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COURAGE, SPIRIT Data
May Support Role of Advanced Imaging and Diagnosis
With IVUS
and FFR
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April 18, 2007 -- RANCHO CORDOVA, Calif.
-- Data
presented at the recent ACC conference suggest the need for more detailed
imaging and diagnosis to optimize stent placement with technologies such as
Intravascular Ultrasound (IVUS) and Fractional Flow Reserve (FFR),
according to Volcano Corporation (Nasdaq: VOLC).
John McB. Hodgson, M.D., FSCAI, a Past President of the Society for
Cardiovascular Angiography and Interventions, and Chief of Academic
Cardiology at St. Joseph's Hospital and Medical Center in Phoenix, AZ,
commented, "Non-invasive imaging modalities, like CT Angiography (CTA) and
other screening tests, are very effective at guiding patients with coronary
artery disease into the cath lab, and allowing interventional cardiologists
to treat the patients that would clearly benefit from interventional
therapy. However, these first pass screening tests also bring patients into
the lab with less severe disease. These patients may also benefit from
medical therapy alone and effective follow-up. In many cases, physicians
are presented with the dilemma of balancing a positive CTA with a negative
angiogram, then having to choose between intervention and medical therapy.
Technologies like IVUS and FFR provide important objective measures of
disease severity -- essentially serving as the 'tie breaker' in these
patients as the data supporting lesion significance related to IVUS and FFR
measurements has been well studied."
The COURAGE data showed that angioplasty and stenting did not reduce
the risk of heart attack or death in the 2,300 patients who participated in
the study with stable coronary disease vs. medical therapy and lifestyle
changes alone. Although the design of the study has been vigorously
debated, the COURAGE data highlights a lack of clarity as to which patients
benefit from stenting, and that angiography alone may not adequately or
reliably triage these target patients. Dr. Steven Nissen, president of the
American College of Cardiology, noted in a national broadcast interview,
"Most heart attacks do not occur because of a blood clot at the site with
the worst narrowing in the coronary. Most heart attacks occur at a site
with relatively minor blockage in the coronary, and so the very sites where
you put a stent are not the ones likely to cause the next heart attack or
sudden death. Putting a stent in the most narrowed area in the artery
doesn't really address the underlying problem," he said.
Scott Huennekens, President and CEO of Volcano Corporation commented,
"Angiography alone is severely limited in this regard as it can only
diagnose vessel narrowing in 2-D, and delivers no detail as to
atherosclerotic plaque present or state of the disease at the narrowed, or
the visually 'clear' parts of the artery. IVUS on the other hand provides a
3-D 'slice' of the diseased artery so physicians can quickly and accurately
measure minimum lumen diameter, remodeled vessel size, and cross sectional
flow area. Volcano's proprietary VH(TM) IVUS technology also provides a
snapshot of the tissue type along the length of the artery, again providing
more detail to supplement angiography. This technique -- used as part of
the PROSPECT trial -- may deliver important insights into what a vulnerable
lesion looks like before a heart attack."
Dr. Hodgson continued, "We learned from the DEFER study that FFR can be
an effective way to assess lesion severity. By measuring the pressure
gradient across a questionable blockage, FFR provides a key objective
benchmark from which to guide appropriate therapy. If the FFR is below
0.75, data suggest that the lesion will likely be associated with ischemia.
In these cases, PCI should alleviate symptoms. If the FFR is above 0.75
data suggest the patient may benefit from medical therapy, follow-up and no
stenting. FFR provides the physician an effective diagnostic tool to
determine the appropriate treatment of the lesion and patient."
An additional important observation of the COURAGE data was that 34% of
patients in the stent group continued to experience angina 12 months after
stent implantation. Huennekens noted, "This observation underlines the fact
that in many cases we are either treating the wrong location because we
didn't use FFR to measure lesion severity, or we are placing the stent
sub-optimally because we are not using IVUS to ensure full apposition and
expansion post intervention. The data is starting to add up."
Gregg W. Stone, M.D., of Columbia University Medical Center and the
Cardiovascular Research Foundation, presented IVUS data from the Abbott
SPIRIT III US Pivotal study where the Xience(TM) drug eluting stent was
randomized against Taxus(R). The data from the core lab showed that despite
the importance of optimal stent placement as part of this key pivotal
trial, of the 133 stents guided by angiography alone, stent mal-apposition
was observed by IVUS in 34.4% in the Xience(TM) group and 25.6% in the
Taxus(R) group.
Marco A. Costa, MD, PhD, FACC, FSCAI at the University of Florida,
Shands Hospital in Jacksonville FL, commented, "The prevalence of sub
optimal drug-eluting stent deployment in patients guided by angiography in
today's clinical practice is staggering. The STLLR study sponsored by
Johnson & Johnson using angiography guided DES treatment in 1,419 patients
showed that current DES deployment techniques lead to some form of
geographic miss in 66.5% of patients. What is more alarming is that
geographic miss has in turn negatively impacted patient outcomes, with
significantly higher TLR, TVR, and myocardial infarction rates in patients
where the stent was not placed properly. A re-examination of stent
placement technique including the use of IVUS is certainly warranted."
IVUS was used in live case broadcasts throughout the ACC to optimize
stent placement.
About Volcano Corporation
Volcano Corporation (Nasdaq: VOLC), offers a broad suite of devices
designed to facilitate endovascular procedures, enhance the diagnosis of
vascular and structural heart diseases and guide optimal therapies. The
company's intravascular ultrasound (IVUS) product line includes ultrasound
consoles that can be integrated directly into virtually any modern cath lab
and single-use phased array and rotational IVUS imaging catheters. Volcano
also has unique advanced functionality options, such as VH(TM) IVUS tissue
characterization. Volcano also provides functional measurement (FM)
consoles and single-use pressure and flow guide wires. Currently, more than
2,500 Volcano IVUS and FM systems are installed worldwide, with
approximately half of its revenues coming from outside the United States.
For more information, visit the company's website at
http://www.volcanocorp.com
Forward-Looking Statements
Statements in this press release regarding Volcano's business that are
not historical facts may be "forward-looking statements" that involve risks
and uncertainties. Specifically, among others, the statements regarding the
potential benefits of the VH(TM) IVUS technology and Volcano's role of
advanced imaging and diagnosis with IVUS and FFR are forward-looking
statements involving risks and uncertainties. Forward-looking statements
are based on current, preliminary expectations of Volcano management and
are subject to risks and uncertainties, which may cause actual results to
differ significantly from the statements contained herein. Readers are
cautioned not to place undue reliance on forward-looking statements, which
speak only as of the date they are made. Volcano undertakes no obligation
to revise or update any forward-looking statements to reflect new
information, events or circumstances after the date hereof, except as
required by law. The potential risks and uncertainties that could cause
actual results to differ from the results predicted are detailed in the
risk factors contained in Volcano's Annual Report on Form 10-K and other
filings made with the Securities and Exchange Commission.
Source: Volcano Corporation
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