Left ventricular diastolic function in patients with breast cancer under chemotherapy

Type of funding sources: None.

Chemotherapy, in particular anthracyclines (A) and trastuzumab (T), have improved disease-free survival and overall prognosis in patients with breast cancer (BC). The use of these two different types of agents may increase myocardial injury and cancer therapy-related cardiac dysfunction (CTRCD). 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%. However, the role of diastolic dysfunction has been insufficiently researched.

We sought to evaluate the impact of cardiotoxic treatments on left ventricular diastolic function.

Retrospective study of patients with first non-metastatic BC treated with A and/or T between Jan 2017 and Dec 2018 who underwent a comprehensive echocardiographic examination before, during, and after chemotherapy. We evaluated parameters of diastolic function derived from pulsed wave doppler interrogation of the mitral valve inflow (E/A ratio and mitral E-wave deceleration time (EDT)) and tissue doppler (E/E’ ratio).

We included 128 patients, all female 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, E/A ratio (p=0,056), EDT (p=0,156) and E/E’ ratio (p=0,319) and left atrial volume index (LAVI) (p=0,056) did not show significant changes. At 2 years of follow-up, these parameters did not differ compared to baseline.

During T therapy, diastolic parameters did not differ from baseline. At the end of T therapy (with or without A), E/E’ ratio had a statistically significant increase (8,61±2,61 vs 9,70±3,59, p<0,05) but no changes in EDT (p=0,461) or E/A ratio (p=0,464) occurred. At 2 years of follow-up, EDT had a statistically significant increase (204,90±44,24 vs 229,10±58,53, p<0,05) but no changes in E/A ratio (p=0,476) or E/E’ ratio (p=0,499) occurred.

In our sample of women with BC who underwent chemotherapy, early significant changes in diastolic parameters did not occur. One parameter of diastolic dysfunction was changed at 2 years of follow-up. In this study, BC chemotherapy has a very modest impact on LV diastolic function. Randomized studies on larger population are required. Other parameters should be considered to determine the diagnostic and prognostic role of LV diastolic function in CTRCD.