Cardiology for the Practitioner Advanced Cardiac Imaging: Worth the pretty pictures?

Transcription

1 Keenan Research Centre Li Ka Shing Knowledge Institute Cardiology for the Practitioner Advanced Cardiac Imaging: Worth the pretty pictures? Howard Leong-Poi, MD, FRCPC Associate Professor of Medicine St. Michael s Hospital University of Toronto St. Michael s Inspired Care. Inspiring Science.

2 Advanced Cardiac Imaging Overview Advances in Cardiac Imaging (Echo, Nuclear, CT and CMR) What do they add? Appropriateness and Quality in Cardiac Imaging Comparative Effectiveness Research in Cardiovascular Imaging

3 Advances in Echocardiography Contrast Increases quality and diagnostic accuracy of stress echo studies Reduces the number of non-diagnostic rest and stress echo studies Improves accuracy and reduces variability of the assessment of LV systolic function and LVEF measurements Improves detection of apical clots, apical hypertrophic cardiomyopathy Safe (no nephrotoxicity, risks 1:10,000) Honos G, et al, Can J Cardiol 2007;23(5):351-6 Mulvagh SL et al. J Am Soc Echocardiogr 2008;21: Senior R et al, Eur J Echocardiogr 2009;10(2):

4 Advances in Echocardiography 3D TTE Removes geometric assumptions and avoids apical foreshortening - imaging remains on-axis Improves accuracy of quantitative LVEF measurements

5 Advances in Echocardiography 3D TEE

6 Advances in Echocardiography 2D Strain Imaging 2D Strain (speckle-tracking) is a measure of myocardial deformation More sensitive measure of systolic function and myocardial contractility than wall thickening and LV ejection fraction (LVEF) Early (subclinical) detection of disease Cardiomyopthies (amyloidosis, diabetic CMP, HCM) Cardiotoxicity in chemotherapy-treated patients

7 Advances in Nuclear Cardiology SPECT No Attenuation Correction Imaging aspects & Protocols Attenuation correction (using CT) Improved detectors and algorithms - improved image quality and lower radiation dose Attenuation Correction

8 Advances in Nuclear Cardiology Positron Emission Tomography (PET) Advantages over SPECT imaging More sensitive, greater resolution Absolute quantification of blood flow - less potential to miss balanced ischemia from 3VCAD or to underestimate perfusion defects in multivessel CAD Myocardial Flow Reserve SPECT PET

9 Advances in Nuclear Cardiology Positron Emission Tomography (PET) Alternative PET tracers to evaluate processes other than perfusion Myocardial viability FDG - a glucose analog utilized to identify glucose avid hibernating myocardium, usually in conjunction with a perfusion tracer

10 Advances in Cardiac Imaging Cardiac CT Cardiac Computed Tomography Angiography (CTA) has been used to assess native coronary arteries, arterial and saphenous vein bypass grafts, coronary stents and anomalous coronary arteries Anomalous Origins

11 Advances in Cardiac CT CT Coronary Angiography Schuijf JD et al. Current applications and limitations of coronary computed tomography angiography in stable coronary artery disease. Heart 2011;97:330e337.

12 Advances in Cardiac CT CT Coronary Angiography Schuijf JD et al. Current applications and limitations of coronary computed tomography angiography in stable coronary artery disease. Heart 2011;97:330e337.

13 Advances in Cardiac CT CT Coronary Angiography Schuijf JD et al. Current applications and limitations of coronary computed tomography angiography in stable coronary artery disease. Heart 2011;97:330e337.

14 Cath CTA More sensitive than invasive angiography for calcification

15 Advances in Cardiac CT Key Points CTA may be particularly valuable to rule out significant CAD in patients without Hx of CAD and intermediate pre-test likelihood CTA is of limited value when an abnormal study is anticipated (high pre-test likelihood) Due to current restrictions in spatial/temporal resolution, CTA cannot precisely assess the degree of stenosis as compared to invasive angiography CTA may offer advantages over invasive angiography for detection of plaque, even in the absence of stenosis A normal CTA study is associated with excellent prognosis Schuijf JD et al. Current applications and limitations of coronary computed tomography angiography in stable coronary artery disease. Heart 2011;97:330e337.

