THURSDAY, March 4, 2004 (HealthDayNews) -- When it comes to stroke treatment, timing is everything.
A new study in the March 6 issue of The Lancet confirms what doctors who treat strokes already suspected -- faster treatment with the stroke medication called tissue plasminogen activator (tPA) leads to better outcomes.
However, the study also found treatment with tPA after the standard three-hour window could still help some patients.
Another study, in the same issue of the journal, found the cholesterol-lowering medications known as statins could reduce the risk of stroke by almost a third in people at high risk.
Each year, about 700,000 people in the United States have a stroke, and every three minutes someone dies from a stroke, according to the American Stroke Association. Symptoms that signal the need for immediate treatment include complete or partial paralysis, often on one side of the body; slurred speech or a change in language; loss of vision in one or both eyes; severe dizziness; numbness; or a severe unexplained headache, says Dr. Robert Felberg, stroke program director at the Ochsner Clinic Foundation Hospital in New Orleans.
"We found a dramatic difference in getting treated at 90 minutes or at three hours," says Dr. Gregory Albers, director of the Stanford Stroke Center at Stanford University School of Medicine and a co-author of the tPA study. "Someone having a stroke should be treated ASAP once they're in the emergency room, but we found that the benefits of tPA extend beyond three hours, though there's quite a bit of variability [in outcomes] once you get past the three-hour window."
For this study, researchers from Europe and the United States pooled data from six smaller randomized, placebo-controlled studies on tPA.
This combined analysis included 2,775 people who were treated for stroke at more than 300 hospitals in 18 countries. The average age of the study participants was 68, and most were white. All were treated within six hours with tPA or a placebo.
Those who were treated within 90 minutes after the onset of stroke symptoms were 2.8 times more likely to survive their stroke, compared to people who didn't receive the drug. People treated between 90 minutes and three hours were 1.55 times more likely to survive than those who didn't receive tPA, while those treated between three hours and four and a half hours had a 1.4 times greater chance of survival. After four and a half hours, the researchers didn't find any benefit from tPA treatment.
"Door-to-needle time is key to how likely someone is to recover from a stroke," says Albers, who adds it's important for treating physicians to realize they don't have three hours to evaluate and treat stroke patients. "The message here is to get the drug in as soon as you can. Less than an hour would be ideal," he says.
Felberg says one of this study's most interesting findings is there is still a benefit to treatment after three hours, particularly because so few people get to a hospital within the three-hour time window.
But, he says, this study also confirms that "the earlier you treat, the better you do. There's a pretty quick slope downwards for every 20 to 30 minutes."
In the second study, researchers from the Clinical Trial Service Unit in Oxford, England, focused on preventing stroke.
The researchers recruited more than 20,000 people at high risk of having a stroke and had them either take 40 milligrams daily of simvastatin or a placebo for five years.
During the study period, 4.3 percent of the people taking simvastatin had a stroke, compared to 5.7 percent from the placebo group. The authors say this represents a 30 percent reduction in risk for stroke for people on simvastatin.