Target INR for most modern mechanical bileaflet prostheses is 2.5, increasing to 3.0 with any of the following: Atrial fibrillation Left ventricular ejection fraction (LVEF) < 35% Mitral or tricuspid position Previous thromboembolism Patients who can self-monitor their INR or follow up with dedicated anticoagulation clinics have less variability in their INR and fewer adverse events.