Background: Adjuvant trastuzumab therapy improves survival of Human Epidermal growth factor receptor 2 (HER2)-positive women with early breast cancer (EBC). Trastuzumab-induced cardiotoxicity is not uncommon. In the setting of community patients, the incidence, timing and phenotype of new onset congestive heart failure (CHF) is unknown.
Methods: Forty hundred and ninety nine consecutive HER2-positive women (mean age 55 ± 11) with EBC treated with trastuzumab between January 2008 and June 2009 at 10 Italian institutions were followed-up for 1 year. We evaluated incidence, time of occurrence, clinical features associated with CHF. Left ventricular ejection fraction (LVEF) was evaluated by echocardiography at baseline and 3, 6, 9and 12 months during trastuzumab therapy.
Results: CHF occurred in 16 patients (3.2%), who were older, more hypertensive and with a higher degree of hypertension in comparison with patients who did not have CHF. All CHF patients had a significant reduction in LVEF with a mean peak of -12 points % detected at 3-month follow-up. CHF occurred in seven patients (44%) within 3-month follow-up, in four patients (25%) between 3-6 months, in three patients (19%) between 6-9 months and in two patients (12%) between 9 and 12 months. Trastuzumab was discontinued in 10 of 16 patients and re-started in five after LVEF recovery and clinical improvement. New onset CHF was predicted by the presence of hypertension [OR 2.9 (CI 1.1-7.9]).
Conclusion: New onset CHF occurs seldom in HER2-positive women with EBC, prevalently in the first 6 months of therapy. CHF is associated with a significant reduction in LVEF and is predicted by a history of hypertension.