Patients who arrived at specific hospitals within an hour of experiencing stroke symptoms received a powerful clot-busting drug twice as often as those who arrived later in the approved time window for treatment, according to a new UCLA study presented today at the American Stroke Association’s International Stroke Conference 2009.

Among the more than 100,000 patients treated at hospitals participating in the American Heart Association’s Get With the Guidelines–Stroke (GWTG–Stroke) quality improvement program, 27.1 percent who arrived within the “golden hour” — the hour following the onset of symptoms — were treated with the clot-busting drug known as tissue plasminogen activator (tPA). Of those who arrived between one and three hours of symptom onset, 12.9 percent received the drug.

“The treatment rate among under-one-hour-arriving patients is good news for Get With the Guidelines hospitals,” said lead author Dr. Jeffrey L. Saver, professor of neurology and director of the UCLA Stroke Center at Ronald Reagan UCLA Medical Center. “Prior studies have suggested that 25 to 30 percent of early-arriving patients are fully eligible for clot-busting drug treatment, and Get With the Guidelines–Stroke hospitals are delivering the therapy to virtually all these individuals.”

The drug is the only approved acute stroke treatment for clot-related, or ischemic, stroke and has been shown to reduce stroke-related disability. However, it is only approved for use within three hours of symptom onset.

Recently, the European Cooperative Acute Stroke Study suggested that tPA was safe and effective up to 4.5 hours after symptom onset for some patients, but the current research reinforces the importance of quick action by patients and physicians.

“These findings support public education efforts to increase the proportion of patients arriving within the first 30 to 60 minutes after stroke onset,” Saver said. “Little has been known about how frequently patients arrive at a hospital within the golden hour or how often hospitals meet the guidelines for beginning tPA infusion within 60 minutes after hospital arrival.”

Researchers reviewed the records of 106,924 ischemic stroke patients treated during a four-plus-year period at 905 GWTG–Stroke hospitals.

The analysis found that:
• 28.3 percent of patients arrived within 60 minutes of symptom onset.
• 31.7 percent arrived one to three hours after symptoms started.
• 40.1 percent arrived more than three hours after symptoms started.

“That more than one-quarter of ischemic stroke patients arrived within the golden hour is a very encouraging finding, because in stroke, time lost is brain lost,” Saver said. “However, more than 70 percent arrived beyond the golden hour, when larger amounts of brain damage have occurred and our chance to reverse damage is much reduced. We have a great deal of additional work to do in educating the public and stroke center staffs. For every minute in which blood flow is not restored, nearly 2 million additional nerve cells die.”

Researchers said golden-hour patients showed significantly more stroke deficits than later arrivals, suggesting that more intense symptoms propelled them to seek medical attention early.

But early and late arrivals were about the same age and were split almost evenly among men and women in each category. African Americans were less often early arrivals: Only 11.8 percent arrived within one hour, and 11.9 percent arrived within three hours.

Once at the hospital, however, the time-to-treatment for golden-hour patients averaged nearly 15 minutes longer than for patients who arrived one to three hours after symptom onset. Hospital-performance improvement activities are needed to shorten the arrival-to-treatment initiation time for patients who arrive within the golden hour, researchers said.

Before stroke treatment can begin, patients must undergo numerous tests, including a brain scan to ensure the stroke’s cause is a blocked artery and not a hemorrhaging blood vessel.

“There are a huge number of reasons for waiting, but they are all trumped by the fact that the longer you wait, the more brain dies,” Saver said. “We need to overcome the natural tendency to relax in the early-arriving patient and to think there is some extra time.”

Additional co-authors included Dr. Lee Schwamm; Dr. Eric E. Smith; Adrian Hernandez, Ph.D.; Dai Wai Olson, Ph.D.; and Xin Zhao, Ph.D.

The American Heart Association funded the study.

UCLA holds intellectual property rights in the Merci Retriever. Saver has served as an unpaid investigator in the National Institutes of Health CLEAR and IMS 3 trials and as a scientific consultant to CoAxia, Talecris and Boehringer Ingelheim. He has received research catheters from Concentric Medical. Other individual author disclosures can be found in the study’s abstract.

The UCLA Stroke Center, recognized as one of the world’s leading centers for the management of cerebral vascular disease, treats simple and complex vascular disorders by incorporating recent developments in emergency medicine, stroke neurology, microneurosurgery, interventional neuroradiology, stereotactic radiology, neurointensive care, neuroanesthesiology and rehabilitation neurology. The program is unique in its ability to integrate clinical and research activities across multiple disciplines and leading departments. A center without walls, the UCLA Stroke Center was founded in 1994.

Source: University of California, Los Angeles (UCLA), Health Sciences