Subclinical Systolic Dysfunction during Chemotherapy for Breast Cancer

Abstract Background Cardiotoxicity is the main complication related to cancer therapy. Studies indicate that global longitudinal strain is an early detector of subclinical dysfunction of the left ventricle, preceding the decline in ejection fraction (EF). However, the reproducibility of such methodology has not been tested outside specialized centers. Objectives To assess the frequency of subclinical cardiotoxicity and to compare global longitudinal strain and EF measurements during the clinical course of patients undergoing chemotherapy for breast cancer. Methods This was an observational prospective study of 78 adult women who underwent serial echocardiograms (baseline and 1, 3, and 6 months after the beginning of chemotherapy), to evaluate biplane and 3D EF and global longitudinal strain. Cardiotoxicity and subclinical dysfunction were defined according to American Society of Echocardiography/European Association of Cardiovascular Imaging criteria. Statistical significance was set at p < 0.05. Results The mean age of the patients was 50.1 ± 11.48 years. The frequency of subclinical cardiotoxicity (defined by global longitudinal strain) was 14.9% after 30 days of chemotherapy, 16.7% after 3 months, and 19.7% after 6 months, compared to 4.5%, 3%, and 6.6%, respectively, when clinical cardiotoxicity was determined according to EF. The group that developed subclinical cardiotoxicity by 30 days (group A) had a higher frequency of clinical cardiotoxicity at 3 months (p=0.028) and a lower mean biplane EF after 30 days (p= 0.036) than the group that showed no evidence of subclinical cardiotoxicity (group B). Conclusion Subclinical cardiotoxicity was frequent and began early, being associated with a drop in EF during the clinical course.

Disfunção diastólica precoce em pacientes com câncer de mama submetidas à quimioterapia / Early diastolic dysfunction in breast cancer patients undergoing chemotherapy

Fundamento: A quimioterapia para o câncer de mama está associada a complicações cardiovasculares graves, como a insuficiência cardíaca. A fração de ejeção do ventrículo esquerdo é o principal parâmetro para avaliar a função sistólica nessas pacientes. Todavia, a ocorrência de disfunção diastólica pode preceder à disfunção sistólica. Objetivos: Avaliar as funções diastólica e sistólica do ventrículo esquerdo de portadoras de câncer de mama em tratamento quimioterápico com antraciclinas. Métodos: Trata-se de estudo observacional, longitudinal, analítico e prospectivo. Estudaram-se 62 mulheres com câncer de mama, com idades de 21 a 75 anos, que realizaram ecocardiogramas basais e após 3 meses de tratamento. Avaliaram-se parâmetros de função diastólica, e as pacientes foram classificadas em disfunção diastólica tipos:1, 2 ou 3. Definiu-se a disfunção sistólica como fração de ejeção do ventrículo esquerdo ≤ 53%. Resultados: Decorridos 3 meses de tratamento, 35 pacientes (56,4%) apresentavam disfunção diastólica tipo 1, e apenas uma (1,6%) do tipo 2. A disfunção diastólica ocorreu em 26 pacientes já na etapa basal e surgiu em dez indivíduos no decurso do tratamento. Os parâmetros de função diastólica velocidade de onda E e relação E/A diminuíram significativamente (p < 0,05) com a quimioterapia, todavia, os demais não tiveram variação significativa. Apenas três pacientes apresentaram disfunção sistólica, porém verificou-se maior redução da fração de ejeção do ventrículo esquerdo no grupo que desenvolveu disfunção diastólica durante o tratamento comparativamente ao grupo que apresentava já disfunção diastólica no período basal (p = 0,04). Conclusão: A disfunção diastólica ocorre precocemente em portadoras de câncer de mama submetidas à quimioterapia. O surgimento de disfunção diastólica no decurso do tratamento se associa à redução significativa da fração de ejeção do ventrículo esquerdo. (AU)

Background: Chemotherapy for breast cancer is associated with serious cardiovascular complications such as heart failure. The left ventricular ejection fraction is the main parameter used to assess systolic function in these patients. However, the occurrence of diastolic dysfunction may precede that of systolic dysfunction. Objectives: To evaluate left ventricle diastolic and systolic functions in women with breast cancer undergoing chemotherapy using anthracyclines. Methods: This observational, longitudinal, analytical, and prospective study included 62 women with breast cancer aged 21­75 years old who underwent echocardiography at baseline and after three months of treatment. Diastolic function parameters were evaluated, and the patients were classified as diastolic dysfunction type 1, 2, or 3. Systolic dysfunction was defined as a left ventricular ejection fraction ≤ 53%. Results: After three months of treatment, 35 patients (56.4%) had type 1 diastolic dysfunction, while one (1.6%) had type 2. Diastolic dysfunction was identified in 26 patients at baseline and developed in 10 patients during treatment. Diastolic function parameters, E wave velocity, and E/A ratio decreased significantly (p < 0.05) with chemotherapy; however, the others showed no significant variations. Only three patients had systolic dysfunction, but there was a greater reduction in left ventricular ejection fraction in the group that developed diastolic dysfunction during treatment versus the group with diastolic dysfunction at baseline (p = 0.04). Conclusion: Diastolic dysfunction occurs early in women with breast cancer undergoing chemotherapy. Its onset during the course of treatment is associated with a significantly reduced left ventricular ejection fraction. (AU)