Changes And Sigificance Of Cardiac Troponin And Myocardial Enzymes In Patients With Invasive Breast Cancer After Anthracycline Chemotherapy

Objective: To analyze the changes of troponin Ⅰ(c Tn I)and creatine kinase isoenzyme(CK-MB)in serum of patients with invasive breast cancer after chemotherapy with anthracycline(ATN),and to explore the significance of these changes in the early diagnosis of cardiotoxicity.Methods: Patients with invasive breast cancer admitted to the Breast Surgery Department of our hospital from June 2019 to June 2020 were selected as the observation objects.Inclusion criteria:(1)Patients with invasive breast cancer in need of chemotherapy who are pathologically confirmed,have a quality of life(KPS)score of more than 60,and are expected to survive more than 6months;(2)who received chemotherapy containing ATN;(3)who have never received chemo or radiotherapy before;(4)no previous heart disease,high blood pressure,diabetes,etc.;(5)no acute myocardial infarction in the past six months;(6)all patients were informed of this study and had signed informed consent.Forty-two patients were eventually enrolled in the study.The changes of serum troponin indexes,myocardial enzymology indexes,ECG and echocardiography were analyzed at three time points: before chemotherapy,after the first cycle of chemotherapy and the next day after the fourth cycle of chemotherapy.All data was analyzed by SPSS25.0 statistical software.Results: The value of c Tn I in 2 patients after 1 cycle of chemotherapy and in 5 patients after 4 cycles of chemotherapy was significantly higher than that before chemotherapy,with statistical significance(P < 0.05),but the value was still within the range of normal.There was no significant change in CK-MB compared with before chemotherapy(P > 0.05).After4 cycles of chemotherapy,the ECG of 5 patients was abnormal,with an abnormal rate of 11.90%(5/42),and the difference was statistically significant compared with that before chemotherapy(P < 0.05).There were no significant changes in LVEF and E/A values of echocardiography in all patients before and after chemotherapy,and the differences were not statistically significant(P > 0.05).The reason may be that the dose of anthracycline does not reach the threshold that would cause cardiotoxicity.Troponin was positively correlated with the abnormal rate of ECG(r = 0.948,P = 0.000).Conclusion: Troponin levels of patients with invasive breast cancer received ATN chemotherapy may increase,but would remain within the normal range,which may be due to the use of safe doses.Troponin and ECG can be used to monitor the early cardiac toxicity of ATN,but changes in troponin value are more sensitive than changes in ECG.LVEF,CK-MB and E/A values can not be used as effective observation items to monitor early cardiotoxicity,but if at least one of them has abnormal changes,it can indicate that serious cardiotoxicity has occurred.