Anemia is associated with poor outcomes in patients with less severe ischemic stroke

Abstract

Anemia is a known predictor of in-hospital mortality among patients with such vascular conditions as acute myocardial infarction, congestive heart failure, and chronic kidney disease. The role of anemia in patients with acute ischemic stroke is less well understood. We sought to examine the association between anemia at hospital admission and the combined outcome of in-hospital mortality and discharge to hospice in patients with acute ischemic stroke. We evaluated data from a retrospective cohort of consecutive ischemic stroke patients presenting within 48 hours of symptom onset at 5 hospitals between 1998 and 2003. Anemia was defined as an admission hematocrit value of <30%. Less severe stroke was defined as an admission National Institutes of Health Stroke Scale score of <10. The outcome was the combined endpoint of in-hospital mortality or discharge to hospice. Among 1306 patients with stroke, anemia was present on admission in 6.4%, and the combined outcome of death or discharge to hospice was present in 10.1%. Anemia was not associated with outcome in patients with severe stroke (anemia, 17.2% [5 of 29] vs no anemia, 28,4% [98 of 345]; P = .20), but was associated with outcome in patients with less severe stroke (anemia, 13.0% [7 of 54] vs no anemia, 2.5% [22 of 878]; P < .0001). After adjustment for stroke severity, admission anemia was independently associated with outcome in patients with less severe stroke (adjusted odds ratio, 4.17; 95% confidence interval, 1.47-11.90), but not in patients with more severe strokes (adjusted odds ratio, 0.82; 95% confidence interval, 0.30-2.22). Our data indicate that anemia is associated with in-hospital mortality or discharge to hospice in patients with less severe ischemic stroke.