This document discusses various cardiac imaging tests for assessing ischemia, including their advantages and limitations. It provides details on exercise stress electrocardiography (EST), stress echocardiography, nuclear perfusion imaging, cardiac MRI, coronary CT angiography, and invasive coronary angiography. The document recommends that in patients with high likelihood of CAD but normal initial testing, noninvasive functional or anatomical imaging like stress echocardiography or coronary CTA should be the initial test, while invasive angiography may be reasonable for very high risk patients. It emphasizes that selecting the best test depends on factors like diagnostic accuracy need, availability, and patient characteristics.
1. Ischaemia assessments:
What, when and which one?
Dr Chong Jen Lim
Cardiologist
Hospital Fatimah, Ipoh
BMedSc HONS. (UPM), MD (UPM), FRCP (UK), FNHAM
BSE (TTE), BSE (TOE), EACVI (CMR Level 3), BSCI (Cardiac CT Level 2)
2. Case Scenario
• A 49 year-old lady with DM and Hpt
• Presented with typical angina for few months
• No worsening in severity
• Examinations were unremarkable, BP 130/80, PR 80bpm
• ECG normal, SR
• HbA1C is 6.9
• Echo, LVEF: 65%, no RWMA. Valves normal.
• Creatinine: normal 70mmol/L
3. What and which test?
a) EST
b) DSE
c) Coronary CTA
d) Nuclear Perfusion
e) Stress MRI
f) Formal invasive angiography
g) a/b/c/d/e
h) b/c/d/e
49 yo female
Typical angina
Echo normal
6. 1. Exercise Stress (ECG) Test
Horizontal or down-sloping ST-segment depression ≥0.1mV, persisting
for at least 0.06–0.08s after the J-point, in one or more ECG leads.
7. ST-segment changes indicative of obstructive CAD
• A treadmill ECG stress test is
considered abnormal when
there is a horizontal or down-
sloping ST-segment depression ≥
1 mm at 60–80 ms after the J
point.(1)
1. Fletcher GF, Ades PA, Kligfield P, et al. American Heart Association
Exercise, Cardiac Rehabilitation, and Prevention Committee of the
Council on Clinical Cardiology, Council on Nutrition, Physical Activity
and Metabolism, Council on Cardiovascular and Stroke Nursing, and
Council on Epidemiology and Prevention. Exercise standards for testing
and training: a scientific statement from the American Heart
Association. Circulation. 2013;128:873–934.
8. • Exercise ECGs with up-sloping ST-
segment depressions are typically
reported as an ‘equivocal’ test.
• In general, the occurrence of
horizontal or down-sloping ST-
segment depression at a lower
workload (calculated in METs) or
heart rate indicates a worse
prognosis and higher likelihood of
multi-vessel disease.
ST-segment changes indicative of obstructive CAD
9. Advantages
1. Widely available and accessible
2. Relatively inexpensive,
3. Extensively validated
4. No requirements for intravenous access
5. No radiation exposure
6. Symptoms and ischemia at a low workload indicates a greater likelihood of severe disease and a worse prognosis
7. Exercise documents the workload that induces symptoms and ischemia.
8. Exercise capacity and hemodynamic responses are predictors of prognosis independent of ischemia.
EST
10. Limitations of EST
1. Patients who are unable to exercise sufficiently due to leg claudication, arthritis, deconditioning,
pulmonary disease, or other conditions
2. ECG abnormalities at rest
Eg.
