Background Anemia has been associated with adverse cerebrovascular outcomes, particularly after cardiac operations. This study was conducted to determine if hemoglobin levels during and after cardiopulmonary bypass (CPB) predict postoperative stroke in cardiac surgical patients, independent of transfusion requirements. Methods Individuals who had sustained a clinical postoperative stroke (cases) were matched 1:2 with controls by age, sex, surgical procedure, and year of operation. In 617 patients, conditional logistic regression was performed to analyze associations between hemoglobin levels before and after CPB, and stroke. Results After adjustment for potentially confounding vascular risk factors, lower hemoglobin after CPB was associated with a higher risk of stroke, even after adjustment for the amount of packed red blood cells transfused (adjusted odds ratio, 1.28; 95% confidence interval, 1.00 to 1.64, per point of lower hemoglobin level; adjusted odds ratio for stroke per higher quartile of packed red blood cells transfused in this model, 1.37; 95% confidence interval, 1.02 to 1.83). Similar associations were not found for hemoglobin concentrations preoperatively nor change in hemoglobin from before to after CPB. A post-CPB hemoglobin level below the median was associated with 37% increased odds of a postoperative stroke occurring (p = 0.02). Conclusions Lower postoperative hemoglobin levels and higher intraoperative transfusion requirements are each independently associated with a higher risk of stroke. Reduced cerebral oxygen delivery due to anemia may contribute to cerebral injury after coronary artery bypass grafting.

Background: Leukoaraiosis and its progression have longitudinally been associated with cognitive decline and dementia. Its role in acute cognitive function and response to acute cerebral ischemia is less well understood. We evaluated whether the presence and extent of leukoaraiosis, or white matter hyperintensities (WMH), had an impact on performance on tests of hemispatial neglect in acute ischemic stroke patients. Methods: A series of 206 acute ischemic right-hemispheric stroke patients at Johns Hopkins Hospital underwent brain MRI and cognitive assessment for hemispatial neglect within 5 days of symptom onset. Error rates on neglect tests were evaluated, as were dichotomized measures of neglect, including ‘any', ‘severe' or ‘worst' neglect, based on Z scores of at least 2 on 1, 2 or 3 tests (respectively) within a neglect battery. Acute infarct volumes were measured on diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery images were reviewed for WMH, using the Cardiovascular Health Study (CHS) rating scale (ranging from 0 to 9, with 9 being ‘most extensive'). Linear regression was used to evaluate ‘error rate on neglect test' as the dependent variable, as a measure of neglect severity, with ‘WMH category' as the primary independent variable, including adjustment for age, sex, race and infarct volume (on DWI). Logistic regression was used to evaluate a binary definition of neglect (defined as above) relative to the same independent variable and covariates. Results: Each 1-point increase in CHS leukoaraiosis category was associated with 1.20-fold increased odds (95% CI: 1.00-1.43) of having any neglect, 1.23-fold increased odds (95% CI: 1.02-1.49) of having severe neglect and 1.33-fold increased odds of having worst neglect (95% CI: 1.01-1.76) after adjusting for infarct volume, age, sex and race. Increasing age and infarct size were also important predictors of neglect severity, with a 2.36% higher error rate (95% CI: 0.75-3.97%) on the line cancellation test associated with each category increase in CHS score; similar results were found for each of the neglect tests. Line cancellation neglect scores were worse in individuals with both severe WMH and large infarcts (p interaction, unadjusted = 0.03). Conclusions: More severe leukoaraiosis is associated with more hemispatial neglect after acute ischemic stroke, independent of infarct volume, age and sex. We found not only more frequent neglect but also more severe neglect, based on error rates on neglect tests, in individuals with increasing leukoaraiosis. This emphasizes the importance of preexisting brain microvascular disease in outcomes of stroke patients. Further studies of the possible mechanism behind this association are needed.

Background and Purpose-Anemia is 1 potential mechanism by which the brain receives inadequate oxygenation. The purpose of this study was to determine in acute stroke patients whether lower hemoglobin values were associated with worse hemispatial neglect. Methods-In 203 subjects, neglect testing batteries were administered within 24 hours of admission for acute right hemispheric stroke. We analyzed the error rate on each test as well as "any neglect" (z score Ն2 on any of 3 selected tests compared with normal controls), as predicted by hemoglobin level, with adjustment for infarct size, National Institutes of Health Stroke Scale score, age, and sex. Results-The association between hemoglobin and neglect varied on the basis of hemoglobin level. At lower hemoglobin levels (Ͻ12 g/dL), each 1-point higher hemoglobin value was protective (adjusted odds ratioϭ0.56; 95% CI, 0.35 to 0.89) from having "any neglect." However, for a hemoglobin value Ͼ14 g/dL, each 1-point higher hemoglobin value was associated with higher odds of having neglect (adjusted odds ratioϭ1.67; 95% CI, 1.09 to 2.57). Similar relations were found for predicted error rate on the horizontal line bisection, line cancellation, and copy Ogden scene neglect tests. These relations seemed to be more pronounced in individuals who had a diffusion/perfusion mismatch. Conclusions-Lower and higher hemoglobin levels were each associated with increased odds of neglect and with worse severity of neglect, independent of stroke size and severity. Higher hemoglobin values may represent dehydration or hyperviscosity. The importance of the extremes of hemoglobin in identifying individuals at risk for worse functional consequences of stroke warrants further study. (Stroke. 2010;41:1641-1645.)