Breast cancer survivors may have a lower prevalence of cardiac risk factors at the time of first myocardial infarction and better outcomes compared with those having a first MI from the general population, according to findings from a retrospective study.
In addition, women without breast cancer were younger at the time of first MI compared with survivors, wrote Srikanth Yandrapalli, MD, of New York Medical College, Valhalla, and colleagues. Their report is in the American Journal of Medicine.
The researchers identified 1,644,032 women with a first MI, 56,842 of whom were breast cancer survivors. The team evaluated differences in the prevalence of cardiac risk factors and related outcomes in breast cancer survivors in comparison to the general population.
At baseline, the mean age of subjects with a history of breast cancer was 77 years (range, 11 years), while the mean age of women without breast cancer was 71 years (range, 15 years).
Clinical data were collected from the United States National Inpatient Sample for January 2005 to September 2015. Other outcomes assessed were differences in baseline characteristics and the rate of in-hospital mortality in both groups.
After analysis, the researchers found that breast cancer survivors had a lower prevalence of diabetes mellitus (30.1% vs. 33.1%), obesity (9.4% vs. 13.0%), and smoking (24.1% vs. 27.0%), but higher rates of dyslipidemia (52.7% vs. 48.4%) and hypertension (73.6% vs. 68.1%), compared with women without breast cancer (All P less than .001).
With respect to age, women without breast cancer were 6 years younger than breast cancer survivors at the time of first acute MI (mean age, 71 vs. 77 years; P less than .001).
In addition, the rate of in-hospital mortality was higher in women without breast cancer (7.9%) compared with survivors (7.1%) (P less than .001). After risk adjustment, these results remained unchanged (odds ratio, 0.89; 95% confidence interval, 0.82-0.94).
“Breast cancer survivors in the U.S. are at least 6 years older than the general population of women without breast cancer, and they had a favorable cardiac risk factor profile at the time of first myocardial infarction,” Dr. Yandrapalli and colleagues explained. “The reason for these findings are unclear and hypothesis generating,” they added.
The researchers acknowledged that a key limitation of the study was the retrospective design. As a result, the potential effects of residual confounding should be considered when interpreting the results.
“The favorable impact of health education and participation in cancer survivorship programs on these observed differences in breast cancer survivors should be further explored,” they concluded.
No funding sources were reported. The authors reported having no conflicts of interest.
SOURCE: Yandrapalli S et al. Am J Med. 2019 Nov 9. doi: 10.1016/j.amjmed.2019.10.018.