O. Adeoye

Warfarin use leads to larger intracerebral hematomas

Background: Among patients with intracerebral hemorrhage (ICH), warfarin use before onset leads to greater mortality. In a retrospective study, we sought to determine whether warfarin use is associated with larger initial hematoma volume, one determinant of mortality after ICH. Methods: We identified all patients hospitalized with ICH in the Greater Cincinnati region from January through December 2005. ICH volumes were measured on the first available brain scan by using the abc/2 method. Univariable analyses and a multivariable generalized linear model were used to determine whether international normalized ratio (INR) influenced initial ICH volume after adjusting for other factors, including age, race, sex, antiplatelet use, hemorrhage location, and time from stroke onset to scan. Results: There were 258 patients with ICH, including 51 patients taking warfarin. In univariable comparison, when INR was stratified, there was a trend toward a difference in hematoma volume by INR category (INR <1.2, 13.4 mL; INR 1.2–2.0, 9.3 mL; INR 2.1–3.0, 14.0 mL; INR >3.0, 33.2 mL; p = 0.10). In the model, compared with patients with INR <1.2, there was no difference in hematoma size for patients with INR 1.2–2.0 (p = 0.25) or INR 2.1–3.0 (p = 0.36), but patients with INR >3.0 had greater hematoma volume (p = 0.02). Other predictors of larger hematoma size were ICH location (lobar compared with deep cerebral, p = 0.02) and shorter time from stroke onset to scan (p < 0.001). Conclusion: Warfarin use was associated with larger initial intracerebral hemorrhage (ICH) volume, but this effect was only observed for INR values >3.0. Larger ICH volume among warfarin users likely accounts for part of the excess mortality in this group. GLOSSARY: AAICH = anticoagulant-associated intracerebral hemorrhage; GERFHS = Genetic and Environmental Risk Factors for Hemorrhagic Stroke; HR = hazard ratio; ICH = intracerebral hemorrhage; INR = international normalized ratio; IVH = intraventricular hemorrhage.

Population-based study of wake-up strokes

Objective: Previous studies have estimated that wake-up strokes comprise 8%to 28% of all ischemic strokes, but these studies were either small or not population-based. We sought to establish the proportion and event rate of wake-up strokes in a large population-based study and to compare patients who awoke with stroke symptoms with those who were awake at time of onset. Methods: First-time and recurrent ischemic strokes among residents of the Greater Cincinnati/Northern Kentucky region (population 1.3 million) in 2005 were identified using International Classification of Diseases–9 codes 430–436 and verified via study physician review. Ischemic strokes in patients aged 18 years and older presenting to an emergency department were included. Baseline characteristics were ascertained, along with discharge modified Rankin Scale scores and 90-day mortality. Results: We identified 1,854 ischemic strokes presenting to an emergency department, of which 273 (14.3%) were wake-up strokes. There were no differences between wake-up strokes and all other strokes with regard to clinical features or outcomes except for minor differences in age and baseline retrospective NIH Stroke Scale score. The adjusted wake-up stroke event rate was 26.0/100,000. Of the wake-up strokes, at least 98 (35.9%) would have been eligible for thrombolysis if arrival time were not a factor. Conclusions: Within our population, approximately 14% of ischemic strokes presenting to an emergency department were wake-up strokes. Wake-up strokes cannot be distinguished from other strokes by clinical features or outcome. We estimate that approximately 58,000 patients with wake-up strokes presented to an emergency department in the United States in 2005.

