Emerging role of PET in nuclear cardiology. Dr. Erick Alexánderson. Rosas

Transcription

1 Emerging role of PET in nuclear cardiology Dr. Erick Alexánderson Rosas

2 PET principles e + e - 180

3 PET/CT Cyclotron Unit UNAM Cyclotron Radiopharmacy PET Camera

4 CT PET

5 PET CT Perfusion Anatomic evaluation of coronary atherosclerosis Diagnosis Prognosis Follow-up

6 Complementary Role of CT and myocardial perfusion imaging CT Anatomic evaluation of atherosclerosis Detection Stadification Ischemia localization Treatment follow-up Myocardial perfusion Functional evaluation of atherosclerosis Asymptomatic Chronic ischemia Endothelial damage Atherosclerosis Atherotrombosis Myocardial damage Endothelial dysfunction ACS C.H.F..

7 PET/CT applications in Cardiology Myocardial perfusion Coronary Angiotomography Cardiac function Oxidative metabolism Myocardial viability Coronary blood flow quantification Endothelial dysfunction Plaque inflammation

8 PET/CT applications in Cardiology Myocardial perfusion Coronary Angiotomography ISCHEMIA Cardiac function Oxidative metabolism NORMAL Myocardial viability Coronary blood flow quantification INFARCTION Endothelial dysfunction Plaque inflammation

9 Myocardial Perfusion Possitron emitting Tracers 82 Rubidium 15 O-Water 11 C-Acetate 13 N-Ammonia Alexanderson E. Arch Cardiol Mex 2005; 75:13-22.

10 Ammonia PET

11 Ammonia PET

12 PET/CT applications in Cardiology Myocardial perfusion Coronary Angiotomography Cardiac function Oxidative metabolism Myocardial viability Coronary blood flow quantification Endothelial dysfunction Plaque inflammation

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15 Calcified Plaque Non-Calcified Plaque

16 Advanced characterization of the coronary plaque: the value of PET Fibrous tissue Fat Calcium Inflammation FDG-PET

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20 PET/CT applications in Cardiology Myocardial perfusion Coronary Angiotomography Hybrid imaging Cardiac function Oxidative metabolism Myocardial viability Coronary blood flow quantification Plaque inflammation

21 FUNCTIONAL IMPACT OF CORONARY ESTHENOSIS OBSERVED WITH CT: THE ROLE OF CT AND 13N- AMMONIA PET 29 patients with the suspicion of CAD were studied with PET Coronary Anatomy and Stenosis were evaluated with CT Stenosis: any reduction in the lumen diameter; it was considered as significative when the reduction was bigger than 50%

22 Results + Coronary CT - Coronary CT + PET PET 1 3 Sensitivity 95.8% Specificity 60% PPV 92% NPV 75% Accuracy 90% p < 0.001

23 Results

24 Results Significative stenosis (>50%) Non-significative stenosis (<50%) Mild ischemia 5 Moderate ischemia 1 Severe ischemia 9 n = 15 Non-ischemic 1 Mild ischemia 4 Moderate ischemia 4 Severe ischemia 0 n = 9 Correlation between coronary stenosis and the severity of ischemia

25 Normal CT Normal CT n=9 n=9 Normal Normal PET/SPECT PET/SPECT n=6 n=6 Abnormal Abnormal PET/SPECT PET/SPECT n=3 n=3 Normal Normal Angiography Angiography n=9 n=9 Non Non-obstructive obstructive CT CT n=16 n=16 Normal Normal PET/SPECT PET/SPECT n=6 n=6 Abnormal Abnormal PET/SPECT PET/SPECT n=10 n=10 Non Non-obstructive obstructive angiography angiography n=16 n=16 Obstructive Obstructive CT CT n=33 n=33 Normal Normal PET/SPECT PET/SPECT n=14 n=14 Abnormal Abnormal PET/SPECT PET/SPECT n=19 n=19 Non Non-obstructive obstructive angiography angiography n=3 n=3 Obstructive Obstructive Angiography Angiography n=11 n=11 Non Non-obstructive obstructive Angiography Angiography n=3 n=3 Obstructive Obstructive Angiography Angiography n=16 n=16 JACC 2006;48(12):

26 Why don t they always match? The coronary stenosis percentage is just one of the factors that interact in coronary resistance; it is not sufficient to determine the plaque s hemodynamic significance. It is difficult to estimate the stenosis degree in soft or very calcified plaques Balanced ischemia Non-Coronary causes of myocardial lesions Coronary Anomalies Ectasia Coronary Aneurysms There may be coronary lesions without ischemia There may be ischemia without coronary lesions Dorbala et al. JACC 2006: 48: Di carli et al. J Nucl Cardiol 2006;13:139-44

27 PET/CT applications in Myocardial perfusion Cardiology Coronary Angiotomography Cardiac function Oxidative metabolism Myocardial viability LVEF 62 % Coronary blood flow quantification Endothelial dysfunction Plaque inflammation LVEF 23 %

28 GATED PET Stress LVEF 73% Rest LVEF 69% NORMAL

29 Gated PET

30 Gated PET

31 LVEF Rest-Stress Non-ischemic n = 5, p < ,00% 70 ± 7.1% 70,00% 68,00% 66,00% 64.6 ± 7.5% 64,00% 62,00% 60,00% Rest Stress Alexánderson E. Presentado en ICNC 8, Praga 2007

32 LVEF Rest-Stress Ischemic 57,00% 56.9 ± 5% n = 12, p < ,00% 53,00% 51,00% 49.8 ± 8.1% 49,00% 47,00% Rest Stress Alexánderson E. Presentado en ICNC 8, Praga 2007

