Abstract
He indications for oral anticoagulant treatment have been extended over the last 10 years. The detection of new congenital thrombophilic risk factors, the stud- ies on non-valvar atrial fibrillation, and the increase in valvar heart surgery have all led to a rise in the number of patients being treated. In 1997, 64 000 valve operations were performed across Europe; in two thirds of these operations mechanical prostheses were used, subsequently requiring lifelong oral anticoagulant treat- ment. w1