MMP9 and atrial fibrillation: The aim of our observational prospective study was to perform a comprehensive fundamental analysis of the factors of inflammation (interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP)), oxidative stress (superoxide dismutase (SOD), reduced glutathione (RG), glutathione peroxidase (GPO), glutathione reductase (GR), malondialdehyde (MDA)), fibrosis (metalloproteinase (MMP)-9), myocardial dysfunction (N-terminal pro-B-type natriuretic peptide (NT-proBNP)), ischemia (troponin I) and omega-3 index associated with new-onset AF after CABG surgery in patients with CAD.