How to evaluate heart disease - Do we need new tools Focus on myocardial circulation

Transcription

1 How to evaluate heart disease - Do we need new tools Focus on myocardial circulation Alf Inge Larsen Professor department of clinical science University of Bergen Head of Cardiovascular Research Group Head of Cardiovascular interventions Stavanger University Hospital 1

2 Macro vascular disease The large vessels of the heart 2

3 Micro vascular disease Dysfunction of the micro vascular bed 3

4 Both macro vascular and micro vascular disease may cause angina pectoris Chest pain during exertion 4

5 Everyday clinical practice Macro vascular disease 5

6 Macro vascular disease= stenosis of a large vessel Obstruction of blood flow Reduced blood flow to working heart muscle too little O 2 Ischemia chest pain (angina) during exertion Reduced pump function Arrhythmias Atherosclerotic plaque 6

7 Progression from stable coronary artery disease to Acute myocardial infarction 7

8 When the membrane over the narrowing rupture (plaque rupture) a blood clot is formed Atherosclerotic plaque Hjerteinfarkt 2/10-17 Current Medicine

9 Obstructive blood cloth Hjerteinfarkt 2/10-17

10 Hjerteinfarkt 2/10-17

11 Ventricular fibrillation Cardiac arrest DEATH Hjerteinfarkt 2/10-17

12 Two - 2 aspects of coronary artery disease Stable artery disease; Flow reduction due to stenosis Acute coronary artery disease Plaque rupture of the actual stenosis 12

13 Available tools to assess macro vascular disease The working horse 13

14 Coronary angiography Assessment of macro vascular disease 14

15 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS - Intravascular Ultrasound OCT - Optical Coherence Tomography (light) NIRS - Near infra red spectroscopy FFR- Fractional flow reserve 15

16 IVUS - Intravascular Ultrasound

17 Plaque Volume 17

18 Virtual Histology 18

19 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS - Intravascular Ultrasound OCT - Optical Coherence Tomography NIRS - Near infra red spectroscopy FFR- Fractional flow reserve 19

20 High resolution, Rupture more likely when thickness of cap over the atherosclerotic plaque is < 60 μm 20

21 Stent strut mal apposition Risk for thrombus Braunwald

22 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS; Intravascular Ultrasound OCT; Optical Coherence Tomography NIRS; Near infra red spectroscopy FFR- Fractional flow reserve 22

23 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS; Intravascular Ultrasound OCT; Optical Coherence Tomography NIRS; Near infra red spectroscopy FFR- Fractional flow reserve 23

24 Near infra red spectroscopy NIRS 24

25 Chemogram; Yellow high=fat content Vulnerable plaque 25

26 The combination of these modalities So far 26

27 Combined OCT-NIRS Fard AM et al Opt Express 2013;

28 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS; Intravascular Ultrasound OCT; Optical Coherence Tomography NIRS; Near infra red spectroscopy FFR- Fractional flow reserve 28

29 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS; Intravascular Ultrasound OCT; Optical Coherence Tomography NIRS; Near infra red spectroscopy FFR- Fractional flow reserve 29

30 Pressure gradient=adequate flow for myocardial metabolism PERFUSION PRESSURE 30

31 Perfusion pressure over a coronary stenosis 31

32 More than 20 % drop in pressure over the stenosis indicates a significant stenosis giving ischemia. Revascularization is associated with improved diagnosis pull-back advance 32

33 Available intra vascular imaging tools that can be used during coronary angiography to improve diagnosis IVUS; Intravascular Ultrasound OCT; Optical Coherence Tomography NIRS; Near infra red spectroscopy FFR- Fractional flow reserve 33

34 Non-invasive techniques 34

35 Coronary imaging wit CT Anatomical stenosis If the plaque is prone to rupture it might be evaluated using PET assessing inflammatory activity in the plaque 35

36 Combination of PET and CT Jack P.M et al Atherosclerosis Volume 272, Pages Atherosclerosis , DOI

37 Inflammation in plaque determines vulnerability 37

38 Can the drop in pressure be evaluated non invasively? We need a new TOOL Coronary CT FRACTIONAL FLOW RESERVE 38

39 pull-back advance 39

40 Coronary imaging wit CT Anatomical stenosis Is the stenosis narrow enough to give a significant reduction in flow Fall in pressure 40

