Abstract WMP58: The Smoker’s Paradox After Acute Ischemic Stroke, is it Real or a Cloud of Smoke?

Abstract

Background: Although tobacco use, the majority of which is cigarette smoking, increases the risk of incident stroke, there are inconsistent data regarding the effect of tobacco use on neurological outcomes after acute ischemic stroke. Several prior studies have suggested that smoking could be protective after stroke, which has been termed the "smoker’s paradox." Methods: We pooled three data sources to explore the effect of tobacco use on neurologic outcome in acute stroke patients. The first was the Blood Pressure after EVT in Stroke (BEST) study, the second was the NINDS tPA trial, and the third was the Interventional Management of Stroke (IMS) III trial. The primary outcome is 90-day mRS 0-2 (good outcome). We fit logistic regression models to good outcome, both unadjusted and adjusted for patient age, NIHSS, and sICH. Results: Our pooled cohort had 1,671 acute stroke patients, of which 480 (28.7%) used tobacco. In an unadjusted model, tobacco use was associated with good outcome (OR 1.42, 95% CI 1.15-1.76, p=0.001). However, in the adjusted model, this association was no longer significant (aOR 0.98, 95% CI 0.76-1.25, p=0.868). If we stratify by placebo-treated (n=310), tPA-treated (n=513), and EVT-treated (n=836), we continue to find that tobacco use is not associated with good neurologic outcome in adjusted analyses specific to these subgroups. An additional subgroup analysis of the EVT-treated patients that adjusted for successful procedural recanalization (TICI 2b-3) was not significant. Patients who used tobacco were younger (mean age, 60.5 vs. 69.2 years, p<0.001). Adjusting for age alone rendered the association between tobacco use and good outcome insignificant (aOR 1.05, 95% CI 0.84-1.32, p=0.666). Conclusions: This is the first adjusted analysis to examine the association between tobacco use and neurologic outcome in EVT-treated patients. We find that tobacco use is not protective after acute ischemic stroke that is untreated or treated with tPA or EVT. The univariate association of tobacco use with good outcome is accounted for by tobacco users being younger.