A left systolic dysfunction study in a group of breast cancer patients and its clinical impact

Abstract Funding Acknowledgements Type of funding sources: None. Background Cancer therapy-related cardiac dysfunction (CTRCD) is one of the major complications being reported in patients with breast cancer (BC) under chemotherapy, in particular with anthracyclines (A) or trastuzumab (T). CTRCD is defined as a reduction of left ventricular ejection fraction (LVEF) >10% to a value <50% or as a relative reduction of global longitudinal strain (GLS) >15%. Purpose We aim to evaluate the frequency of CTRCD and its clinical impact on BC patients. Methods Retrospective study of patients with BC treated with A and/or T between Jan 2017 and Dec 2018 who underwent a transthoracic echocardiography (TTE) before, during, and after chemotherapy. We analysed their baseline characteristics and outcomes based on the type of treatment received, and focusing specially on parameters of ventricular function. Results We included 128 females with median age of 54 ± 11 years-old, treated with A (78; 60.9%), T (14; 10.9%) or A followed by T (36; 28.1%). At the end of A therapy, there was a significant decrease in LVEF (64,2 ± 5,4% vs 62.6 ± 5,3%, p < 0.05) and in GLS (-20,7 ± 1.9% vs -18.8 ± 2.2%, p < 0.001) compared to baseline. No change in tricuspid annular systolic velocity (S") (p = 0,842) was observed. At 2 years of follow-up, this group of patients had no significant difference in LVEF (64,58 ± 5,58 vs 62,63 ± 6,48, p = 0,053) but maintained a significant lower GLS (-20,84 ± 2,13 vs -18,51± 2,52, p < 0,001) compared to baseline. A significant decrease in S’ (14,36 ± 2,55 vs 13,25 ± 2,26, p < 0,05) was observed. During T therapy, there was a significant decrease in LVEF (65,04 ± 5,41 vs 59,30 ± 6,21, p < 0,001), in GLS (-21,21 ± 2,75 vs -17,89 ± 2,77, p < 0,001) and in S’ (14,39 ± 3,05 vs 12,19 ± 1,62, p < 0,001) compared to baseline. At the end of T therapy (with or without A), this group of patients maintained a significant decrease in LVEF (65,11 ± 5,65 vs 61,29 ± 6,39, P < 0,001) and in GLS (-21.41%±2,86 vs -19.54%±3,50, p < 0,01). S’ returned to normal values (p = 0,10). At 2 years of follow-up, this group of patients maintained a significant decrease in LVEF (65,00 ± 5,99 vs 61,18 ± 6,30, p < 0,05) but GLS (p = 0,235) returned to normal values. No change in S’ was observed (p =0,379). During a mean follow-up of 38 months, 35 (27%) patients developed CTRCD with a higher prevalence in patients who took A followed by T (18; 14%), 9 (7%) presented with clinical heart failure, 1 (1%) needed hospitalization, 5 (4%) needed to temporarily suspend treatment and 3 (2%) needed to definitely stop treatment. Conclusions Treatment with A was associated with a decrease in LV systolic function at the end of therapy. A decrease in right ventricular (RV) systolic function was observed at 2 years of follow-up. Treatment with T was associated with a decrease in RV and LV systolic function during therapy. CTRCD occurred in 27%, mainly on patients with both A and T therapy, a frequency within literature data. CTRCD had clinical impact leading to HF and suspension of chemotherapy.