41 Only 1-one commercial company 500 mill dollars funding 41

42 HeartFlow creates a personalized, digital 3D model of the arteries. Powerful computer algorithms solve millions of complex equations to assess the impact that blockages have on blood flow. The result is a color-coded map that aids clinicians in determining, vessel-by-vessel, if sufficient blood is reaching the heart. 42

43 A local co-operation between IRIS UIS and SUS 43

44 Invasive Cardiology and Petroleum technology SUS Nigussie Bogale Jorunn Havnen Ole Jacob Greve Alf Inge Larsen IRIS Jan Ludvig Vinningland Aksel Hiort Tor Ole Gulsrud Ingunn Westvik Jolma SINTEF Conoco Philips 44

45 Stenosis evaluation based on CT imaging and flow simulation CT imagin g Data reconstruction Parallel simulation Hospital (SUS) Industry (Siemens) Research (IRIS) Pressure gradient Viscosity Peripheral ressitance ETC ETC 45

46 Colour codes indicate FFR values 46

47 Compare simulation with real data from invasive procedures pull-back advance 47

48 CT fractional flow reserve (FFR) using computational fluid dynamics. Invasive coronary angiogram coronary lesions assessed FFR are correlated with CT-derived FFR Nakazato R, Circ Cardiovasc Imaging 6:881, 2013.) 48

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50 Coronary Flow Reserve is the ability to increase myocardial flow during exercise Coronary Flow Reserve 50

51 Depends on the ability to reduce peripheral resistance 51

52 Micro vascular function (Coronary flow reserve) can be evaluated with Invasive tools with Doppler wires in the artery Positron emission tomography Transthoracic ultrasound (Non-invasive Doppler) 52

53 Ultrasound/Doppler; Coronary velocity reserve 53

54 Can CFR be calculated from coronary angiogram without using wires and adenosine Automatic estimation of coronary blood flow velocity using X-ray coronary angiography sequence 54

55 Cooperation University of Stavanger Dept. of Electrical Eng. and Computer Science M Khanmohammadi, K. Engan, T. Eftestøl Stavanger University Hospital Department of Cardiology, Stavanger, Norway M Skadberg, C Sæland, AI Larsen 55

56 56

57 Angiograms from patients (N=21) were obtained at the invasive cardiology department of Stavanger university hospital The data: 2D + time X-ray angiography All procedures were performed using a GE coronary angio laboratory using Iomerone 350 contrast dye. Each video of a patient is save in a file with DICOM format. Videos are not synced with the heart beats. X-ray Original photo from: 57

58 Proposed Segmentation algorithm I(x,y) I ~ (x,y) _ Smo oth + + λ 1 λ 1 λ 2 λ 2 Tubular Blob-like Detect tubular structures Pairwise Registration Original video sequence Morpholo gical operation s Vessel segmentation Initially segmented coronary vessels Correct alignment Yes Segme nted Image Preprocessing: Unsharp masking Segmentation enhancement using geometry and anatomy of the coronary arteries N o 58

59 Results in random frames of angiogram from different patients 59

60 Vessel skeleton... vessel branches * Vessel s endpoints * Joint points 60

61 Dye propagation in time From angiography... F_ t1 F_ t2 F_ tn-2 F_ tn-1 F_ tn D = L tn -L tn-1 L: Skeleton length D: Length difference 61

62 3D reconstruction from few views

63 Correlate with Velocity measured with TransThoracic Doppler 63

64 Results compared with velocity measured by Doppler Volumetric flow rate: Q = V t v = Q A v i = l i t i 64

65 A recent publication from September 2018 is evaluating FFR using ordinary coronary angiograms No need for advanced invasive procedures Or Expensive CT/PET procedures?? 65

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67 Fearon et al Circulation Sept

68 Computational fluid dynamics estimating fractional flow reserve from a simple angiogram. Fearon et al Circulation Sept

69 Fearon et al Circulation Sept

70 Conclusions We need new tools for 1) Non invasive imaging for assessing plaque stability, and plaque burden 2) Non invasive assessment of FLOW 3) Easily available assessment of microcirculation 70

71 An example of the combined non invasive approach 71

72 Plaque characterization with NIRS and OCT compared with FFR CT 72

73 Co-operating centres Ålesund Sykehus 73

74 Thank you for your attention 74

75 How to evaluate heart disease - Do we need new tools Focus on myocardial circulation Alf Inge Larsen Professor department of clinical science University of Bergen Head of Cardiovascular Research Group Head of Cardiovascular interventions Stavanger University Hospital 75

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77 CFR, absolute blood flow, coronar resistance etc etc 77

78 CRF measured with PET 78