![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;](https://image.slidesharecdn.com/screeningforheartdiseasegp-200311010941/85/Cardiac-Stress-Test-vs-CT-Coronary-Angiogram-Which-is-better-46-320.jpg)
Cardiac Stress Test vs CT Coronary Angiogram: Which is better?
- 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: [email protected] 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
- 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.
- 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
- 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%.
- 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?
- 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.