3. Head of Cardiology Department , 6th October University
Head of Egypt Hearts Society

4. Pathophysiology of ACS and biochemichal markers release

5. Biochemical profile in ACS patients: vascular inflammation to plaque rupture to ischemia to cell death to myocardial dysfunction
Apple, F. S. et al. Clin Chem 2005;51:
Copyright ©2005 American Association for Clinical Chemistry

6. Interdependence of Cardiac Biomarkers
Pathophysiology Biochemical Markers
Coronary artery disease Risk factors (eg, cholesterol)
Coronary inflammation CRP, Lp-PLA2*, homocysteine, MPO
Plaque instability/disruption MPO, Lp(a), Lp-PLA2
Myocardial ischemia/necrosis Cardiac troponins, CK-MB, myoglobin
Ventricular overload BNP, Nt-proBNP
Adapted from Panteghini. Eur Heart J. 2004;25:
* Lipoprotein associated phospholipase A 2

7. TIME LINE OF MARKERS OF MYOCARDIAC DAMAGE & FUNCTION
Myoglobin assay
RIA for BNP and proANP
RIA for proBNP
CK – MB
CK-MB mass assay
cTnl assay
Electrophoresis for CK and LD
POCT for myoglobin CK-MB, cTnI
AST in AMI
CK in AMI
RIA for ANP
cTnT assay
Immuno assay for proBNP
IMA
Genetic Markers
1950
1960
1970
1980
1990
2000
2005
Time [years]
Timeline history of assay methods for markers of cardiac tissue damage and myocardial function.
AST: aspartate aminotransferase ANP: atrial natriuretic peptide
CK: creatine kinase BNP: brain natriuretic peptide
LD: lactate dehyydrogenase POCT: point-of-care testing
cTn: cardiac-specific troponin IMA: ischaemia-modified albumin

8. CLINICAL CHARACTERISTICS AND UTILIZATION OF BIOCHEMICAL MARKERS IN ACS
USE OF BIOCHEMICAL MARKERS IN THE
INITIAL EVALUATION OF ACS
MANAGEMENT OF NSTEACS
MANAGEMENT OF STEMI

9. USE OF BIOCHEMICAL MARKERS IN THE INITIAL EVALUATION OF ACS
A. Diagnosis of myocardial infarction
1. Biochemical markers of myocardial necrosis
2. Optimal timing of sample acquisition
3. Criteria for diagnosis of MI
4. Additional considerations in the use of bio-markers for diagnosis of MI
B. Early Risk Stratification
1. Biochemical markers of cardiac injury
2. Natriuretic peptides
3. Biochemical markers of inflammation
4. Biochemical markers of ischemia
5. Multimarker approach
6. Other novel markers

10. QUESTIONS ANSWERED BY CARDIAC MARKERS
Rule in/out an acute MI
Confirm an old MI (several days)
Monitor the success of thrombolytic therapy
Risk stratification of patients with unstable angina pectoris
N.B. Risk stratification in apparently healthy persons is not done with cardiac markers, but by measurement and assessment of cardiac risk factors
R. Hinzmann, 2002

11. BIOCHEMICAL MARKERS IN MYOCARDIAL ISCHAEMIA / NECROSIS
CK-MB (mass)
c.Troponins (I or T)
Myoglobin
OUT:
AST activity
LDH activity
LDH isoenzymes
CK-MB activity
CK-Isoenzymes
?CK-Total
FUTURE:
Ischaemia Modified Albumin
Glycogen Phosphorylase BB
Fatty Acid binding Protein

12. “CARDIAC ENZYMES” are Obsolete!

