The sodium-glucose-cotransporter 2 inhibitors (SGLT2i) are the blockbuster antidiabetic drugs that exert cardiovascular protection via pleiotropic effects. We have previously demonstrated that empagliflozin decreased monoamine oxidase (MAO) expression and oxidative stress in human mammary arteries. The present study performed in overweight, non-diabetic cardiac patients was aimed to assess whether the two widely prescribed SGLT2i decrease atrial MAO expression and alleviate oxidative stress elicited by exposure to angiotensin 2 (ANG2) and high glucose (GLUC). Right atrial appendages isolated during cardiac surgery were incubated ex vivo with either empagliflozin or dapagliflozin (1, 10 µm, 12 h) in the presence or absence of ANG2 (100 nm) and GLUC (400 mg/dL) and used for the evaluation of MAO-A and MAO-B expression and ROS production. Stimulation with ANG2 and GLUC increased atrial expression of both MAOs and oxidative stress
the effects were significantly decreased by the SGLT2i. Atrial oxidative stress positively correlated with the echocardiographic size of heart chambers and negatively with the left ventricular ejection fraction. In overweight patients, MAO contributes to cardiac oxidative stress in basal conditions and those that mimicked the renin-angiotensin system activation and hyperglycemia and can be targeted with empagliflozin and dapagliflozin, as novel off-target class effect of the SGLT2i.