Portland, Ore. -- Researchers from the Oregon Stroke Center at Oregon Health Sciences University have always known that battling a stroke is a race against time. Now, two independent studies conducted through the Oregon Stroke Center Hospital Network show medical response time can dictate which treatment may offer the most promising outcome for a patient. Both studies will be printed in the Dec. 1 edition of The Journal of the American Medical Association.
The first study involves a drug known simply as t-PA, often considered the first line of defense by doctors. The drug is used to combat strokes caused by blood clots in the brain. It works to dissolve the clot, clearing the blockage. The drug has proved to improve stroke recovery if it is administered within three hours of a stroke. However, it was not known if t-PA also would work if given after three hours, until now.
Researchers used t-PA to treat more than 600 stroke patients at sites across North America, including 71 patients in Oregon. Patients were given either the drug or a placebo within three to five hours of having their stroke. In patients treated after three hours, researchers noted no benefit in terms of improved recovery when the patients were tested at three months; however, the drug did increase the chance of serious cranial bleeding. These results demonstrate that t-PA should not be used after three hours.
The second study, also to be published in the Dec. 1 issue of JAMA, offers hope for patients who are unable to get treatment within three hours of a stroke. In this situation, another form of therapy has shown promise. This treatment involves the direct application of a clot-busting drug called ProUrokinase to the blocked artery using a catheter. The procedure is called an angiogram. Once again, health centers across North America were involved in the trial, including OHSU and Portland Veterans Affairs Medical Center.