The early alteration of left ventricular strain and dys-synchrony index in breast cancer patients undergoing anthracycline therapy using layer-specific strain analysis

Purpose: The primary aim of this study was to evaluate early changes in cardiac function after anthracycline therapy with layer-specific speckle-tracking echocardiography (STE) and mechanical dys-synchrony.

Methods: A total of 78 breast cancer patients (ranging 31~72 years) exposed to anthracycline treatment were recruited in this study. All patients received both conventional two-dimensional speckle-tracking echocardiographs at baseline, as well as after the completion of 2 and 4 cycles of the regimen. Layer-specific longitudinal strain (LS) and circumferential strain (CS) of the 3 myocardial layers (endocardium, mid-myocardium, and epicardium) were automatically measured. Peak systolic dispersion (PSD) was defined as the standard deviation of the time to peak strain of the 18 segments, divided by the RR interval.

Results: There were no significant differences in conventional echocardiographic parameters during treatment (all P > .05). Peak endocardium CS at basal level decreased significantly after 2 and 4 cycles compared with baseline (both P = .001), while PSD significantly increased in that same period versus baseline (both P = .000). Endocardium and mid-myocardium LS, peak mid-myocardium and epicardium CS at the basal level, peak CS of all three layers at the papillary level, and peak endocardium and mid-myocardium CS at the apical level all significantly decreased after 4 cycles, compared with baseline and 2 cycles (all P = .000).

Conclusion: This study showed that myocardial deformation impairment occurred as early as 2 cycles after anthracycline chemotherapy. Endocardium CS at the basal level and left ventricular dys-synchrony index PSD were the initial cardiac abnormalities in anthracycline-treated breast cancer patients.