Taking 160 mg to 325 mg of aspirin within two days of ischemic stroke offers a small but statistically significant” reduction in stroke death and disability. That’s according to a joint statement from the American Stroke Association, a division of the American Heart Association, and the American Academy of Neurology.
To define the roles of antiplatelets and anticoagulants in acute ischemic stroke, the Joint Stroke Guideline Development Committee searched the literature for large, well-designed, randomized, prospective studies on the topic. They found 310 worthy of full review, but only 10 met all inclusion criteria and formed the basis of the group’s recommendations.
While the benefits of aspirin within 48 hours of stroke onset are evident in these studies, the authors say, there is insufficient data to make recommendations on the use of other antiplatelet agents such as clopidogrel and ticlopidine.
As for the use of anticoagulants, there is no evidence that they reduce death or disability when administered within two days of stroke onset, the team reports. This result emphasizes the importance of reviewing all the evidence to develop practice guidelines, committee chairman Dr. Bruce Coull said in a statement. "Despite decades of use and physiologic reasons for its use, there were surprisingly few randomized trials that addressed the effects of heparin and other anticoagulants within a few hours of onset of symptoms."
"There is some evidence that a fixed dose of heparin given subcutaneously might be helpful for preventing recurrent stroke, but the benefit is balanced against the complication of increased hemorrhage, Dr. Coull said. "With the net effect, there is no benefit to that treatment."
Based on available data, it is recommended that subcutaneous heparin be considered to prevent deep-vein thrombosis (DVT) in some at-risk patients. "Presumably by giving heparin to prevent clotting in the veins, you decrease the likelihood that clots will travel to the lungs and cause a pulmonary embolism," the researcher from the University of Arizona in Tucson, said.
Dr. Coull hopes the statement will have a three-fold effect on clinical practice. First, in the absence of contraindications, all acute stroke patients will receive aspirin; second, that acute stroke patients will have the issue of DVT addressed; and third, that heparin will be used sparingly in this setting.
The new guidelines are published in the July issues of Stroke: Journal of the American Heart Association, and Neurology, the scientific journal of the American Academy of Neurology.