Presentation on theme: "Potential Benefits and Limits"— Presentation transcript:
1Potential Benefits and Limits MSCTPotential Benefits and LimitsAntoine Sarkis, MDAssociate Professor of CardiologyHôtel Dieu de France Hospital
2Compare the diagnostic accuracy of multislice CT and MRI MSCT is a major innovative technique for non-invasive detection of coronary artery stenoses129 patientsCompare the diagnostic accuracy of multislice CT and MRISensitivity for detection of clinically significant coronary stenoses (> or =50%): 82 %Specificity: 90Negative predictive value: 95 %Ann Intern Med Sep 19;145(6):466-7.
3Potential Indications MSCT in asymptomatic personsMSCT in highly suspected Coronary artery diseaseMSCT in known Coronary artery disease: follow-up of graft patency, stents
4MSCT in asymptomatic persons: 1st Scenario: Normal CT Normal CT in a person with no or minimal risk factors for CADGood news, but was-it a surprise? Was the CT really needed?
5MSCT in asymptomatic persons: 2nd Scenario: Plaque or mild to moderate stenosis This patient has risk factors, he is asymptomatic, but CT shows ~ 50% stenosis on LAD and RCA.Nabil HokayemWhat is the next step?
6MSCT in asymptomatic persons: 2nd Scenario: Plaque or mild to moderate stenosis LADRCANabil HokayemLADWhat is the next step?
7He received a total of 36 mSv MSCT in asymptomatic persons: 2nd Scenario: Plaque/or mild to moderate stenosisThis patient had cardiac cath, then cardiac scintigraphy, exactly the inverse classical way of screening asymptomatic patientsHe received a total of 36 mSvKnowing he has multiple risk factors, did CT add information to his status?Final treatment: Statins, Aspirin, AnxiolyticsNabil Hokayem
8MSCT in asymptomatic persons: 3rd scenario: severe disease Khalil Assaa
9MSCT in asymptomatic persons: 3rd scenario: severe disease LADKhalil AssaaRCA
10MSCT in asymptomatic persons: 3rd scenario: severe disease Couldn’t we identify this patient by non invasive testing: Stress test with or without nuclear imaging or echo?Khalil Assaa
11MSCT in asymptomatic persons: 4th Scenario: massive calcium Toufic Khoueiri56 yrs old man, smoker, dyslipidemia, hypertension
12MSCT as a screning test? Pro Growing burden of atherosclerotic diseaseKnown and unknown risk factorsStess test has limited positive predictive value specially for one vessel diseaseMSCT is a cross-sectional imaging techniqueIt shows the contrast-enhanced vessel lumen (like cath)It also has the potential to visualize the vessel wall and non-obstructive soft or calcified coronary atherosclerotic plaquethe only clinically available non-invasive study with this capability.Do it like mammography for cancer screening?
13MSCT as screning test? Cons Come back to the oculo-stenotic reflex?Does CT add to the information obtained by risk scores based on traditional risk factors?Could we identify stable plaques, which will stay stable for years, from vulnerable plaques prone to rupture and MI?CT detects disease, but does it make difference in prognosis?Cost and reimbursment issues
14Best use of MSCTPatients who have equivocal stress-test results, such as a result that is uncertain or suspected to be false positive or false negative; then the CT is a good test to confirm or exclude coronary diseaseIts high negative predictive value suggests it could select patients who should not be referred to conventional angiography, thus avoiding unnecessary coronary angiograms.CT as a first test should be used only in a selected population, perhaps in patients of younger age in whom the likelihood of having a lot of calcium in the coronaries is low. . . .
15MSCT in highly suspected CAD? Typical chest painPositive test for ischemia (Stress test, nuclear imaging)Little place for MSCTGo directly to coronary angiography, you can do PTCA in the same time
16MSCT in known CADFollow-up of CABG ?Follow-up of stent placement ?
17Limitations Need to have a relatively slow, regular rythm Check renal function before injecting IodineProblem raised by calcificationsThere is still some difficulty identifying stenosis in peripheral segmentsIssues raised by high level of radiation
18Effective radiation dose from various coronary diagnostic studies Cardiac Cath = 5-6 mSv.MSCT = mSv.Calcium scoring scan= 2.6 mSvSPECT Thallium = 18 mSv.SPECT Sestamibi = 12.2 mSv.Normal environment radiation is 3.5 mSv/y.Persinakis, health physics 2002.
19Risk of fatal cancerThe International Commission on Radiological Protection (ICRP) has estimated that the additional lifetime risk of fatal cancer is approximately 1 in 20,000 per mSv for the whole populationBased on available estimates, a coronary CT angiogram with an effective dose of 14.7 mSv has a risk of inducing a fatal cancer of 1 in 1,400.Conventional coronary angiography (5.6 mSv) has a risk of 1 in 3,600and a calcium-scoring scan (2.6 mSv) a risk of 1 in 7,700We never thought about this risk before !!
20Hendel RC, Patel MR, Kramer CM, Poon M. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR Appropriateness Criteria for Cardiac Computed Tomography and Cardiac Magnetic Resonance ImagingA Report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions, and Society of Interventional RadiologyHendel RC, Patel MR, Kramer CM, Poon M.J Am Coll Cardiol. 2006;48:
21Report Summary Cardiac Computed Tomography (CCT) 1. CCT is not appropriate for initial screening of the general population or as an initial tool in evaluation of symptomatic individuals suspected of having coronary artery disease (CAD).2. CCT is considered appropriate for evaluation of CAD in patients with prior inconclusive stress test results.3. CCT is considered highly appropriate for detection and evaluation of suspected coronary artery anomalies.4. CCT is not appropriate for evaluation of bypass grafts and stents in asymptomatic patients5. CCT is considered highly appropriate for evaluation of complex cardiac anatomy, especially as related to congenital heart disease.
22Report Summary6. CCT is considered highly appropriate for evaluation of cardiac masses such as tumor or thrombus, when not ideally evaluated with echocardiographic techniques.7. CCT is considered appropriate for evaluation of pericardial disease such as constriction, cyst, or mass when information was not available from echocardiography8. CCT with angiography was considered highly appropriate for evaluation of suspected pulmonary embolus.9. CCT is considered of uncertain appropriateness for risk stratification prior to non-cardiac surgery.
23In conclusion MSCT will undoubtedly modify our way of thinking Its place in the screening of asymptomatic persons with multiple risk factors for CAD needs to be definedWho will resist the temptation of having a look to his coronary arteries by a non invasive technique and without moving one leg ?