http://www.theheart.org/article/1502141.do?utm_medium=email&utm_source=20130208_topStories&utm_campaign=newsletter
The American Heart Association (AHA)/American Stroke Association (ASA) has released new guidelines on the early management of acute ischemic stroke [1].
The document is published online January 31, 2013. The American Academy of Neurology "affirms the value of this guideline as an educational tool for neurologists," and it is further endorsed by the American Association of Neurological Surgeons and the Congress of Neurological Surgeons.
"There's no revolutionary change in these guidelines for us, considering what we published back in 2007," lead author Dr Edward Jauch
(Medical University of South Carolina, Charleston) said in an
interview. "It's more of an evolutionary change, and it solidifies our
understanding of several factors," he said.
Stroke systems
Primary among these is the importance of stroke systems of care, modeled on a page taken from the treatment of MI.
"We've taken a similar approach to stroke
systems of care, by first off, defining stroke capabilities now at four
levels of hospitals," Jauch said. These include comprehensive stroke
centers, now eligible for Joint Commission certification, that
offer 24/7 specialized treatment for all stroke types; primary stroke
centers that also provide around-the-clock care mainly for ischemic
stroke, a ranking that has been established for about six years now;
acute stroke-ready hospitals that can evaluate and treat most strokes
but without specialized capabilities; and community hospitals.
The establishment of these acute stroke-ready
hospitals is based on current experience with telemedicine, Jauch said,
"and that actually has had a large impact in the past decade or less,
where hospitals that would never have a neurologist available or have
one only on a part-time basis now have access to stroke expertise using
the telemedicine system. With the experience we've garnered in the past
five or 10 years, we know these systems can be put in place and can
deliver a quality of care that is comparable to the patient [being
treated] in a primary stroke center," at least for the provision of
thrombolysis.
Some hospitals with telemedicine will be able
to keep the patient in their own stroke unit; others will not, he added,
"but at least they have elevated their acute assessment capabilities
for thrombolysis candidates by having a telemedicine collaboration with
typically a comprehensive stroke center."
The guidelines recommend use of teleradiology systems to support decision making about whether or not to use fibrinolysis.
For patients with hemorrhagic stroke, there
are data now supporting use of neurosurgical procedures such as
decompressive surgery to address malignant edema of the cerebral
hemisphere. "We know that that's a decision that requires a
neurosurgeon, so the goal is, if you think this is necessary, this is
where your systems of care come in," Jauch said. "We've increased the
class and level of evidence for those procedures."
Shorter door-to-needle time, longer window
Another addition to the previous 2007 guideline is incorporation of the 2009 scientific advisory
that recommended the use of tissue plasminogen activator (tPA) in
selected patients presenting within three to 4.5 hours of symptom onset,
based largely on the findings from the ECASS 3 trial.
"That's the first time that's been included in
the guideline as a recommendation," Jauch noted. "That's despite the
fact that the Food and Drug Administration [FDA] has declined to
extend the label. So it's an off-label use of tPA from three to 4.5
hours, but the authors feel it still has merit to consider in the
appropriately selected patients.
"That's an important one, because you always
get a little concerned when the FDA declines to extend the label for
various reasons, but we were able to go back and talk to the parties
involved and find out a little bit more about how the decision was made,
and after that discussion we feel comfortable with our recommendation."
Another new recommendation notes that in
patients eligible for thrombolysis, door-to-needle times should be
within 60 minutes of hospital arrival (class I, level of evidence A).
Intra-arterial thrombolysis
Several new stent retriever devices have now received FDA approval, including the Solitaire FR (ev3 Endovascular, Plymouth, MN) and Trevo (Stryker, Kalamazoo, MI) devices, in addition to Merci (Concentric Medical/Stryker) and Penumbra Systems (Alameda,
CA) coil retrievers. However, data are available suggesting that the
stent retrievers achieve recanalization more rapidly at least than the
Merci devices does and are therefore preferred (class I, level of
evidence A). Data comparing these retrievers with the Penumbra system
are not yet available.
"We always believe that time is brain and
faster is better, so it's one of the things we need to continue to look
at," Jauch said. "The big question is, regardless of which device you
use, is there a benefit to going to the cath lab? So we'll have data
presented next week from the International Stroke Conference
looking at mechanical embolectomy with or without intravenous tPA, and
we'll get a lot more guidance on when and in whom we use these devices.
"They're still worth considering, but we think
they need additional evaluation to really look at their clinical
efficacy when we compare it with say, standard therapy like IV tPA," he
said.
High on the list of these is Randomized Trial of Neuroimaging Selection for Mechanical Embolectomy versus Standard Care for Acute Ischemic Stroke (MR RESCUE) that is examining not only mechanical embolectomy, but also use of perfusion-based imaging to select patients.
Another, the long-anticipated Interventional Management of Stroke 3 (IMS 3) trial, will be presented by principal investigator Dr Joseph P Broderick (University of Cincinnati, OH) at a session dedicated just to this trial.
IMS 3 was a phase 3, randomized but open-label
trial to determine whether a combined intravenous and intra-arterial
approach to stroke treatment is superior to intravenous tPA alone. As
reported previously, the trial was halted in April 2012
when a preplanned interim analysis showed "a low likelihood of
demonstrating the prespecified clinically significant difference in
benefit between treatment arms of the study," according to a statement
from the National Institute of Neurological Disorders and Stroke (NINDS) at that time.
The data and safety monitoring board's
decision was based on the primary outcome of the trial, the modified
Rankin Score at three months, "meeting the threshold for futility," the
statement added. "While enrollment was stopped because of futility, no
serious safety concerns were identified."
In the meantime, the guideline authors did
"hedge" their conclusion, pointing out these data are on the cusp of
being presented and their recommendations may need revision in light of
any new information, he noted. They support use of these devices in
patients who have failed intravenous tPA, although more data are needed
on outcomes with this approach. There is some indication from recent
data that clot size and location are important predictors of patients
who may or may not benefit from rescue therapy, Jauch said.
They continue to support use of intra-arterial tPA, although they note the best dose is not yet known.
Other data are expected to be presented this spring, Jauch added, including SYNTHESIS EXP and the ALIAS and FAST-MAG neuroprotective studies.
"So it's going to be an exciting and maybe
humbling spring when all these trials that are either finished and/or
were stopped are reported, and we'll be able to take a step back and say
now that we have this additional experience, what's the next step,
where do we go from here to further evaluation of stroke therapies, and
most important, how do you tailor the therapies on a more individual
basis, rather than trying to find one size that fits all?"
No comments:
Post a Comment