13. KINETICS OF CARDIAC MARKERS AFTER AMI
MARKER DETECTION PEAK DISAPPEARANCE
Myoglobin 1 – 4 h 6 – 7 h h
CK-MB mass 3 – 12 h – 18 h 2 – 3 days
Total CK 4 – 8 h 12 – 30 h 3 – 4 days
cTnT 4 – 12 h – 48 h 5 – 15 days
cTnI 4 – 12 h – 24 h 5 – 7 days
These values represent averages.
IMA (ischaemia) few minutes 2 – 4 h 6 hours

14. Marker of Ischemia

15. ISCHAEMIA-MODIFIED ALBUMIN (IMA)
Serum albumin is altered by free radicals released from ischaemic tissue
Angioplasty studies show that albumin is modified within minutes of the onset of ischaemia.
IMA levels rise rapidly, remain elevated for 2-4 h + return to baseline within 6h
Clinically may detect reversible myocardial ischaemic damage
Not specific (elevated in stroke, some neoplasms, hepatic cirrhosis, end-stage renal disease)
Thus potential value is as a negative predictor
FDA approved as a rule-out marker in low risk ACS patients (2003).

16. Established biomakrkers:
Creatinin Kinase-MB (mass)
Myoglobin.
Troponin.

17. CREATINE KINASE NORMAL VALUES: PATHOLOGICAL INCREASES:
Vary according to –
age
sex
race
physical condition
muscle mass
PATHOLOGICAL INCREASES:
Myocardial infarction or injury
Skeletal muscle injury or disease
Hypothyroidism
IM injections
Generalised convulsions
Cerebral injury
Malignant hyperpyrexia
Prolonged hypothermia

18. CREATINE KINASE: CK-MB
CK-MB is the most cardiac-specific CK isoenzyme
Sensitive marker with rapid rise & fall
“Gold standard” biochemical marker for ~ 2 decades
Only CK-MBmass should be measured

19. Sensitivity Specificity Myoglobin Troponins Currently earliest marker
Like total CK it is by no means cardio-specific
Troponins
Kinetics comparable with total CK and CK-MB
Cardio-specific
Sensitivity
Specificity
R. Hinzmann, 2002

20. MYOGLOBIN (Mb) Peak at 6 – 9h Normal by 24 – 36h
Excellent NEGATIVE predictor of myocardial injury
2 samples 2 – 4 hours apart with no rise in levels virtually excludes AMI

21. CARDIAC TROPONINS Striated and cardiac muscle filaments consist of:
Actin
Myosin
Troponin regulatory complex
Troponin consists of 3 sub-units TnC, TnT & TnI

22. TROPONIN SUMMARY High specificity for myocardial injury
Sensitive to minor myocardial damage

23. THE DUAL APPROACH LEAVES AN OPEN QUESTION
Troponin concentration ?
normal
acute MI
97.5 th percentile
Acute MI cut-off value

24. Troponin IN UA
Several studies have investigated the role of TnT/I in risk stratification of unstable angina (UA)
Of importance is that UA patients with elevated Tn showed same incidence of cardiac death or AMI at 6 months as did patients with pre-existing AMI (15%)
Risk of AMI in UA patients with normal Tn was 4 %.
Irreversible minor myocardial injury detected by TnT/I may stratify UA patients as high risk for progression to AMI

25. INCIDENCE OF DEATH OR MI IN ACS PATIENTS
Baseline levels of troponin have been shown to predict the risk of adverse cardiac events in patients with non-ST elevation ACS
From: NEJM 1997;337:1648 (Study 1);JACC 1998;32:8 (Study 2); Circulation 1997;95:2053 (Study 3); Am J Cardiol 2002;89:1035 (Study 4).

26. CLINICAL OUTCOME AT DIFFERENT FOLLOW-UP PERIODS
The prognostic information of an elevated cTnI upon presentation is maintained over time.
From: JACC 2000;36:1812 and Am J Cardiol 2002;89:1035

27. CARDIAC TROPONINS IN UNSTABLE ANGINA PECTORIS (UA)
QUESTION:
Does an elevated Troponin level in the absence of other signs reflect irreversible myocardial damage?
Epidemiological studies
Animal experiments
Clinical trials
Sensitive imaging techniques
Say YES!
MI must be REDEFINED!

