Coronary CTA : The Test of Choice for Obstructive CAD

LMLAD

LCxLM

LMLAD

LCx

Intramural hematoma

13.9 mm

LAD

Diag

Septals

LCxRCA

Harvey S. Hecht, MD, FACC, FSCCT Associate Director of Cardiovascular Imaging Professor of Medicine, Icahn School of Medicine at Mount

Sinai

Vessel Analysis

• CTA QCA: measure rather than eyeball

% Stenosis

1. 25-50

2. 50-75

3. > 75

Ostial LAD

62% stenosis

• Area calculation far superior to MLD: MLD has no physiologic significance except in the rare perfectly concentric lesion

Vessel Analysis

• CTA QCA: measure rather than eyeball

Ostial LAD

Obstr Reference % Stenosis

Effective diameter (mm) 3.1 5.8 46

Lumen area (mm2) 7.7 26.0 71

L Main

Calcified plaque

noncalcified plaque

lumen

L Main

MLA 4.3 mm2

L Main

noncalcified plaque

lumen

Calcified plaque

L Main

MLA 4.3 mm2 4.5 mm2

MLA 13.0mm2 3.8 mm2

47 yo asymptomatic male 2 yrs after LCx DES; ST elevation with exercise, nl LM on cath

LAD

LM

bridge

LAD

MLA 2.7 mm2 2.8 mm2

LM

LCxLAD

LCx

LM

LAD

MLA 5.5 mm2 3.6 mm2 3.3 mm2

448

-11

89

70

138

Intramural hematoma

LM/LAD

MLA 5.9 mm2 3.1 mm2 2.5 mm2

dLM oLAD pLAD

hematomahematoma hematoma

hematoma

hematoma

Stents

Normal Normal

in-stent restenosis

stent fracture

jailed branches

edge stenosis

bifurcation stents

inadequate stent expansion

Stent sizing

1% of CTA volume Failure of image acquisition Inability to selectively cannulate a native vessel or graft Severe pressure damping

Requirement for additional information Ostial disease versus spasm Course of anomalous vessels Relationship of bypass grafts to the sternum Graft morphology Chronic total occlusions

J Inv Cardiol 2008;20:1-6

Septals

Diag

RCA

LAD

LADSeptal

CTO

Diagnostic Performance and Comparative Cost-Effectiveness of Non-invasive Imaging Tests in Stable Patients

with Suspected Coronary Artery Disease: A Systematic Overview

Van Wardhuizen.Curr Cardiol Rep 2014;16:537

Diagnostic 13 studiesCost Effect 11 studies

Sens SpecCTA 83-100% 81-92%CMR 87-91% 70-84%SPECT 81-94% 48-85%PET 84-90% 81-88%SE 68-87% 72-93%

CTA best gatekeeper

CTA most cost effective

Accuracy

# Studies Sensitivity Specificity ArteriesSPECT 45 69% 79% CMR 17 84% 83% PET 7 77% 88% CTA 12 97% 93%

Diagnostic Performance of SPECT, CMR and PET for Detection of Obstructive CAD: Meta-analyses

Jaarsma JACC 2012; ;59:1719–28 von Ballmoos. Ann Int Med 2011;154:413-20

Accuracy

Comparison of Nuclear and CTA for >50% Stenosis in Individual Arteries

* Meijer et. AJR 2008; 191:1667–75

Sens Sens Spec ● * Nuclear CTA Segments 90.8% 95.7% proximal 94.2% 94.1% distal 84.8% 96.9%Vessels Lmain 85%† 100% 99.1% pLAD 81% 94.3% 93.8% pLCx 77% 85.3% 95.4% pRCA 75% 95.8% 97.7%

● Mahmarian.JACC 1990:318-29 †Berman JNC 2007;14:521-8

Accuracy

Pre-test vs Post-test Probability of CAD by SPECT MPI, 2DE and CCTA

Nuc Sens 83% Spec 77%Echo Sens 83% Spec 81%

CCTA Sn 94% Sp 89%64 slice 2005-2009

ACC/AHA/ASE 2003 Guidelines for EchocardiographyACC/AHA/ASNC 2003 Guidelines for Cardiac Radionuclide Imaging

Pre-test probability of Disease (Prevalence)

