Use of cardiac biomarkers to improve initiation of cardioprotective therapy in patients with breast cancer receiving cardiotoxic chemotherapy in a multidisciplinary cancer center.

344 Background: Treatment for breast cancer commonly includes anthracyclines and anti-Her2 directed therapy, both of which carry a known cardiovascular risk. In high-risk patients, ESMO guidelines recommend consideration of cardiac biomarker (hs-cardiac troponin) testing for patients undergoing potentially cardiotoxic chemotherapy. Prophylactic use of cardioprotective medications such as angiotensin converting enzyme (ACE) inhibitors, angiotensin renin blockers (ARBs) or beta-blockers (BBs) can be considered to reduce development of cardiotoxicity. We aimed to identify the rates of cardiac biomarker testing performed and rates of abnormalities in patients considered to be high risk for cardiovascular disease undergoing breast cancer treatment with potentially cardiotoxic medication in hope of improving prevention efforts. Methods: We performed a retrospective chart review of patients with breast cancer treated with either anthracycline or anti-Her2 based therapy at our ambulatory cancer center from 2020 to 2023. Pre-treatment cardiovascular risk score was determined based on initial cardiac assessment at time of consultation with cardio-oncology. Completion of troponin biomarker testing and initiation of cardioprotective medication therapy was assessed. Patients who were not established with cardio-oncology or not on active cardiotoxic chemotherapy were excluded. Results: A total of 172 patients (66 on anthracycline based therapy and 106 on anti-HER2 therapy) were assessed. The average age of all patients was 57 years. 47 patients were assessed as high risk for cardiovascular disease. Of these high-risk patients, troponin was checked in 42 of 47 (89.4%) and found to be elevated in 23 of 42 (55%). Rate of troponin elevation was statistically significant for high risk patients compared to all other patients (p<0.05). Cardioprotective medications were utilized in 28 of the 47 patients considered to be high risk (59.6%). Conclusions: In patients with breast cancer who require treatment with a potentially cardiotoxic medication, a clinical risk assessment with cardiology can be utilized to select those who may benefit from additional cardiac biomarker monitoring and potential earlier initiation of cardioprotective therapy. This single center study reveals that the use of clinical assessment of high vs low/medium risk allows us to predict patients with increased risk of cardiotoxicity. Our population had cardiac biomarkers checked in nearly all high-risk patients and troponin was elevated 55% of the time. Further study is needed to investigate if biomarker directed initiation of cardio-protective therapy could reduce cardio-toxicity.