Dr. Ross Davies President Dr. Benjamin Chow Vice-President Dr. Jonathan Leipsic Secretary/Treasurer Office 222 Queen Street Suite 1403 Ottawa, ON K1P 5V9 www.ccs.ca/ nuclear_ct@ccs.ca Evidence for Everyone: Expanding the Reach of Health Technology Assessment 2016 CADTH Symposium, April 10-12, Shaw Centre, Ottawa Panel E4: Making evidence meaningful: Optimal use and adoption of medical imaging equipment, Tuesday April 12, 2016: 1:00-2:30 PM
Dr. Ross Davies President Dr. Benjamin Chow Vice-President Dr. Jonathan Leipsic Secretary/Treasurer Office 222 Queen Street Suite 1403 Ottawa, ON K1P 5V9 www.ccs.ca/ nuclear_ct@ccs.ca Canadian Society of Cardiovascular Nuclear and CT Imaging An affiliate society of the Canadian Cardiovascular Society (CCS) replacing the Canadian Nuclear Cardiology Society (CNCS)
Making Evidence Meaningful: Optimal Use and Adoption of Medical Imaging Equipment Abstract submission by Andra Morrison, Program Office, CADTH Preamble: 10-20% of medical imaging tests are unnecessary or inappropriate- straining finite health finances and wait lists, and with CT (and NM) exposure to unnecessary radiation Purpose: To explore role evidence-based advise, recommendations and tools play in facilitating appropriate use and adoption of medical imaging equipment Discussion to identify: Information requirements of decision makers to support policy and practice Optimal strategies to integrate evidence into decision making processes Barriers to evidence adoption Methods to promote appropriate imaging Goals: To identify meaningful evidence-based products and services that will support appropriate use of new and existing imaging equipment in a Canadian context, and methods to support translation of this evidence into care
Cardiac use of SPECT, PET and CT Mostly for evaluation of CAD Diagnosis (CAD or no CAD, risk stratification of known CAD) Management (medical vs angiography, revascularization- PCI vs CABG) Outcome (MACE, cost) Nuclear Cardiology (functional imaging- reversible perfusion defect) SPECT and PET (+/- CT for attenuation correction) Stress (exercise or pharmacological) Myocardial perfusion imaging (SPECT- Tc99m generator or PET- Rb-82 generator or N-13 ammonia cyclotron) CT (anatomic imaging) Calcium score CT coronary angiography
Canadian Medical Imaging Inventory, 2015 Executive Summary 374 responding sites, nearly 90% public hospitals or tertiary care centres CT 538 units, 5.28M exams/year, 147 exams/1000 people, 63 hours/week, 10 hours/day, mostly non cardiac SPECT 264 units, 0.76M scans/year, 21 scans/1000 people, 40 hours/week, 8 hours/day, more cardiac than other modalities SPECT-CT 214 units, 41 installed and 2 decommissioned (replacement of SPECT with SPECT-CT), 0.72M scans/year, 20 scans/ 100 people, more cardiac than other modalities (22.5%) PET 47 PET or hybrid units mostly PET-CT, 77K scans/year, e scans/1000 people, ¼ sites with cyclotron
What does the survey not tell us? Where the right patients (education of referring MDs) Being referred for the right test (screening of requisitions, protocols) In the right facility (accreditation of facility, training of technologists and physicians, age and quality of equipment) In a timely manner (accessibility and wait times) For the optimal result (cost benefit, radiation dose, diagnosis and outcome)
Typical Example 42 year old obese woman with atypical chest pain referred for exercise ECG by family MD Positive exercise test by ECG criteria Possible false positive, so referred for exercise myocardial perfusion scan, in general nuclear medicine lab in small community with 20 year old camera (15 msv) read by older general radiologist Abnormal due to reversible anterior perfusion defect Possible breast tissue attenuation artefact, so referred for dipyridamole Rb-82 PET scan (5 msv) at teaching hospital with board certified nuclear cardiologist which was normal
Post-Test Likelihood (%) Effect of Non-Invasive Tests on Probability of CAD: Bayes Theorem 100 80 60 40 MPI ECG EX POSITIVE TESTS 20 0 0 20 40 60 80 100 Pre-Test Likelihood (%) NEGATIVE TESTS. Epstein, AJC 46:491,1980
ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SC MR/STS 2013 Multimodality Appropriate Use Criteria for the Detection and Risk Assessment of Stable Ischemic Heart Disease A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons J Am Coll Cardiol 2014;63(4):380-406
AUC Criteria for Imaging Asymptomatic Patients Table 1.2Asymptomatic (Without Symptoms or Ischemic Equivalent) Appropriate Use Key: A = Appropriate; M = May Be Appropriate; R = Rarely Appropriate.A = Appropriate; CAD = coronary artery disease; CCTA = coronary computed tomography angiography; CHD = coronary heart disease; CMR = cardiac magnetic resonance; ECG = electrocardiogram; Echo = echocardiography; M = May Be Appropriate; R = Rarely Appropriate; RNI = radionuclide imaging.
AUC Criteria for Imaging Symptomatic Patients Table 1.1Symptomatic Appropriate Use Key: A = Appropriate; M = May Be Appropriate; R = Rarely Appropriate.A = Appropriate; CAD = coronary artery disease; CCTA = coronary computed tomography angiography; CMR = cardiac magnetic resonance; ECG = electrocardiogram; Echo = echocardiography; M = May Be Appropriate; R = Rarely Appropriate; RNI = radionuclide imaging.
