Abstract Body (Do not enter title and authors here): Introduction: Breast cancer and cardiovascular disease are significant global health concerns for women. Our study is a significant advancement in understanding cardiomyopathy risks associated with breast cancer in the U.S. population. Unlike previous studies focusing mainly on treatment-related cardiomyopathy, our research identifies risks across various cardiomyopathy subtypes in breast cancer patients. This novel approach reveals the intricate relationship between different cardiomyopathies and breast cancer, filling a crucial gap in existing medical research. Moreover, by considering racial disparities, our study offers vital insights into the differential health impacts on diverse demographic groups, enhancing our knowledge of the interplay between these medical fields.

Methodology: The research was conducted as a retrospective cohort analysis using data from the National Inpatient Sample (NIS) spanning 2016 to 2019. It targeted female patients over 18 with a diagnosis of breast cancer, carcinoma in situ, or a personal history of breast cancer. Case identification relied on ICD-10 codes. A pivotal aspect of the methodology was implementing propensity score matching to ensure balanced comparison groups, considering variables like age, race, hypertension, and diabetes. Statistical analysis involved logistic regression, Chi-Square tests, and T-tests, executed using 9.4 SAS software.

Results:
The study compared 589,940 breast cancer patients with an equal number of controls, matched demographically. Comorbidity prevalence was similar in both groups, with slight variations in myocardial infarction and heart failure history. Breast cancer patients exhibited a higher prevalence of cardiomyopathy (4.0% vs. 3.2%), with an increased adjusted odds ratio (OR) especially for dilated, restrictive, and drug-related cardiomyopathies. Interestingly, they had lower odds of obstructive and hypertrophic cardiomyopathy. Racial disparities were evident, with Black patients facing higher risks for most cardiomyopathies, while Hispanic and Asian or Pacific Islander patients showed varied risks. Similar patterns were observed in the control group.

Conclusion: The findings highlight a significant link between breast cancer and an elevated risk of cardiomyopathy, advocating for the integration of cardiovascular monitoring into breast cancer management.