Cardiac Imaging: Yesterday, Today and Tomorrow

Matthew J. Budoff, MD, FACC, FAHAProfessor of Medicine

Endowed Chair of Preventive CardiologyHarbor-UCLA Medical Center, Torrance CA

Conflict of Interest: GE paid consultant

YESTERDAY

• Functional Imaging constituted 95%+ of all work ups for CAD

• Performance of nuclear, stress echo and ETT were adequate, as intermediate and high risk patients were being tested

• LOW threshold to send to cardiac catherization

Sensitivity and Specificity of Non-invasive Tests for the Diagnosis of CAD*

Sensitivity and Specificity of Non-invasive Tests for the Diagnosis of CAD*

Diagnostic Test

Sensitivity% (range)

Specificity% (range)

# Studies # Patients

TMT 68 77 132 24,027

Planar MPI 79(70-94)

73(43-97)

6 510

SPECT 88(73-98)

77(53-96)

8 628

Stress echo 76(40-100)

88(80-95)

10 1174

* NEJM Vol. 344, No. 24 June 14, 2001

TODAY• More statins, preventive therapies,

changing prevalence of obstructive disease

• Less smoking, more diabetes, more women being studied

• More COURAGE to treat medically

Rozanski JACC 2013

Rozanski Conclusions

“CAC scanning, with or without treadmill exercise electrocardiography, could serve as potentially low-cost alternative to more expensive imaging tests for the initial workup of relatively lower-risk diagnostic patients.”

DATA TAKEN FROM “THE DAWN OF A NEW ERA -NON-INVASIVE CORONARY IMAGING” R. ERBEL HERZ 1996; 21, 75-77

DIAGNOSTIC SENSITIVITY

0% 20% 45% 60% 70% 90%

INVASIVE MODALITIES

STRESS ECG $300STRESS ECHO $900

PET SCANNING $2200Coronary Calcium with CT $295

NON-INVASIVE MODALITIES

INTRAVASCULAR ULTRASOUND $3,000CORONARY ANGIOGRAPHY $5,000

STRESS THALLIUM $1600

$150

The best predictor of a life threatening illness is the early

manifestation of a life threatening illness

Sir Geoffrey RoseCardiac Epidemiologist

Known for “The Rose Principle”

Coronary Artery Scanning

SEVERECALCIFICATION

Diagnostic accuracy Outcome• Schuijf JD et al. Am Coll Cardiol. 2006;19:2508-

14.

• Mollet NR et al. Eur Heart J. 2007;28:1872-8.

• Dewey M et al. Eur Heart J. 2007;28:2485-90.

• Ravapati G et al. Am J Cardiol. 2008:101;774-5.

• Nieman K et al. Heart. 2009;95:1669-75.

• Pundziute G et al. Coron Artery Dis. 2009;20:281-7.

• Øvrehus KA et al. Am J Cardiol. 2010;105:773-9.

• Maffei E et al. Heart. 2010;96:1973-9.

• Hamirani YS et al. J Comput Assist Tomogr. 2010;34:645-51.

• Tandon V et al. Eur Hear J. 2012;33:776-82.

• Weustink AC et al. Int J Cardiovasc Imaging.

2012;28:675-84.

• Min JK et al. Am J Cardiol. 2008;102:672-8.

• Cheezum MK et al. J Cardiosvasc ComputTomogr. 2011;5:101-9.

• Shreibati JB et al. JAMA. 2011;306:2128-36.

• Tandon V et al. Eur Hear J. 2012;33:776-82.

• Hachamotvitch R et al. J Am Coll Cardiol. 2012;59:462-74.

• Min JK et al. J Cardiovasc Comput Tomogr. 2012;6:274-83.

• Nielsen LH et al. Eur Heart J CardiovascImaging. 2013;14:449-55.

CTA vs Functional Meta Analysis AHA 2013

Diagnostic accuracy - Nielson EHJI 2014

Sensitivity: CCTA 98% vs. XECG 67%, (p < 0.001)

Sensitivity: CCTA 99% vs. SPECT 73%, (p = 0.001)

Specificity: CCTA 82% vs. XECG 46%, (p < 0.001)

Specificity: CCTA 71 % vs. SPECT 48%, (p = 0.14)

Obstructive CAD at Cath: NCDR 2005-2007 376,430 pts without CAD/MI or prior PCI/CABG Undergoing diagnostic cath to R/O CAD 59% of patients with positive stress tests had no obstructive CAD on

invasive angio (False positive), 73% with equivocal test result

Patel MR, Peterson ED, Dai D, Brennan JM, Redberg RF, Anderson HV, Brindis RG, Douglas PS. NEJM. 2010 Mar 11;362(10):886-95

SCCT 201514

Non-Invasive Functional Testing Prior to Angiography

Cury et al, JCCT 2014.Patel et al, Am Heart J 2014.

