Fractional Flow Reserve Facts Demonstrated Safety, Cost-Effectiveness and Clinical Outcomes
Fractional Flow Reserve (FFR) is a lesion specific, physiological index determining the hemodynamic severity of intracoronary lesions. FFR can accurately identify lesions responsible for ischemia which, in many cases, would have been undetected or not correctly assessed by imaging technologies.
If an operator is uncertain about the ischemic significance of a stenosis, whether or not PCI should be performed to the benefits of the patient, then flow (FFR) should be measured. Various clinical studies demonstrate that physiologic lesion assessment by FFR to guide routine PCI is superior to current angiography guided treatment.
Here are some of the landmark studies on Fractional Flow Reserves.
Published on January 30, 2020 by the Journal of the American Heart Association
Prospective Evaluation of the Strategy of Functionally Optimized Coronary Intervention
Dr Uretsky et al, Central Arkansas Veterans Healthcare System, Little Rock, published a study where the OptoWire is used in an all comer patient population from start to finish to Functionally Optimize Coronary Intervention (FCI).
In this 250 vessels/226 consecutive patients study, the OptoWire was used to diagnose, treat and confirm the treatment. The success rate of FCI with the OptoWire 2 was 92%, the highest success rate ever recorded with a pressure guidewire.
Dr Uretsky has demonstrated in different studies that post PCI measurements with the pressure guidewire was critical to ensure a successful PCI and reduce the Major Adverse Cardiac Event.
OptoWire is the only pressure guidewire on the market that can be used with confidence to diagnose, treat and confirm PCI without device exchange.
Reference: Barry F. Uretsky, MD; Shiv K Agarwal, MD; Srikanth Vallurupalli, MD; Malek Al-Hawwas, MD; Rimsha Hasan, MD; Kristin Miller, RN; Abdul Hakeem, MD, Journal of the American Heart Association. 2020;9, 30 Jan 2020, https://doi.org/10.1161/JAHA.119.015073
Published on August 1st, 2019 by Catheterization and Cardiovascular Interventions
Feasibility And Safety of Jailed-Pressure Wire Technique Using Durable Optical Fiber Pressure Wire for Intervention of Coronary Bifurcation Lesions
Dr Matsuo et al, Department of Cardiovascular Medicine, Gifu Heart Center, and his team studied the safety and feasibility of using the OptoWire in side branches.
Bifurcation is a PCI indication usually leading to more Major Adverse Cardiac Events and where diagnosis is still mainly performed with angiography.
In this study, 51 consecutive lesions/48 patients, Dr Matsuo demonstrated the safety and feasibility of using the OptoWire to assess coronary disease in side branches while jailing the pressure guidewire.
Reference: Hiroyuki Omori MD1 | Yoshiaki Kawase MD1 | Masahiko Hara MD, PhD2 |Toru Tanigaki MD1 | Shuuichi Okamoto MD1 | Tetsuo Hirata MD1 | Jun Kikuchi MD1 |Hideaki Ota MD1 | Yoshihiro Sobue MD, PhD1 | Taiji Miyake MD1 |Itta Kawamura MD, PhD1 | Munenori Okubo MD, PhD1 | Hiroki Kamiya MD, PhD1 |Kunihiko Tsuchiya MD, PhD1 | Takahiko Suzuki MD, PhD3 | Nico H.J. Pijls MD, PhD4 |Hitoshi Matsuo MD, PhD1, Catheterization and Cardiovascular Interventions, Volume 94, Issue 2, August 1, 2019, https://doi.org/10.1002/ccd.28106
Published on August 28, 2018 by European Heart Journal
Comparison of Accuracy of Fractional Flow Reserve Using Optical Sensor Wire to Conventional Pressure Wire
During the European Society of Cardiology in 2019, Dr Tateishi, Department of Cardiology, Kameda Medical Center, presented a study looking at pressure guidewire accuracy.
In this study, the researchers compared in 259 patients the accuracy (amount of drift) seen with traditional piezoelectic guidewires (Abbott) and the modern, 2nd generation fiber optic pressure guidewire (OpSens).
While the drift reported with the traditional guidewire was over 30%, as already documented in the Comet study, the accuracy of OptoWire was superior with a 60% reduction in drift and a statistically significant p-value (p<0.01).