143 pts TVD: >70% 3V or >50% LM+>70% RCA

SPECT MPI for Triple Vessel Disease

Lima et al. JACC 2003;42;64-70

Perfusion Perf+ FunctionNL 18% 12%SVD 36% 28%DVD 36% 35%TVD 10% 25%MVD 46% 60%Specificity 72% 69%

Conc: MPI fails to identify 40% of high risk TVD pts

Accuracy

80/1327 pts without known CAD

LM > 50 % stenosis + >70% other V

MPI Total LM LM+LAD/LCx LM+RCA LM+3VD

NL 10% 9% 20% 9% 4%

Low risk 5% 0% 10% 5% 0%

Hi risk 85% 91% 70% 86% 96%

Berman et al. JNC 2007;14:521-528

Detection of Left Main Stenosis by SPECT Imaging

Conclusion: MPI misses 15% of the highest risk pts

Accuracy

MDCT Meta-analysis of Coronary ISR

Andreini. AJC 2010; 105:645– 655

Sens 89.7%Spec 92.2%PPV 72.5%NPV 97.4%Accuracy 91.9%Non evaluable 9.6%

18 studies 64 MDCT: 1300 pts, 2003 stents

AccuracyStents

Segmental Accuracy Prev Sens Spec PPV NPV

Bypass grafts 19% !00% 100% 100% 100%

Natives Distal runoffs 13% 95% 100% 100% 99% All grafted V 59% 100% 96% 97% 100% All nongrafted V 29% 97% 92% 83% 99%

Westinck et al.JACCImg 2009;2:816-24

Diagnostic Accuracy of CTA in CABG Patients

52 post CABG pts

AccuracyCABG

SVG-LAD

MLA 5.6 mm2 29.5 mm2

• Graft analysis

SVG-M1

MLA 16.6 mm2 2.6 mm2 12.6 mm2 6.8 mm2

Beller. Circulation 2000;101;1465-1478

Meta-analysis of 12,000 pts in 14 studies

Nuclear Stress Testing and PrognosisPrognosis

Stress Echocardiography and Prognosis

Yao et al. JACC 2003;42;1084-1090

1500 pts; 2.7+1.0 yr f/u

Nl Mild/Mod Abnl Sev Abnl

Prognosis

Meta-analysis of Prognostic Value of CTA 18 studies, 9,592 patients, median f/u 20 months

Sens .99Spec .41

Pooled negative likelihood ratio after nl CTA: .008

Hulten. JACC 2011;57:1237-47

Prognosis

Prognostic Value of CCTA during 5 Years of Follow Up Prognosis

1453 pts suspected CADMedian f/u 5.6 y; 58 hard events- death or nonfatal MI

CAD Annual EventsNormal 0.2 %Nonobstructive 0.7 %Obstructive 1.2%

CAD Improves Morise Risk ScoreNonobstructive 0.003# Abnormal segment <0.001

Hadamitsky. JACC 2012;59:A325

CAD and Adverse Events in Symptomatic Patients With 0 CAC Undergoing CTA: CONFIRM

Villines. JACC 2011;58:2533–40

10,037 symptomatic pts, 56 y, 51% 0 CAC, 2.1 y f/u

0 CACNo CAD 84%Nonobstr 13%>50% 3.5%>70% 1.4%

Events 0 CAC +Nonobstr 0.8%0 CAC + >50% 3.9%P <0.001

No mortality diff 0 CAC w/w/o obstr

Prognosis0 CAC

Age, Sex, and Angina Typicality–Based Approach for PretestProbability of Significant CAD by CTA: CONFIRM

Cheng. Circulation 2011;124

>50%DS

Men Women

Typical angina 40% 19%

Observed 29%

Predicted 86%

Atypical angina Observed 15%

Predicted 47%

All Observed 18%

Predicted 51%

14048 patients with suspected CAD Angina typicality, age, sex, for pretest likelihoods of >50% DS

PrognosisSymptoms

Stress echocardiography 0

Tc-99m tetrofosmin rest-stress (10 mCi 30 mCi) 10.6 Tc-99m sestamibi 1-day rest-stress (10 mCi 30 mCi) 12 Tc-99m sestamibi 2-day stress-rest (30 mCi 30 mCi) 17.5 TI-201 stress and reinjection (3.0 mCi 1.0 mCi) 25.1Dual-isotope (3.0 mCi Tl-201 30 mCi Tc-99m) 27.3New nuclear scanners 4-6Stress only 2-3

Retro MDCT coronary CTA (m) 9.6–15.2Retro MDCT coronary CTA (f) 13.5–21.4Retro MDCT coronary CTA (m) dose modulation 7.0-12Retro MDCT coronary CTA (f) dose modulation 9.0-14.0Pro Step & shoot 2-5Retro Iter Recon 3-6Pro Iter Recon Step & shoot 0.26-2

Cardiac catheterization 4-Hiroshima

Radiation Doses (mSv)

Thompson RC, Cullom SJ .J Nucl Cardiol 2006;13:19-23.

