Abstract PS13-21: Cardiac function in patients receiving trastuzumab for HER2+ metastatic breast cancer with left ventricular ejection fraction<50% at baseline

Research objectives and rationale Trastuzumab greatly enhances the efficacy of treatment in HER2+ metastatic breast cancer (MBC). Due to its potential to induce cardiomyopathy, however, trastuzumab is contraindicated in patients with baseline left ventricular ejection fraction (LVEF) 5% below baseline. Exploratory, we compared the incidence of severe cardiotoxicity in patients with and without cardioprotective medication at start trastuzumab. Results Of the 758 patients identified with HER2+ MBC, 41 patients were included with a LVEF Citation Format: Nathalie I Bouwer, Tessa G Steenbruggen, Hanah N Rier, Jos JEM Kitzen, Carolien H Smorenburg, Marlies L Van Bekkum, Albert J Ten Tije, Paul C De Jong, Jan C Drooger, Cynthia Holterhues, Marcel JM Kofflard, Eric Boersma, Gabe S Sonke, Mark-David Levin, Agnes Jager. Cardiac function in patients receiving trastuzumab for HER2+ metastatic breast cancer with left ventricular ejection fraction