Clotting agent improves stroke survival

Most strokes occur due to a blockage in the blood vessels that feed the brain, but some arise when these vessels rupture. Now, new research shows that survival from this latter type of bleeding or “hemorrhagic” stroke can be improved by treatment with an active form of factor VII, a clotting agent found in the body.

Treatment with activated factor VII shortly after the onset of Hemorrhagic stroke limits the size of the expanding blood clot, which, in turn, improves patient survival and functional outcomes.

“The take-home message for me is that everyone with a (Hemorrhagic stroke) should probably get” a clotting agent, Dr. Stephan A. Mayer, from Columbia University in New York, told AMN Health.

Mayer noted that there was a trend toward more side effects with factor VII than with inactive “placebo” treatment, but said that the benefits of such therapy greatly outweighed the risks.

The study was primarily designed to assess growth of the expanding blood clot, he explained, and “the fact that improvements in survival and functional outcomes were also seen is testimony to the magnitude of these benefits.”

The findings, which appear in The New England Journal of Medicine, come from a study of 399 patients who were diagnosed with Hemorrhagic stroke by CT scan within 3 hours of onset. The subjects were randomly selected to receive factor VII, at one of three doses, or placebo, beginning within 1 hour of the CT scan.

The average increase in blood clot size for the placebo group was 29 percent. By contrast, the increase in all of the factor VII groups fell below this amount, ranging from 11 percent for the highest-dose group to 16 percent for the lowest-dose group.

The rate of severe disability or death in the placebo group was 69 percent, whereas the rate in the factor VII groups never exceeded 55 percent. The death rate after 90 days in the placebo group was 29 percent, much higher than the 18 percent rate seen in the factor VII groups combined.

Seven percent of factor VII-treated patients experienced clotting-related side effects, such as heart attack, compared with 2 percent of those who received placebo, the investigators point out.

Mayer said his team is currently conducting another trial that hopefully will provide the confirmatory data needed for regulators to approve factor VII as a treatment for Hemorrhagic stroke.

In a related editorial, Dr. Devin L. Brown and Dr. Lewis B. Morgenstern, from the University of Michigan in Ann Arbor, comment that “this is a very exciting time in the study of (Hemorrhagic stroke). It is possible that we are on the brink of having a successful targeted treatment in factor VII; only time and more investigation will tell.”

The study was supported by Novo Nordisk, Denmark, which markets factor VII under the trade name NovoSeven.

SOURCE: The New England Journal of Medicine, February 24, 2005.

Provided by ArmMed Media
Revision date: July 6, 2011
Last revised: by Andrew G. Epstein, M.D.