This document provides an overview of vulnerable plaque and summarizes the work of pioneers in the field. It describes the different types of vulnerable plaque, such as rupture-prone plaques and eroded plaques. Emerging techniques for detecting vulnerable plaque are also discussed, including intravascular ultrasound, optical coherence tomography, thermography, and various forms of spectroscopy and imaging. The goal is to noninvasively identify high-risk plaques to prevent heart attacks.
2. Everybody has atherosclerosis, the question is who has vulnerable plaque
Sudden Cardiac Death
Acute MI
Vulnerable
Plaque(s)
3. Vulnerable Plaque and Vulnerable
Patient, The Challenge of
Cardiovascular Medicine in 21st
Century
An introductory tutorial from
VP.org
In conjunction with
The Center for Vulnerable Plaque Research
University of Texas Houston and
Texas Heart Institute
4. What Do We Know About
Vulnerable Plaque?
Center for Vulnerable Plaque Research
University of Texas at Houston
Texas Heart Institute
October 2001
Morteza Naghavi, MD
Mohammad Madjid, MD Silvio Litovsky, MD AlirezaZarrabi, MD
Maziar Azadpour, MD ParsaMirhaji, MD CorneliusNwora, MD
Ward Casscells, MD James Willerson, MD
6. Carl von Rokitansky (1804-1878)
Rokitansky gaveearly
detailed descriptionsof
arterial disease. Heis
alleged to haveperformed
30,000 autopsies.
Rokitansky in 1841 championed theThrombogenic Theory. Heproposed that the
depositsobserved in theinner layer of thearterial wall derived primarily from fibrin and other
blood elementsrather than being theresult of apurulent process. Subsequently, theatheroma
resulted from thedegeneration of thefibrin and other blood proteinsasaresult of apreexisting
crasisof theblood, and finally thesedepositsweremodified toward apulpy masscontaining
cholesterol crystalsand fatty globules.
Thistheory cameunder attack by Virchow
7. First studies on inflammation of vessels, particularly phlebitis, Started at
a time when Cruveilhier2had just stated: La phlebite domine toute la
pathologie.3 First a great number of preparatory studies on fibrin,
leukocytes, meta-morphosis of blood, published separately. âŠ
Rudolf Virchow 1821-1902
The Father of
Cellular
Pathology
Virchow appreciates prior works.
Virchow presented hisinflammatory theory. Heutilized thenameof "endarteritisdeformans." By thishe
meant that theatheromawasaproduct of an inflammatory processwithin theintimawith thefibrous
thickening evolved asaconsequenceof areactivefibrosisinduced by proliferating connectivetissuecells
within theintima.
8. Olcott 1931 âplaque ruptureâ
Leary 1934 ârupture of atheromatous abscessâ
Wartman 1938 ârupture-induced occlusionâ
Horn 1940 âplaque fissureâ
Helpern 1957 âplaque erosionâ
Crawford 1961 âplaque thrombosisâ
Gore 1963 âplaque ulcerationâ
Friedman 1964 âmacrophage accumulationâ
Byers 1964 âthrombogenic gruelâ
Chapman 1966 âplaque ruptureâ
Plaque Fissure in Human Coronary Thrombosis (Abstract) Fed. Proc. 1964, 23, 443
Paris Constantinidis
âThedestruction of thehyalinized wall separating lumen from theatheromawas
almost alwaysobserved to bepreceded by or associated with itsinvasion by
lipid containing macrophages.â Friedman and van den
Bovenkamp 1965
Unheralded Pioneers
9. N Engl J Med 1999
âAtherosclerosis; an
inflammatory diseaseâ
Ross R.
Russell Ross
Atherosclerosis; arterial âResponse to Injuryâ
N Engl J Med 1976 Aug 12;295(7):369-77
The pathogenesis of atherosclerosis (first
of two parts).
Ross R, Glomset JA.
10. James T. Willerson 1981
N Engl J Med 1981 Mar 19;304(12):685-91
Plaque Thrombosis
11. Erling Falk Michael Davies
Autopsy Series
Thin Fibrous Cap + Large Lipid Core + Dense Macrophage
A culprit ruptured plaque
1981-1990
13. Seymour Glagov
Compensatory Enlargement
of Human Atherosclerotic Coronary
Arteries N Engl J Med 1987 May
28;316(22):1371-5
<50%
stenosis
Luminal area is not endangered until more than 40% of
internal elastic lamina is destructed and occupied by plaque
Coronary artery disease is a disease of arterial wall
disease not lumen.
