Clinical Evaluation of CAD Diagnostic Testing for Ischaemia

1. Clinical Evaluation of CADDiagnostic Testingfor Ischaemia Joel Niznick MD FRCPC © Continuing Medical Implementation …...bridging the care gap

2. Approach to diagnosis of CAD Classification of chest pain Pre-test likelihood CAD Algorithm for chest pain evaluation in women Indications for stress testing High risk indicators-stress testing Indications for myocardial perfusion imaging (MPI) High risk indicators-MPI Coronary Distribution-Polar Map Comparing Perfusion Agents Sensitivity and specificity of cardiac testing Chest Pain Evaluation © Continuing Medical Implementation …...bridging the care gap

3. Approach to diagnosis CAD -1- • Confirm or deny presence of CAD with TMT • High false positive rate in pre-menopausal females (up to 50%) or low pre-test likelihood CAD • Exclude false positives with perfusion imaging • Assess extent of CAD with perfusion imaging © Continuing Medical Implementation …...bridging the care gap

4. Approach to diagnosis CAD -2- • Assess prognosis combining extent of CAD with severity of LV dysfunction:echo/MUGA • Cardiac Cath:adverse prognostic indicators; refractory symptoms;3VCAD/2VCAD(prox.LAD) plus LV dysfunction (echo or MUGA),AP post MI © Continuing Medical Implementation …...bridging the care gap

5. Classification of Chest Pain Typical angina • Steady retrosternal component • Provoked by exertion or stress • Relieved by rest or NTG Atypical angina • 2 of 3 criteria Non-anginal chest pain • 1 of 3 criteria © Continuing Medical Implementation …...bridging the care gap

6. Prevalence of CAD (%) in Symptomatic Patients According to Age and Sex © Continuing Medical Implementation …...bridging the care gap

7. Indications for Stress Testing • Objective confirmation of ischaemia • Assessing extent of ischaemia • Documenting exercise capacity • Functional assessment of known CAD • Determining risk and prognosis • Determining need for angiography • High risk cut points • Assessing response to treatment © Continuing Medical Implementation …...bridging the care gap

8. Contraindications for stress testing • Acute myocardial infarction (within two days) • Unstable angina pectoris • Uncontrolled arrhythmias causing symptoms of hemodynamic compromise • Symptomatic severe aortic stenosis • Uncontrolled symptomatic heart failure • Active endocarditis or acute myocarditis or pericarditis • Acute aortic dissection • Acute pulmonary or systemic embolism • Acute noncardiac disorders that may affect exercise performance or may be aggravated by exercise © Continuing Medical Implementation …...bridging the care gap

9. Stress Testing Options • Exercise stress alone (usually Bruce protocol) • Exercise stress with nuclear myocardial perfusion imaging (MPI) • Pharmacologic stress nuclear myocardial perfusion imaging (MPI) • Exercise stress echo • Pharmacologic stress echo © Continuing Medical Implementation …...bridging the care gap

10. Sensitivity and Specificity of Non-invasive Tests for the Diagnosis of CAD* * NEJM Vol. 344, No. 24 June 14, 2001 © Continuing Medical Implementation …...bridging the care gap

11. Treadmill or bicycle ergometer Protocols vary - symptom limited Bruce most popular 8 stages Incline and speed increment every 3 minutes Target 85-100% maximum age predicted HR Achieve at least 6 METS for diagnostic accuracy Exercise stress testing © Continuing Medical Implementation …...bridging the care gap

12. ECG Patterns Indicative of Myocardial Ischaemia ECG Patterns Not Indicative of Myocardial Ischaemia

13. High Risk IndicatorsExercise Stress Testing • Early positive-stage I: Mortality >5%/year • Strongly positive > 2.5 mm ST depression • ST elevation > 1 mm in leads without Q waves • Fall in SBP >10 mm HG • Early onset ventricular arrhythmia's • Chronotropic incompetence Ex HR <120/min not due to drugs • Prolonged Ischaemic changes in recovery > 2mm lasting > 6 minutes in multiple leads © Continuing Medical Implementation …...bridging the care gap

14. Suspected false +ve or-ve TMT Resting ST changes LBBB,RBBB,LVH, digitalis,pre-excitation or pacemaker Women with +ve TMT and low or intermediate probability CAD Inability to exercise Prognosis of known CAD Detecting post PTCA or CABG ischaemia Assessing myocardial viability Risk evaluation in non-cardiac surgery patients Assessment functional significance of documented coronary stenosis Indications for Myocardial Perfusion Imaging (Exercise or Pharmacologic Stress) © Continuing Medical Implementation …...bridging the care gap

