Oral anticoagulant-associated intracerebral hemorrhage

Abstract

The incidence of oral anticoagulation-associated intracerebral hemorrhage (OAC-ICH) is growing due to the increasing use of warfarin and the older age of treated patients. Recent population studies reveal that OAC-ICH currently occurs at a frequency comparable to that of subarachnoid hemorrhage. Most frequently, OAC-ICH are located in deep or lobar regions of the brain, although it may also occur in the brainstem. These hemorrhages are larger than spontaneous hematomas and may be fatal in at least 50% of cases. The primary cause of brain injury in patients with OAC-ICH is the direct mechanical disruption of the brain tissue but secondary damage may occur through the intervention of matrix metalloproteinases, glutamate, cytokines, heme, iron, and the chemical toxicity of products such as thrombin, which are released from the clot. The pathogenesis of OAC-ICH also includes the effects of aging, the level of anticoagulation, genetic factors, and a high prevalence of concurrent cerebrovascular conditions, such as cerebral amyloid angiopathy, leukoaraiosis or previous strokes. The treatment of OAC-ICH is challenging and involves rapid reversal of anticoagulation with hemostatic drug therapies such as vitamin K, fresh frozen plasma, prothrombin complex concentrates or recombinant factor VIIa. These therapies may not always be sufficient to stabilize the patient's clinical condition and lacking randomized controlled trials, the best hematological approach to reverse oral anticoagulation is debated. Other difficult decisions reviewed in this article are whether anticoagulation should be restarted after OAC-ICH, and when anticoagulant treatment should be resumed. The newer oral anticoagulants, which are increasingly being introduced for thromboembolism prevention, may confer a lower risk of intracranial bleeding than warfarin, although they do not have an antidote and their anticoagulant effect is difficult to monitor.