28. New criteria for acute, evolving or recent MI
Either one of the following criteria satisfies the diagnosis for an acute, evolving or recent MI :
1. Typical rise and gradual fall (troponin) or more rapid rise and fall (CK-MB) of biochemical markers of myocardial necrosis with at least one of the following:
a) ischemic symptoms;
b) development of pathologic Q waves on the ECG;
c) ECG changes indicative of ischemia (ST segment elevation or depression); or
d) coronary artery intervention (e.g. coronary angioplasty).
2. Pathologic findings of an acute MI

29. Etiologies for Cardiac Troponin Increases
AMI NSTEMI
False +ve
(eg heterophilic antibodies)
Pericarditis
Pulmonary Embolism
Sepsis Shock
Acute LVF
Trauma
Hypertension/Hypotension
Drug Toxicity
Iatrogenic
Cardiac Surgery
PCI
Cardioversion
Cardiotoxin Drugs
EP Ablation

30. TROPONIN AND MI DIAGNOSIS
"It is estimated that about 30% of patients who present with chest pain without ST-segment elevation and would otherwise be diagnosed as having unstable angina because of a lack of CK-MB elevation actually have NSTEMI when assessed with cardiac-specific troponin assays"
From:JACC and Circulation 2002

31. PREDICTION OF RISK/PROGNOSIS
Troponin can be used to efficiently categorise patients into high and low risk groups for appropriate management pathways.
Adapted from: ACC/AHA Guideline Update for the Management of patients with UA and NSTEMI. 2002

32. BIOCHEMICAL MARKERS IN ACS CLINICAL DECISION POINTS
Unstable Angina
AMI
Infarct size
Prognosis
Thrombolysis and Reperfusion
Peri-operative infarcts
Coronary surgery complications
Transplant rejection

33. BIOCHEMICAL MARKERS IN AMI ASSESSMENT OF REPERFUSION
Time
Marker Level
Successful reperfusion
Unsuccessful reperfusion
“Washout” phenomenon – enzymes & proteins have direct vascular access when occluded coronary circulation becomes patent
Peak concentrations earlier & at higher levels if reperfusion successful
Due to short plasma half life (t½ = 10 min) Myoglobin is considered the best re-perfusion marker

34. BIOCHEMICAL MARKERS IN ACS CURRENT RECOMMENDATIONS
AMI – Routine diagnosis Troponins (CK-MBmass)
Retrospective diagnosis Troponins
Skeletal muscle pathology Troponins
Reinfarction Mb, CK-MBmass
Reperfusion Mb, Tn, CK-Mbmass
Infarct size Troponins
Risk stratification in UA Troponins

35. Problems with the current biochemical markers

36. The perfect marker
Marker for myocardial necrosis, and also for cardiac ischemia
Linear relationship between blood levels and extent of myocardial injury (and prognosis)
100% sensitive
100% specific
Immediate increase (+ constant blood level for hours to days)
Test kits : reliable, rapid, universally available and inexpensive

37. What about troponin T and I ?
Very high sensitivity for myocardial necrosis
Related to prognosis
Not 100% specific for atherosclerotic coronary artery disease
myocarditis, cardiomyopathy, myocardial contusion, ...
renal failure, auto-immune diseases, ...)
Up to 6 hours before raised blood levels no early MI diagnosis possible
Raised blood levels for many days troublesome diagnosis of re-infarction
BUT

38. Role for myoglobin ?
Initial elevation : 1 to 4h after onset better early marker than troponins
BUT : early myoglobin is less sensitive and less specific (due to skeletal muscle trauma) than late troponin decisions mainly based on clinical skills, ECG and late troponin (except rarely for reperfusion therapy)
Duration of elevation : 24 – 48h useful for re-infarction diagnosis

39. Role for CK-MB ? Initial elevation comparable with troponins
Less sensitive than troponins
High specificity (comparable with troponins)
Rapid rise and fall (instead of gradual fall for troponins) allowing more accurate estimation of MI extent

40. OTHER MARKERS CURRENTLY UNDER INVESTIGATION
Free fatty acids
Fibrin peptide A
Fatty acid binding protein
Glycogen phosphorylase BB

