Early left ventricular dysfunction in children after hematopoietic stem cell transplantation for acute leukemia: a case control study using speckle tracking echocardiography

Abstract

Background and objectives: Cardiovascular complications are the leading cause of morbidity and mortality in childhood cancer survivors. Hematopoietic stem cell transplantation (HSCT) is a curable therapy for pediatric cancer. However, changes in cardiac function in children after HSCT are not well known. We assessed left ventricular (LV) function in children after HSCT using speckle tracking echocardiography (STE).

Subjects and methods: Forty consecutive patients with median age of 11.9 years (range, 1.5-16 years) who received HSCT for acute leukemia and had comprehensive echocardiography before and after (median 9.2 month) HSCT were included in this study. The LV function parameters including conventional tissue Doppler imaging (TDI) and STE data were collected from pre- and post-HSCT echocardiography. These data were compared to those of 39 age-matched normal controls.

Results: Compared to normal controls, post HSCT patients had similar (p=0.06) LV ejection fraction. However, the following three LV function parameters were significantly decreased in post HSCT patients: rate-corrected velocity of circumferential fiber shortening (p=0.04), mitral inflow E velocity (p<0.001), and mitral septal annular E' velocity (p=0.03). The following four STE parameters were also significantly decreased in post HSCT patients: LV global circumferential systolic strain (p<0.01), strain rate (SR, p=0.01), circumferential diastolic SR (p<0.01), and longitudinal diastolic SR (p<0.001). There was no significant change in TDI or STE parameters after HSCT compared to pre-HSCT. Patients with anthracycline cumulative dose >400 mg/m(2) showed significantly (p<0.05) lower circumferential systolic strain and circumferential diastolic SR.

Conclusion: Subclinical cardiac dysfunction is evident in children after HSCT. It might be associated with pre-HSCT anthracycline exposure with little effect of conditioning regimens. Serial monitoring of cardiac function is mandatory for all children following HSCT.

Keywords: Childhood leukemia; Echocardiography; Heart function; Speckle tracking; Stem cell transplantation; Strain rate.

Fig. 1. Global left ventricular strain (S), strain rate (SR), and diastolic strain rate (DSR) in patients with antracycline cumulative dose <400 mg/m² (black bar) compared to those in patients with anthracycline cumulative dose >400 mg/m² (white bar).