Impact of smoking cessation after the new diagnosis of atrial fibrillation on the risk of stroke: a nationwide cohort study

Abstract Background There are limited data about the impact of modifying behavior such as smoking cessation after atrial fibrillation (AF) diagnosis on the clinical outcome. Purpose To evaluate the association between smoking cessation after newly diagnosed AF and the risk of stroke. Methods Among subjects with new-onset AF between 2010 and 2016, those who received a national health checkup exam within 2 years before and after the AF diagnosis were included. Subjects were categorized into 4 groups according to the status of smoking before and after AF diagnosis: (i) never smoker; (ii) new smoker after AF diagnosis; (iii) quit-smoker after AF diagnosis; and (iv) persistent smoker. The primary outcome was incident stroke during follow-up. Results A total of 97,869 patients were included (mean age 61±12, men 62%, and mean CHA2DS2-VASc 2.3±1.5). During a median of 3 years of follow-up, stroke occurred in 3,121 patients (1.0 per 100 person-years). Never smoker, new smoker, quit-smoker, and persistent smoker was 79%, 2%, 7%, and 12% of the total study population, respectively. After multivariable adjustment, new smoker and persistent smoker were associated with an increased risk of stroke compared to never smoker (hazard ratio [HR] 1.84, 95% confidence interval [CI] 1.48–2.28 for new smoker; HR 1.66, 95% CI 1.48–1.86 for persistent smoker) (Figure). Quit-smoker who stopped smoking after AF diagnosis also showed a higher risk of stroke than never smoker (HR 1.19, 95% CI 1.03–1.38). The quit-smoker group showed a lower compared to those who continued smoking after AF diagnosis (HR 0.720, 95% CI 0.608–0.851). Conclusion Smoking cessation after AF diagnosis showed a lower risk of stroke compared to patients smoking persistently. Lifestyle change as smoking cessation after diagnosis of AF could modify the risk of stroke in patients with new-onset AF. Hazard ratio of smoking status for AF Funding Acknowledgement Type of funding source: None