The goal of this observational study is to test the association between high levels of Galectin-3 and the occurrence of post-operative atrial fibrillation after isolated coronary artery bypass grafting (CABG). The main question[s] it aims to answer are:

• Is Galectin-3 an accurate biomarker to predict higher risk of developing post-operative atrial fibrillation?
• Are high levels of Galectin-3 associated to other post-operative complications and major adverse cardiovascular events? Participants will be enrolled during pre-operative evaluation and a peripheral blood sample collection will be performed in the 24h before CABG. Participants will then be followed for a period of 12 months (daily during hospitalization and 3 appointments after hospital discharge) to determine whether patients with higher levels of Galectin-3 will have worse outcomes.

Prospective, observational, single-center cohort study including patients undergoing coronary artery bypass graft (CABG) surgery.

Patients will be enrolled during preoperative evaluation. A peripheral blood sample will be collected within 24 hours before surgery and patients will be followed during hospitalization and for 12 months after discharge.

Inclusion Criteria:

• Patients undergoing coronary artery bypass graft surgery

Exclusion Criteria:

• Inability to sign the free and informed consent form
• Renal dysfunction with estimated glomerular filtration rate less than 30ml / min / 1.73m² or dialysis therapy
• Moderate to severe left ventricular dysfunction (ejection fraction < 40%)
• Patients with previous atrial fibrillation
• Pregnancy
• Concomitant valve surgery

Single-center cohort study with patients admitted for coronary artery bypass graft (CABG) surgery.