MONDAY, July 26 (HealthDay News) -- Extending the time window to
treat stroke patients with the clot-dissolving drug tPA from 3
hours to up to 4.5 hours after the onset of stroke doesn't result
in any significant delays in treatment and appears to be a safe
option for saving lives, new research suggests.
Still, there was a slight increased risk of death and bleeding
over a three-month period in patients who received the later
treatment -- a finding that reinforces the idea that the treatment
should be given as soon as possible after a stroke to ensure better
outcomes, said Swedish researchers reporting in the July 26 online
The Lancet Neurology.
"We're still targeting to treat as early as you can because that gets the best results," said Dr. Roger Bonomo, director of stroke care at Lenox Hill Hospital in New York City. "But this gets people included in the treatment group who otherwise would have been excluded just because it was 3 hours and 1 minute or 3 hours and 10 minutes after the stroke," he explained.
"The study is saying that the safety is sufficient to warrant continuing to treat patients [with tPA up to 4.5 hours after a stroke] even though these people have more symptomatic hemorrhages," he added.
Tissue plasminogen activator (tPA), also known as the drug
alteplase, is an approved treatment for the most common kind of
stroke -- ischemic stroke -- in which a blood vessel that supplies
blood to the brain is blocked by a blood clot. The three-hour
post-stroke time limit was set because of fears that use of the
clot-dissolving drug beyond that period might cause dangerous
bleeding or other complications.
After the publication of two landmark studies, the American
Heart Association, the American Stroke Association and the European
Stroke Association revised their guidelines in October 2008 to
recommend that tPA be used up to 4.5 hours after the onset of an
Since that time, the number of patients being treated this way
But despite the initial evidence, experts have been worried that
using the longer time window in actual practice might result in
unnecessary delays in treatment, an increase in the number of
intracerebral hemorrhages and still more deaths.
"There were lots of questions and interest in following up on the change in practice," Bonomo said.
The study authors, from the Karolinska Institute in Stockholm,
revisited data on 23,942 patients who had participated in a
clinical trial investigating the longer time window for using
By the end of 2009, three times more patients were being treated
in the later time period (3 hours to 4.5 hours) than before the
change but the average time from admission to treatment stayed the
same, at 65 minutes.
Patients treated in the outer time limit were 44 percent more
likely to suffer an intracerebral hemorrhage and 26 percent more
likely to die within three months. Still, the authors wrote, these
increases "are minor and are outweighed by the benefit of the
According to an accompanying "reflection and reaction" piece,
this elevated risk translated into one additional hemorrhage for
every 200 patients treated and one extra death for every 333
Alteplase is approved by the U.S. Food and Drug Administration
(FDA) and the European Medicines Agency only for use within the
three-hour limit. The accompanying editorial called for regulatory
approval to ensure all patients access to the treatment.
The trial was funded partially by Boehringer Ingelheim, which
The American Stroke Association has more on