Abstract P405: Racial Disparities in Ischemic and Hemorrhagic Post-stroke Mortality in United States Veterans

Abstract

Introduction: Blacks and Hispanics have been shown to have higher stroke mortality than non-Hispanic whites. However, this may be due to higher incidence of strokes in blacks and Hispanics. Fewer studies have investigated health disparities in post-stroke mortality stratified by stroke type. We studied risk of mortality by race/ethnicity after either incident acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH) in a national sample of patients from the Veteran’s Health Administration (VHA). Methods: We included patients with a first occurrence of an inpatient AIS or ICH in a VHA hospital between 2002-2007. We categorized patients as non-Hispanic white, non-Hispanic black, or Hispanic. Veterans with any prior stroke-related code were excluded. For each of AIS and ICH, we constructed a piecewise multivariate survival model for post event all-cause mortality. We separated follow-up intervals into <30 day, 30-90 day, 90 day-1 year, and >1 year post admission. Results: We identified 36,569 patients with an incident stroke in 2002-2007 (91% AIS, 9% ICH). The proportion of white, black, and Hispanic patients with AIS was 68%, 26%, and 6% respectively; and in ICH was 63%, 27%, and 10%. Compared to whites, blacks had better survival for AIS in the first 30 days, while Hispanics tended to have better survival in the 30-90 day and >1 year intervals. With ICH, blacks had higher mortality in the first 30 days. (Table 1) Conclusion: Blacks experience better 30-day survival after AIS compared to whites, but worse 30-day survival after ICH. This may be driven by higher prevalence of hypertension in blacks leading to small vessel occlusion, which is associated with lower mortality, or poorer control of blood pressure in the setting of ICH, which is associated with higher mortality. Hispanic patients may have better long-term survival after stroke compared to whites, a ‘Hispanic paradox’ that has been shown in other studies. Stroke events should be stratified by ischemic and hemorrhagic type when evaluating for racial disparities in outcomes.