• Users Online: 61
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
REVIEW ARTICLE
Year : 2017  |  Volume : 22  |  Issue : 2  |  Page : 83-86

Coronary fractional flow reserve: Clinical importance


Department of Cardiology, CARE Hospitals, Nagpur, Maharashtra, India

Date of Web Publication15-Sep-2017

Correspondence Address:
Vipul Seta
CARE Hospitals, Nagpur, Maharashtra
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jmgims.jmgims_42_17

Rights and Permissions
  Abstract 

Coronary angiography has an important role in invasive imaging of the coronary arteries. However, it has got limitations in the determination of physiologic significance of individual artery lesions. Coronary pressure derived FFR can be used to rapidly assess the hemodynamic significance of individual coronary artery lesions and can be easily performed in catheterization laboratory. FFR has been shown to effectively help coronary revascularization procedures with improved patient outcomes. FFR is a very important tool for determination of functional significance of coronary stenosis. It combines physiological and anatomical information which can be immediately followed by percutaneous coronary intervention (PCI) if required. The technique for FFR measurement is easy, safe and can be rapidly performed in the catheterization laboratory. PCI can be made more effective by proper and systemic use of FFR in dubious situations. The current clinical evidence for FFR is very encouraging for cardiologist to use this tool in the catheterization laboratory as and when required.

Keywords: Fractional flow reserve, percutaneous coronary interventions, Vipul Seta


How to cite this article:
Seta V. Coronary fractional flow reserve: Clinical importance. J Mahatma Gandhi Inst Med Sci 2017;22:83-6

How to cite this URL:
Seta V. Coronary fractional flow reserve: Clinical importance. J Mahatma Gandhi Inst Med Sci [serial online] 2017 [cited 2017 Oct 23];22:83-6. Available from: http://www.jmgims.co.in/text.asp?2017/22/2/83/214758


  Introduction Top


Coronary angiography still has an important role in invasive imaging of the coronary arteries. However, coronary angiography has got limitations in the determination of physiologic significance of coronary stenosis.[1],[2] The most important factor related to outcome is the presence and extent of inducible ischemia.[3],[4] If the coronary stenosis is functionally significant, it should be revascularized if possible.[5],[6],[7] On the other hand, if it has no functional significance, medical treatment is indicated.[7],[8] Intracoronary fractional flow reserve (FFR) has proven to be a reliable method for the measurement of physiological significance of coronary stenosis.[9] An FFR value of ≤0.80 indicates coronary stenosis causing ischemia with more than 90% accuracy.[9],[10],[11] The information provided by FFR is more specific with better spatial resolution as compared to myocardial perfusion studies, because analysis of every artery or segment is done separately and masking of one over other area is avoided.[12],[13]


  Definition Top


FFR is the ratio of maximum blood flow in a stenotic artery to maximum blood flow if the same artery is normal, assuming that these measurements are obtained when the microvascular resistance is minimal and constant.[9],[10],[14],[15],[16] It can be easily measured by a pressure wire and a guiding catheter. FFR equals Pd/Pa, where Pd is the pressure in the coronary artery distal to stenosis and Pa is the aortic pressure, both measured at maximum coronary hyperemia. FFR is linearly related to the maximum blood flow with a normal value of 1.0. It is irrespective of patient, artery, blood pressure, and so on. It is independent of changes in systemic blood pressure, heart rate, and myocardial contractility, and it is highly reproducible.[14],[15],[16],[17]


  Fractional Flow Reserve – Practical Aspects Top


Catheters

Usually, a 6F guiding catheter is used. However, FFR can also be safely measured through a conventional 4F diagnostic catheter.[18],[19]

Wires

Presently, two United States Food and Drug Administration- approved pressure wire systems are available: Pressure Analyzer and Wave Map. Both are 0.014 inch in diameter. The sensor is located 30 mm from the tip.

