Tamoxifen-treated breast carcinoma patients and the risk of acute myocardial infarction and newly diagnosed angina

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.

Tamoxifen treatment in Danish breast cancer patients and 5-year risk of arterial atherosclerotic events: a null association

Although the effectiveness of tamoxifen in preventing the recurrence of breast cancer is well established, associations between tamoxifen and the occurrence of atherosclerotic events are not as clear. Breast cancer patients taking tamoxifen have lower serum cholesterol and other lipid levels than those not taking tamoxifen, suggesting that tamoxifen might prevent atherosclerotic events, but the existing studies are conflicting. We examined the relation between tamoxifen and incident hospitalization of angina pectoris, acute myocardial infarction, heart failure, and stroke. The study population of 16,289 women was identified from the Danish Breast Cancer Cooperative Group nationwide clinical database and includes women diagnosed with stage I or II estrogen receptor-positive breast cancer between 1990 and 2004 at ages 45 to 69. Use of a large population-based sample with complete outcome ascertainment allowed us to calculate precise measures of risks, risk ratios, and adjusted hazard ratios comparing tamoxifen-treated patients with untreated patients. We found strong evidence for null associations for each of the four outcomes of interest during the first year and first 5 years after the start of therapy. These findings are important in risk/benefit analyses as tamoxifen therapy in postmenopausal women is being replaced with aromatase inhibitors.