Low-molecular-weight heparins or heparinoids versus standard unfractionated heparin for acute ischaemic stroke.
BACKGROUND
Low-molecular-weight heparins and heparinoids are anticoagulants that may be associated with lower risks of haemorrhage and more powerful antithrombotic effects than standard unfractionated heparin. This is an updated version of the original Cochrane review first published in Issue 1, 1995 and previously updated in Issue 2, 2005.


OBJECTIVE
To compare the effects of low-molecular-weight heparins or heparinoids with those of unfractionated heparin in people with acute, confirmed or presumed, ischaemic stroke.


METHODS
We searched the Cochrane Stroke Group Trials Register (last searched June 2007). In addition we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2007), MEDLINE (1966 to June 2007) and EMBASE (1980 to June 2007). For previous versions of this review we searched MedStrategy (1995) and also contacted pharmaceutical companies.


METHODS
Randomised trials comparing heparinoids or low-molecular-weight heparins with standard unfractionated heparin in people with acute ischaemic stroke. We only included trials where treatment was started within 14 days of stroke onset.


METHODS
Two review authors independently selected studies for inclusion, assessed trial quality and extracted the data.


RESULTS
Nine trials involving 3137 people were included. Four trials compared a heparinoid (danaparoid), four trials compared low-molecular-weight heparin (enoxaparin or certoparin), and one trial compared an unspecified low-molecular-weight heparin with standard unfractionated heparin. Allocation to low-molecular-weight heparin or heparinoid was associated with a significant reduction in the odds of deep vein thrombosis compared with standard unfractionated heparin (odds ratio (OR) 0.55, 95% confidence interval (CI) 0.44 to 0.70). However, the number of more major events (pulmonary embolism, death, intracranial or extracranial haemorrhage) was too small to provide a reliable estimate of the benefits and risks of low-molecular-weight heparins or heparinoids compared with standard unfractionated heparin for these, arguably more important, outcomes. Insufficient information was available to assess effects on recurrent stroke or functional outcome.


CONCLUSIONS
Since the last version of this review none of the three new relevant studies with 2397 participants have provided additional information to change the conclusions. Treatment with a low-molecular-weight heparin or heparinoid after acute ischaemic stroke appears to decrease the occurrence of deep vein thrombosis compared with standard unfractionated heparin, but there are too few data to provide reliable information on their effects on other important outcomes, including death and intracranial haemorrhage.
Sandercock
Peter A G
PA
Department of Clinical Neurosciences, University of Edinburgh, Neurosciences Trials Unit, Bramwell Dott Building, Western General Hospital, Crewe Road, Edinburgh, UK, EH4 2XU. peter.sandercock@ed.ac.uk
Counsell
Carl
C
Tseng
Mei-Chiun
MC
D000925:Anticoagulants / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000188:drug therapy; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006493:Heparin / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006496:Heparinoids / Q000627:therapeutic use*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000188:drug therapy*
D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D006496:Heparinoids; D006493:Heparin