Reference: Ryo Tateishia,b, Shigeki Kimuraa, Takuya Kawakamia,b, Yoshihiro Hanyua, Nozomu Kanehamaa, Shinichi Tachibanaa, Hirofumi Araia, Kazuto Hayasakaa, Jiro Hirokia, Kenji Yoshiokaa, Shunsuke Kurodaa, Ryota Iwatsukaa,b, Akira Mizukamia, Tatsuya Hayashia, Akihiko Matsumuraa, Department of Cardiology, Kameda Medical Centerb Department of Cardiology, Awa Regional Medical Center, European Heart Journal, Volume 39, Issue suppl_1, August 2018, ehy566.P5502, https://doi.org/10.1093/eurheartj/ehy566.P5502
Published on November 2, 2017 By The Lancet
Percutaneous Coronary Intervention in Stable Angina (ORBITA): a Double-Blind, Randomised Controlled Trial
Dr Al-Lamee et al, Imperial College London, designed the ORBITA study to investigate angina relief between PCI and placebo procedure.
In this study traditional piezoelectric guide wire (Philips Volcano) were used to diagnose the patients and they were then randomized between PCI and placebo (no PCI).
One interesting finding of the study was “pressure-wire related complications in the placebo group”. In fact, while those patients should have been PCI-free, over 4% of them received a bail-out PCI after caused by the pressure guidewire manipulation.
Traditional pressure guidewires designs are not optimal and considered inferior to workhorse guidewire to safely navigate coronary arteries. Although no death was reported, this study highlight some of the risks from traditional piezoelectric pressure guidewires.
Reference: Rasha Al-Lamee, David Thompson, Hakim-Moulay Dehbi, Sayan Sen, Kare Tang, John Davies, Thomas Keeble, Michael Mielewczik,Raffi Kaprielian, Iqbal S Malik, Sukhjinder S Nijjer, Ricardo Petraco, Christopher Cook, Yousif Ahmad, James Howard, Christopher Baker, Andrew Sharp, Robert Gerber, Suneel Talwar, Ravi Assomull, Jamil Mayet, Roland Wensel, David Collier, Matthew Shun-Shin, Simon A Thom, Justin E Davies, Darrel P Francis, on behalf of the ORBITA investigators* The Lancet, Volume 391, issue 10115, P3140, January 06, 2018, https://doi.org/10.1016/S0140-6736(17)32714-9
Published on August 2016 by Circulation Journal
Fractional Flow Reserve, Coronary Pressure Wires and Drift
Dr Nico Pijls et al, Catharina Hospital – Eindhoven, and Dr De Bruyne, Cardiovascular Center Aalst, Aalst published on pressure guidewires and the importance of inaccuracy (drift).
In this publication, they recognize the importance of drift, especially when dealing with smaller gradients, usually present at rest.
They also reported their experience with the OptoWire with not a single case of drift reported after the device was used in 100 patients.
Reference: Nico HJ Pijls, MD, PhD; Bernard De Bruyne, MD, PhD, Circulation Journal, Volume 80, https://doi.org/10.1253/circj.CJ-16-0623
Published on April 16, 2016 by AHA Journal, Circulation: Cardiovascular Interventions
Quantification of the Effect of Pressure Wire Drift on the Diagnostic Performance of Fractional Flow Reserve, Instantaneous Wave-Free Ratio, and Whole-Cycle Pd/Pa
Dr Cook et al, National Heart and Lung Institute, Imperial College London, studied the impact of drift on the coronary disease diagnosis in 447 stenoses.
In this study he simulated Pressure wire drift by offsetting the distal coronary pressure trace by ±2 mm Hg and documented the impact on diagnosis when using FFR, iFR and Pd/Pa.
The cutoff value for FFR is 0.80 while it is 0.89 for iFR and 0.91 for Pd/Pa, defining the treatment decision on 20 units for FFR, 11 for iFR and 9 for Pd/Pa.
Simulating drift on ±2 mm Hg is equivalent to considering that 2 units are corrupted when making the diagnosis.
In this study, the team showed patients misclassification in 1 patient out of 5 with FFR (21%), in 1 patient out of 4 with iFR (25%) and in 1 patient out of 3 with Pd/Pa (33%).
Christopher M. Cook, MBBS; Yousif Ahmad, MBBS; Matthew J. Shun-Shin, MBBS; Sukhjinder Nijjer, MB CHB; Ricardo Petraco, MD; Rasha Al-Lamee, MBBS; Jamil Mayet, MD, MBA, FESC; Darrel P. Francis, MA, MD; Sayan Sen, MBBS, PhD; Justin E. Davies, MBBS, PhD (Cardiovasc Interv. 2016;9:e002988. DOI: 10.1161/CIRCINTERVENTIONS.115.002988.)
Published in September 2012 by The New England Journal of Medecine
Fractional Flow Reserve–Guided PCI versus Medical Therapy in Stable Coronary Disease
The FAME 2, FFR-guided Percutaneous Coronary Intervention plus Medical Treatment vs. Medical Treatment Alone in Patients with Stable Coronary Artery Disease, study was designed to investigate the outcomes of stable angina patients receiving FFR-guided PCI compared with patients who received optimal medical therapy alone.
