Biomarkers of Cardiovascular Disease Future Novel Markers ...
Transcript of Biomarkers of Cardiovascular Disease Future Novel Markers ...
Dr David C. GazeCardiac Research Scientist
Clinical Blood Sciences, St George’s Hospital & Medical School
Visiting Professor of Cardiovascular Biochemistry, Nanjing Tech University ChinaHon. Lecturer, Sports Science & Medicine, Brunel University
Biomarkers of Cardiovascular Disease&
Future Novel Markers of Ischemia
Disclosures
Unrestricted Educational grants
Lecture fees
Consultancy
Not for profit research costs
The Coronary Artery Evolution
Time
Michelangelo di Lodovico Buonarroti Simoni (1475-1564)
Office for National Statistics; Edinburgh (2002)
CHD, 120,891
Stroke, 66,726
Other CVD, 52,650
Lung cancer, 33,509
Colo-rectal cancer,16,155
Breast cancer, 13,011
Other Cancer, 95,848
Respiratory conditions,75,809Injurys and poisoning,
20,120All other causes,
10,1325
0 20000 40000 60000 80000 100000 120000 140000
Number of deaths
Deaths by cause in the UK 2001
IntermediateLesion
FoamCells
AtheromaFattyStreak
FibrousPlaque
ComplicatedLesion/Rupture
Growth mainly by lipid accumulation
From third decade oflife
From fourth decade oflife
Smooth muscleand collagen
Thrombosis,haematoma
From first decade of life
EndothelialDysfunction
Atherothrombosis: With us for life
IrreversibleISCHEMIC CELL DAMAGE
Reversible small area large area
Pro-inflammatoryCytokines Plaque
DestabilisationPlaqueRupture
Acute Phasereactants
Ischemia Necrosis Dysfunction
Atherothrombosis: With us for life
IntermediateLesion
FoamCells
AtheromaFattyStreak
FibrousPlaque
ComplicatedLesion/Rupture
EndothelialDysfunction
Chest Pain Challenge
• Risk Stratification– Must risk-stratify a large patient population
quickly, with limited diagnostic information• Rule In
– Therapy must be administered as soon aspossible to save myocardium
– Problem is identifying these patients in time• Rule Out
– Chest pain patients consume substantial hospitaltime and resources (US $12B year)
– Problem is time/cost to discharge with confidence
Chronological Development ofCardiac Markers
Gaze & Collinson: Exp. Opin. Drug Metab. Toxicol. 2005;1:715-725
1950 19701960 1980 1990 2000
ASTin AMI
CK inAMI
Electrophoresisfor
CK & LD
INHfor
CK-MB
myoglobinRIA
WHODiagnosis
of MI
CK-MBmass
MAbCK-MB
cTnTin AMI
cTnTin UA
cTnI inAMI
cTnrisk
stratification
IMAWB-Ch
Nourin-1
NT-Pro&
BNPESC/ACCdefinition
ofAMI
Faster Recognition Æ Earlier Decisions Æ Better Outcomes
• Time is Muscle
• Therapy must be administered as soon as possible to savemyocardium– Fibrolynitics– Anticoagulants– Antiplatelet Agents (GP IIb/IIIa)– Percutaneous Coronary Intervention (PCI)
All withinminutes
Plaque formationVascular risk markers
• Cholesterol– HDL– LDL– IDL– VLDL– Non HDL cholesterol– Total cholesterol/HDL ratio– Apolipoprotein A1– Apolipoprotein B100
• Lp(a)• Homocysteine
Metabolic markers
• Albumin• Insulin• Gherelin• Leptin• Adiponectin• Resistin
What is Ischemia?
Time
Oxygen
Oxygen supply diminishes withdisease progression
Oxygen demand changesdaily and during life
SA SA UA MI
Ischemia occurs whenO2 demand exceeds supply
Stable Angina (SA) Ischemia due to stable plaque / exertionUnstable Angina (UA) Ischemia due to plaque disruption / thrombusAcute Myocardial Infarction (AMI) Myocardial necrosis due to prolonged ischemiaAcute Coronary Syndromes (ACS) Unstable Angina and Acute Myocardial Infarction
Onset ofnecrosis
PlaqueDisruption
How is Ischaemia Currently Diagnosed
• There is no gold standard for diagnosis of cardiac ischemia
• Diagnosis of ischemia is challenging, and uses multiple imperfect tools
– Clinical Assessment (signs and symptoms)– Presentation ECG (standard of care)– Necrosis Markers (detects consequences of prolonged ischemia)– Other Diagnostic Tools
ê Echocardiogramê Exercise testingê Technetium-99m Sestamibi
• Evaluation of a new diagnostic tool is difficult
Selker et al: Ann. Emerg. Med. 1997
All NecrosisAll Ischemia Some Ischemia, some Necrosis
ACS Sequence and Timing
Plaque
Rupture
OnsetofP
ain
ED
Presentation
Discharge
0-12 to0 hrs
12 to24 hrs
Time
Ischaemiamarker
Necrosismarker
Cardiac Dysfunctionmarker
Am
ountofTissue
Plaque destabilisation: Inflammatory markers
Pentraxins C reactive protein (CRP)
Pentraxin 3
ReactiveOxygenspecies
Surrogate moleculesoxidised low-density lipoproteinmalondialdehyde,myeloperoxidaseIsoprostanes
Uric acid (xanthine oxidase)
Cytokines Tumour necrosis factor (TNF)
Interleukin 6 (IL-6)
Osteoprotegrin
Chemokines Monocyte chemoattractant factor(MCP)
Apoptosis markers FasR
Adhesion molecules CD40
P selectin
E selectin
L selectin
ICAM-1
VCAM-1
Growth factors VEGF
PlGF
HGF
EGF
Soluble CD40 ligand (sCD40L)
• Circulating sCD40L derived from activated platelets.• Triggers inflammatory reaction in vascular endothelial cells via
secretion of cytokines and chemokines
• Increased [sCD40L]
– AMI and UAPAukrust et al: Circulation 1999;100:614-20.Garlichs et al: Heart 2001;86:649-55.
