Correlation between anemia and outcome in patients with acute cerebral infarction

Objective To investigate the correlation between anemia and outcome in a large cohort of unselected patients with acute cerebral infarction. Methods Consecutive acute cerebral infarction patients who were hospitalized were prospectively recruited from August 2010 to November 2013. Eight hundred and fifty-eight patients were enrolled, and the baseline data including age, sex, National Institute of Health Stroke Scale(NIHSS) scores, type of Oxfordshire Community Stroke Project(OCSP: total anterior circulation infarct, partial anterior circulation infarct, posterior circulation infarct and lacunar infarct), serum creatinine, initial hemoglobin level, initial hematocrit level, etc, were recorded. Hemoglobin level and hematocrit level during hospitalization were also recorded. Domestic criteria were used to define if the patient had anemia on admission. Recovery was assessed by modified Rankin Scale (mRS) 180 days after stroke by telephone interview (mRS scores≤2 reflected good prognosis, and mRS scores>2 reflected unfavorable prognosis). The influence on outcome by anemia on admission, initial hemoglobin level, nadir hemoglobin level, nadir hematocrit level was analyzed by multinomial Logistic regression analysis. Results Odds ratio of initial hemoglobin level for poor outcome was 1.013 (95% CI 1.001-1.024, P=0.027) with each decrease in hemoglobin of 1 g/dl.Initial anemia(OR=2.417, 95% CI 1.202-4.859, P=0.013) was a independent prognostic factor for mortality; odds ratio of nadir hemoglobin level for mortality was 1.016 (95% CI 1.002-1.030, P=0.026) with each decrease in hemoglobin of 1 g/dl; odds ratio of nadir hematocrit level for mortality was 1.047(95% CI 1.003-1.093, P=0.037) with decrease in hematocrit of one percentage point. Conclusions Initial hemoglobin level was a independent prognostic factor for poor outcome in patients with acute cerebral infarction. Anemia on admission, nadir hemoglobin level, nadir hematocrit level were independent prognostic factors for mortality in patients with acute cerebral infarction.(Chinese Clinical Trial Registry(ChiCTR-POC-15006274)) Key words: Brain infarction; Anemia; Hemoglobins; Hematocrit; Prognosis