RESUMO
Objective Breast cancer patients who receive chemotherapy may develop cancer therapy-related cardiovascular toxicity, particularly if they have pre-existing cardiovascular risk factors. Notably, right ventricle dysfunction may manifest before the left ventricle. Our study aims to compare conventional echocardiography with global longitudinal strain (GLS) in low cardiovascular risk patients on low-dose anthracycline, focusing on early cardiotoxicity detection. Additionally, we explore the predictive role of right ventricular free wall longitudinal strain (RVFWLS) in cardiotoxicity. Methods In a recent study, 28 women with low cardiovascular risk who underwent low-dose anthracycline chemotherapy for breast cancer were assessed for cardiac function using two-dimensional echocardiography and speckle-tracking echocardiography. The measurements included left ventricular ejection fraction (LVEF), right ventricular systolic function (RVS'), tricuspid annular plane systolic excursion (TAPSE), left ventricular global longitudinal strain (LVGLS), and RVFWLS. All patients had normal LVEF at the beginning of the study. Cardiotoxicity was defined as a new decrease in LVEF by 10% or below 53% and/or changes in LVGLS/RVFWLS by 15%. Results In our study, no significant changes were observed in the LVEF following chemotherapy treatment. The LVEF values remained stable, changing slightly from 63 ± 3.7 to 65.0 ± 3.4, with a t-test value of 1.790 and a p-value of 0.079. Similarly, the analysis found no significant changes in RVS' and TAPSE values following chemotherapy treatment. However, significant changes were observed in strain measurements. LVGLS decreased from -21.2 ± 2.1 to -18.6 ± 2.6 (t-test = -4.116; df = 54, p=0.001), and RVFWLS decreased from -25.2 ± 2.9 to -21.4 ± 4.4 (t-test = -3.82; df = 54, p=0.001). Notably, 35% of participants showed changes in RVFWLS greater than 15%, whereas LVGLS changed by less than 15%. This indicates that RVFWLS is more sensitive to the treatment compared to LVGLS. Conclusions The study results indicate that during the initial phases of chemotherapy treatment in low cardiovascular risk patients, early changes in strain measures reveal subclinical cardiotoxicity. This suggests that GLS measurements are more effective at detecting early signs of myocardial damage and potential deterioration in cardiac function than traditional echocardiographic parameters. Additionally, it is noteworthy that RVFWLS exhibits greater sensitivity to these changes, regardless of the chemotherapy dosage and regimen.
