From the Guidelines
ECG is indicated in breast cancer patients before starting treatment with cardiotoxic chemotherapy agents or in those with pre-existing cardiac conditions, as a baseline assessment of cardiac function. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of baseline cardiac assessments before initiating chemotherapy, especially in patients with HER2-positive breast cancer 1. The study suggests that a baseline electrocardiogram (ECG), including measurement of a heart rate-corrected QT interval (QTc), is recommended for patients with a cancer diagnosis that requires treatment with a potentially cardiotoxic treatment (LOE, I; GOR, A) 1. Some key points to consider when evaluating the need for an ECG in breast cancer patients include:
- The type of chemotherapy being used, as certain agents like anthracyclines or trastuzumab can be cardiotoxic
- The presence of pre-existing cardiac conditions, which may increase the risk of cardiac complications during treatment
- The importance of baseline cardiac assessments, including ECG and left ventricular ejection fraction (LVEF) measurement, to guide treatment decisions and monitor cardiac safety
- The need for ongoing monitoring of potential cardiac complications during breast cancer treatment, which may involve echocardiograms or other imaging modalities in addition to ECGs 1. Overall, while ECG is not a primary diagnostic tool for breast cancer, it plays a crucial role in assessing cardiac function and guiding treatment decisions in patients undergoing cardiotoxic chemotherapy or with pre-existing cardiac conditions.
From the Research
ECG Indication in Breast Cancer
- The use of ECG in breast cancer patients is indicated for monitoring cardiac dysfunction and electrophysiological abnormalities caused by cardiotoxic cancer treatment 2, 3.
- Studies have shown that ECG markers can predict cancer therapy-related cardiac dysfunction (CTRCD) and provide incremental value to established clinical risk factors for CTRCD risk classification 2.
- ECG changes can reflect subclinical cardiac dysfunction before echocardiographic abnormalities, making it a useful tool for early detection of cardiotoxicity 3.
Cardiotoxicity of Breast Cancer Treatment
- Breast cancer treatment, including chemotherapeutic agents, anti-HER2 therapies, and CDK4/6 and mTOR inhibitors, can be associated with significant cardiotoxicity 4.
- Anthracycline- and trastuzumab-related cardiac toxicities have been extensively studied, and substantial evidence is available concerning additional anti-HER2 agents 4.
- Cardiovascular disease is a major cause of mortality in females with early breast cancer, especially in those over the age of 65, highlighting the need for optimal cancer care that does not jeopardize cardiovascular health 5.
Monitoring and Prevention of Cardiotoxicity
- Assessment of baseline risk factors prior to treatment initiation and cardiac imaging before and during treatment remains the optimal way to prevent cardiac dysfunction 4.
- Cardioprotective therapy in primary prevention is still a matter of debate, but new data is promising for the use of dexrazoxane in anthracyclines, and the role of beta blockers and angiotensin converting enzymes inhibitors in anthracyclines and HER-2 monoclonal antibodies such as trastuzumab 5.
- Strategies to mitigate the risks of cardiovascular toxicities are crucial to ensure optimal cancer care and minimize the impact of cardiotoxicity on cancer survivorship 5.