Hemorrhagic complications of long-term anticoagulant therapy.

T he main complication of anticoagulation therapy is bleeding. We have conducted a literature review to determine: (a) the rate of bleeding during long-term anticoagulant therapy in various clinical disorders, and (b) the clinical and laboratory risk factors that predispose patients to bleeding. For the purposes of this review, we defined long-term therapy as lasting greater than 4 weeks. Hemorrhagic complications were also described for 2 other indications, myocardial infarction and hip surgery, where oral anticoagulant therapy was used for a shorter duration (approximately 4 weeks). The analysis was performed in patients with: (1) ischemic cerebrovascular disease (completed stroke, stroke-in-evolution, and transient ischemic attacks); (2) prosthetic cardiac valves; (3) chronic atrial fibrillation with and without associated rheumatic valvular disease; (4) ischemic heart disease (angina, myocardial infarction); and (5) in the prevention and treatment of venous thromboembolic disease. We reviewed each report seeking the following information: