Examining factors associated with experiencing cardiac arrhythmias in Black and White breast cancer survivors who received anthracyclines or trastuzumab.

Purpose: Racial disparities exist regarding cardiovascular (CV) toxicities following breast cancer treatment; however, studies on racial differences in cardiac arrhythmias are lacking. This study examined associations between demographic and clinical factors and arrhythmia diagnosis in Black and White breast cancer survivors.

Methods: This study included a retrospective cohort of Black and White women who were diagnosed with breast cancer and who received potentially cardiotoxic treatment. Cardiac arrhythmia data were captured via International Classification of Diseases, Tenth and Ninth Versions (ICD-10 and ICD-9). Experiences with cardiac arrhythmias were compared across racial groups. The associations of demographic and clinical factors with cardiac arrhythmias were evaluated using logistic regression for all women and in race-stratified models.

Results: Thirty-three percent of the total 860 women in our study sample (mean (standard deviation) age 50.3 (10.7) years) old) experienced cardiac arrhythmias. In bivariate analyses, we observed a statistically discernible association between race and arrhythmia status following a breast cancer diagnosis (p = 0.004); however, this association was no longer significant in the multivariable model. In race-stratified multivariable analysis, the odds of experiencing arrhythmias in Black women over 50 years old are 51% lower than in Black women aged 50 years old or younger (adjusted odds ratio (OR): 0.49; 95% confidence interval (CI): 0.28, 0.86). All else being equal, Black women with hypertension had 2.68 times (95% CI: 1.51, 4.81) higher odds of experiencing arrhythmias than those without hypertension. White women with obesity had higher odds of experiencing arrhythmias than those with normal weight or underweight status. (adjusted OR 1.93: [1.17, 3.20]).

Conclusion: Survivors with chronic conditions like hypertension and obesity may require enhanced cardiac surveillance. Further investigation into hypertension management in Black survivors may shed light on its impact on CV toxicities in this group.