15. Exercise Stress Treadmill Bicycle ergometer Pharmacologic Stress Persantine (dipyridamole) Adenosine Dobutamine Isotopes Thallium 201 Technesium 99m Sestamibi MIBI (Cardiolyte) Tetrofosmin (Myoview) PET Rubidium 82 (flow agent) FDG (viability) Myocardial Perfusion Imaging © Continuing Medical Implementation …...bridging the care gap

16. Persantine (dipyridamole) Coronary vasodilator • With coronary stenosis differential dilatation results in differential flow hence differential uptake of isotope • Side effects • Chest pain 20% • Dizziness12% • Headache 12% • Dyspnea & flushing 5% © Continuing Medical Implementation …...bridging the care gap

17. Persantine (dipyridamole) • 4 minute infusion • Maximum vasodilatation at 3 minutes post infusion • Circulatory effects peak 7-12 minutes post infusion • Isotope injected at 7 minutes • Antidote aminophylline given for side effects • False negatives with recent caffeine intake © Continuing Medical Implementation …...bridging the care gap

18. Persantine (dipyridamole) contra-indications • Recent MI within 72 hours • Unstable angina • Severe lung disease or asthma • Heart failure/severe systolic dysfunction • 2nd or 3rd degree heart block • Resting hypotension © Continuing Medical Implementation …...bridging the care gap

19. Thallium-201 K analogue uptake proportional to blood flow washes out slowly from myocardium-redistribution phase defect normalizes = ischaemia defect unchanged = scar Tl lung uptake- indicates ischaemic LV dysfunction ischaemic LV dilatation on post exercise scan = high risk indicator Tc 99m-Sestamibi uptake proportional to blood flow tissue uptake is fixed true perfusion agent higher energy/better tissue penetration and images tissue fixation permits gated LV Angiogram wall motion ejection fraction Comparing Perfusion Agents © Continuing Medical Implementation …...bridging the care gap

20. Scanning © Continuing Medical Implementation …...bridging the care gap

21. © Continuing Medical Implementation …...bridging the care gap

22. High Risk IndicatorsMyocardial Perfusion Imaging • Increased pulmonary thallium uptake indicating low CO or elevated LVEDP • Ischaemic LV dilatation (TID) • Multiple perfusion defects • Large perfusion defects © Continuing Medical Implementation …...bridging the care gap

23. Coronary Territories © Continuing Medical Implementation …...bridging the care gap

24. Normal Study © Continuing Medical Implementation …...bridging the care gap

25. Reversible LAD Ischaemia © Continuing Medical Implementation …...bridging the care gap

26. SVD - RCA © Continuing Medical Implementation …...bridging the care gap

27. SVD-RCA © Continuing Medical Implementation …...bridging the care gap

28. 2 Vessel Disease LAD & RCA © Continuing Medical Implementation …...bridging the care gap

29. 2 Vessel Disease LAD & RCA © Continuing Medical Implementation …...bridging the care gap

30. Left Main Disease © Continuing Medical Implementation …...bridging the care gap

31. Triple Vessel CAD © Continuing Medical Implementation …...bridging the care gap

32. Global Ischaemia © Continuing Medical Implementation …...bridging the care gap

33. Stress Echo • Based on principle that ischaemic myocardium becomes hypokinetic • Baseline echo to identify regional LV function • Exercise or pharmacologic stress • Immediate echo to look for changes n wall motion © Continuing Medical Implementation …...bridging the care gap

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36. Stress Echo • Indicated to increase sensitivity and specificity of stress testing • Pharmacologic stress-usually dobutamine if exercise no possible • Indicated in women with intermediate probability CAD, LBBB, LVH, resting ST changes © Continuing Medical Implementation …...bridging the care gap

37. Stress Echo Limitations • Technical quality of images • COPD • Obesity • Timing of acquisition of images • Learning curve • Operator dependent • Reproducibility © Continuing Medical Implementation …...bridging the care gap

38. Dobutamine Stress Echo • Positive inotrope and chronotrope • Given in incremental doses 5-10 g/kg/min up to 30-40 g/kg/min to simulate exercise • Induces ischaemia via • Increased HR, BP & contractility • Preferred agent if • Persantine or aggrenox on board • History of asthma or COPD • Critical carotid stenosis © Continuing Medical Implementation …...bridging the care gap

39. Dobutamine Echo contraindications • Ventricular arrhythmias • Recent myocardial infarction (one to three days) • Unstable angina • Hemodynamically significant left ventricular outflow tract obstruction • Severe aortic stenosis • Aortic aneurysm or aortic dissection • Systemic hypertension © Continuing Medical Implementation …...bridging the care gap

