Cardiac stress tests and CT coronary angiography are effective options for evaluating heart disease, with certain advantages and limitations for each. A cardiac stress test such as a treadmill exercise stress test or stress echocardiogram can detect ischemia by provoking the heart during exercise or pharmacologically, but may have lower sensitivity and specificity than imaging tests. A CT coronary angiogram provides detailed images of the coronary arteries but exposes patients to radiation. The optimal test depends on the individual patient's characteristics, risk factors, and the specific question being answered.

1. Cardiac Stress Test vs CT Coronary
Angiogram: Which is better?
PRESENTED BY:
DR JEREMY CHOW
MBBS, MRCP (UK), MRCP (London), M Med (Int Med)
FAMS, FESC, FHRS
Certified Cardiac Device Specialist
Consultant Cardiologist & Electrophysiologist
Director of Electrophysiology Service
Email: drchow.jeremy@asianheart.com.sg
www.ahvc.com.sg

3. www.ahvc.com.sg

4. Overview
✦Why do we need cardiac screening?
✦Who needs to be screened?
✦When should we start cardiac
screening?
✦What is the most appropriate test?
What is the question to be answered?

5. Why do we need cardiac screening?

7. Screening can lead to early intervention

8. Overview
✦Why do we need cardiac screening?
✦Who needs to be screened?
✦When should we start cardiac
screening?
✦What is the most appropriate test?
What is the question to be answered?

10. Standard Cardiac Risk factors

12. Are all Athletes immune from CVD?

13. Overview
✦Why do we need cardiac screening?
✦Who needs to be screened?
✦When should we start cardiac
screening?
✦What is the most appropriate test?
✦What is the question to be answered?

14. Cardiac risk factor screening is indicated for ALL

15. Screening for Risk Factors

17. Cardio-Oncology involvement

19. Overview
✦Why do we need cardiac screening?
✦Who needs to be screened?
✦When should we start cardiac
screening?
✦What is the most appropriate test?
What is the question to be answered?

20. @ Asian Heart & Vascular Centre (AHVC)
✓ Specific heart investigations include:-
✓ 12 Lead ECG, 24-72 hour Holter
✓ 2D Echocardiography
✓ Treadmill exercise stress test
✓ Exercise Stress Echocardiography
✓ Dobutamine Stress Echocardiography
✓ PET Rubidium myocardial perfusion scan / MIBI
✓ Computer Tomography (CT) Coronary Angiogram and calcium
score
✓ Cardiac MRI
✓ Coronary Angiography

21. Approach in selection of diagnostic tests
Functional or stress testing to detect inducible ischemia has
been the conventional “gold standard” and is the most
common noninvasive test used to diagnose IHD.
All functional tests are designed to provoke cardiac
ischemia by using exercise or pharmacological stress
agents.
Induction of ischemia, however, depends on the severity of
stress imposed (i.e., submaximal exercise can fail to
produce ischemia) and the severity of the flow
disturbance.

22. The ischaemic cascade

23. Initial diagnostic management of patients with
suspected stable coronary artery disease
Stepwise approach
Clinical assessment
Determine pretest probability
Non-invasive test to
establish the diagnosis of
stable CAD/ non ob
atherosclerosis
Management post stress test
- Medical
- Revascularisation
Risk stratification

24. Determine pretest probability
Analysis of probability as an aid in the clinical diagnosis of
coronary-artery disease. N Engl J Med. 1979; 300:1350–8.
• Type of pain and age and sex of the patient
can provide a reasonable estimate of the
likelihood of IHD
• 50-yo man with atypical angina, the probability
of CAD is ~50%
• Diagnostic testing is most valuable in
INTERMEDIATE pre-test probability of
Ischemic heart disease
• Duke Databank incorporated
electrocardiographic findings (Q waves or
ST-T changes) and information about risk
factors (smoking, diabetes mellitus,
hyperlipidemia)
• Key contribution is the value of incorporating
data about risk factors into the probability
estimate.

25. How to use pre-test probability (PTP)
Groups in blue boxes have a PTP of
15–65%. They could have an
exercise ECG if feasible as the initial
test. However, if local expertise and
availability permit a non-invasive
imaging based test for ischaemia this
would be preferable given the
superior diagnostic capabilities of
such tests. In young patients radiation
issues should be considered.
Groups in pink boxes have PTPs
between 66–85% and hence should
have a non-invasive imaging
functional test for making a diagnosis
of IHD.
In groups in dark red boxes the PTP
is >85% and one can assume that
IHD is present. They need definitive
work up.
Groups in white boxes have a PTP <15% and
hence can be managed without further testing.

