Use of Trastuzumab in Patients With Breast Cancer and Preexisting Left Ventricular Systolic Dysfunction

By: Jenna Carter, PhD
Posted: Monday, July 1, 2024

The monoclonal antibody trastuzumab is an effective treatment of HER-2 positive breast cancer, but it is often associated with the development of cardiomyopathy and heart failure, including reductions in left ventricular ejection fraction (LVEF). Thus, this side effect has triggered researchers to assess its safety in in patients with preexisting heart conditions. In an article published in the journal Cardio-Oncology, Parisa Firoozbakhsh, MD, of Iran University of Medical Sciences, Tehran, and colleagues reported that treatment with trastuzumab was found to be safe in patients with HER2-positive breast cancer and preexisting left ventricular systolic dysfunction (LVSD). However, they suggest, these patients should be strictly monitored for cardiovascular risk.

A total of 36 patients were included in this retrospective cohort study, based at a single center in Iran. All patients were diagnosed with HER2-positive breast cancer and had asymptomatic mild LVSD, with a LVEF of 40% to 53% without heart failure symptoms. Patients received two cycles of trastuzumab and underwent routine echocardiography and global longitudinal strain assessments every 3 months. Primary outcomes included myocardial infarction, cardiac arrhythmia, heart failure symptoms, and cardiovascular death. The secondary outcomes included a 10% or greater reduction in LVEF or a 15% or more reduction in global longitudinal strain compared with baseline.

Findings revealed a 10% or greater reduction in LVEF in six patients (16.7%) and a 15% or greater reduction in global longitudinal strain in four patients (11.1%). There appeared to be a significant association between reduction in LVEF and baseline systolic blood pressure (P = .04). Additionally, LVEF reduction below 40% was observed in three patients (8.3%) whose trastuzumab treatment was interrupted.

Based on these study findings, the authors recommended strict control of cardiovascular risk factors, especially hypertension, in this patient population. In addition, they added, future studies are warranted to investigate the safety of trastuzumab treatment in patients with a LVEF below 40%.

Disclosure: The study authors reported no conflicts of interest.

Cardio-Oncology

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