41. Markers of myocardial function

42. BIOCHEMICAL MARKERS OF MYOCARDIAL FUNCTION
CARDIAC NATRIURETIC PEPTIDES:
(ANP, BNP & pro-peptide forms)
Family of peptides secreted by cardiac atria (+ ventricles) with potent diuretic, natriuretic & vascular smooth muscle relaxing activity
Levels of these neuro-hormonal factors can be measured in blood
Clinical usefulness (especially BNP/N-terminal pro-BNP)
Detection of LV dysfunction
Screening for heart disease
Differential diagnosis of dyspnea
Stratification of CCF patients
New generation markers currently under development

43. SOME COMMON DISEASES IN WHICH PLASMA CARDIAC NATRIURETIC PEPTIDES HAVE BEEN FOUND TO BE ALTERED, COMPARED TO HEALTHY SUBJECTS
DISEASES ANP/BNP LEVELS
Cardiac diseases Heart failure AMI (first 2 – 3 days) Essential hypertension with CMP
Pulmonary diseases Acute dyspnea Obstructive pulmonary disease
Endocrine & metabolic diseases Hyperthyroidism Hypothyroidism Cushing’s syndrome Primary aldosteronism Addison’s disease Diabetes mellitus
Liver cirrhosis with ascites
Renal failure (acute or chronic)
Greatly increased Greatly increased Increased
Increased Increased
Increased Decreased Increased Increased Normal or increased Normal or increased
Increased
Greatly increased
AMI = acute myocardial infarction; CMP = cardiomyopathy with left ventricular hypertrophy
Clarico; Clin Chem Lab Med, 2003; 41 (17) p876

44. CARDIOVASCULAR RISK FACTORS
EMERGING RISK FACTORS Inflammatory Markers
Sensitive C-reactive protein Interleukins Serum amyloid A Pregnancy-associated plasma protein A ? Chronic infection (Chlamydia pneumoniae, ? Helicobacter pylori, etc) Procoagulant Markers
Plasma Homocysteine +
Tissue plasminogen activator Plasminogen activator inhibitor Lipoprotein A Process Markers Fibrinogen +
D-dimer ? Coronary artery calcification ?
+ Clear evidence, but less clear whether modification of the risk factor decreases the risk of cardiovascular disease
? Risk factor under scrutiny
Boersma et al, Lancet, 2003:361,p849

45. GUIDELINES: USE OF CARDIAC MARKERS IN PATIENTS WITH CHEST PAIN
Serial sampling is critical for accurate diagnosis
Do NOT discharge patients on the basis of negative results on a single (admission) specimen
If onset of chest pain >9-12 h before admission only Troponin is necessary
CK-MBmass is most useful in assessing a recent vs an older MI or to confirm reinfarction (occurs in 17% of AMI’s). Repeat CK-MBmass if chest pain recurs in AMI patients

46. GUIDELINES: USE OF CARDIAC MARKERS IN PATIENTS WITH CHEST PAIN
Mb, CK-MBmass, Troponin POSITIVE
AMI
Mb ONLY POSITIVE
Possible early infarction or skeletal muscle injury
Repeat markers
(NB importance of Mb is as a Negative Predictor)
Mb + CK-MB POSITIVE
Probable early infarction
A rising CK-MB.

47. GUIDELINES: USE OF CARDIAC MARKERS IN PATIENTS WITH CHEST PAIN
TnI < 0.06 ng/mL OR TnT < 0.03 ng/mL
on two specimens > 6 hours apart
Unstable Angina
Troponin I > 0.06 OR TnT > 0.1 ng/mL
(TnT levels > 0.03 and < 0.1 ng/mL are equivocal and
should be repeated)
? High risk ACS(AMI) or non-ischaemic myocardial damage depending on clinical cardiac ischaemia
These patients require follow-up!!
Troponin I > 0.4 ng/mL
“traditional” AMI