Radiation

“The relationship between radiation and the development of cancer is well understood: A single CT scan exposes a patient to the amount of radiation that epidemiologic evidence shows can be cancer-causing.”

We Are Giving Ourselves CancerBy RITA F. REDBERG and REBECCA SMITH-BINDMAN

New York Times Editorial JAN. 30, 2014

Radiation Dose in 256 Coronary CTA

Perisinakis. Circulation. 2010;122:2394-2402

Prospective CTA

Lung Ca RR Life attributable riskWomen 1.0032 24.9/100,000Men 1.0008 7.3/100,000

“The mean projected life attributable risks of radiation-induced cancer in a typical clinical patient cohort undergoing standard prospectively ECG-gated CCTA with a 256-slice scanner were found to inconsequentially increase the natural cancer incidence rates”

Radiation

Stress Myocardial CT Perfusion

Blankstein JACC2009;54:1072–84

Function

Author Scanner Reference N Population Se Sp

Kurata 16CT (stat) SPECT-MPI 12 Susp CAD 90 79

George 64/256CT (stat) QCA/SPECT 27 Pos SPECT 81 85

Blankstein 64DSCT (stat) QCA/SPECT 33 SPECT/ICA 93 74

Ho 128DSCT (dyn) SPECT 35 Recent MPI 83 78

Ko 64DSCT (stat) MRI 41 Known CAD 91 72

Tamarapoo 64DSCT (stat) SPECT 30 Pos SPECT 92 86

Weininger 128DSCT (dyn) MRI 20 Acute CP 93 99

Feuchtner 128DSCT (stat) MRI 30 Kwn/susp. CAD 96 95

Bamberg 128DSCT (dyn) FFR 36 Kwn/susp. CAD 93 87

Ko 320CT FFR 42 Kwn CAD 76 84

CORE320JACC 13Pooled 306 88.3 83.1

CT Perfusion: Diagnostic Performance

Validation Paradox

Echo Cath CTA

IVUSNuclearFFR

PETMRI

Functional tests (stress tests and FFR) and IVUS area criteria are used to judge the anatomic gold standard (cath) by which they were validated

The cath gold standard is flawed; does not correlate with IVUS

Outcomes may be the true gold standard: FFR

Hecht. JCCT 2009: 3, 334–339

PCI of Functionally Nonsignificant Stenosis:5-Year Follow-Up of the DEFER Study

Pijls. JACC 2007;49:2105–11)

325 pts with intermediate (50%) stenosis scheduled for PCI

n FFR PCIDEFER 91 >0.75 no PERFORM 90 >0.75 yesREFERENCE 144 <0.75 yes

Conc: No benefit for PCI when FFR>0.75

Function

FFR vs Angiography for Guiding PCI in Multivessel CAD:2-Year Follow-Up of the FAME Study

Pijls. JACC 2010;56:177–84

Death/MI PCI/CABG Death/MI/RevascAngio 12.9% 12.7% 22.4%FFR 8.4% 10.6% 17.9%P <0.02 0.30 0.08

MI RevascDeferred lesions: 0.2% 3.2%

1005 randomized multivessel CAD pts Angio guided PCI: all lesions stented FFR guided PCI: stent only if FFR< 0.80

FFR in multivessel CAD PCI with DES significantlyreduces 2 yr death/MI compared to angiography-guided PCI

Function

Non-invasive FFR (FFRCT)

50

3-D FFRCT map computed

FFRCT = 0.72(can select anypoint on model)

Computational Model based on CCTA

Calculate FFRCT

No additional imagingNo additional medications

3-D anatomic model from CCTABlood flow equations solved

on supercomputer

Blood Flow Solution

Physiologic models- Myocardial demand- Morphometry-based boundary condi-

tion- Effect of adenosine on microcircula-

tion

Case ExamplesCCTA Invasive angiographyFFRCT FFR

>50% diameter stenosis >50% diameter stenosisFFRCT 0.74 ischemia FFR 0.74 ischemia

