Impact of Persistent Left Ventricular Regional Wall Motion Abnormalities in Childhood Cancer Survivors after Anthracycline Therapy: Assessment of Global Left Ventricular Myocardial Performance By 3D Speckle-Tracking Echocardiography

Background: Previous studies of childhood cancer survivors demonstrated the existence of transient or persistent left ventricular (LV) regional wall motion abnormalities (WMA) after treatment with anthracyclines, but the differential impact on deformation of persistent regional WMA against global LV myocardial performance is unknown.

Methods: To investigate whether childhood cancer survivors after treatment with anthracyclines with persistent LV regional WMA have a poorer LV myocardial performance compared to those without WMA, 34 long-term childhood cancer survivors (mean age 14.6±4.0 years) with a median cumulative anthracycline dose 234.7mg/m² (range 80-625mg/m²) who had been off treatment for ≥ 5 years and a preserved LV ejection fraction (EF) (>55%), and 12 healthy control subjects, were studied by using 3D speckle-tracking echocardiography (3D STE). The 34 patients were divided into two groups according to the existence of regional WMA: group 1 (with WMA, n=14), group 2 (without WMA, n=20). 3D STE was performed to assess LV global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), global area strain (GAS), LV torsion, LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LVEF, and LV systolic dyssynchrony index (SDI: % of SD of time to peak of the 16-segment/R-R interval).

Results: Of the 14 patients with WMA, regional WMA was seen at mid-anterior septum in 13 patients (92.8%) and apical septum in 1 patient (7.2%). There was no statistical difference in LVEDV, LVESV, LVEF, GLS, LV torsion or SDI derived from GLS, GCS, GAS among the 3 groups. In contrast, there were significant differences in GRS (p<0.001), GAS (p<0.018), GCS (p<0.025), and SDI derived from GRS (p<0.01) among the 3 groups. Compared with group 2, group 1 had significantly reduced GRS (14.3±6.1% vs. 33.1±10.1%, p=0.003), GCS (-23.5±3.7% vs. -33.9±6.5%, p=0.026), GAS (-34.3±5.1% vs. -45.41±6.6%, p=0.034, respectively), and greater SDI derived from GRS (16.5±5.1% vs. 6.9±2.9%, p<0.01, respectively). Moreover, existence of WMA was correlated with GRS (p<0.0001), SDI derived from GRS (p<0.0001), LVEF (p=0.036), and cumulative dose (p=0.049). Multiple linear regression analysis identified GRS as a significant determinant of the existence of WMA (β=0.751, p=0.001).

Conclusion: Childhood cancer survivors after anthracycline therapy with persistent regional WMA show a poorer LV myocardial performance with mechanical dyssynchrony compared to those without regional WMA, despite a preserved LVEF.