Blood Pressure and Cardiovascular Risk in Women With Breast Cancer: The Pathways Heart Study.

ABSTRACT

Background: Hypertension is an important contributor to cardiovascular disease (CVD) in breast cancer (BC) survivors; however, research on blood pressure (BP) and CVD outcomes in BC survivors is limited. Objectives: The purpose of this study was to better characterize the association between BP and CVD in a large, longitudinal cohort of BC patients. Methods: Women with invasive BC diagnosed from 2005 to 2013 at Kaiser Permanente Northern California were matched 15 to women without BC. Patient data were obtained from electronic health records. Multivariable Cox regression and penalized spline models were used to explore the linear and nonlinear relationship of systolic blood pressure (SBP) and diastolic blood pressure (DBP) on CVD outcomes. Results: BC cases (n = 12,713) and controls (n = 55,886) had median follow-up of 9.6 years (IQR 5.0-11.9 years). Women with BC had a mean age of 60.6 years; 64.8% were non-Hispanic White. For ischemic heart disease (IHD), every 10 mmHg increase in SBP and DBP was associated with 1.23 (95% CI 1.14-1.33) and 1.10 (95% CI 0.98-1.24) risk, respectively, in women with BC. For stroke, every 10 mmHg increase in SBP and DBP was associated with a 1.45 (95% CI 1.34-1.58) and 1.91 (95% CI 1.68-2.18) risk, respectively. A U-shaped relationship was observed between heart failure/cardiomyopathy and BP. The associations between BP and risk of IHD, stroke, and any primary CVD were not statistically different comparing women with BC to controls, but risks varied by BC status for heart failure/cardiomyopathy (P for interaction = 0.01). Conclusions: Women with and without BC showed similar risks for IHD, stroke, and any primary CVD suggesting similar BP targets should be pursued regardless of BC survivorship status.