0.74

0.85

FFR

>50% diameter stenosis FFRCT 0.85 no ischemia FFR 0.84 no ischemia>50% diameter stenosis

FFR

DISCOVER: Single center trial 103 pts

30% 40% 50% 60% 70% 80% 90% 100%30%

40%

50%

60%

70%

80%

90%

100%

Stress EchoJung, EHJ 2008

cCTAMin, JAMA 2012Koo, JACC 2011Meijboom, JACC 2008Norgaard 2013

SPECTMelikian, JACC CV Interventions 2010

Invasive AngiographyPark, JACC CV Interventions 2012Meijboom, JACC 2008

IVUSWaksman, JACC 2013

cCTA TAGYoon, JACC Imaging, 2012

FFRCTNorgaard 2013

Diagnostic performance of non-invasive imaging vs. FFR*FFR

Gold Standard

Spec

ificity

Sensitivity

NXT FFRCT

*Inclusive of all published studies comparing imaging against invasive FFR

Unsuspected Dissection and PEOther

RUL

LMLAD

LCxLM

LMLAD

LCx

Intramural hematoma

13.9 mm

LAD

Diag

Septals

LCxRCA

Harvey S. Hecht, MD, FACC, FSCCT Associate Director of Cardiovascular Imaging

Professor of Medicine, Icahn School of Medicine at Mount Sinai

Disclosure: Philips Medical Systems Consultant

Coronary Plaque Characterization by CT: Is the Stenosis Paradigm Too Simple?

CTA Characteristics of Plaques Subsequently Resulting in ACS

Motoyama, Narula. JACC 2009;54:49–57

ACS+ ACS- pPR 127 % 113 % .003PV 135 mm3 58 mm3 .001 LAP V 20 mm3 1.1mm3 .001%LAP/ 21.4% 7.7% .001 plaque area

1059 pts suspected or known CAD 27+10 mo f/u

Plaque

Impact of Coronary Plaque Composition by CTAOn Troponin Elevation After PCI in Stable Angina Pectoris

Watabe. JACC 2012;59:1881–8

T+ T- pHU 43 (27-76) 94 (65-109) <0.001RI 1.20 1.04 <0.001Spotty Ca 50% 11% <0.001

107 stable pts : 36 T 3xnl, 101 nl T post PCI

ORRI>1.05 4.54Spotty Ca 4.27

HU<55+RI>1.05+SC PPV 94%HU<55+RI<1.06, -SC NPV 90%

Plaque

CTA Plaque Characteristics and PCI Slow-Flow

Kodama. JACC Intv 2012;5:636–43

40 consecutive slow flow pts; 40 matched controls

SF NSF pCPC 63% 5% <0.001PRI 1.5 1.2 <0.001LAP 23.5 45 <0.001 (9.5-40) (29-86)

OR p CPC 79 <0.001Min HU 0.977 0.013Dyslipid 18 0.04

CPC: >180 deg of perimeter, >1/3 of plaque length

Plaque

Initiation of Aggressive Medical Therapy in Patients with 0 CAC Scores and Noncalcified Plaque.

Plaque

Ultra-aggressive Treatment of Nonobstructive Lesions Plaque

Accelerate Timing of PCIPlaque

Modify Interventions to Prevent PCI Complications Plaque

Override Fractional Flow Reserve (FFR) CriteriaPlaque

FFR 0.81

Smith. BMJ 2003;327:1459–61

We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

Conclusions: As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data.

CTA Functional testingAccuracy ++++ +++Prognosis ++++ +++ Plaque ++++ 0Anatomy ++++ 0Function ++++ +++Fast Dx ++++ ++Radiation + ++Safety ++++ +++Cost ++ +++Other Etiology ++++ 0

Comparison of CTA and Functional Testing

When is Coronary CT Angiography Indicated?

CTA is the best noninvasive test for the evaluation of atherosclerosis, from plaque to stenosis, from prognosis to function, and will be the gatekeeper for PCI

If you thought about doing a stress test, do a CTA instead

Congenital anomalies

Aneurysm, PE and EP evaluation: coronaries should always be done