Trastuzumab cardiotoxicity in patients with breast cancer.

Dear Editor,

We read the article "Detection of Subclinical Trastuzumab-Induced Cardiotoxicity in Patients with Breast Cancer"[1]. Cardio-oncology is a current challenge for cardiologists, due to the high prevalence of cardiovascular toxicity secondary to chemotherapy agents, in addition to the need to determine effective measures to reduce the incidence of that complication[2-4].

The above-cited article is extremely relevant and we would like to congratulate its authors. Its title and objective lead us immediately to believe that a method capable of early detecting subclinical cardiotoxicity (defined as a reduction in ventricular ejection fraction) would be described. However, we could not understand how the authors assumed that the change in diastolic function found preceded systolic dysfunction, because none of the patients studied showed a significant reduction in ventricular ejection fraction in the three-month follow-up. We would like to ask the authors if they attribute the lack of ejection fraction reduction to the short follow-up, to the lack of previous cardiac changes (coronary artery disease, cerebral vascular accident or heart failure), or to the fact that the prevalence of comorbidities (arterial hypertension and diabetes) in the population studied was lower than that reported in the large studies.

Thank you and congratulations for your article.