Downloadable Referral Form for Cardiology Referral Clinic on Ottawa Heart Institute Web Site
Medical Directives for General Cardiology Clinic For patient s presenting with request for risk stratification of ischemic heart disease prior to patient s booked appointment with physician: Retrieve blood work- CBC, Lytes, Creatinine, Fasting Glucose, Fasting Lipid Profile, HgB A1C, TSH (within 3 months) ECG 12 lead For Women: < 50 yrs old Exercise Stress Test, > 50 years old Exercise Myoview (Persantine Myoview if unable to exercise, Persantine PET Rb if > 200 lbs) For Men: < 45 yrs old - Exercise Stress Test, > 45 years old Exercise Myoview (Persantine Myoview if unable to exercise, Persantine PET Rb if > 250 lbs) 13
Wendy Levinson, MD Professor of Medicine, University of Toronto Chair, Choosing Wisely Canada Welch Public Health Conference 2014 October 7, 2014
Campaign Approach Physicians Societies develop lists Disseminate through multiple channels Patients Develop patient materials Disseminate broadly through multiple channels Media Coordinated approach toward media Multiple voices, a common message Stakeholders Work through health care stakeholder organizations to implement and support adoption
Radiation Risk and Cardiac Imaging Need to reduce radiation doses (< 5 msv) 1 SPECT study (10 msv) associated with 1/2000 increased life time risk of developing fatal malignancy
SPECT Radiation Doses from the IAEA Nuclear Cardiology Protocols Study (INCAPS) DOSE Laboratories with mean radiation doses < 9 msv * Not = p < reaching 0.001 ASNC suggested goals Mercuri M et al. JAMA Int Med 2016; 176:266-269
Software and Hardware SPECT Solutions Improved conventional SPECT Optimized iterative reconstruction software New collimators and specialized gantries New dedicated cardiac SPECT scanners Solid-state CZT detectors instead of analog photomultiplier tubes
Half-Time SPECT Myocardial Perfusion Imaging with Attenuation Correction 112 patients GE Hawkeye-4 Evolution 67 male, mean age 58 yrs Intermediate to high pre-test likelihood of CAD Full dose rest/ stress one day 99m Tc-tetrofosmin imaging Half-time and full-time imaging Ali I et al. J Nucl Med 2009;50:554-562
Average Effective Patient Dose (msv) R/S Dose Reduction at the UOHI 14 12 10 8 6 4 2 CZT and Infinia Doses Rest: 160 MBq Stress: 500 MBq Total <5 msv Reduced doses from 11 to 6 msv ECam for R/S 99m Tc-tetrofosmin Infinia CZT imaging UOHI 0 Month
NEJM 2015;372:1291-1300
PROMISE Trial Design Symptoms suspicious for significant CAD Requiring non-emergent noninvasive testing 1:1 Randomization 10,000 patients Stratified by site and intended functional test Anatomic strategy Functional strategy 64+ slice CTA Exercise ECG or exercise imaging Pharmacologic stress imaging Tests read locally; Results immediately available Subsequent testing/management by site care team, per guidelines Minimum follow-up 12 months
Clinical Endpoint Events Primary endpoint composite CTA (n=499 6) Functio nal (n=5007 ) 164 151 All-cause death 74 75 Nonfatal MI 30 40 Unstable angina hosp 61 41 Major procedural complications Primary endpoint plus cath without obstructive CAD 4 5 332 353 Adj HR (95% CI) 1.04 (0.83 1.29) 0.91 (0.78 1.06) P val ue 0.75 0 0.21 7 0.88 (0.67 0.34
Summary PROMISE enrolled a symptomatic, intermediate risk population for whom testing is currently recommended There is a low event rate in this contemporary population There were no significant differences in outcomes between an initial anatomic (CTA) or functional testing strategy with respect to the primary endpoint overall or in any subgroup An initial CTA strategy was associated with a lower rate of invasive catheterization without obstructive CAD Radiation exposure was higher in CTA arm overall, but lower in those patients for whom a nuclear test was specified at randomization as the intended functional test, and who were then randomized to CTA
Conclusions Compared to usual care using a functional testing strategy, use of an initial anatomic testing strategy employing CTA did not improve clinical outcomes in patients with suspected CAD Our results suggest that CTA is a viable alternative to functional testing These real-world results should inform noninvasive testing choices in clinical care as well as provide guidance to future studies of diagnostic strategies in suspected heart disease
Making Evidence Meaningful: Optimal Use and Adoption of Medical Imaging Equipment Goals: To identify meaningful evidence-based products and services that will support appropriate use of new and existing imaging equipment in a Canadian context, and methods to support translation of this evidence into care Work with physician societies such as the CCS (Affiliate societies of Nuclear and CT Imaging, MR and Echo), Canadian Society of Nuclear Medicine and Canadian Association of Radiology Create list of sites performing cardiac imaging and contact person Work with societies to identify projects to work on together such as Education of the public and referring physicians Screening of requisitions for appropriate use Protocols such as radiation reduction Accreditation of facilities and personnel Funding of equipment Outcome studies