FAME 2 was designed to assess whether FFR-guided PCI would result in improved outcomes for a composite endpoint of death, MI or urgent revascularization.
- Of 1,220 enrolled patients:
- 888 (73 %) patients with ≥1 lesion with an FFR score of
- 332 (27 %) patients in whom all stenoses had an FFR ≥0.80 received optimal medical therapy alone (registry group).
- Patients in the medical therapy group showed a significantly higher need for urgent revascularization, compared to patients in the FFR group (11.1 % vs. 1.6 %, P<0.001).
- Patients in the medical therapy group were more likely to have revascularizations triggered by MI or evidence of ischemia (P<0.001).
Recruitment for the FAME 2 study was halted in January 2012, when an independent Data and Safety Monitoring Board (DSMB) recommended early termination of the study. The preliminary results were considered so compelling that research was stopped so patients with FFR <0.80 randomized to optimal medical therapy only could also receive the benefits of PCI.
These data support the idea of treating patients with “Functionally Complete Revascularization.” With this approach, only ischemia inducing lesions require stenting. When used in patients indicated to receive PCI, FFR is the key to determining the right treatment for each patient.
FFR-guided treatment also produced a 14% cost reduction for the hospital after one year thanks to lower procedural costs, reduced numbers of follow-ups for major adverse cardiac events, and shorter hospital stay. When FFR was used in stenting decision, the number of stents was cut by 1/3 and positive outcomes also increased by 1/3, a startling result that leads to the conclusion that placing fewer stents and guiding those placed with FFR makes stenting about 33% more effective.
Reference: De Bruyne B, Pijls NH, Kalesan B, et al. Fractional flow reserve-guided PCI versus medical therapy in stable coronary disease. N Engl J Med 2012;367:991-1001.
Published in 2009 by The New England Journal of Medecine
The FAME study, Fractional Flow Reserve versus Angiography for Multivessel Evaluation, published in 2009, was designed to demonstrate whether patients with multivessel disease had better outcomes with FFR-guided PCI compared to angiography guided PCI.
A total of 1,005 patients with multivessel CAD, recruited from 20 centers in Europe and the U.S., were randomized to undergo angiography-guided PCI or FFR-guided PCI. Angiography-guided PCI involved the stenting of all indicated lesions, and FFR-guided PCI involved the stenting of lesions with FFR measurements ≤0.80. Patients in the angiography group had an average of 2.7 lesions per patient, which was similar to the average of 2.8 in the FFR group (P=0.34). However, the number of stents used per patient was significantly different between the two groups, with 2.7 used in the angiography group and 1.9 used in the FFR group (P<0.001).
At 1-year after stenting, a total of 91 patients (18.3 %) in the angiography group had experienced an event (death, nonfatal MI or repeat revascularization) compared with 67 patients (13.2 %) in the FFR group; these results were statistically significant (P=0.02).
Reference: Tonino PA, De Bruyne B, Pijls NH, et al. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention. N Engl J Med 2009;360:213-24.
Follow up data Published July 2010 by The Journal of American College of Cardiology
Fractional Flow Reserve Versus Angiography for Guiding Percutaneous Coronary Intervention in Patients With Multivessel Coronary Artery Disease: 2-Year Follow-Up of the FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) Study
These follow-up data demonstrate the benefit of FFR measurement in patients with multivessel CAD. When FFR is used prior to PCI, patient outcomes are improved and unnecessary stenting is also prevented.
Reference: Pijls NH, Fearon WF, Tonino PA, et al. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention in patients with multivessel coronary artery disease: 2-year follow-up of the FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) study. J Am Coll Cardiol. 2010;56(3):177-84.
Published in May 2001 by the Journal of the American College of Cardiology
Percutaneous Coronary Intervention of Functionally Nonsignificant Stenosis
The DEFER study was undertaken in patients with stable chest pain and a functionally non-significant coronary stenosis to investigate if PCI of such stenosis is justified. This study indicated that the outcomes of patients referred for PTCA without objective proof of ischemia might vary depending on the severity of coronary stenoses detected by FFR. In patients with FFR scores ≥0.75, PTCA did not appear to improve patient outcomes compared to medical treatment alone. A 5-year follow-up of DEFER patients showed that these outcomes were maintained over time.
Five-year outcome after deferral of PCI of intermediate coronary stenosis based on FFR 0.75 is excellent. The risk of cardiac death or myocardial infarction related to this stenosis is 1% per year and not decreased by stenting. (J Am Coll Cardiol 2007;49:2105–11) © 2007 by the American College of Cardiology Foundation
Reference: Bech GJ, De Bruyne B, Pijls NH, et al. Fractional flow reserve to determine the appropriateness of angioplasty in moderate coronary stenosis: a randomized trial. Circulation 2001;103:2928-34.