PositiveRemodeling
<80%
stenosis
14. Angiographic progression of coronary
artery disease and the development of
myocardial infarction.
Ambrose JA, Tannenbaum MA, Alexopoulos D, Hjemdahl-Monsen CE, Leavy J, Weiss M, Borrico S, Gorlin R, Fuster V.
Department of Medicine, New York Cardiac Center, Mount Sinai Medical Center, New York 10029.
Simultaneously, Little et al, Haft et al reported that majority of culprit
lesions are found on previously non-critical stenosis plaques.
Conclusion:
âMyocardial infarction frequently develops from non-severe lesions.â
J Am Coll Cardiol 1988 Jul;12(1):56-62
Ambrose, Fuster, and colleagues
Angiographically Invisible Plaques
15. Falk E., Shak P.K., Fuster V. Circulation 1995
Non-stenotic (<75%) plaques cause about 80% of deadly MI
16. Macrophage-
driven MMPs
soften plaquecap
and prompt it to
rupture
P.K. Shah
Peter Libby
Thefateof atherosclerosisand
itsthrombotic complication are
governed by immunesystem.
Goran Hansson
and others
Allard van der
Wal
and others
17. âąEroded Plaque
Rupture-prone
plaques are not the
only type of
vulnerable plaque
âąCalcium Nodule
van der Wal - Netherlands
Renu Virmani -USA
Thiene - Italy
Kolodgie F., Burk A.P., Farb A., and Virmani R.
18. Muller JE, Abela GS, Nesto RW, Tofler GH.
Triggers, acute risk factors and vulnerable plaques:
the lexicon of a new frontier.
J Am Coll Cardiol. 1994 Mar 1;23(3):809-13
James E. Muller 1994
Muller coined the term of âVulnerableâ Plaque
Muller likened Vulnerable Plaques to American nuclear missiles stored underground in
Nevada desert where they could be vulnerable to Russiansâ long-range missile attack!
19. âWho is Whoâ
on
www.VP.org
Thefield of vulnerableplaqueisbest owed to
many known and unknown scientistswho have
worked hard to shed light on our way to prevent
and eradicateheart attacksin thefuture.
To seeamorecompletelist pleasevisit:
21. ~70%
Percent of stenosis
Frequency of plaques
âRiskâ per each plaque
Culprit Risk per
each type of
Vulnerable Plaque
(Log)
Culprit lesions found
in autopsy series of
acute MI
Different Types
of Plaque
Vulnerable to
Thrombosis
All
Male
Female
~10% <5% ~20%
50%
Angiography
~80% <5% ~20%
~55% ~20%
<5%
<5% ~20%
Rupture Prone Eroded Calcified NoduleHemorrhage
Positive Remodeling
Fissured /Healed
Natural History
of Vulnerable
Atherosclerotic
Plaques
22. Ruptured Plaques (~70%)
1. Stenotic (~20%)
2. Non-stenotic (~50%)
Non-ruptured Plaques (~
30%)
1. Erosion (~20%)
2. Calcified Nodule (~5%)
Plaque Pathology Responsible for Coronary Thrombotic Death
In summary:
23. ï¶ Culprit Plaque; a retrospective terminology
ï¶ Vulnerable Plaque; a prospective terminology
Vulnerable Plaque = Plaques that are likely to
become future culprit plaque
Clarification of Terminologies
26. Fissured / Healed Plaque
Vulnerable Plaque Naghavi et al, Cur Ath Rep 2001
Mural thrombi
Wounded
plaque
27. Plaque with a Intimal Calcified Nodule
Vulnerable Plaque Naghavi et al, Cur Ath Rep 2001
Calcified nodule
28. Intra-Plaque Hemorrhage with Intact Cap
Vulnerable Plaque Naghavi et al, Cur Ath Rep 2001
Leaking
angiogenesisor
ruptureof vasa
vaserum
29. Critically Stenotic but Asymptomatic Plaque
Naghavi et al, Cur Ath Rep 2001Vulnerable Plaque
>75% lumina
narrowing
30. Different Types of Vulnerable Plaques
Major Underlying Cause of Acute Coronary Events
