Risk Factors and Outcomes During a First Acute Myocardial Infarction in Breast Cancer Survivors Compared with Females Without Breast Cancer

Purpose: The purpose of this research was to study the differences in epidemiology and outcomes of a first myocardial infarction in breast cancer survivors compared with the general female population in the United States. Methods: We retrospectively analyzed the US National Inpatient Sample years 2005-2015 to identify adult women with a first myocardial infarction. In this cohort, breast cancer survivors were identified. Outcomes evaluated were the differences in baseline demographics, comorbidities, and adjusted in-hospital mortality in women with and without breast cancer. Results: Among 1,644,032 first myocardial infarction cases in adult women, there were 56,842 (3.5%) breast cancer survivors. Compared with women without breast cancer, breast cancer survivors were 6 years older (mean age 77 vs 71 years, P < .001), had significantly higher prevalence of dyslipidemia and hypertension, and lower prevalence of obesity, diabetes mellitus, and smoking. Breast cancer survivors were more likely to have a non-ST segment elevation acute myocardial infarction and less likely to receive mechanical revascularization. In-hospital mortality was lower in breast cancer survivors (7.1%) compared with those without (7.9%, P < .001), findings that persisted after risk adjustment (odds ratio 0.89; 95% CI, 0.82-0.94). Conclusions: Breast cancer survivors had a first acute myocardial infarction at an older age and had small but favorable differences in cardiovascular disease risk factors and outcomes compared with women without breast cancer. The favorable impact of health education, preventative medical care, greater motivation for a healthier lifestyle, and participation in cancer survivorship programs on these seemingly paradoxical findings in breast cancer survivors should be further explored.