Background Smoking is a well-established risk factor of stroke and smoking cessation has been recommended for stroke prevention; however, the impact of smoking status on stroke recurrence has not been well studied to date. Methods and Results Patients with first-ever stroke were enrolled and followed in the NSRP (Nanjing Stroke Registry Program). Smoking status was assessed at baseline and reassessed at the first follow-up. The primary end point was defined as fatal or nonfatal recurrent stroke after 3 months of the index stroke. The association between smoking and the risk of stroke recurrence was analyzed with multivariate Cox regression model. At baseline, among 3069 patients included, 1331 (43.4%) were nonsmokers, 263 (8.6%) were former smokers, and 1475 (48.0%) were current smokers. At the first follow-up, 908 (61.6%) patients quit smoking. After a mean follow-up of 2.4±1.2 years, 293 (9.5%) patients had stroke recurrence. With nonsmokers as the reference, the adjusted hazard ratios for stroke recurrence were 1.16 (95% CI , 0.75-1.79) in former smokers, 1.31 (95% CI , 0.99-1.75) in quitters, and 1.93 (95% CI , 1.43-2.61) in persistent smokers. Among persistent smokers, hazard ratios for stroke recurrence ranged from 1.68 (95% CI , 1.14-2.48) in those who smoked 1 to 20 cigarettes daily to 2.72 (95% CI , 1.36-5.43) in those who smoked more than 40 cigarettes daily ( P for trend <0.001). Conclusions After an initial stroke, persistent smoking increases the risk of stroke recurrence. There exists a dose-response relationship between smoking quantity and the risk of stroke recurrence.
Keywords: recurrence; smoking; smoking cessation; stroke.