FFR-CT – Not Ready for Primetime

Leslee J. Shaw, PhD, MASNC,

FACC, FAHA, FSCCT

R. Bruce Logue Professor of Medicine

Co-Director, Emory

Clinical CV Research Institute

Emory University School of Medicine

Atlanta, Georgia

E-mail: leslee.shaw@emory.edu

Disclosures: Dean’s Distinguished Faculty Award – Emory University; Woodruff Foundation; Antinori Foundation: NIH-NHLBI (R01HL118019-02, R01HL111150,1U01HL10556-01), Past-President – ASNC / SCCT.

Source: Fihn JACC 2012;60:e44-e164.

Stress Testing – Diagnostic Evaluation of SIHD

Robust Trial & High Quality Registry Evidence for Stress Testing

Numerous Class I Indications For Stress Echo & Nuclear Myocardial Perfusion Imaging

Cannot Just Wipe Away Decades of Evidence!

(SIHD)

Objective of Anti-Anginal Strategy

Reduce Ischemia & Relieve Symptoms

Source: Gibbons 2002 ACC/AHA Guidelines., Abrams NEJM 2005;352:2524-33.; Shaw Circulation 2008;117:1283-

1291., Boden N Engl J Med 2007;356:1503, Frye NEJM 2009;360:2503., Weintraub NEJM 2008;359:677-87.

Normal Plaque Obstructive

CAD

No Ischemia Ischemic Lesion

SIHD Trials - Stress Test-Guided Care

Pre-Rx: 28%

12m: 2%

33.3%

19.8%

0%

10%

20%

30%

40%

50%

PCI + OMT OMT

p=0.004

COURAGE: Angina-Free

66%

72%

58%

67%

p<0.001

p=0.02 1 yr

3 yr

COURAGE: Ischemia Reduction

Stress Testing is Invaluable for Patient Care

Stress Test Findings (HR, BP, ECG Δ,

Arrhythmias, METs) & Knowledge of

Ischemic Threshold Guide Decision Making

Referral to Cardiac Rehabilitation

Exercise Prescription

Use of Anti-Ischemic Therapies

Depending on Ischemia Severity, Follow-up

May Include Invasive Coronary

Angiography & Consider PCI / CABS

Source: Shaw JAMA Cardiology 2017 [published online May 24, 2017].

Asymptomatic Manifestations

Chest Pain

Exposure Time of Mismatch in Myocardial Oxygen Supply / Demand

Near Term Prolonged P

rog

ress

ive

Man

ifes

tati

on

s o

f D

eman

d Is

chem

ia

Decreased Perfusion

Metabolic Changes

Diastolic Dysfunction

Systolic Dysfunction

Symptomatic Manifestations

ST-T Wave Changes

Moderate

Stenosis

Severe

Stenosis

Optimal CAD Evaluation = Anatomy + Physiology

Source: De Bruyne NEJM 2012;367:991-1001., Tonino NEJM 2009;360:213-224.

These Trials Are Not the

Basis for FFR-CT Use

FFR-CT Must be Highly

Correlated w/ Invasive

FFR

If Stress Testing is

Standard of Care, then

FFR-CT Must Improve

Care

Use in Lower Risk

Patients is the Challenge!

5 Reports = 536 patients, 908

Vessels Only 13% with Intermediate

Stenosis

Diagnostic Accuracy Lowest (46%)

for Vessels w/ FFR-CT 0.70 to 0.80

This Range is Critical to Guide Use

of PCI

Requires Further Exploration!

Systematic Review of FFR-CT

Concordance with Invasive FFR

86% 75% 46% 46% 98%

Source: Cook JAMA Cardiol 2017; Shaw JAMA Cardiol [published online May 24, 2017].

6% 13%

6% 6%

0%

25%

50%

75%

100%

Usual Testing FFR-CT

No-Obs CAD Obs CAD

p=0.95

Source: Douglas Eur Heart J 2015;36:3359–3367.

Prospective Longitudinal Trial of FFR-CT: Outcome &

Resource Impacts (PLATFORM) Study

204 Stable CAD Symptoms; Planned Noninvasive (NI) test No prior CAD; Intermediate Pretest Risk

Exercise ECG (6)

Stress nuclear (15)

Stress echo (29)

Stress MR (2)

CTA (60)

No

FFRCT

FFRCT

CTA

Sequential cohorts

Usual Testing

(n=100)

CTA + FFRCT

(n=104)

1°- Invasive Cath @ 90 d

With No Obstructive CAD

No Assessment Of CTA alone

(n=6) (n=13)

38% with CAD

CAD: Invasive FFR ≤0.80 (any % stenosis) or ≥50% Stenosis

Source: Douglas JACC 2016;9:364-372.

