Coronary stenting: the appropriate use of FFR

Morton J. Kern, MDProfessor of Medicine

Chief of Cardiology LBVAAssociate Chief CardiologyUniversity California Irvine

Orange, California

To treat or not to treat?

Is this lesion producing Ischemia?Is PCI appropriate for situation?

The rationale for using coronary physiology is the inability of the 2D images of angiogram to accurately depict the 3D lesion characteristics limiting flow.

75% Dia

20% Dia

Uncertainty in Critical Angiographic Based Decisions

• Intermediate Stenosis, no evidence ischemia

• Left Main Stenosis

• Multivessel CAD

• Serial Lesions

• Ostial and Branch Disease

Aortic, Pa

Coronary, Pd

FFR= Pd/Pa = 65/90 = 0.72

Measurement of FFR correlates to the results of stress testing and ischemia out of the lab. FFR is a ‘stress test’ for that artery in the lab at time of cath.

AdenosineResting pressures

5 Steps to Accurate FFR

1.Zero guide and wire on table to atmosphere2.Insert wire into guide and match wire/guide pressures in aorta3.Cross lesion 2-3cm distal4.Turn on IV adenosine 2-4 minutes5.Confirm accuracy with pressure pull back

Rely on FFR Avoid pitfalls of pressure and FFR

TechnicalTechnical• loose connectionsloose connections• Improper zeroImproper zero• Calibration offsetCalibration offset

AnatomicAnatomic• Extreme tortuosityExtreme tortuosity• Inability to wire vesselInability to wire vessel• SpasmSpasm

MechanicalMechanicalWire/artery impactWire/artery impact

PharmacologicPharmacologic• Inadequate hyperemiaInadequate hyperemia

Hemodynamic Artifacts:Hemodynamic Artifacts:• Damped pressure Damped pressure

waveforms. waveforms. • Guide obstructionGuide obstruction• Contrast media Contrast media • Very small guide (<5F)Very small guide (<5F)

• Pressure signal driftPressure signal drift• Side holes and ostial Side holes and ostial

‘pseudostenosis’ ‘pseudostenosis’

Rely on FFREffect of Wire Introducer

Rely on FFR – No Guide Catheter Side Holes or Damping

From Nico Pijls

Notch

Notch

Notch

No notch

Rely on FFR – Avoid Signal Drift

Drift Drift True Gradient

Distal wave form is one key to drift

Severe stenosis filters high frequency components – No dichrotic notch

Notch

No notch

IV vs IC Pharmacologic Hyperemic agents

Ref Diam (mm)

% Stenosis for an Cross Sectional Area of 4 mm²

< 4 mm² = significant stenosis ?

025502

3

4

5

Q: Why can we not use IVUS/OCT for functional assessment?A: A single cross-sectional area does not mean the same thing everywhere.

Single anatomic parameters do not predict FFR with confidence

IVUS v FFR

When can you NOT rely on FFR?

False Negative FFR 1. Pressure Damping2. No hyperemia - wrong drug, not mixed

not delivered (IV?) or side holes3.STEMI, culprit. STEMI – non-culprit OK4. LM + LAD when FFRepicardial <0.65. Serial lesion FFR of individual lesion (only gradient

useful)False Positive FFR1. Technical errors (Pressure signal drift,zero, etc.)

Application FFR

Ischemia detection, >15 studies Pos <0.75

Neg >0.80

Deferred angioplasty, >8 studies

(Key Study: Defer)

>0.75

Multivessel FFR guided PCI, LM, Ostial, Jailed Side Branch

(Key Study: FAME I, II)

(Key Study: Hamilos for LM)

(Key Study: Koo BW et al)

>0.80

Endpoint of stenting

*(IVUS better post stent)

>0.94*

Coronary Physiologic (FFR) Criteria and Clinical Outcome Studies

62 yo Man, RCA stent occl 2yr ago with return of CP

LAD FFR=0.86, 0.87 Now 1V CAD and new approach

DEFER Study – 5 year data

JACC 2007;49:2105

RW. 59 yo man with Angina, inferior perf defect3V CAD – CABG vs PCI?

FFR=0.71

2 QuestionsHow Accurate is Stress Test?If PCI needed, FFR directed?

JACC 2010;56:177

FAME study: Death and MI after 2 Years

10

0

5

2 year

12.7 12.7

8.48.4

%

FFR-guided

Angio-guided

P= 0.03

9.59.5

6.16.1

P= 0.03

2 year(exclusion of small

periprocedural infarction)

Tonino et al, NEJM 2009, Pijls et al, JACC 2010

Death or MI MI

-6000

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

6000

-0.100 -0.075 -0.050 -0.025 0.000 0.025 0.050 0.075 0.100

Increm. QALYIn

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m. C

os

t [$

]

FFR Guidance Improves outcomes

FFR Guidance Saves Resources

ICER of 50,000 $ / QALY

Incremental QALY

FFR Guidance Improves Outcomes

FFR GuidanceSaves

Resources

Incr

emen

tal C

ost

[$]

DES

CABG

ROTO

BMS

Balloon

Economic Evaluation of FFR-guided PCI in pts with MVD.

Fearon WF et al. Circ 2010;122:25450-2550

FAME: Angiography vs FFRTonino, P. A. L. et al. J Am Coll Cardiol 2010;55:2816-2821

Angiographic 3- or 2-Vessel Disease does NOT equal Physiologic 3- or 2V CAD

3V CAD Angio = 14% physiol 2V CAD Angio= 43% physiol

FAME II – Ischemia directed PCI+OMT vs OMT alone

Stable patients scheduled for 1, 2 or 3 vessel DES stenting

FFR in all target lesions

When all FFR >0.80

OMT

At least 1 stenosiswith FFR ≤ 0.80

Randomisation 1:1

PCI + OMT OMT

Follow-up after 1, 6 months, 1, 2, 3, 4, and 5 years

Randomised Trial Registry

24

50% randomly assigned to FU

25

Rate of Any Revascularisation

131 88 41 40 40 40 35 4 1 1 1 1REGISTRY:OMT only352 256 144 141 140 139 114 25 18 18 18 18RCT:PCI+OMT339 238 123 119 115 112 83 20 10 10 10 8RCT:OMT only

No. at risk Months after randomisation

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10 12

RCT:PCI+OMT vs. REGISTRY:OMT, p=0.54

RCT:OMT vs. RCT:PCI+OMT = 12.1% vs. 1.7% HR (95% CI): 7.63 (3.24-18.0); logrank p<.0001

Cu

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FAME II

71 yo Man with typical angina, pos stress, CAD risk factors

What’s your best approach?

FFR CFX

FFR CFX=0.88

LAD Xience 3.5x18. 2nd LAD lesion? All done?

?

FFR = 0.68

Physiologic Guidance

1. Appropriate need for Stents

2. Objective info re ischemia

3. Eliminates operator uncertainty

Chest pain, No objective evidence ischemia

FFR

FFR FFR

FFR FFR FFR

FFR

FFR

FFR FFR FFR

FFR FFR

Asymptomatic Patients

Revascularization Approaches per AUC

FFR reduces uncertainty and documents appropriateness

2v CAD with prox LAD

3v CAD

Isolated LM

LM and other CAD

Class IIa Guidelines - ACC/ AHA/ SCAI

Class IA Guidelines - ESC

The Mandate for Physiologic Guidance arises from a decade of outcomes studies and is supported by

guidelines