Transcript Matching the Clinical Question to the Appropriate Imaging

Matching the Clinical Question to the
Appropriate Imaging Procedure:
What a cardiologist wants from
cardiac imaging
Samuel Wann MD, MACC
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class A - APPROPRIATE INDICATIONS
continued
• Detection of CAD, symptomatic
– Intermediate pre-test probability, ecg
uninterpretable, unable to exercise
– Suspected coronary anomalies
– Acute chest pain, intermediate probability
CAD, ecg/enzymes normal
– Uninterpretable or equivocal stress test (ex,
echo, or nuclear)
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class A APPROPRIATE INDICATIONS continued
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Complex congenital heart disease
Coronary evaluation in new onset CHF
Cardiac mass with tech limited echo/MR
Pericardial evaluation with limited echo/MR
Pulmonary venous anatomy pre-ablation
Coronary venous anatomy pre-biV pacer
Coronary & graft evaluation pre-redo surgery
Aortic aneurysm/dissection
Pulmonary embolism
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class U - UNCERTAIN CTA INDICATIONS
Continued
Detection of symptomatic CAD
• Intermediate pre-test probability, ECG
interpretable, can exercise
• Low pre-test probability, normal ecg, enzymes
• “Triple rule-out” normal ecg, enzymes
Detection of asymptomatic CAD
• calcium scoring in moderate or high risk patients
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class U - UNCERTAIN CTA INDICATIONS
Continued
• Pre-op evaluation for non-cardiac surgery in
intermediate or high risk patients
• Chest pain post CABG or stent
• Evaluation of LV function post MI or CHF with
technically limited echocardiogram
• Evaluation of prosthetic valve with technically
limited echo or MR
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class I - INAPPROPRIATE CTA INDICATIONS
continued
• Symptomatic CAD with high pre-test probability,
ST elevation or positive enzymes
• Asymptomatic low or moderate risk
• Moderate to severe ischemia on stress
• Hi CHD risk with negative angio within 2 yrs
• Coronary calcium score >400
ACCF/ACR/SCCT/ACMR/ASNC/NASCI/SIR
Appropriateness Criteria
Class I - INAPPROPRIATE CTA INDICATIONS
continued
• Preop eval low risk surgery intermediate risk
• Bypass grafts <5yrs post CABG
• Detection of in stent restonsis or coronary
anatomy post PCI
• Evaluation of LV function post MI or CHF
• Repeat calcium score <5 years
Non-invasive CV Imaging
2006
• ECHOCARDIOGRAPHY
– Hand carried ultrasound
– Techniques to demonstrate LV dyssynchrony
• NUCLEAR CARDIOLOGY
– Molecular imaging, new tracers
– PET/CT & SPECT/CT
• CARDIAC MAGNETIC RESONANCE
– Demonstration of ischemia and infarction
• CT ANGIOGRAPHY
– The next one-stop-shop
Echocardiography 2006
• Hand-carried ultrasound
• Evaluation of patients for cardiac
resynchronization therapy (CRT)
Echo Guided
Cardiac Resynchronization
Therapy
• Patients with severe CHF & wide QRS
• Pace late activated LV segment to coordinate LV contraction
• Improve ejection fraction & functional
capacity
• Reduce mitral regurgitation
• Reverse ventricular remodeling
Echo Guided
Cardiac Resynchronization
Therapy
• 1/3 of patients fail to respond
• Unknown number of CHF patients with narrow QRS
may respond
• Degree of dyssynchrony not related to QRS width
• CRT expensive, invasive; CHF very common –
need to identify patients who will benefit most
Echo Methods for Detecting
Dyssynchrony
• Septal to Posterior Wall Motion Delay –
M-mode Echo
• Tissue Doppler Imaging - time to peak
systolic velocity
• Real Time 3D Echo – regional time to
minimum systolic volume
• Speckle tracking for Radial Strain –
active versus passive motion
Tissue Doppler Echo
Synchronous wall motion
Dysynchrony
LV uniformly green
LV red lateral wall.
4D Echo
Regional Volume Analysis
Velocity Vector Imaging
NORMAL
RADIAL DYSSYNCHRONY
Strain Rate Imaging
Echo in CRT
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No agreement on which method best
Technically challenging, non-intuitive
No agreement on “normal” values
Only short term follow-up, soft end points
No controlled randomized trials
Few patients with narrow QRS may
respond to CRT
Nuclear Cardiology 2006
• Molecular imaging
• PET/CT & SPECT/CT
Problems with SPECT
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Attenuation artifacts
Abdominal uptake
Small hearts, women
Multi-vessel disease
Intermediate stenoses
Microvascular disease
Complex, time consuming protocols
Prognostic power of
myocardial perfusion imaging
Cardiac death
5
MI
Event Rate, %/Year
4.2*
4
3
2.7**
2.9
2.9*
2.3
2
1
0
0.5
0.8
0.3
n=2946
n=884
n=455
n=898
Normal
Mildly Abnormal
Moderately
Abnormal
Severely
Abnormal
Scan Result
Hachamovitch R, et al. Circulation. 1998;97:535-543.
