Appropriatezza prescrittiva delle tecniche di imaging e limiti delle metodiche: Scintigrafia miocardica

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1 Appropriatezza prescrittiva delle tecniche di imaging e limiti delle metodiche: Scintigrafia miocardica Dr. Francesco Nudi Clinica Madonna della Fiducia, Roma; Ostia Radiologica, Ostia; Etisan, Roma francesco.nudi@gmail.com

2 Diagnostic appropriateness Diagnostic appropriateness rests on the possibility of providing information leading to a potential change in clinical diagnosis and prognosis, and thus therapeutic management. It must take into account the potential risks of the diagnostic procedure, the logistic and economic resources involved, and also pertinent cultural beliefs. Accordingly, an appropriate diagnostic procedure is one for which the expected health benefits exceed the expected health risks by a wide margin. Evidence based medicine methods and findings should form the basis of such trade off analysis.

3 The Economic Consequences of Available Diagnostic and Prognostic Strategies for the Evaluation of Stable Angina Coronary Revascularization % p< Hard Event Rate Death MI Direct Catheterization (n=5423) Initial stress perfusion imaging (n=5826) Shaw LJ et al. (J Am Coll Cardiol 1999)

4 Diagnostic and follow up costs comparing direct cath vs MPS with selective cath Shaw et al, J Am Coll Cardiol 1999

5 Diagnostic accuracy of fractional flow reserve from anatomic CT angiography Non-invasive fractional flow reserve derived from conventional CCTA. Although both patients have obstructive coronary artery disease by computed tomographic angiography (CT), FFRCT identified myocardial ischemia in one patient (A), whereas FFRCT revealed no ischemia in the other patient (B). Multiplanar reformat of a CT angiogram demonstrating obstructive stenosis of the proximal portion of the left anterior descending artery (LAD) and an FFRCT value of 0.62, indicating vessel ischemia. Invasive coronary angiogram demonstrates obstructive stenosis of the proximal portion of the LAD and measured FFR values of 0.65, indicating vessel ischemia. B CT angiogram demonstrating obstructive stenosis of the mid portion of the right coronary artery (RCA) and an FFRCT value of 0.87, indicating no vessel ischemia. Invasive coronary angiogram demonstrates obstructive stenosis of the mid portion of the RCA and a measured FFR value of 0.88, indicating no vessel ischemia (Min JK et al., J Am Med Assoc 2012)

6 SPECT Imaging Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

7 Phase Analysis of Gated Myocardial Perfusion SPECT for the Assessment of Left Ventricular Dyssynchrony Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

8 Segmentation model Nudi et al, J Nucl Cardiol 2014

9 SPECT imaging: a novel and clinically-relevant segmentation approach Prox LAD disease Mid LAD disease LCX disease RCA disease Nudi F, et al (J Nucl Cardiol 2014;21:807-18) Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

10 Risk of death according to maximal ischemia score (MIS) Nudi F, et al (J Nucl Cardiol 2014;21:807-18) Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

11 Vessel related ischemia Nudi et al, J Nucl Cardiol 2016

12 Vessel related ischemia Nudi et al, J Nucl Cardiol 2016

13 Vessel related ischemia Nudi et al, J Nucl Cardiol 2016

14 Vessel related ischemia Nudi et al, J Nucl Cardiol 2016

15 Vessel related ischemia Nudi et al, J Nucl Cardiol 2016

16 SPECT Imaging

17 High-Speed Myocardial Perfusion Imaging: Dawn of a New Era in Nuclear Cardiology? energy resolution count sensitivities spatial resolution Anger cameras 9-10% Kcps 9-11 mm CZT cameras 5.7% Kcps mm HIGHER IMAGE CONTRAST FEWER SCATTERED GAMMA RAYS DUAL ISOTOPE IMAGING ACQUISITION TIME <3 MINUTES SIGNIFICANT DOSE REDUCTION (<3 msv) REDUCED MOTION ARTIFACTS FIRST PASS STUDIES CORONARY FLOW RESERVE MULTIVESSEL DISEASE MYOCARDIAL MASS RV INFARCTION MORE ACCURATE EF HYBRID SPECT/CT Bonow RO (JACC 2008) Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

18 Risk of death due to radiation versus other non iatrogenic causes of death In other words, effective doses of 1 msv and 10 msv lead to, respectively, additional deaths of 5/100,000 and 5/10,000 exposed subjects Thomas C. Gerber et al. (Circulation 2009;119; )

19 Promise of hybrid SPECT/CT Revolution CT: CACS=0.7 msv CCTA=0.5 msv Discovery 530NMc: SPECT=0.9 msv TOTAL=2.1 msv Benz et al, Eur Heart J 2015

20 Cardiac Positron Emission Tomography/Computed Tomography Imaging Accurately Detects Anatomically and Functionally Significant Coronary Artery Disease Kajander S, et al. (Circulation. 2010;122: ) A 69-year-old man with attacks of atypical anginal pain. A, CT showed significant LAD and RCA stenoses with only mild stenosis in the LCx. B, Hybrid images with normal stress PET perfusion (absolute scale, 0 to 3.5 ml g -1 min -1 ). Normal perfusion is >2.5 ml g -1 min -1 (yellow or red). C, ICA with quantitative analysis and FFR. Despite anatomically significant narrowing of the LAD and borderline changes in the RCA, FFR was normal in both vessels, indicating functionally nonsignificant disease. Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

21 Cardiac Positron Emission Tomography/Computed Tomography Imaging Accurately Detects Anatomically and Functionally Significant Coronary Artery Disease A 57-year-old man with atypical chest pain during exertion. A, CT reconstructions show significant stenoses in the LAD, RCA, and a small intermediate branch (IM). LCx was nonstenosed. Yellow dotted line denotes motion artifacts in the RCA. B, Hybrid volumerendered image. Stress myocardial perfusion was reduced only in the area supplied by the LAD. C, ICA with quantitative analysis showed significant 73% luminal narrowing in the LAD. Other vessels were not stenosed. Kajander S, et al. (Circulation. 2010;122: ) Perfusion Viability Contractility Remodeling Dyssinchrony Adrenergic Apoptosis Hybrid-CT

22 Take home messages Myocardial scintigraphic remains a central diagnostic and prognostic test in the management of patients with or at risk for cardiovascular disease. Its unique strengths include its versatility, multidimensional and multiparametric imaging, wealth of information including remodeling, innervation and apoptosis, and very low radiation exposure with state of the art suites.