Anticoagulation in acute ischaemic stroke: deep vein thrombosis preventionand long-term stroke outcomes

Ischaemic stroke accounts for 70-85% of stroke incidence worldwide, causing substantial morbidity and mortality. Antiplatelet agents and carotid endar terectomy are effective in stroke prevention but active therapy for acute s troke is limited at present. Treatments investigated to date include thromb olysis and antiplatelet agents, both of which have been shown to modify the effects of stroke and provide a small long-term benefit in selected patien ts, and anticoagulation with heparin derivatives and oral agents. The value of unfractionated heparin (UFH) in modifying the acute effects of stroke h as never been clearly established, and the risk of intracranial bleeding ha s limited its clinical application. However, disability and death following stroke stem from both the acute cerebral event and the secondary developme nt of venous thromboembolism (VTE). Antithrombotic therapy may therefore, i n principle, provide the dual benefit of retarding ongoing cerebral thrombo sis and preventing secondary VTE. Low-molecular-weight heparins (LMWHs) and one heparinoid may have an improved ratio of antithrombotic action to haem orrhagic effect compared with UFH. Recent trials with these agents demonstr ated a significant reduction in deep vein thrombosis and pulmonary embolism . Evidence has also emerged of improved long-term outcomes in terms of comb ined rates of death and residual disability, but data from different studie s are conflicting. The potential role of LMWHs and heparinoids in acute str oke remains to be clarified. (C) Lippincott Williams & Wilkins.