[Bleeding complications in oral anticoagulant treatment]

Vitamin K-antagonists are recommended for the prevention of stroke in patients with chronic atrial fibrillation, recent myocardial infarction or prostatic heart valves. Anticoagulant therapy is seldom prescribed, however, presumably for fear of haemorrhagic sequelae. The risk of bleeding during anticoagulant therapy has been evaluated in 10 recent studies of warfarin treatment for the prevention of arterial thromboembolism. The mean annual incidences of fatal and major bleeding was 0.5 percent and 1.6 percent, respectively, as compared with the placebo figures of 0.1 percent and 0.6 percent, respectively. In 3 studies where the effect of aspirin has been evaluated the mean annual incidence of fatal and major bleeding was 0.2 percent and 0.8 percent, respectively. The figures for warfarin therapy where lower than those reported from older studies. The reasons for the reduction in incidence may be less intensive anticoagulant treatment than formerly, improved laboratory control by the introduction of the International Normalized Ratio, and careful pretreatment evaluation of patients selected for clinical trials.