Yue Han,1,* Chao Guo,2,* Qianmei Zhu,1 Zijia Liu,1 Yuelun Zhang,3 Shanqing Li,2 Le Shen1 1Department of Anesthesiology, Chinese Academy of Medical Sciences & Peking Union Medical College Hospital, Beijing, People’s Republic of China; 2Department of Thoracic Surgery, Chinese Academy of Medical Sciences & Peking Union Medical College Hospital, Beijing, People’s Republic of China; 3Department of Medical Research Center, Chinese Academy of Medical Sciences & Peking Union Medical College Hospital, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zijia Liu, Department of Anesthesiology, Chinese Academy of Medical Sciences & Peking Union Medical College Hospital, Beijing, 100730, People’s Republic of China, Tel/Fax +861069155580, Email liu-zj02@126.comBackground: Atrial fibrillation (AF) has become the most common postoperative arrhythmia of thoracic surgery. This study aimed to investigate the risk factors and complications of perioperative atrial fibrillation (PoAF) in elderly patients who underwent video-assisted thoracoscopic surgery (VATS).Methods: Data were collected from patients who underwent VATS between January 2013 and December 2022 at Peking Union Medical College Hospital (PUMCH). Univariable analyses and multivariable logistic regression analyses were used to determine the factors correlated with PoAF. Receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the indicators to predict PoAF.Results: The study enrolled 2920 patients, with a PoAF incidence of 5.2% (95% CI 4.4%-6.0%). In the logistic regression analyses, male sex (OR=1.496, 95% CI 1.056– 2.129, P=0.024), left atrial anteroposterior dimension (LAD) ≥ 40 mm (OR=2.154, 95% CI 1.235– 3.578, P=0.004), hypertension (HTN) without regular treatment (OR=2.044, 95% CI 0.961– 3.921, P=0.044), a history of hyperthyroidism (OR=4.443, 95% CI 0.947– 15.306, P=0.030), surgery of the left upper lobe (compared to other lung lobes) (OR=1.625, 95% CI 1.139– 2.297, P=0.007), postoperative high blood glucose (BG) (OR=2.482, 95% CI 0.912– 5.688, P=0.048), and the time of chest tube removal (per day postoperatively) (OR=1.116, 95% CI 1.038– 1.195, P=0.002) were found to be significantly associated with PoAF. The area under the ROC curve was 0.707 (95% CI 0.519– 0.799). 86.9% patients were successfully converted to sinus rhythm. Compared with the non-PoAF group, the PoAF group had significantly greater risks of prolonged air leakage, postoperative acute coronary syndrome, longer ICU stays, and longer hospital stays.Conclusion: Male sex, LAD≥ 40 mm, HTN without regular treatment, a history of hyperthyroidism, surgery of the left upper lobe, postoperative BG, and the time of chest tube removal were associated with PoAF. These findings may help clinicians identify high-risk patients and take preventive measures to minimize the incidence and adverse prognosis of PoAF.Keywords: video-assisted thoracoscopic surgery, aged, atrial fibrillation, risk factor