Window for Stroke Treatment Opens Wider

May 29 -- THURSDAY, May 28 (HealthDay News) -- A new analysis showing that a potent clot-dissolving drug can safely be used to treat strokes four-and-a-half hours after symptoms begin has prompted a change in a current recommendation, which set a three-hour deadline for the medication's use.

The review of 1,622 cases of people treated with tissue plasminogen activator (tPA) in four separate studies finds that the benefit in keeping brain cells alive outweighs the risk of brain-damaging bleeding when the drug is given up to 4.5 hours after first symptoms, according to a report in the May 28 online issue of Stroke. The most convincing results came from the latest study, in which 821 people were treated later than is currently recommended.

"By pooling data from four prior clinical trials in which patients were treated with tPA between three and four-and-a-half hours, we were able to demonstrate that treatment with tPA is beneficial even if it is started between three and four-and-a-half hours of symptom onset," said study author Dr. Maarten Lansberg, an assistant professor of neurology and neurological sciences at Stanford University.

An advisory committee of the American Stroke Association/American Heart Association (ASA/AHA) promptly issued a recommendation that the window for tPA therapy be opened that much wider; that advisory appears in the same issue of Stroke.

"The advisory updates the current guidelines to recommend treatment in select patients in the three- to four-and-a-half hour window, but urges confirmation of the trial's results with further analyses," according to a statement issued by the ASA/AHA.

"In practical terms, wide adoption of the recommendation would mean that 2 percent to 3 percent more people who suffer strokes caused by blockage of a brain artery would receive tPA therapy," said Dr. Jeffrey L. Saver, a professor of neurology at the University of California, Los Angeles, and a member of the advisory committee.

That might not seem a great leap forward, but Saver noted that "right now, at well-performing hospitals, 5 to 10 percent of stroke patients are treated in under three hours."