Hyperemia

It is absolutely necessary to achieve maximal vasodilatation of two vascular compartments of coronary circulation for measurement of FFR. These are epicardial vessels and microvascular arteries. A desirable stimulant should have a rapid onset and short duration of action, should be cost-effective, should not have significant side effects, and should achieve a stable steady state. Intracoronary adenosine creates hyperemia for few seconds and can be used in patients with single-vessel disease. Intravenous adenosine is the gold standard for creating hyperemia. However, it is contraindicated in case of severe asthma.[20],[21],[22],[23]

Anticoagulation

Heparin adjusted to weight is used for anticoagulation to achieve an activated coagulation time of 250 s or it can be used as per the body weight.


  Fractional Flow Reserve – Clinical Relevance Top


Intermediate coronary lesion

The ability of coronary angiography to evaluate the hemodynamic significance of intermediate lesion is limited. It has been shown that in such cases FFR is more accurate than other modalities. It is strongly recommended to use FFR measurements as a guide to take decision about revascularization in intermediate lesions.[10]

Left main coronary artery disease

Left main coronary artery (LMCA) disease has got critical prognostic importance, and it determines the type of treatment.[17] There are significant variations in the assessment of LMCA lesions by different observers.[24] FFR can identify LMCA disease responsible for ischemia. It has been proved that FFR-guided therapy for equivocal LMCA disease is safe and has got favorable clinical outcomes.[25],[26],[27],[28],[29] The influence of left anterior descending (LAD) and left circumflex (LCx) on FFR of LMCA depends on the severity and location of distal stenosis. Basically, it depends on the amount of myocardium affected by distal stenosis.

Tandem lesions

They are defined as two separate lesions in the same coronary artery separated by angiographically normal segment and each with more than 50% stenosis.[30],[31] Each lesion will influence the hyperemic blood flow and FFR across other. A pullback maneuver with maximum hyperemia is the best way to define the exact location and physiological importance of such lesions and guide intervention accordingly.

Bifurcation lesions

Percutaneous coronary interventions (PCIs) are more challenging for bifurcation lesions than regular lesions. The principle of FFR-guided PCI applies very much for bifurcation lesions.[32],[33]

Multivessel coronary artery disease

It is very important to determine which particular lesion is physiologically significant and causing reversible ischemia in patients with multivessel coronary artery disease. In such patients, it was demonstrated that one or two physiologically significant lesions identified by FFR yielded a favorable outcome as surgery.[34]

Diffuse and long lesions

FFR is useful in quantifying the severity of coronary artery stenosis in diffusely affected vessels. This can be done by withdrawing the pressure wire from distal to proximal vessel very slowly during maximum hyperemia.[35] The pressure curve represents the pressure gradient over the entire length of vessel and helps to demonstrate the exact location and severity of lesion.

Myocardial infarction

The decrease of viable myocardium and impairment of coronary resistance vessel do not affect the calculation of FFR, and it is still a reliable indicator. The FFR assessment criteria are valid in detecting reversible ischemia after at least 6 days after myocardial infarction (MI).[36]

Unstable angina

FFR assessment criteria are also valid in patients with unstable angina. The strategy based on FFR is superior to the approach based on stress perfusion scintigraphy.[37]

Coronary artery bypass graft surgery

The assessment of stenosis severity in such patients is not different from that in native vessels. At present, there are no data available for use of FFR in graft stenosis.


