FFR Assessment of the Left Main

Stem and Downstream Coronary

Stenoses

Dr Phil MacCarthy

Consultant Cardiologist

King’s College Hospital

A meeting of Interventional Cardiologists in 1808…

Diagnostic techniques have evolved considerably…

1958 — The diagnostic coronary angiogram — the key to selective

imaging of the heart was discovered by Dr Mason Sones

The coronary angiogram has limitations

This lady received grafts for this lesion…

But her chest pain continues 10 years later!

Figure 4. Relation between FFR values and the 2 reviewers’ visual estimations (lesions were classified as significant, nonsignificant, and unsure).

Hamilos M et al. Circulation 2009;120:1505-1512

Copyright © American Heart Association

We’re not very good at guessing the physiology from the angiogram

Figure 2. Scatterplots showing the distribution of percent DS and the corresponding FFR

values.

Hamilos M et al. Circulation 2009;120:1505-1512

Copyright © American Heart Association

Copyright ©2010 American College of Cardiology Foundation. Restrictions may apply.

Kern, M. J. et al. J Am Coll Cardiol 2010;55:173-185

Why Does the Angiogram Fail to Predict Physiology?

This is particularly true of the short, often acutely angulated LMS

Copyright ©2009 American College of Cardiology Foundation. Restrictions may apply.

Gould, K. L. J Am Coll Cardiol Img 2009;2:1009-1023

Reference Standard for Visual Percent Stenosis

The consequence of using the angiogram alone

Why would anyone rely on angiography alone?

Is it safe to use FFR to guide

revascularization?

Figure 5. Kaplan–Meier mortality curves showing percent survival (A) and major adverse

cardiac events (MACE; B) in the 2 study groups.

Hamilos M et al. Circulation 2009;120:1505-1512

Copyright © American Heart Association

JACC 2012;5:697-707

JACC 2012;5:697-707

Scenario 1 – LM Bifurcation

Always interrogate both limbs

Figure 1. IVUS classification for LMCA bifurcation plaque distribution.

Oviedo C et al. Circ Cardiovasc Interv 2010;3:105-112

Copyright © American Heart Association

82% stenoses involve both limbs

Scenario 2 – Significant downstream

disease

‘Maximal hyperaemia’ is limited

Modest LMS ‘taper’

Critical prox LAD disease

FFR(A)pred = Pd - (Pm/Pa) Pw

Pa - Pm + Pd -Pw

FFR(B)pred = (Pa - Pw) (Pm - Pd)

Pa (Pm - Pw)

Pw = Coronary occlusive pressure De Bruyne et al, Circulation 2000

LMS lesion is often a ‘serial stenosis’

JACC 2012;5:697-707

Maximal hyperaemia is

only achievable across the

LMS when down-stream

disease has been treated

JACC CI 2012;5:1021-1025

JACC CI 2012;5:1021-1025

Scenario 3 – Ostial LMS

Equalise PW in the guide catheter

Back the guide out

3 mm

3 mm

3 mm 1.8 mm

2.1 mm

2.4 mm 64%

49 %

36 %

Area

Stenosis

8F

7F

6F

Guiding Catheter in Ostium = Stenosis

Scenario 4 - LMS with collateralised,

occluded RCA

Flow is greater than normal across the LMS

Opening the RCA will decrease this – and increase your FFR

Conclusions (1)

• The FFR principles are the same in the LMS

• Why rely on angiography alone?

• FFR-guided LM revascn seems safe (no RCT)

• The LMS is often a ‘serial stenosis’ – ability to

achieve maximal hyperaemia is limited

– Severe downstream disease increases LM FFR

– ‘Composite FFR’ can be used as a guide

• Back the guide out and use central, iv

adenosine

• Interrogate both limbs (LAD and Cx)

• Use in conjunction with IVUS to fully

characterise (not instead of)

Conclusions (2)

Thank you

Reproducibility of Coronary Pressure Measurements

ADO IC 1 ADO IC 2 ADO IC 3

FFR = 0.53 FFR = 0.53 FFR = 0.54

How did angio severity relate to FFR?

JACC 2010;55:2816-21

Consultant Colleague’s Mother…

…made simple

? ?

Thank you

Acknowledgements:

• Bernard De Bruyne

• Nico Pijls

Intracoronary Bolus of Adenosine 20 µg

time-to-peak: 15”

Plateau: 5”

Total duration: 35”

Reproducibility of Coronary Pressure Measurements

ADO IC 1 ADO IC 2 ADO IC 3

FFR = 0.53 FFR = 0.53 FFR = 0.54

Intravenous Infusion of Adenosine 140 µg/kg/min

Adenosine IV

Femoral

Intravenous (Femoral) Infusion of ATP 140 µg/kg/min

ATP STOP

Aortic Pressure, Pa

Distal Coronary Pressure, Pd

Coronary Flow Velocity

time-to-peak: 20”

Plateau: 12”

Total duration: 60”

Intracoronary Bolus of Papaverine 20 mg

Ventricular Tachycardia After 20 mg IC Papaverine

P d /P a (ADO)

P d

/P a

(DO

B 4

0)

0.4 0.6 0.8 1.0

0.4

0.6

0.8

1.0

Pd/P

a (

Ad

en

osin

e)

Pd/Pa (Dobutamine)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Bas

elin

e

Pap

a 1

ADO 20

ADO 40

ATP

20

ATP

40

Con

tras

t

ADO f

140

ADO f

180

ADO p

140

ADO p

180

ATP

f 14

0

ATP

f 18

0

ATP

p 140

ATP

p 180

Pap

a 2

Pd / Pa

Papaverine, Adenosine and ATP for Resistance Vessel Dilation

Practical tips

• Induction of hyperaemia

• ‘Pull-back’ under maximal hyperaemia

• Guide catheters

• Pressure wire ‘drift’

Angiogram

Angiogram

Distal LAD Guide catheter

Distal LAD Guide catheter

FFR-guided

30 days

2.9% 90 days

3.8%

180 days

4.9%

360 days

5.3%

Angio-guided

Absolute Difference in MACE-Free Survival

FAME study: Event-free Survival

Practical tips

• Induction of hyperaemia

• ‘Pull-back’ under maximal hyperaemia

• Guide catheters

• Pressure wire ‘drift’

3 mm

3 mm

3 mm 1.8 mm

2.1 mm

2.4 mm 64%

49 %

36 %

Area

Stenosis

8F

7F

6F

Guiding Catheter in Ostium = Stenosis

Femoral Artery Guiding Catheter

Distal Coronary Artery

Rest Hyperemia

FFR = 63 / 81 = 0.78

Influence of the Guide Cath in the Ostium

Guide = Engaged into Ostium

FFR = 63 / 88 = 0.71 Femoral Artery Guiding Catheter

Distal Coronary Artery

Rest Hyperemia

Influence of the Guide Cath in the Ostium

Guide = Disengaged