Objective To compare the clinical effect of left atrial appendage(LAA)plus atrial septal defect(ASD)closure therapy and ASD closure therapy in treating ASD associated with atrial fibrillation(AF).Methods A total of 102 patients with ASD complicated by non-valvular AF,who were admitted to the General Hospital of Northern Theater Command of China from January 2016 to December 2023,were enrolled in this study.Of the 102 patients,simultaneous one-stop interventional transcatheter LAA plus ASD closure was performed in 52(LAA+ASD closure group)and ASD closure was performed in 50.(ASD closure group).The perioperative and postoperative 30 d,90 d,180 d clinical safety and efficacy were compared between the two groups.Telephone follow-up was conducted,the complications such as embolization and bleeding were recorded,and the medium-to-long-term follow-up results were compared between the two groups.Results The immediate surgical success rate in both groups was 100％.The immediate postoperative monitoring showed that the occlusion effect was satisfactory.In LAA plus ASD closure group,LACBES LAA occluder was used in 27 patients and LAmbre LAA occluder was adopted in 25.There were no statistically significant differences in the patients' baseline characteristics between the two groups(all P＞0.05).In the LAA+ASD closure group,3 patients developed cardiac tamponade,among them 2 patients were cured after pericardiocentesis drainage and one patient was referred to the surgery department to receive occluder removal and intracardiac repair.Medium-to-long-term follow-up was conducted in 101 patients with a median follow-up period of 37.6 months.The incidence of embolic events in the LAA+ASD closure group was lower than that in the ASD closure group(3.9％vs.18.0％,P=0.028).The incidence of bleeding events in the ASD closure group was higher than that in the LAA+ASD closure group(16.00％vs.1.96％,P=0.016).Kaplan-Meier analysis indicated that the risk of occurring embolic events and bleeding events in the LAA+ASD closure group was strikingly lower than that in the ASD closure group(HR=4.295 and 7.888 respectively,95％CI:1.317-14.010 and 2.135-29.140 respectively,P=0.040 9 and P=0.020 8 respectively).Conclusion Simultaneous interventional transcatheter LAA plus ASD closure can effectively prevent embolic events such as stroke,etc.in patients with ASD complicated by AF,and its bleeding risk is lower than simple ASD closure.