TongXin Wang ¹ Xinyi Wang ^1,2 Tao Zhang ² Jie Zhang ³ Runmin Lai ¹ Jiqian Zhang ^1,2 Dan Ma ¹ Yan Jia ^1,2 Qiyu Liu ¹ Qiuyi Li ¹ Jundi Jia ¹ Wende Tian ¹ Jianqing Ju ^1* Hao Xu ^1*

• ¹ National Clinical Research Center for Chinese Medicine Cardiology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
• ² Beijing University of Chinese Medicine, Beijing, Beijing Municipality, China
• ³ Department of Integrative Cardiology, China-Japan Friendship Hospital, Beijing, Beijing Municipality, China

Abstract Background: The relationship between serial changes in physical activity and the risk of developing atrial fibrillation (AF) has been rarely studied. Objectives: To evaluate the association between changes in physical activity over time and the incidence of AF. Methods: A total of 11,828 participants without AF at baseline (visit 1: 1987-1989) from the ARIC Study were included. Physical activity was measured using the modified Baecke Physical Activity Questionnaire at three different visits between 1987 and 2013. Physical activity trajectories over 25 years were identified using latent class trajectory modeling. The primary outcome was the incidence of AF. Multivariable Cox hazard regression models were used to evaluate the relationship between physical activity trajectories and the incidence of AF. Results: Over a median follow-up of 24 years, 2,108 AF cases (17.8%) occurred. Four distinct physical activity trajectories were identified: light (n = 5,266 [43.3%]); reduced moderate (n = 3,583 [29.0%]); moderate (n = 2,691 [25.0%]); and vigorous intensity (n = 288 [2.8%]). Compared to the light group, the hazard ratio (HR) and 95% confidence interval (CI) for AF were 1.18 (1.07-1.30) (p < 0.001) for the reduced moderate group, 0.61 (0.53-0.70) (p < 0.001) for the moderate group, and 0.82 (0.59-1.12) (p = 0.21) for the vigorous group, after multivariate adjustments. Conclusion: Maintaining moderate levels of physical activity is associated with a lower risk of AF, while a decrease in activity from moderate to light levels increases the risk. These findings highlight the importance of sustaining adequate physical activity levels for the prevention of AF. Condensed Abstract: This study analyzed data from 11,828 participants in the ARIC study, initially free of AF. It found that moderate physical activity reduced AF risk compared to light activity, while reducing activity from moderate to light increased the risk. These results stress the importance of maintaining sufficient physical activity to prevent AF. (ClinicalTrials.gov Identifier: NCT00005131, Recruitment Status: Completed, First Posted: May 26, 2000, Last Update Posted: April 14, 2016, Sponsor: National Heart, Lung, and Blood Institute (NHLBI). Information provided by: National Heart, Lung, and Blood Institute (NHLBI))