Abstract Background: Near complete estrogen deprivation (NCED) with ovarian function suppression and aromatase inhibition improves survival outcomes in premenopausal women with HR+ breast cancer (BC). Despite the association of premature menopause with cardiovascular (CV) morbidity in non-cancer populations, the CV health in premenopausal women undergoing BC treatment remains underexplored. As advanced CV imaging is uncommon and guidelines discourage routine cross-sectional imaging in early-stage BC, cardiac and extracardiac imaging findings in these young women are largely uncharacterized. Methods: The Cardiac Outcomes with Near-complete Estrogen Deprivation (CROWN) study is an NIH-funded 3-site study utilizing serial stress cardiac magnetic resonance (CMR) and coronary computed tomography angiography (CCTA) to characterize the natural history of CV health in premenopausal women with stage I-III BC receiving NCED for HR-positive disease and for a comparator cohort with HR-negative disease. Here we describe unexpected cardiac and extracardiac findings on baseline CMR and CCTA imaging of CROWN participants and assess whether these findings led to changes in clinical management. Findings noted were categorized as “unexpected” if they were not included in the study’s primary or secondary endpoints which are myocardial perfusion reserve and other surrogates of large and small vessel disease such as coronary calcium. We excluded clinically insignificant findings such as atelectasis, small hiatal hernias, trace valvular regurgitation, and trace effusions. Results: 72 patients were included (median age of 44 years). 61 patients had HR+ disease (3 HER2+) and 11 had HR- disease (3 HER2+). A total of 37.5% of patients had one or more unexpected finding (37 findings in 27 patients), of which 30 were extracardiac and 7 were cardiac TABLE. Of the cardiac findings, 3 were congenital heart disease, 3 were mild structural heart disease, and 1 was a cardiac (vascular) finding. Of all patients, 4.2% were referred to cardiology for management of congenital or vascular (cardiac) findings, and 1.4% were referred for cardiovascular procedures. Further, 9.7% of patients had serial imaging for monitoring of extracardiac findings. 2.8% had a biopsy resulting in diagnosis of BC recurrence. Conclusion: In this first prospective cohort of premenopausal women with BC undergoing serial advanced CV imaging, unexpected baseline cardiac and extracardiac findings leading to clinical action occurred with some frequency, with a handful of findings being of immediate clinical consequence. These results highlight the need to further understand CV health in premenopausal women with BC as we seek to evaluate the impact of both anti-neoplastic therapy and of cancer itself on women with decades of life to protect. Full cohort data of 90 participants to be presented at the meeting. Citation Format: A. Broderick, S. Hatcher, R. B. D'Agostino, Jr., N. O'Connell, R. Bansal, C. Anders, S. Telloni, K. Westbrook, A. Natarajan, N. J. Pagidipati, D. Wendell, E. Douglas, K. Ansley, C. J. Park, K. M. Richardson, S. R. Sirkisoon, M. Hackney, H. Vachhani, M. Ross, L. N. Vélez-Torres, J. H. Jordan, A. Thomas. Frequency, characterization, and clinical impact of unexpected cardiac and extracardiac imaging findings in premenopausal women on the CROWN study abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-05-24.
Broderick et al. (Tue,) studied this question.