  Special Features Top


  1. FFR has a theoretical normal value of 1 for every patient, artery, and myocardium [35]
  2. FFR has a well-defined cutoff value. There is a very narrow gray zone between 0.75 and 0.80. Stenoses with FFR <0.75 are almost able to induce myocardial ischemia. Stenoses with FFR >0.80 are almost never associated with exercise-induced ischemia
  3. FFR is not affected by systemic hemodynamics [17],[38]
  4. FFR always takes into account the blood flow through collaterals.[8],[9]



  Limitations Top


Fractional flow reserve at gray zone

Stenoses with FFR between 0.75 and 0.80 have shown conflicting outcome data.[39],[40] It is rational for cardiologists to make decisions based on clinical judgment and other imaging modalities with all available information to deliver safe and suitable care for patients whose FFR is into the gray zone. FFR should never be used as a gatekeeper.[41]

Acute myocardial infarction

During the acute phase of MI, maximum hyperemia cannot be achieved.[42],[43] In addition, thrombus embolization, stunning of myocardium, and microvascular dysfunction may make achieving complete microvascular vasodilation difficult.[19] During the acute phase of MI, FFR measurement cannot reflect the actual value. FFR can be applied as in routine practice usually after 6 days of acute MI.

Myocardial bridge

Usually, myocardial bridge is clinically silent. Sometimes, it may present as angina, MI, arrhythmias, and even sudden cardiac death.[44],[45],[46] The flow pattern in bridge segment is entirely different from that in atherosclerotic lesions.[26],[47] There is the possibility that FFR may be abnormal in patients with myocardial bridge. FFR may not be as reliable as in fixed stenosis.[48]


  Conclusion Top


FFR is very valuable for the determination of functional and physiological significance of coronary stenosis. It combines both anatomical and physiological information. It can be immediately followed by PCI if required. FFR can be performed rapidly, safely, and easily. By proper use of FFR, PCI can be more effective in intermediate lesions and multivessel disease. The current clinical evidence should encourage cardiologists to use FFR routinely in practice.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Vogel RA. Assessing stenosis significance by coronary arteriography: Are the best variables good enough? J Am Coll Cardiol 1988;12:692-3.  Back to cited text no. 1
    
2.
White CW, Wright CB, Doty DB, Hiratza LF, Eastham CL, Harrison DG, et al. Does visual interpretation of the coronary arteriogram predict the physiologic importance of a coronary stenosis? N Engl J Med 1984;310:819-24.  Back to cited text no. 2
    
3.
Shaw LJ, Iskandrian AE. Prognostic value of gated myocardial perfusion SPECT. J Nucl Cardiol 2004;11:171-85.  Back to cited text no. 3
    
4.
Metz LD, Beattie M, Hom R, Redberg RF, Grady D, Fleischmann KE, et al. The prognostic value of normal exercise myocardial perfusion imaging and exercise echocardiography: A meta-analysis. J Am Coll Cardiol 2007;49:227-37.  Back to cited text no. 4
    
5.
Davies RF, Goldberg AD, Forman S, Pepine CJ, Knatterud GL, Geller N, et al. Asymptomatic Cardiac Ischemia Pilot (ACIP) study two-year follow-up: Outcomes of patients randomized to initial strategies of medical therapy versus revascularization. Circulation 1997;95:2037-43.  Back to cited text no. 5
    
6.
Shaw LJ, Heller GV, Casperson P, Miranda-Peats R, Slomka P, Friedman J, et al. Gated myocardial perfusion single photon emission computed tomography in the clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial, Veterans Administration Cooperative study no 424. J Nucl Cardiol 2006;13:685-98.  Back to cited text no. 6
    
7.
Tonino PA, De Bruyne B, Pijls NH, Siebert U, Ikeno F, van' t Veer M, et al. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention. N Engl J Med 2009;360:213-24.  Back to cited text no. 7
    
8.
Pijls NH, van Schaardenburgh P, Manoharan G, Boersma E, Bech JW, van't Veer M, et al. Percutaneous coronary intervention of functionally nonsignificant stenosis: 5-year follow-up of the DEFER Study. J Am Coll Cardiol 2007;49:2105-11.  Back to cited text no. 8
    
9.
Pijls NH, Van Gelder B, Van der Voort P, Peels K, Bracke FA, Bonnier HJ, et al. Fractional flow reserve. A useful index to evaluate the influence of an epicardial coronary stenosis on myocardial blood flow. Circulation 1995;92:3183-93.  Back to cited text no. 9
    