26. So which is better?

27. Treadmill Exercise Stress Test
1918 - Bousfield noted ST depressions during
angina
1929 - Masters and Oppenheimer developed a
standardized exercise test
Target HR: 220 - patient’s age (SD: 10-12 beats/min)
x 0.85
End-Point: Heart Rate, Blood Pressure, Exercise
Capacity, ECG, Symptoms
• Achieve 85% max predicted HR (220‐age), for an
optimal test
Advantages - Widely available - Least expensive -
Provides a good measure of functional capacity
Limitations - Non-diagnostic with abnormal baseline
ECG: - LBBB, paced rhythm, LVH, ST-segment
depressions 0.5 mm - Lower sensitivity and specificity
than imaging - Non-localizing (unless ST segment

28. Baseline ECG

29. Peak Exercise ECG

30. Treadmill+ Echo
End-Point: HR, BP, Exercise Capacity, ECG, Symptoms, ECHO images, Wall
motion abnormalities and POST peak LVEF
Target HR: 220 - patient’s age (SD: 10-12 beats/min) x
0.85
Advantages
- Readily available
- Provides direct visualization of wall
motion, LV function, and anatomy
- Can localize region of abnormality
- May detect valvular abnormalities
- Higher specificity than perfusion imaging
(77-89% vs 70-88%)
- Higher sensitivity than Treadmill alone
(70-85% vs 61-68%)
- No radiation
Limitations
- Technically difficult with poor acoustic
windows
- Requires an experienced sonographer
- Less sensitive than myocardial perfusion
imaging (requires ischemia)
- Fewer clinical data than perfusion imaging
- Interpretation is subjective
- Interpretable image quality may be obtained
during submaximal HR

31. Dobutamine Stress Echo
End-Point: HR, ECG, Symptoms and ECHO images, Wall motion abnormalities (demand state), PEAK
stress LVEF
Dobutamine: Beta-agonist: ↑ Heart Rate, ↑ Inotropy
Target HR: 220 - patient’s age (SD: 10-12 beats/min) x
0.85
Application:
- Reactive airway
disease, severe
COPD
- Second degree AV
block
- Caffeine consumption
within 24 h
Advantages:
- Used for risk-stratifying
patients prior to vascular
surgery
- Preferred over vasodilator
nuclear test for assessment of
regional wall motion
- At low-dose stages allows
viability and ischemia
assessment in segments with
abnormal function at rest
Disadvantages:
- Small risk of drug-specific
adverse events: VT/VF and MI
(1:2,000)
- Poor image quality (patients
with
advanced lung disease)
- May need Atropine (max 2mg)
to augment HR
- Intolerable symptoms:
palpitations, nausea,

32. Nuclear Myocardial Perfusion Scan
PET Rb / MIBI
Indications:
• Abnormal baseline
ECG : Atrial fibrillation,
LBBB, paced, LVH etc
• Unable to exercise
adequately
• Patients with prior
revascularization
• Patients with a higher
likelihood for disease
• Poor Echo acoustic
Advantages:
-After successful PCI, to
evaluate symptoms
suggesting new disease
-Ischemia assessment after
CABG
-Prior to intermediate or high
risk non-cardiac surgery
-PET has higher sensitivity
for CAD detection, in women
and obese
Disadvantages:
-Risk of drug-specific
adverse events:
bronchospasm in COPD,
AV block
-Global reductions in
myocardial perfusion (i.e. left
main or 3V CAD), can result
in balanced reduction
ischemic burden
-Radiation

33. Large, severe, reversible defect involving the anterior wall,
septum, apex and inferior wall -> Cath confirmed 85% mid
LAD stenosis

34. Large-sized area of severely decreased uptake in
the inferior wall.
This defect is almost fully reversible on rest
images, EF 44%.