40. Dobutamine Stress Echo • Half life 2 minutes/steady state 10 minutes • Atropine needed concurrently to increase HR 36% of time • Side effects • Palpitation 35% • Chest pain 19% • Nausea 8% • Anxiety 6% © Continuing Medical Implementation …...bridging the care gap

41. Dobutamine Stress Echo • Development of new wall motion abnormalities indicates ischaemia • Improvement of existing wall motion abnormalities indicates viable myocardium • Wall motion may worsen at higher doses with onset of ischaemia © Continuing Medical Implementation …...bridging the care gap

42. Prognostic value of stress echo compared with stress thallium in patients evaluated for CAD • 248 patients, age 56 ± 12yrs, simultaneous treadmill stress echo and SPECT thallium studies • Follow up 3.7 ± 2.0 years • Outcome: death, MI, revascularization, hospitalization for congestive heart failure or unstable angina © Continuing Medical Implementation …...bridging the care gap Olmos, L.I. et al Circulation 1998;98: 2679-86

43. Prognostic value of stress echo compared with stress thallium in patients evaluated for CAD Baseline Characteristics of the Initial Study Population % n Male 189 76 Chest pain 77 31 History of myocardial infarction 86 35 Diabetes mellitus 43 17 Hypertension 97 39 Hypercholesterolemia 100 40 Smoking 109 44 Obesity 41 17 Prior revascularization 57 23 Age (mean ± SD) was 56.3 ± 12 y. n=248 Olmos, L.I. et al Circulation 1998;98: 2679-86 © Continuing Medical Implementation …...bridging the care gap

44. Prognostic value of stress echo compared with stress thallium in patients evaluated for CAD Event-free survival curves for total cardiac events with use ofexercise 201TI SPECT and exercise echocardiography (echo).WMA indicates wall motion abnormality. © Continuing Medical Implementation …...bridging the care gap Olmos, L.I. et al Circulation 1998;98: 2679-86

45. 0.85 NS P < 0.05 0.80 NS 0.75 Area Under the Curve 0.70 0.65 0.60 Clin + Ex ECG Clin + Ex ECG + Rest Echo Clin + Ex ECG + Ex201TI Clin + Ex ECG + Ex Echo Prognostic value of stress echo compared with stress thallium in patients evaluated for CAD Comparison of AUCs of 4 models tested in predicting all cardiac events. • Clin (clinical parameters) • Ex (exercise) • Echo (echocardiography) Olmos, L.I. et al Circulation 1998;98: 2679-86 © Continuing Medical Implementation …...bridging the care gap

46. Prognostic value of stress echo compared with stress thallium in patients evaluated for CAD Conclusions: • In patient evaluated for CAD, both exercise echo and SPECT thallium significantly improve the prognostic power of clinical variables including stress ECG and provide comparable prognostic information. • The choice of imaging modality in a particular setting depends on several factors including availability, feasibility, expertise and cost considerations. Olmos, L.I. et al Circulation 1998;98: 2679-86 © Continuing Medical Implementation …...bridging the care gap

47. Prognostic implications of stress echo in women Event-free survival of patients with normal results on exercise echocardiograms, ischemia, infarction and ischemia with infarction. Event-free survival according to the presence (+) or absence (-) of ischemia by exercise echocardiography (ExE) or exercise ECG © Continuing Medical Implementation …...bridging the care gap Heupler, J. et al J Am Coll Cardiol 1997;30: 414-20

48. Prognostic implications of stress echo in women Incremental value of exercise testing (ExECG) and exercise echocardiography (ExE) to clinical data (Clin), illustrated by the global chi-square of sequential Cox models incorporating clinical, exercise testing and echocardiographic data. Subanalysis to examine the incremental value of exercise testing (ExECG) and exercise echocardiography (ExE) to clinical data (Clin) in patients with (white bar) and without (black bars) a history of known CAD. Global chi-square Global chi-square © Continuing Medical Implementation …...bridging the care gap Heupler, J. et al J Am Coll Cardiol 1997;30: 414-20

49. Algorithm for Chest Pain Evaluation in Women Low Probability of CAD (< 20 %) • Consider no test • High likelihood false + result Intermediate Probability of CAD (20-80%) • Perfusion imaging or stress echo High Risk Probability of CAD (> 80%) • Perfusion imaging or stress echo • Consider direct angiography © Continuing Medical Implementation …...bridging the care gap

50. Comparison of Non-invasive Modalities in the Diagnosis of CAD in Women © Continuing Medical Implementation …...bridging the care gap