Association between admission haematocrit and mortality among men with acute ischaemic stroke

Objective Anaemia is associated with higher mortality among patients with non-stroke cardiovascular conditions;less is known regarding the relationship between anaemia and mortality among patients with acute ischaemic stroke.Methods Medical records were abstracted for n=3965 veterans from 131 Veterans Health Administration facilities who were admitted with ischaemic stroke in fiscal year 2007.Haematocrit values within 24 hours of admission were classified as≤27%,28%-32%,33%-37%,38%-42%,43%-47% or≥48%.Multivariate logistic regression was used to examine the relationship between anaemia and in-hospital,30-day,6-month and 1-year mortality,adjusting for age,medical comorbidities,modified Acute Physiology and Chronic Health Evaluation-III and stroke severity.Impact factors were calculated to standardise comparisons between haematocrit tier and other covariates.results Among n=3750 patients included in the analysis,the haematocrit values were≤27%in 2.1%(n=78),28%-32% in 6.2%(n=234),33%-37%in 17.9%(n=670),38%-42% in 36.4%(n=1366),43%-47% in 28.2%(n=1059)and≥48% in 9.1%(n=343).Patients with haematocrit≤27%,compared with patients in the 38%-42% range,were more likely to have died across all follow-up intervals,with statistically significant adjusted ORs(aORs)ranging from 2.5 to 3.5.Patients with polycythaemia(ie,haematocrit≥48%)were at increased risk of in-hospital mortality(aOR=2.9;95%CI 1.4 to 6.0),compared with patients with mid-range admission haematocrits.Pronounced differences between patients receiving and not receiving blood transfusion limited our ability to perform a propensity analysis.Impact factors in the 1-year mortality model were 0.46(severe anaemia),0.06(cancer)and 0.018(heart disease).Conclusions Anaemia is independently associated with an increased risk of death throughout the first year post stroke;high haematocrit is associated with early poststroke mortality.Severe anaemia is associated with 1-year mortality to a greater degree than cancer or heart disease.These data cannot address the question of whether interventions targeting anaemia might improve patient outcomes.