Warfarin Use in Stroke Patients
A patient with chronic atrial fibrillation and metallic prosthetic mitral valve using oral anticoagulant (warfarin 5 mg per day) suffers an embolic stroke. One day later, a CT scan shows hemorrhagic transformation. What is the best therapeutic approach concerning warfarin?

Marcos Martins da Silva, MD

Vitamin K antagonists are recommended for the prevention of stroke in patients with chronic atrial fibrillation, recent myocardial infarction, or prosthetic heart valves. Cerebral hemorrhage in anticoagulated patients with mechanical valvular prosthesis poses a feared, yet uncommon but difficult management problem. Predictors of anticoagulant-related intracerebral hemorrhage are advanced patient age, prior ischemic stroke, hypertension, and intensity of anticoagulation. The risk of such intracranial hemorrhage may be reduced by judicious prescribing, identification of patients at high risk of bleeding, and close monitoring by experienced staff. In such situations, guidelines for immediate reversal of anticoagulation include administration of vitamin K₁ and factor replacement with either factor concentrates or fresh frozen plasma. Furthermore, prothrombin complex concentrates lead to faster -- and more complete -- correction of coagulation and may be associated with improved neurologic status.

The absolute rate reduction of ischemic stroke by anticoagulation must offset accentuation of brain hemorrhage. If anticoagulation is desired, treatment with intravenous heparin (partial thromboplastin time 1.5-2 times baseline value) after normalization of the INR may be considered. Other suggestions include the use of unfractionated heparin or with low-molecular weight heparin while judiciously balancing the risk of recurrent hemorrhage. With regard to restarting warfarin, studies are conflicting, with some suggesting that recurrent bleeding within 6 months of the resumption of anticoagulation is common, while others suggest that temporary cessation of warfarin is safe and risk of recurrent hemorrhage is low.