In recent years, a growing body of research has shown that diabetes plays an important role in the development and recurrence of atrial fibrillation. How to achieve the treatment and prevention of recurrence of atrial fibrillation through appropriate blood glucose control is the current focus of clinical research. Glycosylated hemoglobin (HbA1c) is the product of a non-enzymatic reaction in which hemoglobin in red blood cells is combined with sugars in the serum (mainly glucose). The purpose of this multicenter, randomized controlled study is to compare the effects of different glycosylated hemoglobin control strategies on the effectiveness of Cox-Maze IV procedure for atrial fibrillation during cardiac surgery.

Inclusion Criteria:

• Age ≥18 years
• Elective cardiac surgery
• A clear diagnosis of diabetes mellitus, and HbA1c ≥ 7.5% at the time of initial diagnosis and treatment
• Preoperative combination of persistent or long-term persistent atrial fibrillation

Exclusion Criteria:

• Emergency surgery or limited-term surgery
• Previous cardiac surgery
• Left atrial diameter > 65 mm
• Serum creatine > 1.8 mg/dL
• Previous severe liver disease
• Pregnant or planning to become pregnant
• Have a malignant tumor