Normal
Rupture-prone
Fissured Eroded
Critical Stenosis Hemorrhage
Naghavi et al, Cur Ath Rep 2001
33. - Raman Spectroscopy
- Near-Infrared Diffuse Reflectance Spectroscopy
-Fibrousis and lipid measurement
-pH and lactate measurement
- Fluorescence Emission Spectroscopy
- Spectroscopy with contrast media
⊠Invasive Techniques
Intravascular (Photonic) Spectroscopy
Intra-coronary assessment of endothelial function
Intra-coronary measurement of MMPs and cytokines
34. Emerging Diagnostic Techniques
B. Non-Invasive Techniques:
A. MRI
1- MRI without contrast media
2- MRI with contrast media: Gadolinium-DPTA
2- MR Imaging of Inflammation: Super Paramagnetic
Iron Oxide (SPIO and USPIO)
3- MR Imaging of Thrombosis using monoclonal Ab
B. Electron Beam Tomography (EBT)
C. Multi-Slice Fast Spiral / Helical Computed Tomography
D. Nuclear Imaging (18-FDG, MCP-1, Annexin V, CD40)
35. Emerging Diagnostic Techniques
C. Blood Tests / Serum Markers
- CRP
- ICAM-1, VCAM, p-Selectin, sCD40-L
- Proinflamatory cytokines
- Lp-PLA2
- Ox-LDL Ab
- PAPP-A
D. Endothelial Function Test
-Intra coronary acethylcholine test
-Noninvasive flow mediated dilatation of
brachial artery
- Anti-body against endothelial cells
36. Angioscopy
Advantages:
ïIntuitive (anatomic)
ïSimple (easy to understand)
Disadvantages:
ïVisualizes only the surface of the plaque
ïRequires a proximal occluding balloon
ïThe spatial resolution is limited
Glistening
yellow plaque
Uchida et al, Japan
37. Intravascular Ultrasound (IVUS):
Advantage:
ïReveals the morphology
of the plaque
ïDiffers between soft
(hypo-echoic) and Hard
(hyper-echoic) plaques
Disadvantages:
ïDoesnât give information about plaque
inflammation
ïLow spatial resolution (~ 200 ”m)
Nissen, Yock, and
Fitzgerald
38. Optical Coherence Tomography (OCT)
Advantage:
ïVery high-resolution
Disadvantages:
ïNeeds continuous saline wash / proximal
occlusion
ïLimited penetration
ïDoes not give information
about plaque inflammation
Light Lab Inc.Mark Brezinski, James Fujimoto, Eric Swanson
40. Casscells W, et al.
Thermal detection of cellular infiltrates in living atherosclerotic
plaques: possible implications for plaque rupture and thrombosis.
Lancet. 1996 May 25;347(9013):1447-51.
Vulnerable plaques are hot and acidic!
Ward Casscells and James Willerson showed ex-vivo that human
carotid atherosclerotic plaques have temperature heterogeneity
and plaques with thinner cap and higher macrophage infiltration
give off more heat. Two years later Morteza Naghavi invented
Thermosensor Basket catheter and showed invivo temperature
heterogeneity in Hypercholestrolemic Dogs and Watanabe
Rabbits. Coincidentally Stefanadis et al in 1999 confirmed
significant temperature heterogeneity invivo in patients with
unstable angina and acute MI.
Stefanadis C, et al.
Thermal heterogeneity within human atherosclerotic coronary arteries detected in
vivo: A new method of detection by application of a special thermography catheter.
Circulation. 1999 Apr 20;99(15):1965-71.
41. Photonic Spectroscopy
Advantage:
ï Chemical compounds
Disadvantage:
ïBased on statistical analysis and
ïcalibration is always an issue
ïS/N is a serious problem
ïStill not proven to be able to distinguish
vulnerable plaques from stable ones
Near Infrared Reflectance Spectroscopy
InfraReDx Inc.
