Atrial fibrillation (AF) is the most common arrhythmia, which leads to reduced cardiac output and promotes the occurrence of heart failure, and abnormal hemodynamic changes in the left atrium induce thrombosis, which seriously reduces the quality of life, and even leads to death. For patients who need cardiac surgery combined with the Cox-Maze IV (CMIV) surgical ablation, oral amiodarone postoperatively for three consecutive months was recommended as the preferred treatment option. However, the study found there were still 15%-35% of patients at risk of AF recurrence. Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, has been widely used for the treatment of type 2 diabetes mellitus and heart failure. Nonetheless, it remains unknown whether dapagliflozin can improve the recurrence of AF and reduces adverse cardiovascular events for patients who need CMIV ablation, and whether it can be routinely used for AF patients without diabetes or heart failure. Therefore, this study aims to explore the effect of postoperative oral dapagliflozin on the recurrence of AF after CMIV.

Inclusion Criteria:

• Age ≥18 years
• Patients with persistent or long-term persistent atrial fibrillation who need isolated surgical Cox-Maze IV procedure
• Patients who need cardiac surgery combined with Cox-Maze IV procedure
• Patients who have the ability and willingness to abide by all the subsequent reviews and requirements
• Sign the informed consent

Exclusion Criteria:

• Dapagliflozin allergy
• Hyperthyroidism
• Patients with acute myocardial infarction, cerebral apoplexy, and other vascular diseases during the past 6 months
• Patients who received heart surgery within the last 3 months
• eGFR<45ml/min
• History of oral SGLT2i
• Estimated survival period < 12 months
• Pregnant and lactating women
• Left atrial diameter > 65 mm
• Refusing to sign the informed consent