Smoking is Not a Good Prognostic Factor following First-Ever Acute Ischemic Stroke

There is evidence that smoking increases stroke risk; however, the effect of smoking on functional outcome after stroke is unclear. The aim of this study was to explore the effect of smoking status on outcome following acute ischemic stroke.

We assessed 1,117 patients with first-ever acute cerebral infarction and no prestroke disability whose functional outcome was measured after three months. A poor outcome was defined as a modified Rankin Scale score of ≥2. Smoking within one month prior to admission was defined as current smoking. Our analysis included demographics, vascular risk factors, initial National Institutes of Health Stroke Scale (NIHSS) score, stroke subtype, onset-to-admission time, thrombolytic therapy, initial blood pressure, and prognostic blood parameters as covariates.

At baseline, current smokers were predominantly male, approximately 10 years younger than non-smokers (mean age, 58.6 vs. 68.3 years), and less likely to have hypertension and atrial fibrillation (53.9% vs. 65.4% and 8.7% vs. 25.9%, respectively), with a lower mean NIHSS score (4.6 vs. 5.7). The univariate analyses revealed that current smokers had a better functional outcome and significantly fewer deaths at three months follow-up when compared with non-smokers (functional outcome: 64.0% vs. 58.4%, P=0.082; deaths: 3.0% vs. 8.4%, P=0.001); however, these effects disappeared after adjusting for covariates (P=0.168 and P=0.627, respectively).

In this study, smoking was not associated with a good functional outcome, which does not support the paradoxical benefit of smoking on functional outcome following acute ischemic stroke.