2336 - Can Simulation CTs be Used to Identify and Intervene on Incidental Coronary Artery Disease in Patients with Breast Cancer?
Presenter(s)
K. Chen1, E. Mihalakakos1, C. Bergom1, S. Brown1, D. Caruthers1, J. Mitchell2, C. G. Robinson1, M. A. Thomas1, J. Tran1, I. Zoberi1, and J. C. Yang3; 1Washington University School of Medicine, Department of Radiation Oncology, St. Louis, MO, 2Washington University School of Medicine, Department of Medicine, Cardiovascular Division, St. Louis, MO, 3Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO
Purpose/Objective(s): Coronary artery disease (CAD) is a leading cause of morbidity and mortality among post-menopausal women and can be visualized on non-contrast CT as coronary artery calcifications (CAC). The presence of CAC predicts for future adverse cardiac events, but assessment for CAC on simulation CT acquired for radiotherapy (RT) planning is not standard of care. Furthermore, the prevalence of incidental CAC previously undiagnosed or untreated is not well defined. In a cohort treated for breast cancer, we hypothesize that a majority of women with CAC detectable by simulation CT had no prior diagnosis of CAD at the time of RT.
Materials/Methods: A cross-sectional study was performed for women between 50 to 75 years old with breast cancer receiving adjuvant RT from 2020-2021 at a single institution. The presence of CAC in a major coronary artery was visually determined on non-contrast simulation CT while blinded to the clinical data. Next, we compared mean body mass index (BMI) and incidence of cardiovascular comorbidities (hypertension, hyperlipidemia, diabetes, or active tobacco use) between those with detectable CAC versus absent CAC using a t-test and chi-squared test, respectively. Among women with CAC detected on simulation CT, we determined the proportion of those with no prior diagnosis of CAD, use of preventative medication, and/or established cardiology care. We also ascertained the number of referrals to a cardiologist made by the treating radiation oncologist after simulation.
Results: Among 407 women in our study, 43% had CAC present on simulation CT. These women had clinical risk factors for CAD, including significantly increased mean BMI (33.3 vs 30.3, p < 0.0001) and incidence of at least one other cardiovascular risk factor (85% vs 48%, p < 0.0001). Despite this increased cardiovascular risk among women with detectable CAC, 85% had no prior diagnosis of CAD at the time of simulation. Of these women with subclinical disease, 42% were not taking an aspirin or statin. Nearly 80% had no prior care with a cardiologist, a quarter of whom were later seen by a cardiologist either in the clinic or hospital on average 26 months (range: 1-45 months) after completing RT with angina as the most common reason for consultation. Given that simulation CT is not standardly used for CAC assessment, no women were referred to a cardiologist by a radiation oncologist after simulation.
Conclusion: A majority of patients with breast cancer who have CAC on simulation CT had no prior diagnosis of CAD. This is a particularly important finding in women, in whom cardiovascular disease is both underrecognized and undertreated. As patients with pre-existing CAC have a high baseline risk for future cardiac events and may receive oncologic therapies which affect cardiac health, use of simulation CT to identify CAC may present an opportunity for escalation of cardiac care.