Stroke, Death, and TIA Rates Significantly Reduced With Closed-Cell Carotid Stents

Stroke, Death, and TIA Rates Significantly Reduced With Closed-Cell Carotid Stents

May 22, 2007

Data From Multicentre Registry Show Significant Benefit
With Closed-Cell Stents in the Treatment of Carotid Artery
Stenosis

    PARIS, May 22 /Xinhua-PRNewswire/ -- Boston Scientific
Corporation (NYSE: BSX) welcomed results from a large
independent registry confirming the benefit of closed-cell
stents in patients with carotid artery stenosis. The
results, published in the February 2007 issue of the
European Journal of Vascular and Endovascular Surgery, show
that symptomatic patients treated with closed-cell stents
had significantly fewer complications after the stent was
implanted than patients who received open-cell stents. In
particular, the Carotid WALLSTENT(TM) was used in 66% of
patients in the registry and had the lowest 30-day
post-procedural event rate of 1.2% in symptomatic
patients.(1) 

    The 3,179 patients with carotid artery stenosis
(narrowing of the arteries in the neck supplying blood to
the brain) included in the registry experienced
significantly fewer strokes, deaths or transient ischaemic
attacks (TIA) within 30 days of the procedure if they
received a closed-cell stent (P = 0.002). These stents
cover more of the artery wall than open-cell stents because
they have overlapping or fully connecting struts, and have
less space between struts (a smaller free cell area). A
free cell area of less than 2.5 mm(2) was associated with a
post-procedural complication rate of 1.2%, compared with
3.4% for a free cell area of more than 7.5 mm(2) (P =
0.006).(1)

    The differences were even greater in patients with
symptomatic disease who had already suffered a TIA or
stroke and were at higher risk of having another event. In
these patients, the post-procedural event rate was 1.3% for
closed-cell stents (< 5 mm(2) free cell area), compared
with 6.3% for open-cell stents (> 5 mm(2) free cell
area) (P < 0.0001).(1) The post-procedural rates for
free cell areas of < 2.5 mm(2) and > 7.5 mm(2) were
1.2% and 7.0%, respectively (P < 0.0001).(1)

    Lead investigator Dr. Marc Bosiers, from the Department
of Vascular Surgery, St Blasius Academic Hospital,
Dendermonde, Belgium, explains the importance of these
results: "After carotid angioplasty and stenting,
patients are at risk for post-procedural complications
within 30 days of the procedure. Closed-cell stents, with
their smaller free cell area, provide better scaffolding
and lesion coverage and were shown to reduce
post-procedural adverse events in our study. In the
symptomatic population, late complication rates were
highest for the open-cell stents and increased with larger
free cell area. For the time being, consideration should be
given to the use of stents with a small free cell area,
especially in symptomatic patients."

    About 4-8% of the population has advanced carotid
artery disease,(2) Which puts them at high risk of a TIA or
stroke. TIAs involve stroke symptoms lasting only a few
minutes or hours and provide an important clinical
indicator for potential future stroke, with 10-20% of
sufferers having a full-blown stroke within a month.(3)
Approximately one-third of people who have had a stroke die
within a month and one-third are left with disabilities.(4)

    Carotid artery stenting is a minimally invasive
procedure in which a stent is delivered to the site of the
blockage and expanded to open the carotid artery and
restore blood flow. Stents are tiny wire mesh tubes that
are inserted into arteries to help keep the vessel open and
therefore maintain blood flow. Closed-cell stents, such as
the Carotid Wallstent(TM) and the NexStent(TM) Carotid
Stent, have overlapping or fully connecting struts, so they
have less free cell area and cover 5-10 times more of the
artery wall than open-cell stents.

    The registry recorded outcomes from carotid stenting
using a range of closed- and open-cell stent devices at
four centres in Belgium and Italy. The closed-cell stents
included the Carotid WALLSTENT(TM) (1.08 mm(2) free cell
area), Xact(R) (2.74 mm(2)) and NexStent(TM) (4.07 mm(2)).
The open-cell stents included Precise(R) (5.89 mm(2)),
Exponent(R) (6.51 mm(2)), Protege(R) (10.71 mm(2)) and
Acculink(R) (11.48 mm(2)).(x) The Carotid WALLSTENT(TM) was
the most frequently used stent and was placed in 2,107 of
the 3,179 patients.(1)

    "As a leader in the field of cardiovascular device
technology, Boston Scientific is delighted that this
independent registry confirms the value of closed-cell
stents, such as the Carotid WALLSTENT(TM) or the
NexStent(TM), which provide excellent scaffolding and
lesion coverage," said Jeff Goodman, President of
Boston Scientific International. "Our Carotid stents
offer a triple combination of benefits for the patient:
optimal scaffolding, cell design and radial force."

    Boston Scientific Corporation is a worldwide developer,
manufacturer and marketer of medical devices whose products
are used in a broad range of interventional medical
specialties. For more information, please visit
http://www.bostonscientific.com .

    This press release contains forward-looking statements.
Boston Scientific wishes to caution the reader of this press
release that actual results may differ from those discussed
in the forward-looking statements and may be adversely
affected by, among other things, risks associated with new
product development and commercialization, clinical trials,
intellectual property, regulatory approvals, competitive
offerings, Boston Scientific's overall business strategy,
and other factors described in Boston Scientific's filings
with the Securities and Exchange Commission.

    References

    (1) Bosiers M, de Donato G, Deloose K, et al. Does free
cell area influence the outcome in carotid artery stenosis.
Eur J Vasc Endovasc Surg 2007;33:135-141.
    (2) Dodick DW, Meissner I, Meyer FB, Cloft HJ.
Evaluation and management of asymptomatic carotid artery
stenosis. Mayo Clin Proc 2004;79:937-944.
    (3) The Stroke Association. Stroke statistics sheet R11
http://www.stroke.org.uk/information/our_publications/factsheets/r11_
stroke.html (last accessed 21 May 2007). (Due to the length
of this URL, it may be necessary to copy and paste this
hyperlink into your Internet browser's URL address field.
Remove the space if one exists.)
    (4) Global burden of stroke. WHO Atlas of Heart Disease
and Stroke 2004.
http://www.who.int/cardiovascular_diseases/en/cvd_atlas_15_burden_stroke.pdf
(last accessed 21 May 2007).
    (x)Carotid WALLSTENT and NexStent are trademarks of
Boston Scientific Corporation. Xact and Acculink are
trademarks of Abbot Laboratories. Precise is a trademark of
Cordis Corp. Exponent is a trademark of Medtronic Vascular,
Inc. Protege is a trademark of ev3, Inc.


    For more information, please contact: 

    Geraldine Varoqui
    Boston Scientific PR Manager International
    Tel:   [phone]
    Email: [e-mail]

    Tracy Paul
    BSC press office, 
    Tel:   [phone]
    Email: [e-mail]