•Ventricular preexcitation (Wolff-Parkinson-White pattern)
•Ventricular paced rhythm
•Left bundle branch block
•Greater than 1 mm ST depression at rest
•Digoxin use with associated ST-T abnormalities
•Left ventricular hypertrophy with ST-T abnormalities
•Hypokalemia with ST-T abnormalities
3. Poorer sensitivity compared to the other tests
11. Do not use exercise ECG to diagnose or exclude stable
angina for people without known CAD. NICE 2010
ESC 2019
14. DSE
Pros Cons
Can be done to those unable to
exercise adequately
Accuracy of test is highly dependent
on pts’ echo window (Can be better
with the use of LV contrast but not
widely used in Malaysia yet)
Can be performed to those with
abnormal baseline ECG
IV line is required
Preferred when there
is already a significant resting wall
motion abnormality
Good echo skill required
No radiation Inter-observer bias
17. 3. Radionuclide myocardial perfusion imaging (rMPI)
Pros Cons
Can be done to those unable to
exercise adequately
Radiation
Can be performed to those with
abnormal baseline ECG
Cost
Independent of echo window Less widely available
Well validated
19. 4. Stress Cardiac MRI
Pros Cons
Can be done to those unable
to exercise adequately
Not widely available
Can be performed to those
with abnormal baseline ECG
IV line required
Independent of echo window High cost
No radiation Not for patients with
claustrophobia
Contraindicated for advanced
CKD
Not for pts with metallic
implant
21. 5.1 Appropriate Indications for Coronary Calcium Score
• Low global CVD risk with family history of premature CAD
• Intermediate global CVD risk with no family history of premature CAD
Consensus Statement on the Utilisation of Cardiac CT 2015
23. Coronary CT Angiography
Pros Cons
Can be done to those unable to
exercise adequately
Rapid (>70 bpm) and irregular HR
Can be performed to those with
abnormal baseline ECG
May not be performed to pts with
high calcium scores (>400)
Independent of echo window May not be suitable for pts with
stent
Excellent negative predictive value Contrast requirements (Cr > 2.0
mg/dl or 177umol/L)
Non invasive Unable to visualise small vessels
(<1.5 mm) and collaterals
Mimics invasive angiogram Obese and uncooperative patients
Radiation
24. 6. Invasive Coronary Angiogram
Advantages Disadvantages
“Gold standard” Invasive nature
Attendant risks
Inability to assess the
microcirculation
Cost
25. Advantages Disadvantages
“Gold standard” Invasive nature
Attendant risks
Inability to assess the
microcirculation
Cost
Invasive angiography is indicated as the first diagnostic test for CHD only in
select, high-risk patient populations
6. Invasive Coronary Angiogram
The composite rate of major complications associated with routine femoral diagnostic catheterization—mainly bleeding
requiring blood transfusions—is still 0.5-2%. The composite rate of death, MI, or stroke is of the order of 0.1-0.2%.
ESC 2019
26.
27.
28. Typical effective doses of the most common
cardiac imaging procedures
European Heart Journal, Volume 35, Issue 10, 7 March 2014, Pages 633–638
29. European Heart Journal, Volume 35, Issue 10, 7 March 2014, Pages 633–638
Estimated risk of acute death due to an imaging procedure
38. Take home messages
1. In a patient with a high clinical likelihood of CAD, symptoms unresponsive to
medical therapy or typical angina at a low level of exercise, and an initial
clinical evaluation (including echocardiogram and, in selected patients,
exercise ECG) that indicates a high event risk, proceeding directly to
invasive coronary angiography (ICA) without further diagnostic testing is a
reasonable option.
2. In other patients in whom CAD cannot be excluded by clinical assessment
alone, it is recommended to do noninvasive functional imaging of
ischaemia or anatomical imaging using coronary CT angiography (CTA) as
the initial test for diagnosing CAD.
3. Coronary CTA is the preferred test in patients with a lower range of clinical
likelihood of CAD, no previous diagnosis of CAD, and characteristics
associated with a high likelihood of good image quality.
39. Take home messages
4. Exercise ECG may be considered as an alternative test to rule-in and
rule-out CAD when non-invasive imaging is not available
5. In addition to diagnostic accuracy and clinical likelihood, the selection
of a non-invasive test depends on other patient characteristics, local
expertise, and the availability of tests