Most Popular Angioplasty Web Site
supported by Volcano Corporation
Fractional Flow Reserve (FFR) Gains in Updated ACC/AHA/SCAI Guidelines

FloWire® Doppler Guide
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
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
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