Background and Purpose: Smoking is a well-established risk factor for stroke. However, several studies have shown that smokers with stroke have better outcomes after thrombolysis, a phenomenon commonly known as the smoking-thrombolysis paradox. We investigated whether clinical and procedural outcomes differ between smokers and non-smokers with large vessel occlusion stroke after endovascular therapy.
Methods: We reviewed our prospectively collected endovascular database at a tertiary care academic institution between Sep 2010-Dec 2016. All patients that underwent endovascular therapy for anterior circulation large vessel occlusion acute ischemic stroke were included and categorized into two groups: (1) current smokers and (2) non-smokers. The 2 groups were then matched for age, baseline NIHSS and glucose levels using a weighted Euclidian distance method. Baseline, procedural, and radiological characteristics, as well as outcome parameters were compared.
Results: A total of 326 (163 matched pairs) qualified for the study. Smokers had higher rates of dyslipidemia (48.5% vs 28.8%, p<0.001), lower body mass index (26.7[23.5-31.3] vs 28.4[24.9-32.6], p=0.03) and shorter procedures (63[45-82] vs 73.5[46-116], p=0.03). Other baseline characteristics including baseline NIHSS, ASPECT scores, CT Perfusion parameters (ischemic core and penumbra volumes) and median time to treatment were well balanced. When compared with non-smokers, smokers also had similar rates of good outcomes at 90 days (mRS 0-2) (58.2% vs 52.4%, p=0.33), successful reperfusion (mTICI 2b-3) (92% vs 89.6%, p=0.44), parenchymal hematomas (7.4% vs 6.7%, p=0.83) and mortality at 90 days (14.9% vs 15.6%, p=0.86). On multivariate analysis, age (OR 0.97 95%CI [0.94-0.99], p=0.006), pretreatment glucose (OR 0.99 95%CI [0.98-0.99], p=0.02), baseline NIHSS (OR 0.92 95%CI [0.87-0.97], p=0.002) and successful reperfusion (OR 6.98 95%CI [2.19-22.25] were associated with good outcome.
Conclusion: Our data shows that smoking is not associated with outcomes in patients with large vessel occlusion stroke treated with mechanical thrombectomy.