Epstein KA, et al. - The clinicians performed this study to evaluate whether smoking cessation after an ischemic stroke or TIA improved outcomes compared to continued smoking. After an ischemic stroke or TIA, cessation of cigarette smoking was correlated with significant health benefits over 4.8 years in the Insulin Resistance Intervention After Stroke (IRIS) trial cohort.

• A prospective observational cohort study of 3,876 nondiabetic men and women enrolled in the Insulin Resistance Intervention After Stroke (IRIS) trial was conducted.
• The clinicians randomized them into pioglitazone or placebo within 180 days of a qualifying stroke or TIA and followed up for a median of 4.8 years.
• They obtained tobacco use history at baseline and updated during annual interviews.
• The primary outcome was a recurrent stroke, myocardial infarction (MI), or death which was not prespecified in the IRIS protocol.
• They used Cox regression models to evaluate the differences in stroke, MI, and death after 4.8 years, with correction for adjustment variables prespecified in the IRIS trial: age, sex, stroke (vs TIA) as index event, history of stroke, history of hypertension, history of coronary artery disease, and systolic and diastolic blood pressures.

• A total of 1,072 (28%) patients were current smokers at the time of their index event.
• 450 (42%) patients had quit smoking by the time of randomization.
• Compared to 22.6% for patients who continued to smoke, the 5-year risk of stroke, MI, or death was 15.7% among quitters (adjusted hazard ratio 0.66, 95% confidence interval 0.48-0.90).