Heparin in acute ischemic stroke revisited.
The evidence gathered in clinical trials of low molecular weight heparins (LMWHs) or with unfractionated heparin (UH) given subcutaneously at low or medium doses to patients with acute stroke cannot be extrapolated to the insufficiently tested effects of intravenous, weight-adjusted UH. Recent small studies have provided encouraging results but are potentially confounded and deserve confirmation in larger randomized controlled trials. In accordance with the current understanding of the biology of acute ischemic stroke and the pharmacology of UH, the new randomized controlled trials on heparin should give appropriate credit to the importance of a short therapeutic window, adequate dose adjustment of the drug, intravenous administration, and close monitoring of biological effects. UH is an orphan drug and only an academic driven trial would be able to face such an enterprise. Meanwhile, recommendations against the value of "early" anticoagulation with full dose of weight adjusted UH in the setting of acute ischemic stroke are not based on direct evidence but on extrapolations.
Chamorro
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Functional Unit of Cerebrovascular Diseases, Hospital Clínic, Barcelona, Spain. achamorro@ub.edu
D000208:Acute Disease; D000925:Anticoagulants / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy*; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D020521:Stroke / Q000188:drug therapy* / Q000453:epidemiology / Q000209:etiology; D013925:Thromboplastin / Q000502:physiology
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006493:Heparin; D013925:Thromboplastin