1-Year Outcomes – No Added Prognostic Value of FFR-CT

FFR-CT - More Questions Than Answers

? Thresholds for Abnormality

• Standard thresholds - Potential for Unnecessary / Excessive Invasive

Angiography

How to Follow? What to do with a Borderline Result or in Mild Stenosis?

Ignore? Stress Testing?

Which Studies to Send?

• Potential for Overuse in Mild Stenosis

? Clinical Value in Women, Diabetics…

Anatomic Considerations: Calcium Obscuring a Stenosis, Plaque

Composition / Volume, Lumen Shape, Stenosis Length,…

Source: Kern Catheterization & CV Interven 2014;84:414-415.

FFR-CT Misses!

Correlation of Invasive FFR with FFR-CT Important for Revascularization

Decision Making

Outpatient Cohorts - Much Lower Risk with Low Prevalence of Obstructive

CAD Only 13% of Patients have an Intermediate Stenosis

Only a Fraction of Intermediate Stenosis will be Ischemic, FFR-CT will

Provide Limited Guidance to Few Patients

More Data - FFR-CT-Guided Strategy Among Outpatients Remains Vital to

Growing Utilization of this New Technology

X

Stress Imaging – Test of Choice for Stable

Ischemic Heart Disease

FFRCT

& Patient-Centered Care

Not Real-Time Decision Making:

Send the CT Data to Heartflow

Wait! and Wait! For the Remote Read 20-24 hrs

What to do with the Patient?

Cost Inefficient:

High Cost ($1,450)

Low Prevalence of CAD – Benefit Few Patients

Limitations in Diverse Patients: Requires Good Image Quality

No Data on Diverse Populations – Obese,

Women, Diabetics…

Save Your Money!

Reduces adverse

events

Healthier People

Avoid unnecessary

testing

Better Care

Reduce costs

Smarter Spending

Triple Aim of Healthcare

Fewer Patients

with Adverse

Events

Unnecessary

Procedures

Avoided

Eliminate cost

waste / Improve

efficiency

Source: www.ihi.org/Engage/Initiatives/TripleAim/Pages/default.aspx.

No CAC Mild CAC

Moderate CAC Very High Risk CAC

Coronary Artery Calcium (CAC) Scanning

Low Cost (CMS: $59)

Adds Anatomic Data with

MPI or Use as The Index

Procedure

Guides Preventive

Management

FFRCT

Not Ready for Primetime!

Disruptive Technology - Continue to Evolve with Real Time FFR…

Info to Guide Anti-Ischemic Therapy, Patient’s Daily Life, etc. Needed

? Added Prognostic Value Remains Uncertain

Concordance with PET, SPECT?

What is the Clinical Value of FFR-CT?

In Women, Diabetics…

Anatomic Considerations – Eccentricity, Compositional / Volumetric Plaque,…

Development of a Strategy – How to Follow? Serial Measures? …

Randomized Trial – Effectiveness of an FFR-CT Guided Strategy Needed

Costly ($1,450) Technology

We need a greater maturity of the evidence! How & when we utilize the varied physiologic & anatomic components within our armamentarium remain fundamental to improving efficiency, timeliness, & quality of care for the millions of patients evaluated with SIHD each year.

Source: Shaw JAMA Cardiology (in press).

CT-Directed Medical Therapy &

Revascularization For Patients With

Stable Ischemic Heart Disease (SIHD)

Noninvasive Test Strategy To Guide SIHD Management

Effectiveness of Integration of Selective Ischemia Testing Remains Ill-Defined?

Comparative Effectiveness of

Noninvasive Ischemia / Coronary

Flow Reserve, FFR-CT, or

Invasive Measures is Lacking!

High Grade

Lesions

Initial CTA Strategy

Define Stenosis Severity &

Atherosclerotic Plaque

Features & Diffusivity

Intermediate

Stenosis

Define Ischemia

Modify Risk with Intensified

Preventive / Symptom-Guided Care

Atherosclerosis-Guided Prevention