FFR – The Basics Haitham Amin FACC , FSCAI MKCC, Bahrain.
Invasive physiological assessment of coronary disease
Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
Outline 1. 2. 3. 4. 5. 6. 7.
Introduction What is FFR When is it used How is the result interpreted How is it performed Certain caveats Conclusion
Inferior STEMI
50 year old man with atypical chest pain and positive EST
Same scenario
• In patients with CAD, inducible ischemia is an important risk factor for adverse clinical outcome ( MI , death). • Revascularization of hemodynamically significant lesions is more effective in reducing ischemia than OMT alone.
• Non-invasive stress tests and angiography may provide incomplete functional data about a particular stenosis. • FFR provides functional, hemodynamic and physiological assessment of a coronary stenosis.
What is FFR ?
(Pa) max. achievable “ normal” blood flow
(Pd) max. achievable “stenotic” blood flow
Pressure sensor A ratio of (blood) flows that is measured by ratio of pressures
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 3
Fractional Flow Reserve •
Defined as the maximum achievable blood flow in the presence of a stenosis divided by maximum flow in that same distribution as it would be if the supplying artery were normal.
•
FFR can be calculated by pressure measurements in the coronary circulation under maximum vasodilated circumstances using a PressureWire.
•
Theoretically, normal FFR equals 1.0 for any vessel.
Pd / P a
When is FFR useful? • Borderline or intermediate lesions • ( 30-70%) • ? Significant lesions • ? Ischemia • ? Require revascularization • Guides treatment strategy
How is the result interpreted?
How is FFR performed ?
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 4
Adenosine : vasodilator
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
Š 2013 Europa Edition. All rights reserved.
Table 1
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 5
FFR Caveats
Myocardial Blood Flow • Epicardial Blood flow • Microcirculation • Collateral Flow
FFR Caveats • FFR ( myo) = FFR • Flow here refers to Maximal Myocardial Blood Flow, taking into account both anterograde and retrograde collateral blood flow. • Flow also depends on the size / mass of viable myocardium
Lesions similar – 75% stenosis ( similar CSA 4mm2)
Identical Anatomic Coronary vessels with different Physiologic sequealae
Post Myocardial Infarction
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 14
Acute Myocardial Infarction • FFR CANNOT be used in IRA- Infarct Related Artery- ( microcirculation abnormal) • Non-culprit vessels can have accurate FFR • FFR after 5 days in IRA feasible.
IVUS vs FFR
Collateral flow to stenosed artery
Collateral flow from ” normal” artery
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 7
LAD : borderline stenosis RCA occlusion
FFR wire FFR 0.70
RCA territory
LAD Territory
Collateral Flow
LAD : borderline stenosis RCA Stent FFR wire FFR 0.85
RCA territory
LAD Territory
Collateral Flow
Wire Pullback –spatial localization
The PCR-EAPCI Textbook – Percutaneous interventional cardiovascular medicine
Invasive physiological assessment of coronary disease Pim A.L. Tonino, Jan-Willem E.M. Sels, Nico H.J. Pijls
© 2013 Europa Edition. All rights reserved.
Figure 13
Conclusion • FFR is the Gold Standard for ischemia detection related to a particular stenosis – Unequivocal normal value ( 1.0) – Accounts for collateral flow / viable mass – FFR < 0.75 : inducible ischemia – Highly reproducible – Spatial resolution
Thank You