[Intensity of oral anticoagulant therapy after heart valve replacement]

In recent years randomized clinical trials using standardized prothrombin time (international normalized ratio, INR) for the control of oral anticoagulant therapy have demonstrated that the use of a less intense therapeutic range decreases the rate of bleeding without reducing antithrombotic efficacy. Based on these results, the following guidelines for therapeutic ranges in heart valve replacement can be presently recommended: INR of 2.0-3.0 in patients with bioprosthetic valves for the first 3 months-except, probably, for patients with tissue valves in aortic position who are in sinus rhythmus; long-term anticoagulation corresponding to an INR of 2.0-3.0 in all patients with bioprosthetic valves and either atrial fibrillation or postoperative arterial embolism or a left atrial thrombus at surgery; long-term treatment equivalent to an INR of 2.5-3.5 in all patients with mechanical prosthetic heart valves.