time for the improvement of event-freesurvival and life quality in children with acute leukemia.Methods:With retrospective analysis, Seventy-five AL children (hospitalizedin Dalian Children’s Hospital from2007to2012, male:25, female:10, F:M=2.5:1;ALL:32, AML:3; Age:0-10years old) who received a cumulative anthracyclinedose of0-50mg/m2,50-165mg/m2,165-330mg/m2and more than330mg/m2wereevaluated for signs of clinical cardiotoxicity. Cardiac injury was assessed byelectrocardiogram(ECG), echocardiography (left ventricular ejection fractionLVEF or myocardial performance index MPI) and biochemical indicators (creatinekinase CK, creatine kinase CK-MB, cardiac troponin I cTnI),all patients excludedthe following diseases, congenital heart diseases, and hypertension, arrhythmia,myocarditis, cardiomyopathy, genetic and metabolic diseases, and trisomy21-syndrome.Results:1. After anthracycline therapy,17of35cases children with acute leukemiahad an abnormal ECG, but LVEF, MPI, CK, CK-MB and cTnI are normal.2. Abnormal ECG is positive related to the accumulated dose of Anthracycline：The main ECG abnormalities include the changing of the ST segment, T wave,and ST-T; but no abnormal PR segment, QRS wave, QT interval were found.3. Anthracycline drugs of different accumulated dose ST segment, T wave andST-T changes abnormal rate:①The ST segment, T wave and ST-T changes are most common in theelectrocardiogram of17cases children. With the anthracycline drugs accumulateddose increased, the abnormal rate are also raised.②No statistical significance of ST segment changing when compare in twoaccumulated dose of165-330mg/m2and0-50mg/m2, that means ST segment maynot be used as a useful factor, must be combined with other index.4. In every accumulated dose:There are no statistical significance between ST segment, T wave, and ST-Tchanging, that indicate any one individual form of ECG is not specific marker.5.We have also observed the following contents:①Single atrial premature beats in1patients with the accumulated dose of50-165mg/m2, no malignant arrhythmia;②1case had a sinus heartbeat bradycardia with ST-T changes at theaccumulated dose of0-50mg/m2, but vanished when the dose increased;③6cases children had an abnormal ECG but normal B-type natriureticpeptide (BNP).Conclusion:①Anthracycline drugs induced heart injury which correlated with theaccumulated dose;②Earlier change were found in ECG if cardiotoxicity happened;③After anthracycline therapy in children AL, The common changes in ECGinclude ST segment, T wave and ST-T changes, rarely arrhythmia;④During the period of anthracycline therapy, when we found the ECGabnormalities, we should intervened immediately, and that can effectively preventthe progression of heart injury;⑤Further study will be needed to confirm which is more prognostic factor invaluating cardiotoxicity, ECG or BNP.