The use of Cardiac CT and MRI in Clinical Practice

1. The use of Cardiac CT and MRI in Clinical Practice Matthew W. Martinez, MD Assistant Professor of Medicine LVPG - Lehigh Valley Heart Specialists Lehigh Valley Health Network Oct. 3, 2009

2. DISCLOSURE Relevant Financial Relationship(s) None Off Label Usage None

3. Learning Objectives • Review basics of cardiac MRI and CTA • Review utility of cardiac CT and MRI in clinical practice • Clinical cases

4. Echo SPECT TMET CT MRI PET Noninvasive Tests for the Diagnosis of Coronary Artery Disease

5. Cardiac MRI Black-Blood (Spin-Echo) Delayed Enhancement White-Blood SSFP Still Images Morphology Edema Cine Imaging Morphology and function Still Images Delayed Enhancement

6. SSFP = 2D echo

7. Delayed Enhancement-MRI • Images obtained 10-15 minutes post-contrast (Gd) • Normal myocardium – Black * • Necrosis/scarring/inflammation – Hyperenhanced Image in Press – Nature of Clinical Practice

8. Infarct size by MRI Delayed Enhancement • Abundance of validation data in animal models • Dog with near-transmural infarct • Visible on SPECT and DE-MRI • 3 dogs with subendocardial infarcts • Visible on DE-MRI only CP1302151-4

9. Hyperenhancement Patterns Ischemic Nonischemic Subendocardial infarct Mid-wall HE Epicardial HE Transmural infarct • Idiopathic dilated cardiomyopathy • Myocarditis • Hypertrophiccardiomyopathy • Right ventricularpressure overload • Sarcoidosis • Myocarditis • Anderson–Fabry disease Shah DJ et al: Magnetic resonance of myocardial viability

10. RV Function Mass Cardiomyopathies

11. LVEF LV mass Wall Motion LV ESV LV EDV LV stroke volume RV ESV RV EDV RV Stroke volume RVEF Cardiac MRI Functional Analysis Tissue characterization • Infarct identification • Infarct size • Viability

12. Evaluation of Chest Pain Function Infarct size Unstable Hemodynamics and Complications Imaging Prognosis Viability ACS CP1210291-8

13. LVEF LV mass Wall Motion LV ESV LV EDV LV stroke volume RV ESV RV EDV RV Stroke volume RVEF Cardiac MRI Functional Analysis Tissue characterization • Infarct identification • Infarct size • Viability • Prognosis

14. Sudden onset of achy, continuous, substernal, 8/10 chest pain Radiating to back Pain came on at rest Cardiac Risk Factors Never Smoker Hyperlipidemia (untreated) Sedentery Lifestyle Case 157-year-old woman Troponin – 0.56, 0.5 (3h), 0.36 (6h)

15. Echocardiogram

16. Cardiac Catheterization

17. Cardiac Catheterization

19. Cardiac MRI

20. Cardiac MRI Acute MI

21. Importance of unrecognized Myocardial scar • Aim: Assess the prognostic significance of unrecognized myocardial scar by MRI in patients without a history of MI • 195 patients without known prior MI • 1) Pts with unknown status of CAD referred for assessment of LV fxn, scar • 2) Pts with angiographic CAD referred for prediction of segmental wall motion after revascularization (22) • 16 month follow-up Circulation, 2006

22. History of Present Illness 46 year old man presents to ED, 6:30 AM with 10/10 chest pain Began 4:30 AM - Radiated to left arm No SOB, no n/v Feeling ill with episodic CP over past 2 weeks Past Medical History Hyperlipidemia at health fair Medications none Case Presentation 2 • Social History • 30 pack year history, currently smokes 1 pack/week

