Background: The status of smoking as a risk factor for the occurrence of stroke is well established. However, there is a paucity of data on the relationship between smoking status and acute stroke outcomes. We evaluated the role of recent smoking as a prognostic factor following acute ischemic stroke.
Methods: We analyzed data from patients enrolled in the Intravenous Magnesium Efficacy in Stroke (IMAGES) trial. Outcome measures studied included change in IMAGES stroke score, poor functional outcomes at day 30 and 90 (defined as Rankin Scale >1 and Barthel Index <95), and survival over the first 3 months after stroke. The independent effect of smoking status (subjects who had smoked in the past year) on outcome was evaluated by logistic regression analysis and Cox's proportional hazards model, adjusting for variables known to predict outcome after ischemic stroke.
Results: There were 2,386 subjects in the IMAGES efficacy dataset, including 615 recent or current smokers and 1,771 nonsmokers, among whom smokers were younger (p < 0.0001). After adjusting for covariates, smokers had increased odds of poor 90-day functional outcome independently of other statistically significant predictor variables, as assessed by Rankin Scale (odds ratio 1.38; 95% confidence interval 1.09-1.75) and Barthel Index (odds ratio 1.42; 95% confidence interval 1.13-1.79) at day 90. Smoking status did not affect survival at day 90.
Conclusions: Current or recent smokers experience poorer functional outcomes than nonsmokers 3 months after acute ischemic stroke.