The relationship between smoking and clinical outcome in ischemic stroke patients undergoing reperfusion therapy

It has been suggested that smokers have higher recanalization rate, lower risk of cerebral hemorrhage and better prognosis than non-smokers (smoking paradox) after reperfusion therapy in patients with acute ischemic stroke (IS). This study aimed to assess the effects of smoking on recanalization, intracranial hemorrhage, and clinical outcomes in patients with acute IS following reperfusion therapy.

Patients were categorized into smokers and non-smokers, with data collected on types of reperfusion therapy, demographics, medication use, comorbidities, stroke etiology, mRS and NIHSS scores, TICI and ECASS classifications.

The study involved 662 patients (344 men and 318 women) treated with rtPA and/or thrombectomy. Smoking was more prevalent among men. Smokers were typically younger, had lower hypertension rates, lower systolic blood pressure, and higher triglyceride and HDL levels compared to non-smokers. They exhibited a higher incidence of cardioembolic strokes and strokes with known causes but a lower incidence of small vessel occlusion. Smokers had higher GCS scores and more posterior cerebral circulation strokes upon hospital admission. NIHSS scores were lower at admission and on the third day, and poor outcome rates (mRS) were lower at both hospital admission and three months post-stroke for smokers. However, smokers who developed hemorrhagic complications had a higher frequency of parenchymal hematoma according to ECASS classification.

Our findings did not support claims that smoking increases recanalization rates, reduces cerebral hemorrhage risk, or improves clinical outcomes. Further prospective studies with larger samples are needed to explore smoking's impact on stroke outcomes.