Researchers Say tPA Not Given for Mild Strokes Because of Bleeding Risk
By Charlene Laino
WebMD Health News
Reviewed by Laura J. Martin, MD
Latest Neurology News
Feb. 10, 2011 (Los Angeles) -- Giving clot-busting drugs to people with mild strokes could prevent more than 2,000 of them from becoming disabled each year, researchers say.
A stroke occurs when a clot cuts off blood flow to parts of the brain. Those parts of the brain soon start to die. A drug called tissue plasminogen activator (tPA) dissolves clots and restores blood flow.
Mild strokes -- characterized by such symptoms as clumsiness in the hand, weakness of an extremity, some slurred speech, temporary loss of vision, and/or dizziness -- account for more than half of strokes in the U.S.
But people with mild strokes are typically denied tPA because the studies that established its effectiveness excluded mild cases, says Pooja Khatri, MD, of the University of Cincinnati.
It's been assumed that people with mild strokes "generally [do] well and the risk of tPA treatment, which includes a slight but significant risk of life-threatening bleeding in the brain, would not be worth the benefit," she says.
In fact, one in three people who suffer a mild stroke are disabled three months later, Khatri says.
Khatri and colleagues analyzed hospital records from 441 patients diagnosed with mild stroke in the Greater Cincinnati/Northern Kentucky region in 2005. All arrived at the hospital within three and a half hours of symptom onset, when tPA works best.
Of the total, 251 were considered to have mild strokes, with a score of 5 or less on the 42-point National Institutes of Health Stroke Scale.
Only four patients (1%) were given tPA. But 150 (62%) of the remaining patients would have been candidates for the drug if the mildness of their stroke had been disregarded as a reason to deny them tPA treatment.
If these figures were extrapolated to the entire nation, over 43,000 people with mild strokes would be eligible for tPA each year, Khatri says. Assuming tPA is as effective as suggested by previous research, this means 2,176 to 3,761 fewer patients would be disabled from mild stroke each year -- saving the health care system an estimated $200 million annually, she says.
The findings were presented at the American Stroke Association International Stroke Conference (ISC).
Steven Greenberg, MD, PhD, vice chair of the ISC meeting committee and professor of neurology at Harvard Medical School, tells WebMD that the findings underscore the need to take mild stroke seriously.
"It would be hard to find patients who consider a mild stroke unimportant. It's not mild to them," he says. "You can almost argue there is no such thing as a mild stroke."
The drug tPA isn't without risks, chiefly brain bleeding. But studies suggest people with mild stroke are less likely to have bleeding than those with the more severe strokes for which it is routinely used, Khatri says.
The drug costs about $2,000, but studies suggest it is more cost-effective to treat patients with tPA compared to the later costs related to a disability, says Philip B. Gorelick, MD, MPH, head of neurology and stoke research at the University of Illinois in Chicago.
Still, further study of tPA in mild stroke is needed, Khatri says. A large study for people with mild strokes that aren't clearly disabling is planned, she says.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES: American Stroke Association International Stroke Conference 2011, Los Angeles, Feb. 7-11, 2011.Pooja Khatri, MD, associate professor of neurology; director of acute stroke, University of Cincinnati Academic Health Center.Steven Greenberg, MD, PhD, vice chair, ISC meeting committee; professor of neurology, Harvard Medical School.Philip B. Gorelick, MD, MPH, head of neurology and stoke research, University of Illinois, Chicago.
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