35. How much radiation?

36. Advances in Cardiac CT
✓ High quality images of the heart
✓Improved tissue and material characterization
✓ Advances in radiation dose reduction techniques
✓ High accuracy and negative predictive value make CT well
suited to exclude obstructive coronary artery disease in the low
to intermediate risk population
✓Myocardial perfusion CT option available to obtain functional
information from CT. It has higher specificity (68–98%) and
PPV (55–94%) in the diagnosis of myocardial ischaemia
compared to conventional CT
✓Large multicenter trials have also established the role of CT in
predicting major cardiovascular events which helps in
prognostication and early initiation of preventive therapy at
subclinical stage
Cardiovasc Diagn Ther 2017;7(5):429-431

37. Pooled results of the shorter-term trials revealed significantly fewer
myocardial infarctions with CTA (3.8% vs. 5.6%, P= 0.038), as well as higher
rates of revascularization (49% vs. 21%, P= 0.01) compared with UC.
There were no differences in death, ICA, or chest pain readmission
Circ Cardiovasc Imaging.
2016;9:e004419.

38. Functional Testing or Coronary Computed Tomography
Angiography in Patients With Stable Coronary Artery Disease
! The Danish National Registry compared 53 744 stable CAD patients evaluated by
functional testing (80% treadmill testing, 20% MPI) and 32 961 patients evaluated by
CTA, with a 3.6 year follow-up period
! There was a lower risk of myocardial infarction following CTA (hazard ratio 0.71;
95% confidence interval 0.61–0.82) and comparable all-cause mortality (hazard ratio
0.96; 95% confidence interval 0.88-1.05)
Jørgensen, M.E. et al. J Am Coll Cardiol. 2017;69(14):1761–70.

39. Case
40 yo Indian Male.
No CVRF except positive family history of
CABG
PMhx of GERD on PPI
Went for EHS and had exercise TMX.
Asymptomatic on TMX

40. Case 3 - TMX was reported to be positive

41. Case
What would you do next?
1. Refer to Cardiologist
2. Advise to do CT coronary angiogram
3. Repeat another stress test

43. LCA

44. CAC Scoring - What it means
! In multiple studies the following definitions have been used
to correlate the CAC score and the coronary plaque
burden:
!0 No identifiable disease
!1 – 99 Mild Disease
!100 – 399 Moderate Disease
!>400 Severe Disease

45. Five-Year Mortality Rates in Framingham Risk Subsets by
Coronary Calcium Score
Shaw et al. Radiology 2003; 228:826-833
*
*
*
*p<0.001

46. Coronary CT Angiography and 5-Year Risk
of Myocardial Infarction
The SCOT-HEART Investigators
N Engl J Med
2018;379:924-33
• CTA compared with SC for the primary
endpoint of death from CAD or non-fatal
myocardial (2.3% [48 patients] vs. 3.9%
[81 patients]; hazard ratio, 0.59; 95%
confidence interval [CI], 0.41 to 0.84; P =
0.004).
• More preventive therapies were initiated
in patients in the CTA group (odds ratio,
1.40; 95% CI, 1.19 to 1.65), as were more
antianginal therapies (odds ratio, 1.27;

47. Calcium score 0

48. What is myocardial bridging?

49. JACC. Vol 68(25),2016

50. CT Coronary Angio - Case 1
52 YO Malaysian Male
Complained of intermittent resting chest pain
Brother just had stroke and PCI for IHD
Patient request for CTCA

51. LCX and LAD disease

52. PCI to LAD and LCX

53. PCI to LAD

54. CT Coronary Angio - Case 2
63 YO Female
No CVRF except smoking
Referred by internal med for CTCA
Complained of intermittent palpitation
LDL 115 mg/dL, Fasting Glu 103 mg/dL
Incidental elevated CEA (7.4) and needed CT
Thorax

57. Coronary angioplasty was done

58. CT Myocardial Perfusion Imaging
A, Curved multiplanar reformatted view of left anterior descending artery shows
noncalcified plaque (arrow) with critical stenosis in proximal segment. B and C,
Long-axis (B) and four-chamber (C) views show hypoattenuation of anterior and
apical subendocardial myocardium (arrowheads) consistent with acute infarction.

59. Take Home
Screening for heart disease should be routinely
considered in patients with conventional cardiac
risk factors.
Cancer patients who are in survivorship will need
cardiac surveillance.
Modality of choice depends on patient’s profile
and the pre-test probability.

60. THANK YOU!
ANY QUESTIONS?
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