Clot-buster more likely to work in women-study

By Megan Rauscher

NEW YORK (Reuters Health) – Women suffering a sudden
“ischemic” stroke caused by a blood clot in the brain are more
likely than men to be helped from treatment with a commonly
used clot-buster called tPA (tissue plasminogen activator), a
study has shown.

Past studies have shown that women are less likely to
receive tPA than men and that women, in general, have a worse
outcome after stroke than men. “Our study,” Dr. Magdy Selim
said, “suggests that women should be treated as they may
respond better to this treatment.”

Ischemic stroke, the most common type, occurs when a clot
or blocked artery cuts off blood flow to the brain.
Clot-busters such as tPA, if given intravenously within 3 hours
of the start of a stroke, can reduce or even prevent the
long-term complications of an ischemic stroke.

Among 22 men and 17 women with this type of stroke who
received early intravenous tPA in the current study, blood flow
was restored in 94 percent of the women compared with just 59
percent of the men, investigators report in Stroke: Journal of
the American Heart Association.

The superior response to tPA seen in women held up in
analyzes adjusted for potentially confounding factors, Selim,
from Beth Israel Deaconess Medical Center in Boston, and
colleagues note in the paper.

“This is the first study to show a biological difference in
response to tPA between men and women,” Selim told Reuters
Health. “This could be due to anatomical, hormonal or chemical
differences between the sexes, which we will be investigating.”

The findings, if confirmed in larger studies, could prompt
changes in the way this type of stroke is treated in men, the
researcher added. It may result in using higher doses of tPA or
encouraging a more aggressive treatment in men, Selim
explained.

SOURCE: Stroke July 2005.