Value of Myocardial Strain in Monitoring Fluorouracil-Based Chemotherapy-Related Cardiac Dysfunction in Gastrointestinal Cancer Patients.

Objectives: To investigate the predictive value of myocardial strain for cardiotoxicity associated with fluorouracil-based chemotherapies in gastrointestinal cancer patients.

Methods: Patients with diagnosis of gastrointestinal cancers, who were hospitalized for chemotherapy involving antimetabolic drugs, were eligible in this prospective study. Echocardiography was performed before and after each chemotherapy cycle during hospitalization until the completion of chemotherapy. Cancer therapy-related cardiac dysfunction (CTRCD) was identified if there was a decrease in left ventricular ejection fraction (LVEF) by at least 5% to an absolute value of < 53% from the baseline, accompanied by symptoms or signs of heart failure; or a decrease in LVEF of at least 10% to an absolute value of < 53% from the baseline, without symptoms or signs of heart failure. Subclinical cardiac impairment is defined as a decrease in the left ventricular global longitudinal strain (GLS) of at least 15% from baseline.Clinical data and myocardial strain variables were collected. Changes of echocardiographic indexes after chemotherapy at each cycle were observed and compared to those of pre-chemotherapy. Cox regression analysis was used to determine the associated indexes to CTRCD, and receiver operating characteristic (ROC) curves were plotted for evaluation of their predicting efficacy.

Results: Fifty-one patients completed 4 cycles of chemotherapy and were enrolled in the study analysis. LVEF, GLS, GLS epicardium (GLS-epi), and GLS endocardium (GLS-endo) were decreased after the 4 cycles of chemotherapy. Throughout the chemotherapy period, 6 patients (11.8%) progressed to CTRCD. The Cox regression analysis revealed that the change in left atrial ejection fraction (LAEF) and LAS during the reservoir (LASr) phase after the first cycle of chemotherapy (C1v-LAEF and C1v-LASr, respectively) were significantly associated with the development of CTRCD [C1v-LAEF (HR=1.040; 95%CI: 1.000-1.082; P=0.047); C1v-LASr (HR=1.024; 95%CI: 1.000-1.048; P=0.048)]. The sensitivity and specificity were 50.0% and 93.3%, respectively, for C1v-LAEF predicting CTRCD when C1v-LAEF > 19.68% was used as the cut-off value, and were 66.7% and 75.6%, respectively, for C1v-LASr predicting CTRCD when C1v-LASr > 14.73% was used as the cut-off value. The areas under the ROC curve (AUC) for C1v-LAEF and C1v-LASr predicting CTRCD were 0.694 and 0.707, respectively.

Conclusions: GLS changes among patients with subclinical impairment of cardiac function who were treated with fluorouracil-based chemotherapies, and C1v-LAEF and C1v-LASr of the left atrium are early predictors of cardiac function deterioration.