10.
Pijls NH, De Bruyne B, Peels K, Van Der Voort PH, Bonnier HJ, Bartunek J Koolen JJ, et al. Measurement of fractional flow reserve to assess the functional severity of coronary-artery stenoses. N Engl J Med 1996;334:1703-8.  Back to cited text no. 10
    
11.
De Bruyne B, Pijls NH, Bartunek J, Kulecki K, Bech JW, De Winter H, et al. Fractional flow reserve in patients with prior myocardial infarction. Circulation 2001;104:157-62.  Back to cited text no. 11
    
12.
Lima RS, Watson DD, Goode AR, Siadaty MS, Ragosta M, Beller GA, et al. Incremental value of combined perfusion and function over perfusion alone by gated SPECT myocardial perfusion imaging for detection of severe three-vessel coronary artery disease. J Am Coll Cardiol 2003;42:64-70.  Back to cited text no. 12
    
13.
Pijls NH. Optimum guidance of complex PCI by coronary pressure measurement. Heart 2004;90:1085-93.  Back to cited text no. 13
    
14.
De Bruyne B, Baudhuin T, Melin JA, Pijls NH, Sys SU, Bol A, et al. Coronary flow reserve calculated from pressure measurements in humans. Validation with positron emission tomography. Circulation 1994;89:1013-22.  Back to cited text no. 14
    
15.
Pijls NH, van Son JA, Kirkeeide RL, De Bruyne B, Gould KL. Experimental basis of determining maximum coronary, myocardial, and collateral blood flow by pressure measurements for assessing functional stenosis severity before and after percutaneous transluminal coronary angioplasty. Circulation 1993;87:1354-67.  Back to cited text no. 15
    
16.
De Bruyne B, Bartunek J, Sys SU, Heyndrickx GR. Relation between myocardial fractional flow reserve calculated from coronary pressure measurements and exercise-induced myocardial ischemia. Circulation 1995;92:39-46.  Back to cited text no. 16
    
17.
de Bruyne B, Bartunek J, Sys SU, Pijls NH, Heyndrickx GR, Wijns W. Simultaneous coronary pressure and flow velocity measurements in humans. Feasibility, reproducibility, and hemodynamic dependence of coronary flow velocity reserve, hyperemic flow versus pressure slope index, and fractional flow reserve. Circulation 1996;94:1842-9.  Back to cited text no. 17
    
18.
Legalery P, Seronde MF, Meneveau N, Schiele F, Bassand JP. Measuring pressure-derived fractional flow reserve through four French diagnostic catheters. Am J Cardiol 2003;91:1075-8.  Back to cited text no. 18
    
19.
Pijls NH, Sels JW. Functional measurement of coronary stenosis. J Am Coll Cardiol 2012;59:1045-57.  Back to cited text no. 19
    
20.
Di Segni E, Higano ST, Rihal CS, Holmes DR Jr., Lennon R, Lerman A. Incremental doses of intracoronary adenosine for the assessment of coronary velocity reserve for clinical decision making. Catheter Cardiovasc Interv 2001;54:34-40.  Back to cited text no. 20
    
21.
De Bruyne B, Pijls NH, Barbato E, Bartunek J, Bech JW, Wijns W, et al. Intracoronary and intravenous adenosine 5'-triphosphate, adenosine, papaverine, and contrast medium to assess fractional flow reserve in humans. Circulation 2003 15;107:1877-83.  Back to cited text no. 21
    
22.
Sonoda S, Takeuchi M, Nakashima Y, Kuroiwa A. Safety and optimal dose of intracoronary adenosine 5'-triphosphate for the measurement of coronary flow reserve. Am Heart J 1998;135:621-7.  Back to cited text no. 22
    
