Has Fractional-Reserve Banking Really Passed the Market Test?
Fractional Flow Reserve
Transcript of Fractional Flow Reserve
![Page 1: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/1.jpg)
Fractional Flow Reserve
Interventional Conference
![Page 2: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/2.jpg)
![Page 3: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/3.jpg)
Fundamentals
• Supply and Demand Equation of normal coronary physiology:
– Myocardial Flow will increase to meet demand and is influenced by:
• Heart Rate• LV wall stress• Contractility
![Page 4: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/4.jpg)
Fundamentals
• Sources of perfusion of a vessel:– Epicardial – Myocardial – Collaterals
![Page 5: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/5.jpg)
As per equation stenosis physiology is very flow dependent
![Page 6: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/6.jpg)
• Doppler guidewire sends out 12-15MHz signal reflecting off moving Red Cells
• Measures velocities rather than actual flow – changes in vessel diameter therefore become important
Coronary Flow Reserve
Adenosine given
![Page 7: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/7.jpg)
CFR Definition:
Coronary Flow Reserve
=
Ratio of maximal Flow / resting Flow
Hyperemic to Resting flow ratio and normally greater > 2
![Page 8: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/8.jpg)
![Page 9: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/9.jpg)
CFR
• Normal CFR implies that resistances across epicardial vessels and
microcirculation are low (normal)
• An abnormal CFR is therefore unable to distinguish microvascular impedance to
epicardial impedance due to atherosclerotic disease
![Page 10: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/10.jpg)
Relative Coronary Flow Reserve
Ratio of 2 CFR = One in a target vessel/One in a normal vessel
Assumes basal flow is similar and therefore eliminates effect of the microcirculation
Also derived by separate doppler measurements
Assumes normal vessel is truly “normal”, therefore clinically not very useful
![Page 11: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/11.jpg)
Intra-Coronary FFR
• Lesions produce energy loss by friction, separation and turbulance
• Energy is taken out as heat and pressure loss occurs
![Page 12: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/12.jpg)
FFR=
Maximal Flow in Target artery / Flow in the same artery before the stenosis
Derived by pressure distal to the stenosis and aorta at the time of maximal hyperemia induced by adenosine
![Page 13: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/13.jpg)
![Page 14: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/14.jpg)
![Page 15: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/15.jpg)
![Page 16: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/16.jpg)
FFR differs from CFR in 3 ways
FFR is unaffected by changing the basal flow parameters
FFR is unaffected by systemic pressure
Hypertension decreases CFR
FFR is unaffected by hemodynamics
Increased contractility increases CFR
Tachycardia will increase CFR
![Page 17: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/17.jpg)
![Page 18: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/18.jpg)
![Page 19: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/19.jpg)
Drugs used to induce hyperemia
Drug Dose Onset ½ Life Side E.
Papaverine IC
15mg LCA
10mg RCA
30 – 60 s 2 min QT prolong
TdP
Adenosine
IV
140mcg/kg/min
60 - 120 s 1 – 2 min Hypotension
CP
Avoid in asthma
Adenosine
IC
>30 LCA
24-36 RCA
5 – 10s 0.5 – 1 min AV Block in dominant artery
Repeated in escalating doses
Dobutamine
IV
20 - 40 g/kg/min
60 -120 s 3 – 5 min Tachycardia
Elev. BP
Nitroprusside IC
0.3-0.9 g/kg 20 s 1 min Dec. BP
![Page 20: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/20.jpg)
FFR vs. IVUS vs. Spect
![Page 21: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/21.jpg)
![Page 22: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/22.jpg)
![Page 23: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/23.jpg)
Conclusion
• FFR is comparable to IVUS and SPECT imaging
• FFR < 0.75: – Specificity 100%– Sensitivity 88%– PPV 100%– Accuracy 93%
![Page 24: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/24.jpg)
Radi Wire
![Page 25: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/25.jpg)
Handling characteristic almost similar to standard guidewires
Compatible with monorail balloon catheter systems
![Page 26: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/26.jpg)
Intermediate lesions with Normal FFR
![Page 27: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/27.jpg)
Importance of lesion assessment
![Page 28: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/28.jpg)
![Page 29: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/29.jpg)
![Page 30: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/30.jpg)
![Page 31: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/31.jpg)
Mild Angiographic disease with positive FFR
![Page 32: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/32.jpg)
Angiographically unremarkable LAD in patient with angina
Area with significant FFR reduction identified with pressure wire assessment
![Page 33: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/33.jpg)
![Page 34: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/34.jpg)
Serial Stenosis and Diffuse Disease
![Page 35: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/35.jpg)
![Page 36: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/36.jpg)
Multiple sequential lesions:
Can be assessed by a gradual pull back and guide intervention
Illustrated are a significant step up at the distal and proximal stenosis
Mibi Spect is usually unable to differentiate between severe stenosis in a single vessel
![Page 37: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/37.jpg)
Multivessel Disease
• Number of small studies examined tailored approach selective PCI for hemodynamically significant stenosis + medical therapy vs. CABG
• After 2 years follow up no difference in event free survival with decreased repeat revascularization compared to standard trials
![Page 38: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/38.jpg)
Considerations
![Page 39: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/39.jpg)
![Page 40: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/40.jpg)
FFR = 0.94
![Page 41: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/41.jpg)
FFR with ostial lesions
• No indication for stenting for ostial lesions with normal FFR
• Many case reports on FFR measurements in jailed sidebranches after bifurcation stenting
• No studies on the validity of FFR in this lesion subset
![Page 42: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/42.jpg)
FFR for Stent Deployment
![Page 43: Fractional Flow Reserve](https://reader033.fdocuments.in/reader033/viewer/2022051816/5467bbb8af79597e338b568e/html5/thumbnails/43.jpg)
-FFR does not help with stent implantation is because the stent implantation relies on the anatomic structures surrounding the stent.
-However, FFR does provide prognosis and can identify gross under deployment in many patients.