23. Initial ECG

24. Angiography Results • Troponin Elevation: • Baseline 0.44 3 hr 0.48 6 hr 0.49

25. Cardiac MRI

26. Delayed Enhancement Myocarditis

27. Plaque rupture mediated necrosis STEMI nSTEMI Alterations in coronary vasomotor tone Coronary spasm Subarachnoid hemorrhage Intracranial hemorrhage Apical Ballooning Syndrome Transplant vasculopathy Sub-endocardial myocyte necrosis CHF Hypertensive crisis Acute pulmonary embolism Tachycardia-mediated – CHF, Pressure overload Volume-Pressure overload (renal failure, CHF, fluid resuscitation) Anemia Hypotension Aortic Stenosis and / or Regurgitation Hypertrophic Cardiomyopathy Amyloid heart disease Etiologies of Elevations of Cardiac Troponins

28. Problem Solving Tool • Troponin is extremely sensitive for detecting myocardial cell necrosis • 9-14% of patients who present with ACS will have normal or non-significant disease on coronary angiography • This cohort of patients have been shown to have a poorer prognosis; potentially from clinical uncertainty(TACTICS-TIMI-18)

30. MDCT4-slice1998 MDCT16-slice2002 MDCT40-slice2005 MDCT320-slice2008 DSCT128-slice2009 MDCT8-slice2001 MDCT64-slice2004 DSCT64-slice2006 Development of CT 2000 2010 2015

32. CT Scanning Minimally Invasive Angiography

33. Nuclear Cardiac ImagingDiagnostic Accuracy “GOLD” Standard - Angiography

34. MDCT in Clinical PracticeA Clinician’s Viewpoint • Gold Standard • Anomalous coronary vessels • Coronary fistula, aneurysms • Coronary Disease • Great for ruling out CAD • OK (but not great) for disease severity

35. High Probability Intermediate Probability Low Probability Patient Population “Definite” signs of CAD: • Typical chest pain • ECG changes & cardiac enzyme elevation • Personal history of CAD

36. High Probability Intermediate Probability Low Probability Patient Population “Indeterminate” signs of CAD: • Atypical chest pain • Discordant symptoms & stress test results • High risk factors & negative stress test • Low risk factors & positive stress test • Patient reluctant to have a cath

37. High Probability Intermediate Probability Low Probability CTA Patient Population

38. High Probability Intermediate Probability Low Probability Patient Population “Doubtful” signs of CAD: • “Worried well”

39. High Probability Intermediate Probability Low Probability ? CTA ? Patient Population

40. High Probability Intermediate Probability Low Probability ? CTA ? CTA Patient Population

41. History • 49yr female previously healthy • 6+ months of dyspnea on exertion • No personal history of hyperlipidemia, HTN, CAD, smoking, and family history • Currently on no cardiac medications • BMI = 36.

42. History • Exercise Time: 7.3 minutes • Test was stopped due to dyspnea and leg fatigue • 32,736 (SBP x HR) • Stress Echo with an area of anterior ischemia was noted from mid to the base • ECG was negative

43. Appropriateness for CT

48. References supporting the use of coronary CTA following equivocal exercise sestamibi • Schuijf, J., et. al, “Relationship between Noninvasive Coronary Angiography with Multi-slice Computed Tomography and Myocardial Perfusion Imaging” Journal of the American College of Cardiology; December 19, 2006. • Rubinstein, R., et. al, “Usefulness of 64-slice multidetector computed tomography in diagnostic triage of patients with chest pain and negative or nondiagnostic exercise stress test result” American Journal of Cardiology 2007; 99: 925-929. • Danciu, S., et. al, “Usefulness of multislice computed tomography coronary angiography to identify patients with abnormal myocardial perfusion stress in whom diagnostic catheterization could be avoided” American Journal of Cardiology 2007; 100: 1605-1608. • Dewey, M., et. al, “Head-to-head comparison of multislice computed tomography and exercise electrocardiography for diagnosis of coronary artery disease” European Heart Journal 2007; 28: 2485-2490.

49. Case 2 –chest pain 55 y/o woman Substernal chest discomfort 2 mos Emotion and sometimes exertion Today 10 min chest and back pain at rest  ED Postmenopausal Prior smoker >15 yrs ago No FH No meds Mild HTN

50. Exam: no murmur BP 142/88 Troponin: <.01 Creat: 0.8