|
Fractional Flow Reserve
(FFR) Gains in Updated ACC/AHA/SCAI Guidelines
|
 |
Fractional
Flow Reserve
(FFR) helps determine if a
blockage
needs treatment
(courtesy, Volcano Corp.) |
|
November
25, 2009 -- The use of Fractional Flow Reserve (FFR)
to determine whether or not to treat a coronary blockage
with angioplasty or stents has received a boost from the
newly released "Focused Updates to the ACC/AHA/SCAI
Guidelines on Percutanous Coronary Intervention."
The chief evidence demonstrating the benefits of FFR-guided
intervention has been the FAME study -- the one year results
were published in the New England Journal of Medicine in
January. Followup results, presented at the 2009 TCT meeting
in September but not yet published, showed the benefits of
FFR were sustained at two years.
|
The ACC/AHA/SCAI Focused Updates to the Guidelines
have incorporated this information, raising the "level of evidence" for
use of FFR to "A" and
expanding recommendations, stating FFR "can be useful to
determine whether PCI of a specific coronary lesion is warranted."
The FAME Study
The FAME study randomized 1,005 patients
to two groups: in one cohort the decision of whether or not to place
a stent
was guided by the
angiographic
image alone (the standard method used in most cath labs); in the
second group, the blockage also was given a functional measurement
with FFR to
determine
the actual impact of this blockage on blood flow, and the stent was
placed only if the FFR reached a certain measure, regardless of the
angiographic image.
The result was that one-third fewer stents were
used in the FFR group, but more strikingly, the
outcomes at one
year for the FFR group showed a 28% lower incidence of
MACE (major adverse cardiac events, such as repeat procedure to
open the artery, heart
attack or death). When looking only at heart attack and death,
the reduction was 34% in the FFR group. The take-away was that FFR
could significantly improve patient outcomes and save money at the
same time, since unnecessarily stenting blockages that do not limit
flow not only increased costs, but may also have had some negative
aspects on the progression of coronary artery disease.
Scott Huennekens,
Volcano Corporation |
|
Currently Fractional Flow Reserve
is used in only 5% of cases in the U.S. and only slightly more
in Europe. However, the results of the FAME study, now combined
with this incremental boost in the new Guidelines update, may
increase the utilization of this technology in the catheterization
lab.
Scott Huennekens, President and CEO of Volcano Corporation,
one of two manufacturers of FFR equipment, recently stated
that he expects the Functional Measurement (FM) market to grow
to
the high 20-30% over the next few years in the United States.
In fact Minneapolis-based device manufacturer St. Jude Medical
Inc. acquired the other FM manufacturer, Radi Medical Systems
of Sweden, last December (Radi sponsored the FAME study). |
The 5% penetration, however,
is an average. As is the case with many new technologies, those
who utilize FFR use it often. One
interventional cardiologist who uses both IVUS and FFR on most
of his cases is Dr. Augusto Pichard, Director of the Cardiac
Catheterization Lab at the Washington Hospital Center. In a
statement to Angioplasty.Org, Dr. Pichard commented on the Focused
Update regarding FFR:
"This
should give the physicians more confidence that they're using
something
that's
approved, that's in the guidelines. My concern for some is
the lack of reimbursement. So if someone uses it a lot, they
have to answer for using so much of it.
I don't seem to have that problem in that I've
proven
to the hospital that we're saving money by doing optimal
procedures to begin with."
|
|
Augusto D.
Pichard, MD
Washington Hospital Center |
The section of the Focused Updates to the ACC/AHA/SCAI
Guidelines on Percutaneous Coronary Intervention concerning Fractional
Flow Reserve is posted as follows:
10.1 Fractional Flow Reserve
Coronary angiography is often performed in clinical situations in which preprocedural
functional testing has not been obtained. Additionally, in the setting
of multivessel disease, the need to treat individual stenosis is often
difficult to determine. Although revascularization of ischemia-producing
lesions improves patient outcomes, the clinical benefits of revascularization
of stenotic but non–ischemia-producing lesions are less clear. Intraprocedural
assessment of the functional significance of individual stenosis may help
define the optimal revascularization strategy.
The objective of the FAME trial (Tonino
PA, De Bruyne B, Pijls NH, et al. Fractional
flow reserve versus angiography for guiding percutaneous
coronary intervention N Engl J Med. 2009;360:213-224)
was to compare clinical outcomes after PCI on the basis of
conventional angiographic determination of lesion severity
versus fractional flow reserve (FFR) combined with angiography
in patients with multivessel disease. This prospective, randomized,
multicenter trial included 1005 patients selected from 1905
screened patients at 20 medical centers who were randomized
to either angiography-guided or FFR-guided (for lesions with
FFR less than or equal to 0.80) PCI. Before randomization,
lesions that required PCI were prespecified on the basis
of the angiographic appearance. Patients assigned to angiography-guided
PCI had all identified lesions treated with DES, whereas
those assigned to FFR-guided PCI had only identified lesions
with an FFR of 0.80 or less treated with DES. The primary
end point of the trial was the rate of death, nonfatal MI,
and repeat revascularization at 1 year.
No difference was evident in the number of
intended lesions to be treated per patient (2.7±0.9
versus 2.8±1.0, P=0.34) in the angiography- and FFR-guided
groups, respectively. In the FFR group, 37% of lesions had
an FFR greater than 0.80. Evaluation of ischemia, as defined
by an FFR less than 0.80, resulted in fewer lesions receiving
stents (2.7±1.2 versus 1.9±1.3, P<0.001).
At 1 year, the composite event rate was 18.3% in the angiography-guided
group compared with 13.2% in the FFR-guided group (P=0.02).
The results of the FAME trial suggest that
identification of ischemia-producing lesions by use of systematic
assessment of FFR in patients undergoing multivessel PCI is
associated with improved clinical outcomes compared with angiographic
assessment alone. Further evidence is needed regarding the
added value of assessing FFR in lesions with greater than 90%
stenosis. |
(Note: Dr. Pichard will be discussing in more detail
his use of FFR and IVUS in an upcoming exclusive interview on Angioplasty.Org.)
Reported by Burt Cohen, November 25, 2009
|
