1. Quantitative Flow Ratio (QFR)
Computed FFR based on two angiographic projections
Hector M. Garcia-Garcia MD,
MSc, PhD, FESC, FACC
Director, Angio and IVUS/NIRS corelab
Chairman, Clinical Event Committee

2. Disclosure Statement of Financial Interest
Within the past 12 months, I or my spouse/partner have had a financial interest/arrangement or affiliation with the organization(s) listed below.
Affiliation/Financial Relationship
Company
None

3. Functional Assessment of Coronary Stenosis Using
Angiography: will you treat it?
diameter stenosis (DS): 53%
Anatomy: DS = 53%
vs.
Physiology: FFR = 0.85
Quantitative Coronary Angiography (QCA)

4. Functional Assessment of Coronary Stenosis Using
Angiography: Background
Traditional Methods
Issues
Invasive – need a wire
Need for adenosine:
Discomfort; Arrythmia
Time consuming
Pullback device not available
For bifurcations, wire in both main vessel and sidebranch
Expensive for patient/hospital
Worldwide acceptance 7-10%
Echavarria-Pinto M, Garcia-Garcia HM et al. Interventional Cardiology. Oct 2015 ,Vol. 7, No. 5, 483
Gonzalvez PA, Garcia-Garcia HM et al. JACC: Cardiovascular Imaging. Vol. 8, No. 11, Nov 2015, 1322.

5. Functional Assessment of Coronary Stenosis Using
Angiography: Background
Traditional Methods
Computer Tomography Methods
Echavarria-Pinto M, Garcia-Garcia HM et al. Interventional Cardiology. Oct 2015 ,Vol. 7, No. 5, 483
Gonzalvez PA, Garcia-Garcia HM et al. JACC: Cardiovascular Imaging. Vol. 8, No. 11, Nov 2015, 1322.

6. Quantitative Flow Ratio - QFR: One-stop shop?

7. Quantitative Flow Ratio Relies on 3D QCA
3D vessel modelling is the backbone for the PCI procedure:
Allows the calculation of the functional significance parameter QFR
Optimal viewing angle for PCI
Precise stent sizing
Co-registration with OCT or IVUS

8. In-procedure time: < 5 min
Quantitative Flow Ratio - QFR (Quantitative Flow Ratio = Medis’ QCA derived FFR)
3D model reconstructed from 2 angiographic projections with angles ≥ 25º apart, acquired by monoplane or biplane systems. Patient-specific volumetric flow rate (at hyperaemia) calculated using the combination of contrast bolus front frame count and 3D QCA;
In-procedure time: < 5 min
QFR = 0.87
FFR = 0.85
Based on EuroPCR presentation by Aarhus University Hospital, Skejby, Denmark

9. Quantitative Flow Ratio Study Results – FAVOR I

10. Quantitative Flow Ratio Study Results
FFRQCA versus FFR FN FP
Difference: 0.00 ± (p = 0.541)
Tu et al. JACC Cardiovasc Interv 2014, 7:

11. Quantitative Flow Ratio Study Results – FAVOR II Pilot

12. Functional Assessment of Coronary Stenosis Using
Angiography: Background
1. fQFR: a fixed empiric hyperemic flow velocity (HFV) of 0.35 m/s that was derived from previous FFR studies was used for computation.
2. cQFR: frame count (FC) analysis was performed, without pharmacologically induced hyperemia, to derived the HFV.
3. aQFR: FC analysis was performed during hyperemia, induced by intravenous administration of adenosine or adenosine triphosphate. The “real” HFVs were derived and the software calculated 2 new QFR pullbacks.
Flow velocity is segment length in 3D QCA divided by dye flow time from FC.
Tu S et al. JACC: Cardiovascular Interventions. Vol 9, Issue 19, 10 Oct 2016,2024–2035 .

13. Functional Assessment of Coronary Stenosis Using
Angiography: Background
Tu S et al. JACC: Cardiovascular Interventions. Vol 9, Issue 19, 10 Oct 2016,2024–2035 .

14. QFR analysis in a dedicated offline software (Medis Suite XA)
Certified QFR analysis team
Vessel QFR = 0.54 Lesion QFR = 0.56
Note: The wire based FFR is 0.57

15. Functional Assessment of Coronary Stenosis Using
Angiography: Background
(A) Per patient (73) (B) Per vessel (84).
Tu S et al. JACC: Cardiovascular Interventions. Vol 9, Issue 19, 10 Oct 2016,2024–2035 .

16. Conclusions from Authors
Fast computation of FFR from coronary angiography (QFR), acquired with or without pharmacological hyperemia-induction, is feasible.
Contrast-flow QFR (cQFR) based on conventional diagnostic coronary angiography provides results similar to QFR based on hyperemic conditions, and is superior to fixed-flow QFR.
The favorable results of cQFR bears the potential of a wider adoption of FFR-based lesion assessment, as cQFR might reduce procedure time, risk, and costs (no need to use pressure wire, and no need to induce maximal hyperemia) .
The use of QFR is not without a stiff learning curve, which requires that users be certified by the offline software provider (Medis) before being able to start.
Current indications: Patients with stable angina;
Under investigations: MI, bifurcation lesions, lengthy diffuse disease, etc.

17. QFR Ongoing Studies FAVOR II study Q2FR trial ALL AMI trial
FDA IDE submission
ALL AMI trial