Age, sex, and racial differences in neuroimaging use in acute stroke: A population-based study

BACKGROUND AND PURPOSE: Limited information is available regarding differences in neuroimaging use for acute stroke work-up. Our objective was to assess whether race, sex, or age differences exist in neuroimaging use and whether these differences depend on the care center type in a population-based study. MATERIALS AND METHODS: Patients with stroke (ischemic and hemorrhagic) and transient ischemic attack were identified in a metropolitan, biracial population using the Greater Cincinnati/Northern Kentucky Stroke Study in 2005 and 2010. Multivariable regression was used to determine the odds of advanced imaging use (CT angiography/MR imaging/MR angiography) for race, sex, and age. RESULTS: In 2005 and 2010, there were 3471 and 3431 stroke/TIA events, respectively. If one adjusted for covariates, the odds of advanced imaging were higher for younger (55 years or younger) compared with older patients, blacks compared with whites, and patients presenting to an academic center and those seen by a stroke team or neurologist. The observed association between race and advanced imaging depended on age; in the older age group, blacks had higher odds of advanced imaging compared with whites (odds ratio, 1.34; 95% CI, 1.12–1.61; P < .01), and in the younger group, the association between race and advanced imaging was not statistically significant. Age by race interaction persisted in the academic center subgroup (P < .01), but not in the nonacademic center subgroup (P = .58). No significant association was found between sex and advanced imaging. CONCLUSIONS: Within a large, biracial stroke/TIA population, there is variation in the use of advanced neuroimaging by age and race, depending on the care center type.

The adverse effect of spasticity on 3-month poststroke outcome using a population-based model.

Several devices and medications have been used to address poststroke spasticity. Yet, spasticitys impact on outcomes remains controversial. Using data from a cohort of 460 ischemic stroke patients, we previously published a validated multivariable regression model for predicting 3-month modified Rankin Score (mRS) as an indicator of functional outcome. Here, we tested whether including spasticity improved model fit and estimated the effect spasticity had on the outcome. Spasticity was defined by a positive response to the question “Did you have spasticity following your stroke?” on direct interview at 3 months from stroke onset. Patients who had expired by 90 days (n = 30) or did not have spasticity data available (n = 102) were excluded. Spasticity affected the 3-month functional status (β = 0.420, 95 CI = 0.194 to 0.645) after accounting for age, diabetes, leukoaraiosis, and retrospective NIHSS. Using spasticity as a covariable, the models R 2 changed from 0.599 to 0.622. In our model, the presence of spasticity in the cohort was associated with a worsened 3-month mRS by an average of 0.4 after adjusting for known covariables. This significant adverse effect on functional outcomes adds predictive value beyond previously established factors.

Stroke Incidence Is Decreasing in Whites But Not in Blacks: A Population-Based Estimate of Temporal Trends in Stroke Incidence From the Greater Cincinnati/Northern Kentucky Stroke Study * Supplemental Material

Background and Purpose— Although other studies (in largely white populations) have found that stroke incidence declined during the 1990s, we previously reported that stroke incidence in our population (18% of which was black) did not change during that decade and that incidence rates in blacks were significantly higher than in whites. We sought to update temporal trends in stroke incidence by adding new data obtained from our large, biracial population in 2005. The objective of this study was to examine temporal trends in stroke incidence and case-fatality within a large biracial population over time by comparing stroke incidence rates from 1993 to 1994, 1999, and 2005. Methods— Within the Greater Cincinnati/Northern Kentucky population of 1.3 million, all strokes among area residents were ascertained at all local hospitals during July 1993 to June 19/94 and calendar years 1999 and 2005. A sampling scheme was used to ascertain cases in the out-of-hospital setting. Only first-ever strokes were included in this analysis. Race-specific incidence rates, standardized to the 2000 US Census population, and case-fatality rates were calculated. Results— The number of physician-confirmed first-ever strokes in patients ≥20 years of age was 1942 in 1993 to 1994, 2041 in 1999, and 1921 in 2005. In all study periods, blacks had higher stroke incidence than whites, and case-fatality rates were similar between races. In contrast to previous study periods, we found a significant decrease in overall stroke incidence in 2005. When stratified by race and stroke subtype, this change was driven by a decrease in ischemic stroke incidence among whites, whereas ischemic stroke incidence in blacks was unchanged. Hemorrhagic stroke incidence was unchanged in both races. Conclusions— For the first time, we report a significant decrease in stroke incidence within our population, which is consistent with other reports in the literature. This decrease was found only among whites, which suggests a worsening of the racial disparity in stroke incidence.