23.
Jeremias A, Filardo SD, Whitbourn RJ, Kernoff RS, Yeung AC, Fitzgerald PJ, et al. Effects of intravenous and intracoronary adenosine 5'-triphosphate as compared with adenosine on coronary flow and pressure dynamics. Circulation 2000;101:318-23.  Back to cited text no. 23
    
24.
Lindstaedt M, Spiecker M, Perings C, Lawo T, Yazar A, Holland-Letz T, et al. How good are experienced interventional cardiologists at predicting the functional significance of intermediate or equivocal left main coronary artery stenoses? Int J Cardiol 2007;120:254-61.  Back to cited text no. 24
    
25.
Hamilos M, Muller O, Cuisset T, Ntalianis A, Chlouverakis G, Sarno G, et al. Long-term clinical outcome after fractional flow reserve-guided treatment in patients with angiographically equivocal left main coronary artery stenosis. Circulation 2009;120:1505-12.  Back to cited text no. 25
    
26.
Bech GJ, Droste H, Pijls NH, De Bruyne B, Bonnier JJ, Michels HR, et al. Value of fractional flow reserve in making decisions about bypass surgery for equivocal left main coronary artery disease. Heart 2001;86:547-52.  Back to cited text no. 26
    
27.
Legutko J, Dudek D, Rzeszutko L, Wizimirski M, Dubiel JS. Fractional flow reserve assessment to determine the indications for myocardial revascularisation in patients with borderline stenosis of the left main coronary artery. Kardiol Pol 2005;63:499-506.  Back to cited text no. 27
    
28.
Lindstaedt M, Yazar A, Germing A, Fritz MK, Holland-Letz T, Mügge A, et al. Clinical outcome in patients with intermediate or equivocal left main coronary artery disease after deferral of surgical revascularization on the basis of fractional flow reserve measurements. Am Heart J 2006;152:156.e1-9.  Back to cited text no. 28
    
29.
Suemaru S, Iwasaki K, Yamamoto K, Kusachi S, Hina K, Hirohata S, et al. Coronary pressure measurement to determine treatment strategy for equivocal left main coronary artery lesions. Heart Vessels 2005;20:271-7.  Back to cited text no. 29
    
30.
De Bruyne B, Pijls NH, Heyndrickx GR, Hodeige D, Kirkeeide R, Gould KL. Pressure-derived fractional flow reserve to assess serial epicardial stenoses: Theoretical basis and animal validation. Circulation 2000;101:1840-7.  Back to cited text no. 30
    
31.
Park SJ, Ahn JM, Pijls NH, De Bruyne B, Shim EB, Kim YT, et al. Validation of functional state of coronary tandem lesions using computational flow dynamics. Am J Cardiol 2012;110:1578-84.  Back to cited text no. 31
    
32.
Koo BK, Kang HJ, Youn TJ, Chae IH, Choi DJ, Kim HS, et al. Physiologic assessment of jailed side branch lesions using fractional flow reserve. J Am Coll Cardiol 2005;46:633-7.  Back to cited text no. 32
    
33.
Koo BK, Park KW, Kang HJ, Cho YS, Chung WY, Youn TJ, et al. Physiological evaluation of the provisional side-branch intervention strategy for bifurcation lesions using fractional flow reserve. Eur Heart J 2008;29:726-32.  Back to cited text no. 33
    
34.
Botman KJ, Pijls NH, Bech JW, Aarnoudse W, Peels K, van Straten B, et al. Percutaneous coronary intervention or bypass surgery in multivessel disease? A tailored approach based on coronary pressure measurement. Catheter Cardiovasc Interv 2004;63:184-91.  Back to cited text no. 34
    
35.
De Bruyne B, Hersbach F, Pijls NH, Bartunek J, Bech JW, Heyndrickx GR, et al. Abnormal epicardial coronary resistance in patients with diffuse atherosclerosis but “Normal” coronary angiography. Circulation 2001;104:2401-6.  Back to cited text no. 35
    
