729 Exercise Training Attenuates Anthracycline-Induced Myocardial Injury in Early-Stage Breast Cancer Patients

Abstract

Anthracycline chemotherapy (AC) is associated with dose-dependent myocardial injury that is associated with increased risk of heart failure in breast cancer (BC) survivors. This study investigated whether supervised exercise training can attenuate AC-induced myocardial injury. This is a secondary and preliminary analysis of a 4-month randomized trial in which 61 women with early-stage BCa (mean age 51±8 years) scheduled for AC were randomized to usual care (UC, n=31) or three weekly sessions of multi-modal exercise training during AC (ET, n=30). Assessments were completed prior to- and 3-4 weeks following the completion of AC. Myocardial injury was assessed by troponin-I and regional and global left-ventricular (LV) function was assessed by echocardiography. 56 participants completed follow-up testing (n=28 in each group). Mean adherence to ET was 79%. Both groups experienced a significant increase in troponin [mean change, UC: 41.6 ng/L (95% CI 27.3, 55.9), p<0.001 vs ET: 26.4 ng/L (18.0, 34.8), p<0.001], but this was attenuated in ET [net difference: -15.9 ng/L (-31.0, -0.2), group-by-time, p=0.039]. There was a small reduction in LV ejection fraction [UC: -2.6% vs ET: -2.9%, time-effect p<0.01) and global longitudinal strain (UC: 1.3% vs ET: 1.1%, time-effect p<0.01) that was not different between trained and untrained subjects. Measures of diastolic function did not change with chemotherapy. AC results in biochemical evidence of myocardial injury that is attenuated by structured exercise training in BC survivors. The clinical significance of this effect requires further long-term follow-up.