An Introduction to Heparin

What is Heparin?

• Heterogeneous collection of straight chain anionic sulfated mucopolysaccharides usually obtained from animal lung or intestine
• Potentiates activity of antithrombin III - an endogenous inhibitor of coagulation factors IIa, IXa and Xa
• Binds to platelets and plasma proteins

Heparinoids and Low Molecular Weight Heparinseparin

Pharmacological

• Reduced anti-IIa effect, primary effect on Xa
• Reduced platelet interaction
• Reduced plasma protein binding

Clinical

• Assay activity as anti-Xa units
• Longer  half-life
• Reduced bleeding

Intravenous Heparin for Partial Stable Stroke

• 225 patients with acute ischemic stroke and partial motor deficits
• Onset within 48 hours
• Exclusions:
  • Progression within 1 hour
  • Diastolic BP > 110
  • Cardiac source

Progression at 7 days

• Heparin - 19/112 (17%)
• Placebo - 22/113 (19.5%)
• p=.62 - 95% CI -8.7 to +13.7%
  • No difference in number improved, overall functional status or death

Late Results

• Three months
  • No difference in functional activity level
• One year
  • Higher mortality in heparin group (p<.01)
  • No difference in functional activity level

Source: Ann Internal Med 1986: 105:825-828

 

This presentation was written by Dr. William J. Powers, co-director of the Stroke Center at Barnes-Jewish Hospital and the Washington University School of Medicine.

Last Revised: March 26, 2001