Abstract WP164: Role of Risk Factors in the Paradoxical Effect of Smoking on Peri-procedural Stroke in SAMMPRIS

Abstract

Background: A previous SAMMPRIS analysis of patients randomized to stenting showed that peri-procedural ischemic infarcts were significantly associated with diabetes, basilar stenosis, age, and smoking status with never smokers having a higher risk (odds ratio = 8.8, p< 0.001). We sought to determine if this finding could be due to a higher burden of other risk factors in never smokers. Method: Baseline features in 213 patients undergoing stenting in SAMMPRIS were compared between never smokers vs. former and current smokers in univariate and multivariate analyses. Logistic regression was used to determine the effect of smoking on peri-procedural ischemic infarcts after adjusting for factors related to smoking. Data: Univariate results are shown in Table 1. Never smokers were significantly (P<0.05) more likely to be female, diabetic, hypertensive, and have another intracranial stenosis, but in multivariate analyses only hypertension and another intracranial stenosis remained significantly (P<0.05) associated with smoking status. In a multivariate model that incorporated hypertension and another intracranial stenosis along with smoking status, diabetes, basilar stenosis, and age, smoking status remained significant with an increased risk among patients who never smoked (odds ratio = 5.3, p = 0.005). Conclusion: While never smokers had significantly higher rates of some risk factors compared to active or previous smokers, these risk factors do not explain all the increased risk of early stroke in never smokers after stenting in SAMMPRIS. Another contributory factor may be that smoking accelerates the conversion of clopidogrel to its active form.