FFR/iFR/PdPa/RFR Caveats:What are the Traps, Common Physician Errors

Morton J. Kern, MDChief of Medicine, VA Long Beach HCS

Professor of MedicineUniversity California Irvine

Orange, California103019 Scripps

Disclosure: Morton J. Kern, MD

Within the past 12 months, the presenter or their spouse/partner havehad a financial interest/arrangement or affiliation with the organizationlisted below.

Company Name RelationshipCompany Name RelationshipAbbott / St Jude SpeakerBSC SpeakerPhilips / Volcano SpeakerAcist Speaker/ConsultantOpsens Speaker/Consultant

• 74 y/o man with HBP, HDL, DM, ESRD on HD, LBBB, andCAD mid LAD stent 6mo. ago (NSTEMI) now with ACS,CP w exertion.

• Same symptoms in 12/2018 which resolved after• Same symptoms in 12/2018 which resolved afterrotablator atherectomy followed by 3.0x38 mm SynergyDES post-dilated to 3.5mm.

FFR=0.86

Diagonal branch narrowing assessed

FFR=0.86

• Successful PCI mid LAD 3.0x23mmXience Sierra DES overlapping theprior LAD stent.

• Provisional bifurcation LAD stentingpinched D1 branch.pinched D1 branch.

• D1 iFR = 0.90; Pd/Pa 0.91; FFR = 0.86,

• Further D1 intervention deferred.

FFR

FFR =Pdistal (hyper)

Paortic (hyper)

Invasive Translesional Pressure Measurements

Non-hyperemic Pressure ratios, NHPRFFR

iFR

iFR =Pdistal (rest, wfp)

Paortic (rest, wfp)

Pd/Pa =Pdistal (rest)

Paortic (rest)

Non-hyperemic Pressure ratios, NHPR

Definitions – Physiologic Indices

Pd

Ahn JM, TCT 2018.

Comparison Physiologic Indices – IRIS FFR Registry

Pd

Ahn JM, TCT 2018.

HyperemicNon-HyperemicPressure Ratios

(NHPR)

Diastolic/Sub-CycleWhole-Cycle

Translesional Coronary Pressure Measurements 2019

Sub maxHyperemic

FFRAll

Systems

≤0.80

Diastolic/Sub-CycleWhole-Cycle

DFR™Boston

Scientific

iFR®Philips

RFR™Abbott

Pd/PaAll

Systems

≤0.91 ≤0.89

dPROpsens

cFFRAll

Systems

≤0.83

Traps and Errors in the use of FFR and NHPR

1. Equipment factors (FFR/NHPR):

– Erroneous zero,(tubing/connector leaks)

– Faulty electric wire connection

– Pressure signal drift,miscalibration, ECG

NHPRRmiscalibration, ECG

2. Procedural factors

– Guide catheter damping

– Incorrect sensor position

– Inadequate hyperemia

– Changing basal flow

FFR

NHPRR

NHPRR

Trap #2: Watch the Pressure Waveformfor Damping?

Courtesy of Nico Pijls.

Traps and Errors in the use of FFR and NHPR

2. Procedural factors

– Guide catheter damping

– Incorrect sensor position

– Inadequate hyperemia– Inadequate hyperemia

– Changing basal flow

– Pick the SMART Minimum FFR

According to Matt Price MD

Why We don’t do FFR…We hate… Solution

Set up, zero, driftAutomatic zero, plug/play, signalstability

Adenosine Pd/Pa, cFFR, NHPRs

Mediocre pressure wire handling,multiple exchanges, etc.

Improved wire construction and micro-monorail catheters

Pull back accuracy Angiographic co-registrationPull back accuracy Angiographic co-registration

Not knowing if microvascular diseaseis really a problem…

It depends…

PW can’t last through complexanatomy, multi lesion, bifurcations

2nd Gen sensors/wires--One-wire startto finish

That I don’t get paid to FFR, but I dofor stenting…

We should do the right thing for thepatient anyway…

Traps and Errorsin the use of FFR and NHPR

Physiological, clinical factors, conceptual barriers

– Serial lesions

– LM

– STE/ACS

– LVH?

– LVEDP?

– RA?

– AS/TAVR

Common Conceptual Barrier: Accepting the angiogram for what it can and cannot tell you

Trap: Are you done? Use of Post-PCI-FFR

574 patients SA/ACS

Improvementin func class

Johnson N, et al. JACC 2014 64(16):1641-54.

Agarwal S, et al. JACC Cardiov. Interv. 2016;9(10):1022-31.

Fournier S, et al.JAMA Cardiol 2019.

Vessel orientedclin outccome

When Can We Use FFR in ACS?

Fearon WF, JACC. 2016 Sep 13;68(11):1192-4. (Table 1).

Is FFR Useful in Culprit Vessel During AcuteMI?

Pijls and Sels, JACC 2012;59:1045.

Baseline Pd/Pa = 0.94 FFR = 0.80

How to Understand Discordancebetween NHPR and FFRbetween NHPR and FFR

Discordance between NHPR and FFR:2 ways to get FFR

De Waard G et al,Eurointervention, Jan 2017.

Predictors of Discordance Between iFR/FFR:Stenosis Location, Severity, HR, Age, and BB’s

(FFR+/iFR-)=69/587(FFR-/iFR+)=52/587

Derimay F, et al. Cath and CV Interven 2019:1-8.

(FFR-/iFR+)=52/587

Physiological Pattern of Diseasehas an Influence on FFR/iFR Discordance

Warisawa T, et al. Circ Cardiovasc Interv.2019;12(5):e007494.

FFR-/iFR+In Diffuse Disease

Intermediate lesion with Pd/Paassessment

Pd/Pa > 0.93Defer

Pd/Pa = 0.87-0.93

Contrast FFR (cFFR) assessment

Pd/Pa < 0.87Intervene

Algorithm for FFR/iFR Discordance

cFFR > 0.83Defer

cFFR = 0.76-0.82

FFR assessment

FFR > 0.80Defer

cFFR < 0.75Intervene

FFR < 0.80Intervene

Clinical Challenges– Patient Outcome Studies in Specific Subgroups