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.
(SIHD) 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! Source: Fihn JACC 2012;60:e44-e164.
Objective of Anti-Anginal Strategy Reduce Ischemia & Relieve Symptoms Normal Plaque Obstructive CAD SIHD Trials - Stress Test-Guided Care COURAGE: Ischemia Reduction 50% 40% 33.3% p=0.004 Pre-Rx: 28% 30% 19.8% 20% No Ischemia Ischemic Lesion 12m: 2% COURAGE: Angina-Free 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. 10% 0% 1 yr 3 yr PCI + OMT 66% 72% OMT 58% 67% p<0.001 p=0.02
Progressive Manifestations of Demand Ischemia 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 Symptomatic Manifestations Chest Pain Asymptomatic Manifestations ST-T Wave Changes Systolic Dysfunction Diastolic Dysfunction Metabolic Changes Decreased Perfusion Severe Stenosis Moderate Stenosis Exposure Time of Mismatch in Myocardial Oxygen Supply / Demand Near Term Prolonged Source: Shaw JAMA Cardiology 2017 [published online May 24, 2017].
Optimal CAD Evaluation = Anatomy + Physiology 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! Source: De Bruyne NEJM 2012;367:991-1001., Tonino NEJM 2009;360:213-224.
Systematic Review of FFR-CT Concordance with Invasive FFR 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! 86% 75% 46% 46% 98% Source: Cook JAMA Cardiol 2017; Shaw JAMA Cardiol [published online May 24, 2017].
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 Usual Testing (n=100) Exercise ECG (6) Stress nuclear (15) Stress echo (29) Stress MR (2) CTA (60) Sequential cohorts CTA + FFR CT (n=104) FFR CT CTA No FFR CT 38% with CAD 1 - Invasive Cath @ 90 d With No Obstructive CAD CAD: Invasive FFR 0.80 (any % stenosis) or 50% Stenosis 100% 75% 50% 25% No-Obs CAD 0% 6% Usual Testing Obs CAD No Assessment Of CTA alone (n=6) p=0.95 13% 6% 6% FFR-CT (n=13) Source: Douglas Eur Heart J 2015;36:3359 3367.
1-Year Outcomes No Added Prognostic Value of FFR-CT Source: Douglas JACC 2016;9:364-372.
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.
X 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
Stress Imaging Test of Choice for Stable Ischemic Heart Disease
FFR CT & Patient-Centered Care Triple Aim of Healthcare Healthier People Reduces adverse events Better Care Avoid unnecessary testing Smarter Spending Reduce costs Fewer Patients with Adverse Events Unnecessary Procedures Avoided Eliminate cost waste / Improve efficiency 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! Source: www.ihi.org/engage/initiatives/tripleaim/pages/default.aspx.
Coronary Artery Calcium (CAC) Scanning Low Cost (CMS: $59) Adds Anatomic Data with MPI or Use as The Index Procedure Guides Preventive Management No CAC Moderate CAC Mild CAC Very High Risk CAC
FFR CT 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! Initial CTA Strategy Define Stenosis Severity & Atherosclerotic Plaque Features & Diffusivity Atherosclerosis-Guided Prevention Intermediate Stenosis High Grade Lesions Define Ischemia Modify Risk with Intensified Preventive / Symptom-Guided Care