February 7, 2000
Volume 52, No. 20
New drug widens stroke treatment window
By Holly Korschun
Unlike other promising treatments for acute stroke that improve recovery only if administered within three hours of symptom onset, a report in the Dec. 1 issue of the Journal of the American Medical Association (JAMA) describes a treatment that offers significant long-term benefits if administered up to six hours after symptom onset.
A team of investigators from Emory and elsewhere collaborated on the Prouro-kinase for Acute Cerebral Thromboembolism (Proact II) trial to determine if an experimental drug--recombinant prourokinase (r-proUK)--improved the outcome of patients experiencing a certain type of stroke. The principal investigator was Anthony Furlan of the Cleveland Clinic Foundation.
"As compared with patients receiving low dose, intravenous heparin [a blood thinner] only, patients with ischemic stroke treated with r-proUK plus low-dose heparin a median of 5.3 hours from onset were 58 percent more likely to have slight or no neurological disability at 90 days," the authors reported.
The multisite team evaluated 180 patients who either received r-proUK plus heparin or heparin alone. Five study subjects were enrolled by Emory investigators at Grady Hospital, and two others were enrolled at Emory Hospital.
The Emory team was led by Michael Frankel, associate professor of neurology and chief of neurology at Grady. Randomized patients received the r-proUK via microcatheter-based "injections" made directly into the artery that supplies blood to each half of the brain.
"The group of patients treated in the study had the most severe types of strokes-the kind that almost always have a poor prognosis," Frankel said. "Overall, the impact of this new therapy was remarkable.
Many patients recovered completely or had minor disabilites from what would have been devastating brain injuries."
Other key members of the Emory team include Sharon Sailor, Owen Samuels, Greg Joseph, David Owens, Barney Stern, Janet Braimah, Marc Chimowitz and Harriet Howlett-Smith.
Until now, the only medication shown to be effective and approved by the Food and Drug Administration for acute ischemic stroke is a clot buster called tissue plasminogen activator, given intravenously within three hours of symptom onset.
According to Frankel, "The Proact study is the first to clearly show that we can successfully intervene within six hours from the onset of stroke symptoms by using direct delivery of a clot buster."
Stroke--or brain attack--occurs when parts of the brain become starved for blood. Ischemic stroke, which accounts for 85 percent of strokes, occurs when a blood vessel in the brain becomes blocked, and hemorrhagic stroke is caused by a ruptured blood vessel in the brain.
The May 1999 issue of Georgia Epidemiology Report states: