Association between global longitudinal strain and occurrence of cardiovascular events among pediatric patients following high-dose cyclophosphamide chemotherapy: a prospective cohort study.

Background: The fatal cyclophosphamide cardiotoxicity is associated with high mortality in the adult population, and the study of its effects on children represents a gap in the field. This study aimed to evaluate the potential of global longitudinal strain (GLS) as a predictor of cardiovascular events among children with high-dose cyclophosphamide chemotherapy.

Methods: This was a prospective cohort study of patients aged 14 years or younger who received high-dose (>120 mg/kg) cyclophosphamide chemotherapy recruited consecutively. Blood collection and echocardiography were performed 1 day before and after cyclophosphamide chemotherapy, and patients were followed up for 30 days with echocardiography. GLS and other echocardiography indicators were calculated accordingly. The primary outcome was the occurrence of cardiovascular events within 30 days after cyclophosphamide chemotherapy. The association between GLS and outcome was analyzed by using univariate and multivariable-adjusted Poisson regression.

Results: A total of 29 subjects were included. Among them, 10 patients (34.48%) developed cardiovascular events during a median follow-up of 10 (interquartile range, 5-13) days. Although similar before cyclophosphamide chemotherapy, GLS 1 day after cyclophosphamide chemotherapy was significantly lower in the cardiac injury group than in the noncardiac injury group (-18.33%±1.81% vs. -20.03%±1.49%, P=0.01). In the multivariable analysis adjusted for total cyclophosphamide dose (160 vs. 120-159 mg/kg) and global circumferential strain, GLS remained an independent predictor for cardiovascular events [incidence rate ratio: 1.46, 95% confidence interval: 1.02-2.09, P=0.04].

Conclusions: GLS after cyclophosphamide chemotherapy may be a reliable indicator to predict cardiovascular events in patients receiving cyclophosphamide chemotherapy, which might be essential in optimizing treatment strategies for this high-risk patient group.