Instantaneous Wave-Free Ratio

Transcription

1 Instantaneous Wave-Free Ratio Alejandro Aquino MD Interventional Cardiology Fellow Washington University in St. Louis Barnes-Jewish Hospital

2 Instantaneous Wave-Free Ratio Alejandro Aquino MD Disclosure No disclosures

3 Outline ifr Basics ifr Data Future Directions Wash U Experience Cases - Caveats

4 Physiologic Assessment of CAD Basis of FFR modality linear relationship between pressure and flow under constant and minimized coronary resistance 1 P = Q x R Pressure = Flow x Resistance or P = Q x R Change in Pressure = Change in Flow x Constant Resistance Under these conditions, changes in pressure across a stenosis can be a surrogate for blood flow to myocardium 1) Spaan JA. Physiologic basis of clinically used coronary hemodynamic indices. Circulation 2006.

5 Intracoronary Resistance Intracoronary resistance fluctuates in a phasic pattern Reflects interaction between myocardium and microvasculature Systole High Intracoronary resistance Microvasculature compression Diastole Low Intracoronary resistance Microvasculature decompression P =Q x R Pressure = Flow x Resistance

6 FFR Minimizing IC resistance during measurement of FFR Calculated during hyperemia (adenosine) Average over several cycles HYPEREMIA P =Q x R Pressure = Flow x Resistance

7 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.

8 Can a time of naturally occurring stable resistance be identified?

9 ifr Instantaneous pressure ratio across a stenosis during the wave-free period, when resistance is naturally constant and minimized in the cardiac cycle Wave Free Period Pd/Pa P =Q x R Pressure = Flow x Resistance Davies J. Primary Results of ADVISE. TCT 2011.

10 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 PROOF OF CONCEPT Identify diastolic interval in which IC resistance is equal to timeaveraged resistance during FFR Tested hypothesis by comparing ifr with FFR measurements J Am Coll Cardiol. 2012;59(15):

11 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

12 Correlation between ifr and FFR ifr correlates closely with FFR in all coronary arteries

13 Diagnostic accuracy of ifr as compared to FFR cutoff value of 0.8 AUC = 93%

14 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

15 VERIFY ifr did change during hyperemia 0.82 ± ± 0.18 ROC ifr similar to resting Pd/Pa and trans-stenotic pressure gradient

16 ifr vs FFR

17 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

18 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

19 Hybrid ifr-ffr Approach Hybrid ifr-ffr decision-making strategy: implications for enhancing universal adoption of physiology-guided coronary revascularisation (Euro Intervention, Dec 2012)

20 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

21 DEFINE FLAIR Clinical Endpoints Study Objectives: Determine safety and efficacy of PCIguided 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= Sites, 17 countries

22 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

23 0.25 Sensitivity 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 Diagnostic Accuracy of ifr Best Cut-point ifr = 0.91 Sensitivity = 86% Specificity = 86% Area under curve = , 95%CI 0.83 to Specificity

24 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 May be used in routine clinical practice, saving time and money

25 Cases

26 1 2 Arterial F IO2 & Hct (or Hb) Lilly, L. Pathophysiology of Heart Disease. Lippincott, th ed.. 26

27 Coronary Reserve

28 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.

29 Past Medical History CAD: Promus Element 3.5 x 20mm and 2.5 x 16mm stents placed in LAD/2 nd 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

30 Patent Stents

31 RCA

32 IFR/FFR Analysis of RCA Lesion 6 French JR4 guide catheter Volcano Verrata pressure wire Runthrough wire to anchor guide

33 IFR Assessment of the mid-rca

34 FFR with IV Adenosine

35 Stent Deployment 4.0x15mm Resolute DES

36 Results

37 Why the discordance? Intact microvasculature needed to achieve minimal resistance?

38 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

39 CFX

40 Functional Assessment

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43 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.

44 LAD

45 LAD Assessment ifr markedly +

46 RCA

47 Hemodynamic Assessment of the RCA lesion

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49 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