急性腦中風的新指引

New AHA/ASA
Guidelines for Acute Stroke Treatment

Susan Jeffrey

Jan 31, 2013

The American Heart Association/American Stroke Association
has released new guidelines on the early management of acute ischemic stroke.

The document is published online January 31 and will appear in the March issue
of Stroke. 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," Edward Jauch, MD, lead
author of the guidelines and director of the Division of Emergency Medicine at
the Medical University of South Carolina, Charleston, told Medscape Medical
News.

"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 myocardial infarction by
cardiologists.

"We've taken a similar approach to stroke systems of
care, by first off, defining stroke capabilities now at 4 levels of
hospitals," Dr. 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 6 years now; acute stroke-ready hospitals, which 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, Dr. Jauch said, "and that
actually has had a large impact in the last decade or less, where hospitals
that would never have a neurologist available, or have one only on a part-time
basis now has access to stroke expertise using the telemedicine system. With
the experience we've garnered in the last 5 or 10 years, we know these systems
a) can be put in place, and b) can deliver a quality of care that is comparable
to if the patient had been 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, whereas 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 to use fibrinolysis.

For patients with hemorrhagic stroke, data now support 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," he said. "We've increased the
class and level of evidence for those procedures."

Shorter Door-to-Needle, Longer Window

Another addition to the previous 2007 guideline is
incorporation of the 2009 Scientific Advisory that recommended the use of tissue
plasminogen activator (t-PA) in selected patients presenting within 3 to 4.5
hours of symptom onset, largely on the basis of the findings from the third
European Cooperative Acute Stroke Study (ECASS 3) trial.

"That's the first time that's been included in the
guideline as a recommendation," Dr. 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 t-PA from 3 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).

Intraarterial Thrombolysis

Several new stent retriever devices have now received FDA
approval, including the Solitaire FR and Trevo devices, in addition to Merci
and PenumbraSystem coil retrievers. However, available data suggest that the
stent retrievers achieve recanalization more rapidly, at least to the Merci,
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," Dr.
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 to say, standard therapy like IV t-PA," 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), which is examining not only mechanical
embolectomy but also use of perfusion-based imaging to select patients.

Another, the long-anticipated Interventional Management of
Stroke III (IMS-III) trial, will be presented by principal investigator Joseph
P. Broderick, MD, from the University of Cincinnati, Ohio, at a session
dedicated just to this trial.

IMS III was a phase 3, randomized, open-label trial
assessing whether a combined intravenous and intraarterial approach to stroke
treatment was superior to intravenous tPA alone. As reported
previously by Medscape Medical News, the trial was halted in
April 2012 when a preplanned interim analysis showed "a low likelihood of
demonstrating the pre-specified clinically significant difference in benefit
between treatment arms of the study," according to a statement from the National Institute of Neurological
Disorders and Stroke 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 3 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 in whom intravenous tPA
has failed, although more data are needed on outcomes with this approach.
Recent data indicate that clot size and location are important predictors of
patients who may or may not benefit from rescue therapy, Dr. Jauch said.

They continue to support use of intraarterial tPA, although
they note the best dose is not yet known.

Other data are expected to be presented this spring, Dr.
Jauch added, including SYNTHESIS-EXP(Intra-arterial versus Systemic
Thrombolysis for Acute Ischemic Stroke) and the ALIAS (Albumin in Acute
Ischemic Stroke) and FAST-MAG (Field Administration of Stroke
Therapy-Magnesium) 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 evaluate stroke therapies and most importantly, how do you tailor the
therapies on a more individual basis, rather than trying to find a one size
that fits all."

The American Heart Association/American Stroke Association
receives funding mostly from individuals. Foundations and corporations donate
as well and fund specific programs and events. Strict policies are enforced to
prevent these relationships from influencing the association's science content.
Financial information for the American Heart Association, including a list of
contributions from pharmaceutical companies and device manufacturers, is
available at www.heart.org/corporatefunding.

Stroke. Published
online January 31, 2013. Abstract

Medscape
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