Download Thomas C. Gerber, MD, PhD PET, SPECT, Stress Echo and MRI

PET, SPECT, Stress Echo and MRI:
Choosing the Best for Myocardial Ischemia
Thomas C. Gerber, MD, PhD
Cardiovascular Diseases/Diagnostic Radiology
Mayo Clinic; Rochester, MN
Presenter Disclosure
Information
Thomas C Gerber, MD, PhD
Cardiovascular CT and MRI
Disclosure Information
Royalty payments from UpToDate®
Unlabeled/Unapproved Use:
Use of gadolinium chelates for cardiac MR is off-label and
not FDA approved
Best for Ischemia:
SPECT/PET/Echo/MRI
• Is that really all you want to know?
• “Best” for whom?
• What do you mean by “best”?
Imaging Modalities For CAD
Echo
Nuclear
SPECT (Tc/Tl)
PET
MRI
Gadolinium
Stress
- exercise
- pharmacol
- exercise
- pharmacol
Iodinated
contrast
No gadolinium
MRA
Stress
CT
Stress
- pharmacol
CTA
How About Exercise ECG?
Morton T. Chest. 119(3):907-925, March 2001.
Best for Ischemia:
SPECT/PET/Echo/MRI
• Is that really all you want to know?
• “Best” for whom?
• What do you mean by “best”?
Best For Whom?
Asymptomatic
Symptomatic
(Screening/
Risk Assessment)
(Diagnosis/
Prognosis)
2010 ACCF/AHA Guideline for
Assessment of Cardiovascular
Risk in Asymptomatic Adults
Developed in Collaboration with the American Society of Echocardiography, American Society of Nuclear Cardiology, Society of Atherosclerosis Imaging and Prevention, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, and Society for Cardiovascular Magnetic Resonance
Recommendations for General
Approaches to Risk Stratification
I IIa IIb III
Global risk scores (such as the Framingham
Risk Score [FRS]) that use multiple traditional
cardiovascular risk factors should be obtained
for risk assessment in all asymptomatic adults
without a clinical history of CHD. These scores
are useful for combining individual risk factor
measurements into a single quantitative estimate
of risk that can be used to target preventive
interventions.
Recommendation for Stress
Echocardiography
I IIa IIb III
Stress echocardiography is not indicated for
cardiovascular risk assessment in low- or
intermediate-risk asymptomatic adults.
Recommendations for Myocardial
Perfusion Imaging
I IIa IIb III
Stress MPI may be considered for advanced
cardiovascular risk assessment in asymptomatic adults
with diabetes or asymptomatic adults with a strong
family history of CHD or when previous risk
assessment testing suggests high risk of CHD, such as
a coronary artery calcium (CAC) score of 400 or greater.
I IIa IIb III
Stress MPI is not indicated for cardiovascular risk
assessment in low- or intermediate-risk asymptomatic
adults.
Recommendation for Coronary
Computed Tomography Angiography
I IIa IIb III
Coronary computed tomography angiography is
not recommended for cardiovascular risk
assessment in asymptomatic adults.
Best for Ischemia:
SPECT/PET/Echo/MRI
• Is that really all you want to know?
• “Best” for whom?
• What do you mean by “best”?
Ischemic Cascade
Shaw LJ. J Am Coll Cardiol. 2009;54:1561-75
Functional vs Anatomic Imaging
Shaw LJ. Cardiology Clinics. 2009;27:597
Functional vs. Anatomic Imaging
• RESCUE (Randomized Evaluation of Patients With
Stable Angina Comparing Diagnostic Examinations) –
NCT01262625
• PROMISE (PROspective Multicenter Imaging Study
for Evaluation of Chest Pain) – NCT01174550
• ISCHEMIA (International Study of Comparative Health
Effectiveness with Medical and Invasive Approaches) –
NCT01471522
Hierachy of Diagnostic Evidence
Fryback DG, Thornbury JR. Med Decis Making 1991;11:88– As reproduced in: Radiology 2001;220:566
Imaging: Effect on Outcomes
Finding data …
Imaging: Effect on Outcomes
ERROR: data not found!
Choice of Testing:
Estimating Pre-Test Probability
Nonanginal
Atypical
Typical
Age
Men
Women
Men
Women
Men
Women
30 – 39
4
2
34
12
76
26
40 – 49
13
3
51
22
87
55
50 – 59
20
7
65
31
93
73
60 – 69
27
14
72
51
94
86
Diamond GA, Forrester JS. NEJM 1979;301:230
Choice of Testing:
Risks
• Exercise
– arrhythmia, MI, SCD
• Pharmacologic stress
– arrhythmia, bradycardia,
bronchospasm
• Ionizing radiation
– young individuals, women
• Implanted electronics
• Iodinated contrast media
– allergy, renal failure
• Gadolinium
– nephrogenic systemic
fibrosis
Choice of Testing:
Patient Factors
• Ability to exercise
– sufficient functional capacity for ≥85% PMHR
• ECG interpretability (LBBB, PM)
• Cardiac medication use
• Body habitus
(echo for low risk, SPECT for high-risk)
Choice of Testing:
Cost Effectiveness
• Estimates
– Mixed methods, decision analysis
– Change with decreasing reimbursement rates
• Variable findings
• Results vary by pre-test likelihood
Choice of Testing:
Cost Effectiveness
Cheezum MK et al. JCCT 2011;5:101-9
Choice of Testing:
Cost Effectiveness
Cheezum MK et al. JCCT 2011;5:101-9
Testing for Ischemia:
Sensitivity
100%
97%
90%
90%
82%
70%
50%
70%
61%
91%
88%
85%
72%
91%
88%
85%
80%
60%
91%
83%
83%
93%
Testing for Ischemia:
Specificity
100%
89%
90%
90%
88%
90%
90%
86%
86%
80%
77%
77%
70%
60%
50%
70%
81%
81%
79%
75%
70%
80%
Testing for Ischemia:
Right Test for Right Patient
• Stress testing safe? (AMI, ACS, arrhythmia, AS, …)
– No → cCTA
• Can patient exercise?
– No → pharm stress imaging, cCTA
• Can resting ECG be interpreted
– No → exercise imaging
Testing for Ischemia:
Right Test for Right Patient
• Initial choice of test in patients who
– can exercise and have an
– interpretable ECG
= Exercise ECG
Summary
• Most asymptomatic patients do not need
imaging for ischemia
• Value of functional vs anatomic strategies
for the diagnosis of ischemia in
symptomatic patients being examined in
RCTs
• Evidence base for CMR and cCTA still
trailing behind SPECT and echo
Summary
• Test of first choice for patients able to
exercise with interpretable ECG: exercise
ECG
• Choice of imaging exercise or stress test
should depend on patient-specific factors
and risk, and local availability and expertise
Final Thoughts
Thank you
for your patience!