Association Between Smoking History and Response to Rhythm Control Therapy in Atrial Fibrillation Patients Across Race-Ethnicity

Introduction: Although smoking is associated with increased risk of developing atrial fibrillation (AF) and stroke, whether it also predicts response to rhythm control therapy across race-ethnicity remains unclear. Hypothesis: We hypothesize that smokers are less likely to respond to rhythm control therapy for AF than non-smokers. Methods: In this cohort study, patients managed with rhythm control strategy at the time of enrollment to the study were prospectively enrolled in an AF multi-center clinical-DNA biorepository. Rhythm control includes antiarrhythmic drugs (AADs) and\or catheter ablation. Successful response was defined as continuation of the same AAD for at least 6 months and/or successful catheter ablation without recurrence of AF for 12 months. Results: Of the 362 enrolled, 132 (36.4%) were European American, 155 (42.8%) were African- American and 75 (20.7%) were Hispanic American. 125 patients were smokers and 237 patients were non-smokers. Baseline clinical characteristics were similar in both groups (Table 1). Compared to nonsmokers, smokers were less likely to respond to rhythm control strategy (odds ratio [OR] 1.36, 95% confidence interval [CI]: 0.88-2.11, P-value: 0.07). Adjusted for the type of rhythm control, smokers were more likely to have a recurrence of AF catheter ablation as compared with nonsmokers ([OR] 1.38, 95% [CI]: 1.031-2.348, P-value: 0.044). However, there was no significant difference between smokers and non-smokers in terms of response to AADs ([OR] 1.25, 95% [CI]: 0.560-2.809, P-value: 0.292). Conclusions: Patients with a smoking history were less likely to respond rhythm control therapy as compared to nonsmokers. After adjusting for the type of rhythm treatment, smokers were more likely to have a recurrence of AF when compared to non-smokers but there was no difference in response to AADs between the two groups.