CONVERSELY, 70% of all CCTA had obstructive disease, still 30% false positives

Data from an analysis of more than 385,000 patients at over 1,100 US hospitalsPATEL M NCDR AHJ 2014

45% 44% 45% 45%

Non-obstructive CADObstructive CAD

SPECT Stress Echo Exercise Stress Test CMR

EVINCI STUDYCirc 2015

• So Anatomical Testing is more accurate than Functional Testing

• What about CV outcomes?

CTA vs Functional Meta AnalysisMyocardial infarction

Nielson EHJI 2014

SPARC STUDYHlatky JACC April 2014

P<0.0001

PROGNOSIS: Exercise Testing vs CTA

Pontone JACC 2013

“CTA may be a better diagnostic tool and may play a key role in prognostic stratification”

PROMISE NEJM 2015

PROMISE TRIAL

PROMISE TRIALPrimary Endpoint – Death, MI, and UA

Coronary CTA: Obstructive CAD >70%

C-Index: 0.72 (95% CI: 0.68, 0.77) 0.64 (95% CI: 0.59, 0.69) p=0.014

Net Reclassification Index (NRI)

Reclassification is based on the change (continuous) in the estimated risk probability.

Anatomical Testing Functional Testing

FRS plus Test Results vs. FRS Alone

Proportion of Events

correctly Reclassified

Proportion of Non-events correctly

Reclassified

NRI (95% Bootstrap CI)

Proportion of Events

correctly Reclassified

Proportion of Non-events correctly

ReclassifiedNRI (95%

Bootstrap CI)

Death/MI/UA 0.18 0.49 0.67 (0.49, 0.86) -0.37 0.76 0.40 (0.24, 0.56)

CV death/MI/UA 0.32 0.55 0.88 (0.68, 1.00) -0.27 0.76 0.49 (0.31, 0.68)

CV death/MI 0.41 0.07 0.47 (0.19, 0.74) -0.55 0.75 0.20 (0.02, 0.41)

PROMISE

• Discriminatory ability of coronary CTA was significantly better than functional testing (c-index: 0.73 (95% CI: 0.69, 0.77) vs. 0.64 (95% CI: 0.59, 0.69); p=0.011).

• Net Reclassification Index: CCTA 0.70 (95%: 0.52, 0.89) and Functional 0.40 (95%: 0.24, 0.56).

• CCTA provided higher discrimination, reclassification and more robust event prediction

SCOT HEARTLancet 2015

• 4,146 patients (mean age: 57 years, 56% male) who presented with chest pain due to suspected coronary artery disease

• Changes in diagnosis occurred in 25% of patients receiving CTCA and only 1% of pts receiving standard protocol (P < .001).

• after 3 years, the proportion of patients with events was reduced by 50% in the CTCA group (~2.5% vs ~1.7%, P = .015).

Future of Cardiac Imaging

• More emphasis on early atherosclerosis and aggressive medical/lifestyle management

• Less emphasis on obstruction and stenting• Continued decline, probably rapidly, of

functional testing – concerns of cost, accuracy and radiation

So, We can Continue what we are doing….

CT ANGIOGRAM = LARGE SOFT PLAQUE, INSTITUTE STATIN, ASPIRINLIFESTYLE….

Or with CTAWe can do better!!

FUNCTIONAL TEST RESULT =NORMAL STUDY, Reassure patient

• Superior test performance– false negative test results/untreated CAD

• coronary events• Better detection of non-obstructive CAD

• Improved preventive treatment and adherence

– Longer ‘warranty’ period with fewer repeat tests • hospitalizations during follow up

Why is CTA-Superior?Why is CTA-Superior?

NICE ALGORITHM

Testing and Costs Go Down after implementation of NICE – BMJ

2015

SYMPTOMATIC ALGORITHM

Low Pretest Probability (0-50%)

High Pretest Probability

Intermediate Pretest Probability(50-80%)

UK NICE Guidelines 2016

Where does Stress Nuclear and Stress Echocardiography fit into chest pain evalution in new guidelines?

What About FFR-CT?

FFR 0.94

FFRCT 0.93

LAD stenosis 70-90%

FFRCT Model

Per-Patient Diagnostic Performance vs. CT

Nørgaard et al, JACC 2014: ePub ahead of print; DOI: 10.1016/j.jacc.2013. 11.043

%

CT (>50%) FFRCT (≤ 0.80)

* **

*p<0.001

Platform Study – Douglas et al

35

CONSERVE Trial – ESC 2016

CONSERVE RESULTS

CONSERVE

0.9 mSv1.3 mSv 2.0 mSv

1.2 mSv

1.3 mSv(interquartile range 0.8-1.9)

Current CCTA dose is significantly reduced

Source: Labounty, Leipsic, Earls, Min et al. AJC 2010

Multicenter study of 449 patients undergoing CCTA after implementation of a standardized image acquisition protocol that employed prospective gating, reduced tube voltage, lower

tube current and reduced Z-axis coverage

Annual BackgroundRadiation

Conclusions

• With increasing accuracy and decreasing radiation exposure, CT angiography will become the dominant method to evaluate coronary artery disease

• For Preventive-minded physicians, the ability to see atherosclerosis will enhance patient selection and improve adherence