“Prognostic value” word search
Nuclear cardiology
Coronary CTA
Pubmed – 12,005 entries
Pubmed – 0 entries
Google - 29,500 entries
Google – 5 entries
Fused PET/CTA
Namdar et al.
J Nucl Med 2005; 46:930–935
Circumflex Stenosis
CTA
Namdar et al. J Nucl Med 2005;
46:930–935
Cath
Fused
PET/CTA
ADENOSINE INDUCED
HYPEREMIA
Cardiovascular MR 2006
• Structure and function
• Stress wall motion analysis
• Delayed contrast ehancement of infarcted
myocardium
• Myocardial perfusion
Dobutamine Stress MRI
Black blood images of the heart showing bright signals in the right ventricular (RV) free
wall (arrow) consistent with fatty deposits suggestive of arrhythmogenic RV dysplasia
Lima, J. A.C. et al. J Am Coll Cardiol 2004;44:1164-1171
Copyright ©2004 American College of Cardiology Foundation. Restrictions may apply.
Completed LAD distribution MI: 3 weeks prior
Anterior MI with Apical Thrombus
Intra-arterial coronary angiography
–a tarnished “gold standard”
• 1 million diagnostic cath/year US (20-40%
insignificant disease)
• 1.5% morbidity, 0.2% mortality
• High inter- and intra-observer variability
• Poor correlation with post-mortem
anatomy
• Physiologic relevance of stenosis not
directly demonstated
Cardiac MR
• Superb Structure & Function
– volumes, mass, regurgitation, gross anatomy
• Perfusion, infarction
• No radiation
• Time consuming, multiple acquisitions, intense
operator interaction
• Limited availability – limited to highly specialized
units.
• Limited application to coronary anatomy
“But there is a disorder of
the breast marked with
strong and peculiar
symptoms…. The seat of it,
and sense of strangling, and
anxiety with which it is
attended, may make it not
improperly be called angina
pectoris. They who are
afflicted with it, are seized
while they are walking, with a
painful and most
disagreeable sensation in the
breast, which seems as if it
would extinguish life, if it
were to increase or
continue...”
Heberden W. Med Trans. 1772.
Netter illustrations used with permission of Elsevier Inc. All rights reserved.
Opportunities for Imaging
CT
DETECTION
OF
CORONARY ARTERY DISEASE
THE
FOR CT ANGIOGRAPHY
CT CORONARY ANGIOGRAPHY
CIRCUMFLEX STENOSIS
How accurate is 64 slice CT?
N
Rotation
Sens. Spec. NPV
Unevaluable
Leschka 53
370 ms
94%
97%
99%
Raff
70
330 ms
86%
95%
98%
Leber
59
330 ms
73%
97%
99%
Mollet
52
330 ms
99%
95%
99%
2%
Ropers 82
330 ms
95%
93%
99%
4% segments > 1.5
Fine
330 ms
95%
96%
95%
6% arteries > 1.5
66
12%
Assessment of
Intracoronary Stent
Coronary CTA for Evaluation
of Left Main Stent Patency
100
100
100
91
N = 70
80
67
60
%
40
20
0
Sensitivity
Specificity
Negative
Predictive
Value
Positive
Predictive
Value
Van Mieghen CAG et al. Circulation 2006;114:645-653
NON-CALCIFIED
“SOFT” PLAQUE
Echo LV Dyssynchrony
• No gold standard
• Multiple echo methods and measurements,
no widely accepted “normal” values
• Short-term, “soft” end points assessed for
efficacy of echo/CRT
• No randomized controls
• Few patients with narrow QRS respond to
CRT
First-pass, adenosine-augmented multidetector computed tomography (MDCT) myocardial
perfusion imaging in a patient referred for invasive angiography after single-photon
emission computed tomography showed a fixed perfusion deficit in the inferior and
inferolateral territories
George, R. T. et al. J Am Coll Cardiol 2006;48:153-160
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.
In this pig with subendocardial infarction, the transmural differentiation of viable and
nonviable myocardium is demonstrated with DE-MSCT in short-axis view (B) and long-axis
view (C) with TTC pathology as standard of reference (A)
Baks, T. et al. J Am Coll Cardiol 2006;48:144-152
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.
DE-MSCT provides higher spatial resolution than DE-MRI
Baks, T. et al. J Am Coll Cardiol 2006;48:144-152
Copyright ©2006 American College of Cardiology Foundation. Restrictions may apply.
First-pass short-axis image of the heart obtained after injection of contrast agent revealing
a hypoenhanced area in the lateral wall (arrow) consistent with myocardial ischemia
Lima, J. A.C. et al. J Am Coll Cardiol 2004;44:1164-1171
LA thrombus
3D PV Measurement & Pre-Ablation
Mapping
3D PV Measurement & Pre-Ablation
Mapping
Challenges for Cardiac CTA
• Reduce radiation dose
• Improve temporal and spatial
resolution
• Perfusion and infarction
• Plaque morphology
WISCONSIN HEART HOSPITAL
Pretest likelihood
CT
0%
50%
100%
MPI
Fractional flow reserve in 77 yo
with intermediate LAD lesion
From: Kern: Circulation, Volume 114(12).September 19, 2006.1321-1341