MPO and atrial fibrillation: MPO was the only significantly increased protein in the EAT secretome (FC 18.08, p = 0.003), EAT (FC 21.37, p = 0.005), and myocardium (including marginally EAT) (FC 8.51, p < 0.001) of patients with versus without AF (Additional file 1: Fig. S4).