33 LVEF and Magnitude of affected myocardium LVEF Reserve(%) LVEF Reserve (%) Scar Rev Mild-mod Rev Severe CAD 0 vessels CAD 1 vessel CAD 2 vessels CAD 3 vessels ortci Results PET Rb 82 Disease extension with Angiography Dorbala et al. J Nucl Med 2007;48

34 PET/CT applications in Myocardial perfusion Cardiology Coronary Angiotomography Cardiac function Coronary blood flow quantification Endothelial dysfunction Oxidative metabolism Myocardial viability Plaque inflammation

35 Myocardial blood flow quantification Early detection of coronary artery disease Precise diagnosis of ischemia Physiological impact of stenosis Campisi R, Di Carli M: J Nucl Cardiol 2004:11:3-11.

36 Stress Rest

37 Myocardial blood flow Determination of myocardial blood flow. 17 healthy controls quantification 13 patients with CAD previously diagnosed with PCI. 13N-Ammonia myocardial perfusion imaging Quantification of coronary blood flow. Comparison with cardiac catheterism.

38 Coronary flow quantification Improves the diagnosis of CAD. ml/m in/g 1,8 1,6 1,4 1,2 1 0,8 0,6 0,4 0,2 0 0,54 0,5 BCF 1,74 1,1 SCF ,55 RFC CFR 2,38 Healthy Ischemic Healthy Ischemic Unidad PET-Ciclotrón, UNAM, México

39 Relationship between coronary flow and coronary stenosis Stress cronary flow Less than 50% 50% to 70% 70% to 90% 90% to 100% Coronary stenosis percentage

40 Relationship between coronary stenosis and coronary vasodilation reserve Coronary vasodilation reserve Stenosis percentage

41 Myocardial blood flow quantification Detection of endothelial dysfunction DM: CFR Systemic Hypertension: EDVI Anti-phosfolipid syndrome: EDVI Normal perfusion Patients follow-up Vascular disease might be ruled-out

42 PET/CT applications in Myocardial perfusion Cardiology Coronary Angiotomography Cardiac function Ammonia 18-FDG Coronary blood flow quantification Discordant Endothelial dysfunction Oxidative metabolism Concordant Myocardial viability Plaque inflammation

43 The goal of viability imaging Identify patients with a bad cardiac function in which revascularization might improve: Left ventricular function Symptoms Survival

44 PET viability Criteria Ammonia 18-FDG DISCORDANT CONCORDANT Circulation 1983; 67:

45 Diagnostic accuracy of viability tests evaluated with PET Modificado de Bax et al. Curr Probl Cardiol 2001

46 18 F-FDG 13 N-ammonia 18 F-FDG 13 N-ammonia 18 F-FDG 13 N-ammonia

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48 18FDG 13N Ammonia Viability

49 Long-term prognosis of patients with left ventricular dysfunction and viability evaluated with PET and recieved therapy With Mismatch Without Mismatch Probabilidad de sobrevivir Revascularization Medical Probabilidad de sobrevivir Revascularization Medical Time (months) Time (months) Di Carli et al. JTCVS 1998

50 Risk of suffering a MACE in patients with evidence of viability demonstrated with PET treated with revascularization or medical therapy n= 634 patients Relative risk and CI 95% Di Carli. J Nucl Cardiol 2002

51 Mortality rate in patients with or without viability treated with revascularization or medical therapy Allman et al. JACC 2002

52 PET/CT applications in Myocardial perfusion Cardiology Coronary Angiotomography Cardiac function Coronary blood flow quantification Endothelial dysfunction Oxidative metabolism Myocardial viability Plaque inflammation

53 Atherosclerotic plaque inflammation Evidence of FDG uptake in the carotid arteries. Arauz A, Alexánderson E. Clin Neurology and Neurosurgery 2007, 109:409-12

54 Atherosclerotic plaque inflammation Arauz A, Alexánderson E. Clin Neurology and Neurosurgery 2007, 109:409-12

55 Atherosclerotic plaque inflammation Evidence of FDG uptake in the aorta

56 Alexanderson E, et al. J Nucl Cardiol 2008

57 PET/CT applications in Myocardial perfusion Cardiology Coronary Angiotomography Cardiac function Coronary blood flow quantification Endothelial dysfunction Myocardial viability Plaque inflammation Molecular imaging

58 Molecular Imaging 11 C Palmitato IPPA BMIPP AGL K+ 201 Tl+ 82 Rb+ Misonidazole 18 FDG ATP ATP ADP Glucosa Glucógeno ADP Na+ [O 2 ] 11 C-CGP Glucosa-6-P AGL-CoA Depósitos de lípidos ATP Glucólisis β oxidación Adenosina Piruvato Krebs Fosforilación oxidativa 11 C-HED 18 F Dopamina 18 F NE Lactato 11 C-Acetato 15 O 2 11 C-Homocisteína

59 CONCLUSIONS Innovative Non-invasive. Anatomic and functional information of the heart (coronary and cardiac anatomy, calcification and characterisation of the plaque, myocardial perfusion and ventricular function) Still pending to determine the diagnostic and prognostic value of this imaging technique Which patients obtain a benefit with both techniques? Is there a testing sequence? Is there an improvement in the patient management? The big radiation dose and the costs make of the PET/CT an inappropiate technique for check-ups The combination of perfusion imaging and CT is the best available method to predict cardiovascular outcomes.