Abstract： Objective: Exploring the risk factors for postoperative recurrence of atrial fibrillation after concomitant Maze IV ablation for cardiac surgery and constructing a Nomogram model for risk prediction Methods: Data on 596 patients admitted to the Department of Cardiac Macrovascular Surgery of the First Affiliated Hospital of Nanjing Medical University for cardiac surgery with simultaneous Maze IV ablation were collected between January 2014 and December 2022, and baseline, clinical and surgical data of the patients were counted.The endpoint of this study was recurrence of atrial fibrillation, defined as the development of new-onset atrial fibrillation or electrocardiographically confirmed atrial tachycardia with a duration greater than 30 s after 3 months postoperatively. All patients were completed at least 1 year of postoperative follow-up and divided into two groups based on whether AF recurred within 1 year of surgery, comparing the data of the two groups and deriving the risk factors for AF recurrence at 1 year postoperatively.Independent risk factors for recurrence of atrial fibrillation are derived using COX multifactorial analysis and we construct a predictive model for the risk of recurrence of atrial fibrillation. Results: Of the 596 patients, 263 (44.1%) are male, with a median age of 60 years and a median follow-up time of 33 months. 477 patients are persistent atrial fibrillation, 116 are paroxysmal atrial fibrillation, and 3 atrial flutter.Within 1 year after surgery, there are 150 recurrences (25.2%). Univariate analysis show that age, duration of atrial fibrillation, left atrial anterior-posterior diameter (LAD), right atrial anterior-posterior diameter (RAD), previous pacemaker placement, and early atrial fibrillation recurrence are the risk factors for postoperative recurrence of atrial fibrillation, while multifactorial analysis show that age, duration of atrial fibrillation, LAD, and early atrial fibrillation recurrence are the independent risk factors.COX regression analyses yield significant differences in age (HR=1.047[1.025,1.068], P<0.001), AF duration (HR=1.004[1.001,1.006], P=0.002), LAD (HR=1.024[1.005,1.045], P=0.015), use of a hinged ablation forceps (HR= 3.445 [2.153,5.511], P<0.001), and early postoperative AF recurrence (HR=3.751 [2.616,5.379], P<0.001) are independent risk factors for AF recurrence.The cut-off values for age, AF duration, and LAD analysed based on the receiver operating characteristic curves (ROC curves) are 59.5 years, 9.5 months, and 51.5 cm, respectively.Based on the COX results, a Nomogram model is constructed. Conclusion: Maze IV has good long-term efficacy in maintaining sinus rhythm. In patients with atrial fibrillation undergoing cardiac surgery, older age, longer LAD, and duration of atrial fibrillation can adversely affect the ablation outcome, and the hazard model constructed on the basis of this result has good predictive efficacy.