Surgical occlusion of the left atrial appendage (LAAO) is sometimes performed during the cardiac surgery to reduce long-term risk of stroke.A previous study found that LAAO may be associated with increased risk of postoperative atrial fibrillation.New-onset atrial fibrillation (NOAF) after coronary artery bypass graft is related to an increased short-term and long term risk of stroke and mortality.Marshall ligament amputation may reduce the occurence of atrial fibrillation. However, little is known whether this approach is justified during the coronary artery bypass graft.Therefore, this study aimed to investigate whether LAAO and Marshall ligament amputation during off-pump coronary artery bypass was associated with reduced risks of postoperative new-onset atrial fibrillation and stroke.