16 Advances in Cardiac MRI Advantages Excellent spatial resolution - image quality consistently excellent, with natural tissue contrast & characterization Quantitative - LVEF, LV volumes and LV mass - has become the non-invasive gold standard Delayed enhancement data valuable for assessing viability in ischemic heart disease and in assessing the etiology of cardiomyopathies

17 Ischemic vs Non-Ischemic Cardiomyopathy Non ischemic Ischemic

18 Advances in Cardiac MRI Sarcoidosis HCM SLE Slaughter RE et al. JACC Cardiovasc Imaging Jul;3(7):

19 What cardiac imaging test have you ordered in 2013? 1. Echo and/or Nuclear (SPECT) alone 2. Echo and/or Nuclear (SPECT) + CMR 3. Echo and/or Nuclear (SPECT) + CT angio 4. Echo and/or Nuclear (SPECT) + CMR + CT angio 5. I have NOT ordered any cardiac imaging test

20 Cardiac Imaging Trends and Costs Blecker S et al. JACC Cardiovasc Imaging. 2013;6(4): CV Imaging costs are increasing exponentially Focus of efforts to ensure growth is appropriate and of value Efforts to constrain further growth in utilization of noninvasive imaging Shaw LJ et al. JACC Cardiovasc Imaging Jul;3(7):

21 Advances in Cardiac Imaging Appropriateness Criteria

22 Echocardiography Indications and Appropriateness l Total of 202 indications (97-appropriate, 34-uncertain, 71- inappropriate) for rest TTE, stress TTE and TEE. Eg. Murmur, Coronary heart disease/myocardial infarction, Valvular stenosis, Valvular Regurgitation, Dyspnea, Edema and Cardiomyopathy, Suspected Structural Heart Disease, etc etc. Indication Evaluation of suspected pulmonary hypertension including evaluation of right ventricular function and estimated pulmonary artery pressure Routine surveillance (<1 y) of moderate or severe valvular regurgitation without a change in clinical status or cardiac exam Routine surveillance (<3 y) of mild valvular stenosis without a change in clinical status or cardiac exam Echo (A) 9 (U) 6 (I) 3 * Score 7-9: Appropriate test for specific indication ACCF/ASE/AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography. J Am Soc Echocardiogr 2011;24:

23 Echocardiography Indications and Appropriateness

24 Standards for Provision and Accreditation of Echocardiography in Ontario In March of 2010, the Ontario Ministry of Health and Long Term Care (MOHLTC) and Ontario Medical Association (OMA) jointly commissioned a Working Group to make recommendations regarding the provision and accreditation of echocardiographic examinations in Ontario. To discuss potential options, measures, and initiatives that could be implemented to further improve patient care and appropriateness in the delivery of community-based echocardiography; and To make recommendations, including the development of workplans, timelines, and options Standards for Provision of Echocardiography in Ontario Sanfilippo AJ, et al. Can J Cardiol Mar;29(3):396-8.

25 Advances in Cardiac Imaging Comparative Effectiveness Research Critical to reform of our current system is the imperative to develop an imaging evidence base that justifies the cost of imaging based on the benefits of downstream decision making. What is desperately needed is more support for comparative effectiveness randomized trials of imaging guided strategies to reliably guide healthcare coverage and medical necessity decisions. This is the optimal means to devise indications for testing and provide high-quality imaging-guided care. Shaw LJ et al. JACC Cardiovasc Imaging Jul;3(7): Medical Imaging Trials NEtwork of Canada MITNEC Testing the diagnostic accuracy of 99mTc SPECT, CMR, CT and stress echocardiography to detect significant CAD (vs fractional flow reserve (FFR) as the gold standard)

26 Advanced Cardiac Imaging Predictions for the FUTURE Echo studies will be performed and quantified in 3D Cardiac PET imaging will grow, and supplant SPECT for myocardial perfusion imaging (MPI) and myocardial viability Echo and Nuclear will remain primary imaging modalities, and will not be entirely supplanted by cardiac CT and CMR CT angiography will increase in utilization, but will not replace conventional angiography CMR will become a first line test in the assessment of cardiomyopathies Cardiac imaging utilization/reimbursement will be increasingly driven by evidence from RCTs, and on demonstration of quality and accreditation