introduction to instantaneous wave-free ratio€¦ · define flair clinical endpoints study...
TRANSCRIPT
![Page 1: Introduction to Instantaneous Wave-Free Ratio€¦ · DEFINE FLAIR Clinical Endpoints Study Objectives: • Determine safety and efficacy of PCI-guided iFR vs. FFR • Determine if](https://reader031.vdocuments.us/reader031/viewer/2022021622/5b8e7b0d09d3f223638db3a0/html5/thumbnails/1.jpg)
Alejandro Aquino MD
Interventional Cardiology Fellow
Washington University in St. Louis
Barnes-Jewish Hospital
Instantaneous
Wave-Free Ratio
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Alejandro Aquino MD
Disclosure
No disclosures
Instantaneous Wave-Free Ratio
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Outline
• iFR Basics
• iFR Data
• Future Directions
• Wash U Experience
• Cases - Caveats
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Physiologic Assessment of CAD
• Basis of FFR modality linear relationship between
pressure and flow under constant and minimized
coronary resistance1
• Under these conditions, changes in pressure across
a stenosis can be a surrogate for blood flow to
myocardium
P = Q x R Pressure = Flow x Resistance
1) Spaan JA. Physiologic basis of clinically used coronary hemodynamic indices. Circulation 2006.
or ∆P = ∆Q x R Change in Pressure = Change in Flow
x Constant Resistance
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Intracoronary Resistance
• Intracoronary resistance fluctuates in a phasic pattern
• Reflects interaction between myocardium and
microvasculature
High Intracoronary resistance
Microvasculature compression
Low Intracoronary resistance
Microvasculature
decompression
Systole Diastole
P =Q x R Pressure = Flow x Resistance
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FFR
HYPEREMIA
• Minimizing IC resistance during measurement of FFR • Calculated during hyperemia (adenosine)
• Average over several cycles
P =Q x R Pressure = Flow x Resistance
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Do we need adenosine?
• Contraindicated or disliked by patients
• Adds to procedural time
• Adds to procedural costs
Davies J. Primary Results of ADVISE. TCT 2011.
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Can a time of naturally occurring stable
resistance be identified?
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iFR
• Instantaneous pressure ratio across a stenosis during
the wave-free period, when resistance is naturally
constant and minimized in the cardiac cycle
Davies J. Primary Results of ADVISE. TCT 2011.
Wave Free Period
Pd/Pa
P =Q x R Pressure = Flow x Resistance
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Development of iFR
• Development and Validation of a New Adenosine-Independent
Index of Stenosis Severity From Coronary Wave–Intensity Analysis:
Results of the ADVISE (ADenosine Vasodilator Independent Stenosis
Evaluation) Study
J Am Coll Cardiol. 2012;59(15):1392-1402.
Tested
hypothesis by
comparing iFR
with FFR
measurements
Identify diastolic
interval in which
IC resistance is
equal to time-
averaged
resistance during
FFR
PROOF OF CONCEPT
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Resistance During the Wave Free Period
Within a defined diastolic wave-free period, resting coronary
resistance was similar to that seen during adenosine-mediated FFR
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Correlation between iFR and FFR
iFR correlates closely with FFR in all coronary arteries
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AUC = 93%
Diagnostic accuracy of iFR as compared to
FFR cutoff value of 0.8
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VERIFY
• Prospective, multicenter study of 206 consecutive pts
referred for PCI and 500 archived pressure recordings
• Excluded h/o CABG, extreme tortuosity, severe calcification,
MI w/in 5 days
• Diagnostic Performance of iFR 0.83 vs FFR 0.80
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VERIFY
• iFR did change during hyperemia
• 0.82 ± 0.16 0.64 ± 0.18
• ROC
• iFR similar to resting Pd/Pa and
trans-stenotic pressure gradient
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iFR vs FFR
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ADVISE Registry
• Evaluated the relationship between iFR and FFR in pts
with intermediate lesions
• Lesions where functional assessment is clinically relevant and in
agreement with guidelines
• 312 pts with 339 coronary stenoses
• AUC 0.86
• Identified optimal
iFR cutoff value of
0.89 to match
FFR value of 0.8
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ADVISE Registry Agreement between
Repeated Measurement of
FFR
Agreement between iFR
and FFR
Overall
classification
agreement of 85%
Overall
classification
agreement of 8o%
Taking into account the FFR repeatability (85%), iFR/FFR
agreement was 94% for classifying lesions as
significant/insignificant
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Hybrid iFR-FFR Approach • Hybrid iFR-FFR decision-making strategy: implications for
enhancing universal adoption of physiology-guided coronary
revascularisation (Euro Intervention, Dec 2012)
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ADVISE II