48. GUIDELINES: USE OF CARDIAC MARKERS IN PATIENTS WITH CHEST PAIN
FOR ASSESSMENT OF:
Reperfusion Mb, CK-MBmass
Intra- or post-operative AMI Troponin
MI after percutaneous Troponin ( in % patients)
coronary artery intervention CK-MB ( in % patients)
(compare with baseline or use fold higher cut-off level)
Reinfarction serial CK-MBmass determinations

49. Prognostic Markers and Markers of Risk Stratification
C-reactive protein
Myeloperoxidase
Homocysteine
Glomerular filtration rate

50. C-Reactive Protein
Multiple roles in cardiovascular disease have been examined
Screening for cardiovascular risk in otherwise “healthy” men and women
Predictive value of CRP levels for disease severity in pre-existing CAD
Prognostic value in ACS

51. Myeloperoxidase
Released by activated leukocytes at elevated levels in vulnerable plaques
Predicts cardiac risk independently of other markers of inflammation
May be useful in triage of ACS (levels elevate in the 1st two hours)
Also identifies patients at increased risk of CV event in the 6 months following a negative troponin
NEJM 349:

52. Homocysteine
Intermediary amino acid formed by the conversion of methionine to cysteine
Moderate hyperhomocysteinemia occurs in 5-7% of the population
Recognized as an independent risk factor for the development of atherosclerotic vascular disease and venous thrombosis
Can result from genetic defects, drugs, vitamin deficiencies, or smoking

53. Homocysteine
Elevated levels appear to be an independent risk factor, though less important than the classic CV risk factors
Screening recommended in patients with premature CV disease (or unexplained DVT) and absence of other risk factors
Treatment includes supplementation with folate, B6 and B12

54. Glomerular Filtration Rate
Reduced GFR has been associated with:
Increased inflammatory factors
Abnormal lipoprotein levels
Elevated plasma homocysteine
Anemia
Arterial stiffness
Endothelial dysfunction

55. So much information!
What does it all mean?!?

56. The Future of Cardiac Biomarkers
Many experts are advocating the move towards a multimarker strategy for the purposes of diagnosis, prognosis, and treatment design
As the pathophysiology of ACS is heterogeneous, so must be the diagnostic strategies

57. Multiple Markers Are Needed for Diagnosis and Prognosis of ACS
No single ideal marker exists for ACS
Complicated diseases are not likely to be associated with single markers
Multiple markers define disease categories
Multi-marker panels can aid in differential diagnosis 57

58. 4/21/2017 58

59. markers of inflammation
Leukocyte chemoattractants (MCP-1, IL-8, PDGF, MC-SF)
Procoagulant activity (tissue factor)
Cytokines (TNFa, FAS,CD40L)
NO ET-1
Adhesion molecules E-selectin, ICAM-1, VCAM-1
Permeability
Apoptosis

60. Markers of protection?

61. T T markers of inflammation
IL-10
Leukocyte chemoattractants (MCP-1, IL-8, PDGF, MC-SF)
Procoagulant activity (tissue factor)
Cytokines (TNFa, FAS,CD40L etc.)
NO ET-1
Adhesion molecules E-selectin, ICAM-1, VCAM-1
Permeability
Apoptosis T
hepatocyte
growth factor

62. SUMMARY “Cardiac Enzymes” are obsolete
Medical & laboratory progress has required a redefinition of Myocardial Infarction
Cardiac Troponins & Myoglobin now play a pivotal role in the diagnosis of AMI
Cardiac Troponins play an important role in the risk stratification of ACS patients
Elevated Troponin levels in patients without ECG changes & with normal CK-MB levels may identify patients at increased risk of cardiac events

63. SUMMARY
Elevated Troponins in the absence of clinical signs of ischaemic heart disease require consideration of other causes of cardiac injury
Additional roles for cardiac markers in:
Reperfusion monitoring
Infarct size/prognosis
Intra/post-operative MI (non-cardiac/cardiac surgery).

64. الحمد لله الذى بنعمته تتم الصالحات
Thank You
الحمد لله الذى بنعمته تتم الصالحات 64