36.
Claeys MJ, Bosmans JM, Hendrix J, Vrints CJ. Reliability of fractional flow reserve measurements in patients with associated microvascular dysfunction: Importance of flow on translesional pressure gradient. Catheter Cardiovasc Interv 2001;54:427-34.  Back to cited text no. 36
    
37.
Leesar MA, Abdul-Baki T, Akkus NI, Sharma A, Kannan T, Bolli R, et al. Use of fractional flow reserve versus stress perfusion scintigraphy after unstable angina. Effect on duration of hospitalization, cost, procedural characteristics, and clinical outcome. J Am Coll Cardiol 2003;41:1115-21.  Back to cited text no. 37
    
38.
Bech GJ, De Bruyne B, Pijls NH, de Muinck ED, Hoorntje JC, Escaned J, et al. Fractional flow reserve to determine the appropriateness of angioplasty in moderate coronary stenosis: A randomized trial. Circulation 2001;103:2928-34.  Back to cited text no. 38
    
39.
Courtis J, Rodés-Cabau J, Larose E, Déry JP, Nguyen CM, Proulx G, et al. Comparison of medical treatment and coronary revascularization in patients with moderate coronary lesions and borderline fractional flow reserve measurements. Catheter Cardiovasc Interv 2008;71:541-8.  Back to cited text no. 39
    
40.
Lindstaedt M, Halilcavusogullari Y, Yazar A, Holland-Letz T, Bojara W, Mügge A, et al. Clinical outcome following conservative vs. revascularization therapy in patients with stable coronary artery disease and borderline fractional flow reserve measurements. Clin Cardiol 2010;33:77-83.  Back to cited text no. 40
    
41.
Melikian N, De Bondt P, Tonino P, De Winter O, Wyffels E, Bartunek J, et al. Fractional flow reserve and myocardial perfusion imaging in patients with angiographic multivessel coronary artery disease. JACC Cardiovasc Interv 2010;3:307-14.  Back to cited text no. 41
    
42.
Fearon WF, Shah M, Ng M, Brinton T, Wilson A, Tremmel JA, et al. Predictive value of the index of microcirculatory resistance in patients with ST-segment elevation myocardial infarction. J Am Coll Cardiol 2008;51:560-5.  Back to cited text no. 42
    
43.
Lim HS, Yoon MH, Tahk SJ, Yang HM, Choi BJ, Choi SY, et al. Usefulness of the index of microcirculatory resistance for invasively assessing myocardial viability immediately after primary angioplasty for anterior myocardial infarction. Eur Heart J 2009;30:2854-60.  Back to cited text no. 43
    
44.
Alegria JR, Herrmann J, Holmes DR Jr. Lerman A, Rihal CS. Myocardial bridging. Eur Heart J 2005;26:1159-68.  Back to cited text no. 44
    
45.
Möhlenkamp S, Hort W, Ge J, Erbel R. Update on myocardial bridging. Circulation 2002;106:2616-22.  Back to cited text no. 45
    
46.
Bourassa MG, Butnaru A, Lespérance J, Tardif JC. Symptomatic myocardial bridges: Overview of ischemic mechanisms and current diagnostic and treatment strategies. J Am Coll Cardiol 2003;41:351-9.  Back to cited text no. 46
    
47.
Bernhard S, Möhlenkamp S, Tilgner A. Transient integral boundary layer method to calculate the translesional pressure drop and the fractional flow reserve in myocardial bridges. Biomed Eng Online 2006;5:42.  Back to cited text no. 47
    
48.
Singh IM, Subbarao RA, Sadanandan S. Limitation of fractional flow reserve in evaluating coronary artery myocardial bridge. J Invasive Cardiol 2008;20:E161-6.  Back to cited text no. 48
    




 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Definition
Fractional Flow ...
Special Features
Limitations
Conclusion
Fractional Flow ...
References

 Article Access Statistics
    Viewed100    
    Printed4    
    Emailed0    
    PDF Downloaded20    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]