Hemorrhagic complications of long-term anticoagulant therapy for ischemic cerebral vascular disease.

The main complication of anticoagulant therapy is bleeding. Although the use of long-term oral anticoagulants in patients with transient cerebral ischemia and/or minor stroke is controversial, anticoagulants are still used in some instances. We have carried out a literature review of the risk of hemorrhage during long-term oral anticoagulant therapy in patients with cerebrovascular disease to determine the rate of bleeding and the clinical and laboratory risk factors which predispose patients to bleeding. The risk of bleeding was substantial with major bleeding episodes ranging from 2% to 22% per year and fatal bleeds from 2% to 9% per year. Only hypertension emerged as an identifiable risk factor and its presence increased the relative risk of bleeding to more than two fold. Major bleeding was almost always intracranial, possibly because of associated hypertension or because of cerebrovascular disease per se. We could not detect a relationship between bleeding and the intensity of anticoagulant therapy, although major bleeding occurred frequently even with only moderately intense anticoagulant therapy. The net gain or loss in efficacy rate of treating patients with minor stroke with long-term oral anticoagulant therapy was examined and it was concluded that in order for such treatment to be beneficial, a risk reduction of more than 50% in stroke rate, and a major bleeding rate of less than 2% per year are required. Since the risk reduction for stroke and death with anticoagulant therapy is unlikely to be 50% and the risk of major bleeding likely to be more than 2%, the present evidence does not support the use of anticoagulant therapy in minor stroke.