– Following PCICipollone et al: Circulation 2003;108:2776-82
Soluble CD40 ligand (sCD40L)
sCD40L in ACS (OPUS-TIMI 16)
Varo et al: Circulation 2003;108:1049-52
Varo et al: Circulation 2003;108:1049-52
Plaque Rupture I
Ischemia
• WB Choline• Unbound free fatty acids• Ischemia modified albumin
Necrosis
Cytosolic CK-MBMyoglobinHeart fatty acid bindingprotein (HFABP)
Structural Cardiac troponinscardiac troponin Tcardiac troponin IMyosin light chains(MLC)
Whole blood Choline
• Choline is released by cleavage of membrane phospholipidsby phospholipase D to yield plasma choline (PCHO).Choline is then taken by red blood cells.
• Phospholipase activation occurs in a number of processesthought to be involved in plaque destabilisation.
• Ischemic membrane damage produces phospholipidbreakdown and uptake into red blood cells by a cholinetransporter.
• WBCHO was measured by HPLC-mass spectrometry prospectively on
admission in 327 patients.
• Final Dx of AMI by ESC/ACC criteria using cTnT/I
• 30 day follow up as the outcome measure.
• WBCHO was a good indicator of major adverse cardiac events (MACE)
whether used alone or in combination with cardiac troponins.
• It was not a good marker for a subsequent diagnosis of AMI but did
distinguish between high risk and low risk patients without AMI.
Dane O et al: Am. J. Cardiol. 2003;91:1060-1067
Whole blood Choline
Increased risk of death or arrestat 30 days associated withincreasing quartiles of Choline
Unbound Free Fatty Acids (FFAu)
• Ischaemia is associated with the release of fatty acids (FFA) frommuscle tissue, especially cardiac muscle.
• The majority of FFA are bound to albumin but a small amount ofunbound free fatty acids (FFAu) are found in the serum.
• Coronary angioplasty model of ischaemia.• 22 patients• Measurements at 5 minutes pre-procedure and 30 minutes post
procedure.
• Accompanying ST segment changes in the ECG occurred in only 11of the patients, but was associated with the highest FFAu values.
Kleinfeld et al: Am. J. Cardiol. 1996;78:1350-4
Unbound Free Fatty Acids (FFAu)
• Post-PTCA [FFAu] higher (mean =103 nM) than pre-PTCA[FFAu].
• Mean post-PTCA [FFAu] 14-fold higher than the 7.5 nM valueobserved in healthy subjects.
• Accompanying ST segment changes (n=11) associated withthe highest FFAu values.
Kleinfeld et al: Am. J. Cardiol. 1996;78:1350-4
r=0.8
Coronary Angioplasty model
• 88 patients undergoingangioplasty
• Blood taken at– Baseline– Post procedure– 6 hours post– 24 hours post
Collinson et al: Clin. Chem. 2003;49:A38
IMA Values PCI Group
Sample timing peri-PCI
IMA24HIMA6HIMAPOSTIMAPRE
IMA
U/m
l
160
140
120
100
80
60
40
20
P=0.0002
P=0.004
IMA as Aid to Diagnosis of AMI
• Rule Out Myocardial Infarction (ROMI) trial
• >400 Patients, 4 US Hospitals
• IMA + Troponin have higher sensitivity, especially atpresentation
Wu et al: Cardiovascular Toxicology 2001
Matrix metalloproteinasesand their inhibitors
Matrix metalloproteinase 1-27 (MMP1-27)Tissue inhibitors of matrix metalloproteinases 1-4(TIMP1-4)
Collagen peptides Procollagen III aminopropeptide (PIIINP)
Procollagen type I carboxy-terminal peptide (PICP)Procollagen type I amino-terminal peptide (PINP)Type I collagen telopeptide (ICTP)Basement membrane laminin (BML)
Matrix glycoproteins/lectins Tenascin COsteopontinGalectin-3
Extracellular matrix turnover and remodelling
Plaque Rupture II
Biomechanical strain
Natriuretic peptidesAtrial natriuretic peptidepro-B-type natriuretic peptideN-terminal pro-B-type natriuretic peptide
Interleukin 33/ST2 (IL33/ST2)
Growth differentiation factor 15 (GDF 15)
Plaque Rupture III
Neurohormonal activation
AldosteronePro-ADH (Copeptin)
Adrenomedullin
Apelin
Endothelin
Relaxin
Urotensin
Evolution of Troponin Assays
• Better Precision with high sensitivity assays
• Definable Reference population
• Utility as a risk marker rather than eventmarker
Not Measureable
Evolution of Troponin Assays
Troponin Concentration
Freq
uenc
y
99th Percentile
Hig
hSe
nsiti
veLo
D
Not
Mea
sure
able
!
