Lifestyle Factors and Thromboembolic Risk in Atrial Fibrillation: Age‐Dependent Effects of Smoking and Alcohol Consumption

Background Atrial fibrillation (AF) relates to cardioembolic stroke (CS), but the role of lifestyle factors, including smoking and alcohol, remains unclear. Methods This retrospective, nationwide, multicenter case–control study used the Inpatient Clinico‐Occupational Database of the Rosai Hospital Group from 2005 to 2022. Patients with AF and CS were identified using ICD‐10 codes. Smoking status and alcohol consumption were assessed at admission through structured interviews. We examined age‐stratified differences in smoking and alcohol consumption and evaluated the impact of smoking and alcohol intake on the risk of CS. Results Among 26 915 patients, 5688 had AF‐related CS and 21 227 had AF without CS. Current smoking was more prevalent in AF patients with CS aged from 40–49 to 80–89 years than those without (all p < 0.001). Multivariable logistic regression showed smoking was independently associated with CS overall (all p < 0.001) and by age group, and daily alcohol intake was associated with CS overall and in patients ≤ 75 years ( p = 0.021 and 0.044). The combined score of chronic heart failure, hypertension, age > 75‐year (weighted × 2), and diabetes mellitus (CHA 2 D, range 0–5) increased with age, from 0.66, 0.67, 1.36, 2.43, 2.83, and 2.94 (average) in the 40–49, 50–59, 60–69, 70–79, 80–89, and ≥ 90‐year groups ( p < 0.001), whereas the prevalence of current smoking and daily alcohol consumption declined progressively with age ( p < 0.001). Conclusions Smoking and daily alcohol consumption associate with CS risk in AF patients, especially younger individuals with low CHA 2 D scores, highlighting the role of lifestyle in risk assessment.