Baisc Concept and Technique of FFRBaisc Concept and Technique of FFR

FuWai Hospital

JieQian

Hemodynamic of Coronary Flow

Special Stess Test in Cathlab

Complementary to CTA

Physiology Of Coronary Flow

The Coronary Circulation-AnatomyThe Coronary Circulation-Anatomy

AoAo

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CollateralsCollaterals MyocardiumMyocardium

epicardial arterial vessels - myocardial microcirculation - venous component

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MICROMICROMACROMACRO

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Physics Law

Klocke, FJ, Measurement of Coronary Flow Reserve: Defining Klocke, FJ, Measurement of Coronary Flow Reserve: Defining pathophysiology versus making decisions about patient care; pathophysiology versus making decisions about patient care; CirculationCirculation: 1987; 76: pp 1183-1189: 1987; 76: pp 1183-1189

5.05.0

3.03.0

1.01.0

Coronary pressureCoronary pressure

Maximum vasodilationMaximum

vasodilationCoronary

flowCoronary

flow

Coronary reserve

Coronary reserve ==

FlowFlow dilateddilated

FlowFlow initialinitial

The Coronary Circulation-Physiologic RegulationThe Coronary Circulation-Physiologic Regulation

CFR

CFR ＝ Qsmax /Qs

rest

Normal Vaulue Vary

Pathology of Coronary Flow

CFR :3 － 5 times？Is it specially to lesion?

No ，Yew ， but no speciality

rCFR(RFR)=Qsmax /Qn’

max

Rstenosis

Rmyocardial

FFR

CFR

CFR and rCFR: What Do They Investigate?

Hypothetical Case

A ： 60 ％ DM

B ： 80 ％ no DM

CFRa maybe =CFRb ＝ 2 or 1.7

Interventional Carlogist Care What？

If Intervention

Ischemia

Research

Better Criteria？

Yes

FFR ＝ Qsmax /Qn

max=Pd/Pa

Why Flow (Q) = Pressure

Coronary Stenosis RheologyCoronary Stenosis RheologyPressure-Flow RelationshipPressure-Flow Relationship

Pressure drop across stenosis increases with flow in a non-linear fashionPressure drop across stenosis increases with flow in a non-linear fashion

Entrance effects Separation losses

Friction loss

FFR Definition

FFR Definition

FFR Definition

FRACTIONAL FLOW RESERVE:

The index FFR (Fractional Flow Reserve)is based upon the two following principles:

• It is not resting flow, but maximum achievable flow which determines the functional capacity (exercise tolerance) of a patient

• At maximum vasodilation (corresponding with maximum hyperemia or with maximum exercise), blood flow to the myocardium is proportional to myocardial perfusion pressure

(~hyperemic distal coronary pressure)

Normal Value of Myocardial Fractional Flow Reserve

Normal FFR = 1

Pa Pd

FFR = Pa

Pd

0.014”

3 cm

Pressure Monitoring Guide Wires

Coronary Hyperemic Stimuli

PRACTICE OF CORONARY PRESSUREMEASUREMENT AND FFR （ 1 ）

1. Verification of equal signals when sensor at tip of the guiding catheter. Equalization if necessary

2. Advance wire, sensor crosses stenosis

3. Induce maximum hyperemia and measure FFR

4. Because sensor is 3 cm from tip, easily pull-back and push-up for exact spatial information.

If desirable, perform pull-back recording

PRACTICE OF CORONARY PRESSUREMEASUREMENT AND FFR （ 2 ）

5. PCI if indicated, with possibility for Pw measurement for collateral flow assessment

6. Followed by FFR measurement to check result.

If desired, perform hyperemic pull-back recording

7. verify absence of drift at the end of procedure, or between measurement in several vessels

LAD

resting adenosine i.v.

pull-back across LAD plaque

hyperemic pull-back recording

200

100

0

200

100

0

Aortic Pressure = 122 mm Hg Aortic Pressure = 89 mm Hg

Coronary Pressure = 52 mm Hg Coronary Pressure = 40 mm Hg

ΔP = 70 mmHG

FFR = 52/122 = 0.43 FFR = 40/89 = 0.45

Influence of Systemic Pressure on Transstenotic Gradient

ΔP = 49 mmHG

1

ExerciseTest

ThalliumScan

Dobut.echo

0.3 0.4 0.5 0.6 0.7 0.8 0.9True Positive Stress Tests

Negative Stress Tests

FFR and Non-Invasive Stress Testing in Lesions of Intermediate Severity

Pijls NHJ, de Bruyne B, Peels K et al. New Engl J Med 1996

Ischemic Threshold Values of FFR AAAuuuttthhhooorrrsss RRReeefff PPPaaatttiiieeennntttsss ### TTTeeesssttt TTThhhrrreeessshhhooolllddd

De Bruyne et al. Circ 1995 1-VD 60 Bicycle ECG 0.72*

Pijls et al. Circ 1995 1-VDpre+post PCI

60 Bicycle ECG 0.74*

Pijls&De Bruyne NEJM 1996 1-VD,Intermediate Sten

45 Bicycle ECG +TL+Dobut Echo

0.75*

Bartunek et al. JACC 1996 1-VD 75 Dobutamine Echo 0.78*

Chamuleau et al. JACC 2000 MVD 127 MIBI-Spect 0.74**

Abe et al. Circ 2000 1-VD 46 Thallium 0.75*

De Bruyne et al Circ 2001 Post MI 57 MIBI-Spect 0.75 - 0.80*

* 100 % Specificity; ** Optimal Cutoff Value* 100 % Specificity; ** Optimal Cutoff Value0.750.75

Hemodynamic of Coronary Flow

Special Stess Test in Cathlab

Complementary to CTA

Thanks