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Antithrombotics in Acute Ischemic Stroke: Practice Survey and New Guidelines

A recent survey finds that, in treating acute ischemic stroke, many factors affect physicians' decision to use antithrombotics. New guidelines should help physicians make this decision.

The question "Do the data matter?" seems almost heretical in this day of evidence-based medicine and randomized prospective trials. But the survey by Al-Sadat and colleagues demonstrates that the data are not the only factors influencing neurologists' decisions about the use of heparin for acute stroke. Neurologists in the U.S. and Canada were mailed surveys presenting 5 acute-stroke scenarios and asking whether the neurologist would treat with intravenous (IV) heparin and whether medicolegal factors influence such decisions in clinical practice.

More than 80% of the 250 respondents indicated that they would use IV heparin in the setting of atrial fibrillation, even though clinical studies provide no evidence for a net benefit from this practice. Compared with their Canadian counterparts, U.S. neurologists were more often inclined to treat with heparin in all 5 scenarios. Perhaps contributing to this difference, more U.S. neurologists also reported that such decisions were influenced by concern that failure to do so might expose them to litigation.

On these points and others, evidence-based recommendations on anticoagulants and antiplatelet agents in acute ischemic stroke, prepared jointly by expert panels from the AAN and the AHA, should be extremely helpful. The guidelines include recommendations such as these: (1) "Dose-adjusted, unfractionated heparin is not recommended for reducing morbidity, mortality, or early recurrent stroke in patients with acute stroke (i.e., in the first 48 hours) because the evidence indicates it is not efficacious and may be associated with increased bleeding complications . . ."; and (2) "Patients with acute ischemic stroke presenting within 48 hours of symptom onset should be given aspirin (160 to 325 mg/day) to reduce stroke mortality and decrease morbidity, providing contraindications . . .are absent, and the patient has or will not be treated with tissue-type plasminogen activator."

Comment: These guidelines should substantially advance standardization of acute-stroke treatment, but undoubtedly they will not be the final word. Lack of evidence does not prove lack of efficacy, and it remains possible that heparin might benefit certain subgroups of patients with high risk for recurrence of acute stroke. In addition, the prospective clinical trials are dominated by use of heparinoids and fixed-dose subcutaneous heparin, rather than the dose-adjusted, unfractionated IV heparin that is commonly used in North America. Nevertheless, this clearly written summary and evaluation of the clinical data should greatly increase the impact of such trials on neurologists' clinical practice.

— Raymond A. Swanson, MD

Dr. Swanson is Associate Professor of Neurology, Veterans Affairs Medical Center and University of California, San Francisco.

Published in Journal Watch Neurology September 6, 2002

Citation(s):

Al-Sadat A et al. Use of intravenous heparin by North American neurologists: Do the data matter? Stroke 2002 Jun; 33:1574-7.

• Original article (Subscription may be required)
• Medline abstract (Free)

Coull BM et al. Anticoagulants and antiplatelet agents in acute ischemic stroke: Report of the Joint Stroke Guideline Development Committee of the American Academy of Neurology and the American Stroke Association (a division of the American Heart Association). Neurology 2002 Jul 9; 59:13-22.

• Original article (Subscription may be required)
• Medline abstract (Free)