[The risk of hemorrhage versus the thromboembolic risk in patients with prosthetic valve].

376 adults were followed up for between 2 and 153 months after surgery (mean: 3.8 years); all of them, with the exception of 8, received anticoagulant treatment. The results were subjected to statistical analysis using several tests. Thromboembolic complications occurred in 16 per 100 after 5 years, and 8.5. per 100 of them were fatal. Among the factors favoring this complication are the type of valvular disorder (the rate of throembolism being 4 times greater with mitral valve defects), the type of prosthesis, and the efficiency of the anticoagulant therapy (the risk of thromboembolism being four times greater in those patients whose treatment has been inneffective). Against the vitamin antagonists must be set the haemorrhages: the incidence of lethal haemorrhage in this series was 6.4 per 100 patients per treatment year. There was a proven hypoprothrombinaemia to below the desirable level in two thirds of these cases, and in one case out of four an additional predisposing factor could be demonstrated. Haemorrhage and thromboembolism are together responsible for one in four of the late deaths. In order to reduce the mortality, several solutions are considered, one of which is to utilise anti-aggregation treatment. However, the vitamin K antagonists remain an essential part of treatment in the majority of cases; it can only be justifiable to withhold them in those patients in whom the risks of haemorrhage are for various reasons considered to be too high. The introduction of biological valves or of valves with a lessened risk of embolism is highly desirable in such cases.