Abstract 107: Differential Ischemic Stroke Risk Among Women Veterans Across Age Strata

Abstract

Background: Ischemic stroke disproportionately affects women. Women have a higher lifetime risk of stroke, experience worse functional recovery post-stroke, and are more likely to be institutionalized after stroke than men. Despite the pronounced differences in which stroke may affect women compared to men, stroke research specifically focusing on women has not been published until recently. For instance, stroke specific guidelines for women were not published until 2014. This study sought to determine whether differences in stroke risk exist between women and men across age strata using the Framingham Stroke Risk (FRS) score in a large cohort of Veterans. Methods: Study participants were Veterans receiving care within Veterans Health Administration facilities between April 2011 and May 2012 (N=57,072). In this secondary analysis, patients were excluded (n=39,978) based on age less than 55 years and prior history of stroke. FRS was calculated for each patient based on race- and sex-specific pooled cohort equations that accounted for age, atrial fibrillation, systolic blood pressure, diabetes mellitus, cigarette smoking, prior cardiovascular disease, and antihypertensive medication use. FRS scores ≥15% were classified as high risk for stroke. SAS Version 9.1 statistical software was used to calculate FRS, perform chi-square analysis, and perform logistic regression analysis. Results: Among 39,978 eligible patients, the mean age (standard deviation [SD]) was 71.6 ± 10.1 years with 1,842 (4.6%) patients within the cohort being women. The mean FRS score for women was 11.29 (± 4.29 SD) and was 14.52 (± 4.37 SD) for men. Risk factors for stroke including age, atrial fibrillation, systolic blood pressure, diabetes mellitus, and antihypertensive use were significant predictors of women’s high 10-year risk of stroke in unadjusted OR unadjusted analyses? ( P =<.0001). When stratified into groups of high 10-year risk of stroke, this study found that nearly half (47.9%) of all Veterans were high-risk for stroke. Women 55-73 years old had a lower risk of future stroke than men of the same age; however, women Veterans 71 years and older had a higher risk of future stroke than similarly aged men ( P <0.001). Conclusions: Nearly half of all women Veterans were found to be at high risk of ischemic stroke within the next 10-years. Furthermore, sex differences were noted across age strata, with women having a lower risk of stroke then men at younger ages and a higher risk at older ages. Given that women tend to have more severe strokes, higher mortality, and delayed diagnosis compared to men, further work is required to understand reasons for the differential stroke risk across sexes. Based on these study findings, implementing primary prevention programs for women Veterans would help to mitigate future ischemic stroke risk.