NIR Spectroscopy
Robert Lodder, James Muller, and Pedro Moreno
42. Intravascular Elastography
Advantages:
ïProvides novel information, showing stiffness
ïSmall added cost to IVUS
Disadvantage:
ïDoes not give any chemical â compositional data,
nor shows inflammation
de Korte et al. Thorax Center, Erasmus University Rotterdam
43. Intravascular Nuclear Imaging
Immuno-scintigraphy
Advantage:
ïOne may use radio-labeled antibodies to detect
specific antigens in plaque like MCP-1
Disadvantages:
ïRadiation and safety problems
ïPoor resolution and flow artifacts
ïLack of specificity
ImetrX Inc.William Strauss and Vartan Ghazarossian
44. Magnetic Resonance Imaging
Plaque Characterization and Angiography
Advantages:
ïLack of ionizing radiation
ïNon-invasive
ïProvides enormous information about flow as
well as plaque
ïEnhancement by contrast agents and NMR
spectroscopy
Disadvantages:
ïIneligibility of patients with metal prostheses
ïHigh cost
ïLonger time for adoption by cardiologists
47. Fuster and Fayad and colleagues reinforced earlier MRI investigation of plaque for invivo
non-invasive detection of vulnerable plaque with large lipid pool and thin fibrous caps.
49. Intravascular MRI
Advantages:
ïLack of ionizing
radiation
ïHigh resolution
ïPotential for NMR spectroscopy
Disadvantages:
ïInvasive and slower than fluoroscopy
ïNeeds open/short bore high field magnet
ïLonger time for adoption by cardiologists
Surgi-Vision Inc.Ergin Atalar
IVUS
50. Coronary Calcium Imaging
EBT and MSCT
Advantages:
ïQuick and easy
ïProvide information about total
burden of atherosclerosis
Disadvantages:
ïCannot distinguish vulnerable from stable plaque
(poor plaque characterization)
ïInadequate specificity, may not accurately
predict near future event
ïMay not be suitable for monitoring treatment
Calcium Score
Imatron Inc.Rumberger, Aard, Raggi, and others
51. Race for Non-Invasive Coronary
Angiography
âą Multi-Slice Fast Computed
Tomography (MSCT)
âą Magnetic Resonance
Angiography
(MRA)
âą Electron Beam Tomography
(EBT)
53. Morphology vs. Activity Imaging
Inactive and
non-inflamed
plaque
Active and
inflamed
plaque
Appear Similar in
IVUS OCT MRI
w/o CM
Morphology
Show Different
Activity
Thermography, Spectroscopy,
immunoscientigraphy, MRI with
targeted contrast mediaâŠ
54. High Level of Sensitivity and Specificity
Needed
âą Knowing the extensive prevalence of
atherosclerosis, in order to accurately
detect vulnerable plaques and
vulnerable patients, it is imperative to
obtain information about both structure
and activity of plaque assuring a
minimum of false positive and false
negative results.
NO MORE TREADMILL TEST!
57. The Question seems to be
MORE THAN ONE:
2.Who hasvulnerableblood?
3.Who hasavulnerablemyocardium?
4.Who isavulnerablepatient?
1.Who hasvulnerableplaque?â
58. Who Has Vulnerable Blood?
âą Patients whose blood tends to create an
occlusive thrombus on a vulnerable
plaque, thereby resulting in an acute
clinical syndrome.
âą In other words:
Who has hyper-coagulable or âvulnerable bloodâ?
59. Who Has A Vulnerable
Myocardium?
âą Those patients whose heart is more
sensitive to an acute ischemic episode
thereby resulting in a fatal arrhythmia
and sudden out-of-hospital cardiac
arrest?
âą In other words:
Who has arhytmogenic or âvulnerable
myocardiumâ?
60. Who Is
A Vulnerable Patient?
A patient with a high likelihood of plaque, blood, and
heart vulnerability. In other words, one with high
likelihood of becoming a victim of heart attack over
the next year.
Vulnerability Score (VP Score)
An index of having heart attack in the next 12
months
61. Prevention of unheralded acute coronary
events by early detection and treatment
of vulnerable plaques/patients.
The Grand Goal:
62. 2001 2050
Genomic
Proteomic
2010 2020 2030 2040
Cellomic?!
VP Treatment
Home-based VP
Screening Test
Heart Attack
Eradicated
Annual
Death of MI
<10,000
Cloning Heart
VP Rx as OTC or
Vaccine?
Eradication of Heart Attack
VP Detection
Mission:
Vaccine Against Vulnerable Plaque