Con
tem
pora
ryLo
D
10% CV
Histological loss of cTn following occlusion
Dog LV 45min total occlusion
a) Patchy hypereosinophilia *b) cTnI loss in region of necrosis *
Left papillary muscle rat 3hr ofocclusion
c) Subtle hypereosinophilia *d) cTnI immunostaining variable but
decreased amounts of staining *
Fishbein et al: Cardiovascular Pathology 2003;12:65-71
Histological loss of cTn following ischemia
Fishbein et al: Cardiovascular Pathology 2003;12:65-71
Dog LV 6hr occlusion no reperfusion
a) Oedema/hypereosinophilia *b) cTnI immunostaining *c) cTnI immunostaining (x60)
Dog LV 1hr occlusion/3hr reperfusion
d) Hypereosinophilia in necrosis zonee) cTnT loss at infarct edgef) cTnI immunostaining (x60)
Your cardiactroponin result
suggestsyou’re in good
health
Cardiac Troponin - The Holy Grail?
What's the Catch? There’s Always a Catch…
Lab tests are not a replacementfor clinical assessment.
AMI remains a clinical diagnosis.
cTn+ does NOT equal AMI butcardiac myocyte injury.
Any troponin elevation requiresexplanation, not dismissal.
cTn elevation in non-ACS
Elevated cTnI in “normals”predicts an adverse outcome
• Predicts an adverse outcome.
• Increased event rate observed in thosepatients with low level but detectable cTnvalues.
• Zethelius, B. et al. Circulation 2006;113:1071-78• Wallace TW, et al Circulation 2006;113:1958-65
Zethelius, B. et al. Circulation 2006;113:1071-1078
All-cause mortality at 10 year follow up in relation to cTnI in men free from CVDat baseline and in men with prevalent CVD at baseline
Elevated cardiac troponin innon-ACS populations
• Secondary and Non-ischemic CardiacInjury
• Pathophysiology: direct myocardialinjury+/- cardiac ischemia
SICI: Secondary Ischaemic Cardiac Injury(NOT Primarily due to a Ruptured Coronary Plaque)
Coronary intervention
Sympathomimetics
Pulmonary embolusCoronary artery spasmCoronary artery embolisationCoronary artery inflammationwith microvasular occlusionEnd stage Renal FailureRhythm disordersAcute Heart failure
Direct coronary traumaExtreme endurance exercise
Primary/Elective Distal embolisation from atheroma debrisPTCA Side branch occlusionsCABG Global ischaemia from inadequate perfusion,
myocardial cell production of anoxia
CocaineCatecholamine Storm Head injury/CVA/intracerebral bleed
Presumed right heart strainJapan - upto 10% of admissionsClot, air or CABG
VasculitidiesConnective tissue disease/damage/SLESevere disease, but 50% normal coronariesProlonged tachycardia/bradycardia
Only if due to IHDStabbing/chest contortionExtreme marathons - Wall motion abnormalitiescTn positive deaths possibly due extreme O2 debt producingischaemia
Collinson & Stubbs: Heart 2003;89:1285-87
Known causes ofmyocarditis
Cardiac Trauma
Metabolic/toxic
Infection BacterialViral
InflammationAutoimmune Polymyositis
SclerodermaSarcoidosis
Drug-induced AlcoholChemotherapyEnvenomation
Direct Road traffic accidentStabbing
Cardiac Surgery
Renal failureMultiple organ failure (MOF)
NICI: Non Ischaemic Cardiac Injury
Collinson & Stubbs: Heart 2003;89:1285-87
Key Take Home Messages• Biochemical investigations are central to the Dx and
Management of CVD.
• Many biomarkers exist targeting different parts of thedisease continuum.
• Markers upstream of necrosis may be sensitive but atthe expense of specificity.
• cTn determined using high sensitivity assays can detectischemia.
• cTn may evolve in time from an acute event marker to arisk marker.
Any Questions?