[Abstract] Introduction. Cardiotoxicity represents a major limitation for the use of anthracyclines or trastuzumab in breast cancer patients. Data on longitudinal studies about early and late onset cardiotoxicity in this group of patients is scarce. The objective of the present study was to assess predictors of early and late onset cardiotoxicity in patients with breast cancer treated with A. Methods. 100 consecutive patients receiving anthracycline-based chemotherapy (CHT) to treat breast cancer were included in this prospective study. All patients underwent evaluation at baseline, at the end of CHT, 3 months after the end of CHT and 1 and 4 years after the beginning of CHT. Clinical data, systolic and diastolic echo parameters and cardiac biomarkers including high sensitivity Troponin T (TnT), N-terminal pro-brain natriuretic peptide (NT-proBNP) and Heart-type fatty acid binding protein (H-FABP) were assessed. Results. Mean doxorubicin dose was 243 mg/m2. Mean follow-up was 51.8 ± 8.2 months. At one-year incidence of anthracycline related-cardiotoxicity (AR-CT) was 4% and at the end of follow-up was 18% (15 patients asymptomatic left ventricular systolic dysfunction, 1 patients heart failure and 2 patients a sudden cardiac death). Forty-nine patients developed diastolic dysfunction (DD) during first year. In the univariate analysis DD during first year was the only parameter associated with AR-CT (Table 1). In the logistic regression model DD was independently related with the development of AR-CT, with an odds ratio value of 7.5 (95% CI 1.59–35.3). Conclusions. Incidence of late-onset cardiotoxicity is high but mostly subclinical. Diastolic dysfunction early after chemotherapy is a strong predictor of anthracycline cardiotoxicity. Instituto de Salud Carlos III; RD06/0014/002 Instituto de Salud Carlos III; RD12/0042/0067
