How Does BMI Affect Cardiac Health for Patients With Breast Cancer Receiving Chemotherapy?

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A study covering the northeast region of Colombia found nearly 12% of patients with a high body mass index (BMI) being treated for breast cancer at a regional center experienced cardiotoxicity during chemotherapy. The study will be presented at the upcoming American College of Cardiology Latin America 2023 Together With Asociación Costarricense de Cardiología conference.

“Cardiotoxicity is a relatively recent concern in cancer care, and its recognition as a significant issue is still evolving. In regions with limited research infrastructure and resources, there may be a lack of specific studies or initiatives addressing cardiotoxicity in the context of breast cancer treatment,” said the study’s lead author Ivetteh Gaibor Santos, MD, an internal medicine specialist at Universidad Autónoma de Bucaramanga/Fundación Oftalmológica de Santander-Foscal in Bucaramanga, as well as a cardiology fellow-in-training at Fundación Universitaria de Ciencias de la Salud/Hospital de San José in Bogotá.

Study Methodology

An anonymized database of patients with breast cancer who started chemotherapy with doxorubicin or trastuzumab between January and December 2021 was used for the study. The analysis only included patients who had a baseline echocardiogram and at least one follow-up echocardiogram. The database also recorded sociodemographic, oncologic, cardiovascular, and echocardiographic variables.

Cardiotoxicity was defined as a decrease in left ventricular ejection fraction (LVEF) of more than 10% reaching a value below 50%, or a relative reduction of more than 15% in global longitudinal strain in patients with a normal LVEF. For reference, a normal ejection fraction is 50% or higher.

The study cohort included 67 patients, with an average age of 55 years old and mean BMI of 26.18 kg/m². Baseline characteristics of the study cohort included obesity (20.9% of patients), hypertension (14.9%), and type 2 diabetes (13.4%). All of the patients had a normal LVEF before starting chemotherapy.


Researchers found that the prevalence of cardiotoxicity in the patient cohort was 11.94%. A BMI of 25 and above (indicating overweight/obesity) was the only predisposing risk factor for developing this adverse effect.

“Obesity is itself a risk factor for the development of breast cancer and cardiovascular disease like heart failure, but it isn´t often properly managed, unlike other prevalent risk factors like high blood pressure,” said Dr. Gaibor Santos, who added that all patients in this study were also taking antihypertensive drugs. Chemotherapeutic agents—which are formulated according to body surface area instead of body composition—may lead to further risk of cardiotoxicity in patients with obesity due to over- or underdosing, she said.

To raise awareness about the risks of cardiotoxicity in cancer treatment among health-care professionals and the general population, the researchers suggest several actions, including:

  • Enhanced medical education on cardiotoxicity in both medical schools and continuing medical education
  • Multidisciplinary collaboration among specialties to improve the understanding of cardiotoxicity among clinicians and patients and facilitate early detection and intervention
  • Encouraging and supporting research initiatives focused on cardiotoxicity in cancer treatment
  • Use of digital resources to provide clinicians with easy access to up-to-date information on cardiotoxicity.

“Addressing obesity in patients [with cancer] before starting chemotherapy as well as considering the potential risk for cardiotoxicity requires a comprehensive approach,” Dr. Gaibor Santos said. “Some strategies clinicians can consider include pretreatment assessment, lifestyle interventions, and cardiovascular risk management. It is important to note that these strategies should be tailored to each patient’s specific needs and in accordance with current evidence-based guidelines.”

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.