Risk of Cardiovascular Diseases Among Older Breast Cancer Survivors in the United States: A Matched Cohort Study

Background: It has been suggested that cardiovascular risks are increased in breast cancer survivors, but few studies have quantified the risks of a range of specific clinically important cardiovascular outcomes in detail. Patients and Methods: Women aged >65 years with incident breast cancer from 2004 to 2013 in the SEER-Medicare linked database were matched with 5 cancer-free female counterparts (5:1 ratio). Prevalence of specific cardiovascular outcomes at baseline was measured, then Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals for the risk of individual cardiovascular outcomes during follow-up. Modification of the effect was investigated by time since diagnosis, race/ethnicity, prior cardiovascular disease (CVD), and age. Results: In all, 91,473 women with breast cancer and 454,197 without breast cancer were included. Women with breast cancer had lower baseline prevalence of all CVDs. Compared with cancer-free controls, breast cancer survivors had substantially increased risks of deep vein thrombosis (adjusted HR, 1.67; 95% CI, 1.62-1.73; 386,484 person-years of follow-up) and pericarditis (HR, 1.43; 95% CI, 1.38-1.49; 390,776 person-years of follow-up); evidence of smaller increased risks of sudden cardiac arrest, arrhythmia, heart failure, and valvular heart disease (adjusted HRs ranging from 1.05-1.09, lower CI limits all $1); and evidence of lower risk of incident angina, myocardial infarction, revascularization, peripheral vascular disease, and stroke (adjusted HRs ranging from 0.89-0.98, upper CI limits all #1). Increased risks of arrhythmia, heart failure, pericarditis, and deep vein thrombosis persisted >5 years after cancer diagnosis. Conclusions: Women with a history of breast cancer were at increased risk of several CVDs, persisting into survivorship. Monitoring and managing cardiovascular risk throughout the long-term follow-up of women diagnosed with breast cancer should be a priority.