• Prospective, observational, nonrandomized, double blind, global, multi-center
registry
• iFR value to characterize coronary stenosis as determined by FFR
• n=797 patients evaluated
1) 94.0% match to FFR
2) 65.1% of patients may be free from hyperemic agents
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DEFINE FLAIR Clinical Endpoints
Study Objectives:
• Determine safety and efficacy of PCI-
guided iFR vs. FFR
• Determine if iFR is non-inferior to FFR
to guide PCI
Primary Endpoints:
• Major adverse cardiac events (MACE)
rate in the iFR and FFR groups at 1
year
• MACE (combined endpoint of death,
non-fatal MI, or unplanned
revascularization)
Largest Physiology Study to
Date
• n=2500
• 51 Sites, 17 countries
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Summary Slide
• ADVISE
• Proof of Concept
• ADVISE Registry
• Intermediate Lesions
• Overall good agreement
• Less so around cutoff points
• Hybrid iFR-FFR
• Introduced concept
• ADVISE II
• Hybrid approach tested prospectively
• DEFINE FLAIR
• Ongoing
• Testing clinical endpoints
• VERIFY
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Wash U Experience • Prospective, observational study
• 46 consecutive lesions at BJH Cathlab
• 44 lesions with both FFR and iFR performed
• Mean age 65 ± 8 years
• 26% with diabetes
• All vessels, ostial, proximal, mid and distal lesions
0
.25
.5.7
5
1
Sen
sitiv
ity
0 .25 .5 .75 11 - Specificity
Area under curve = 0.9157, 95%CI 0.83 to 0.99
Diagnostic Accuracy of iFR
Best Cut-point iFR =
0.91
Sensitivity = 86%
Specificity = 86%
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Conclusions – Part 1 • iFR has good correlation with FFR
• High correlation coefficient
• High area under the ROC curve
• Correctly classifies 86% of lesions
• It thus appears to be reasonably reliable in assessing
the functional significance of intermediate lesions
• Recognize the gray zone between 0.86 – 0.93
• May be used in routine clinical practice, saving time
and money
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Cases
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26
1 2
FIO2 & Hct (or Hb) Arterial
Lilly, L. Pathophysiology of Heart Disease. Lippincott, 2007. 4th ed..
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Coronary Reserve
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History of Present Illness
63yo gentleman with a history of CAD with prior
PCI and ischemic cardiomyopathy.
Presents with 2-3 weeks of worsening chest
tightness and dyspnea with exertion.
Given rapid progression of symptoms over the last week he is referred for L heart catheterization.
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Past Medical History
• CAD:
• Promus Element 3.5 x 20mm and 2.5 x 16mm stents placed in
LAD/2nd diagonal bifurcation in 2012
• Promus Element 2.5x28 and 2.5x20 placed in mid LCx in 2012
• Ischemic cardiomyopathy
• EF 25-30% since 2012
• Status post ICD for primary prevention
• HTN
• HLD
• Former tobacco use
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Patent Stents
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RCA
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IFR/FFR Analysis of RCA Lesion
• 6 French JR4 guide
catheter
• Volcano Verrata™
pressure wire
• Runthrough™ wire to
anchor guide
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IFR Assessment of the mid-RCA
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FFR with IV Adenosine
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Stent Deployment
• 4.0x15mm Resolute DES
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Results
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Why the discordance?
• Intact microvasculature needed to achieve minimal
resistance?
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Case 2
• 50yo with ESRD, HTN, HepB
• Prior PCI to RCA with BMS in 2004 (known occlusion of the stent in 2007)
• Prior PCI to LAD with Xience DES in 9/2013
• Presented with unstable angina
• Echo 3/2014: EF 56%, mild concentric LVH
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CFX
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Functional
Assessment
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Case 3
• 81yo with prior CAD admitted with USA and CHF.
• Known EF 30%.
• PCI to LCx and LAD in 2006
• Recent history of GI bleeding resulting in
discontinuation of Plavix.
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LAD
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LAD Assessment – iFR markedly +
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RCA
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Hemodynamic Assessment
of the RCA lesion
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Conclusions – Part 2
• iFR (basal late diastolic) may be more accurate in
patients with tachycardia, LVH , anemia and elevated
LVEDP, ESRD – due to increased basal flow and
max’d out vasodilatory reserve +/- paradoxical
response to adenosine
• FFR is more accurate in patients with damaged or
diseased resistance vessels (ischemic
cardiomyopathy, prior infarct in terrritory and myopathic
supplied muscle) - need intact resistance vessels to
achieve minimal resistance
• Most other subsets have excellent correlation