Risk of cardiovascular disease in women with and without a history of breast cancer: The Pathways Heart Study.

Abstract

12016 Background: Breast cancer (BC) survivors are at increased risk of cardiovascular disease (CVD) following diagnosis, as compared to women without BC. To provide a population-based estimate of CVD risk in BC survivors, we compared risk of CVD events in women with and without BC history enrolled in the Kaiser Permanente Northern California (KPNC) integrated health system. Methods: Data were extracted from KPNC electronic health records. All invasive BC cases diagnosed between 2005-2013 were identified and matched 1:5 with non-BC controls on birth year, race/ethnicity and KPNC membership at date of BC diagnosis. Cox regression models were used to assess differences in the hazard of four major CVD events (ischemic heart disease (IHD), heart failure (HF), cardiomyopathy, and stroke). Models were adjusted for factors known to influence risk of breast cancer or CVD.Other CVD events included arrhythmia, cardiac arrest, carotid disease, myocarditis/pericarditis, transient ischemic attack, valvular disease, and venous thromboembolism (VTE). We additionally examined subgroups of cases who received chemotherapy, radiation, and endocrine therapy, and their controls. Results: A total of 14,942 women with a new diagnosis of invasive BC were identified and matched to 74,702 women without BC history. On average, women were 62.0 years, 28.3 kg/m2BMI, 64.9% non-Hispanic white. Among all cases and controls, there were no significant differences in hazard of developing IHD, cardiomyopathy, and stroke; there was a borderline difference in HF (HR: 1.08, 95% CI: 0.99, 1.19). Cases were more likely to have a cardiac arrest (HR: 1.39, 95% CI: 1.09, 1.78) and develop VTE (HR: 1.97, 95% CI: 1.74, 2.23). Women treated with chemotherapy were more likely than controls to develop HF (HR: 1.44, 95% CI: 1.21, 1.72), cardiomyopathy (HR: 2.01, 95% CI: 1.02, 3.98), and VTE (HR: 3.15, 95% CI: 2.62, 3.79). Women who received radiation therapy were more likely to develop carotid disease (HR: 5.49, 95% CI: 1.22, 24.66) and VTE (HR: 1.65, 95% CI: 1.35, 2.03) than controls. Women who received endocrine therapy were more likely to experience a cardiac arrest (HR: 1.49, 95% CI: 1.07, 2.09) and develop VTE (HR: 1.70, 95% CI: 1.42, 2.03) than controls. Conclusions: Women with BC were at increased risk of heart failure, cardiomyopathy, cardiac arrest, VTE and carotid disease. These risks varied by cancer treatment, with higher risk in those who received chemotherapy. Future studies should explore the effects of chemotherapy class and radiation dose exposure on diverse CVD endpoints in BC survivors.