Diagnostic value of cardiac markers
According to the ESC/ACC consensus definition, an increase of troponin during the first 24 hours following the onset of symptoms is indicative of myocardial injury.
[Myocardial infarction redefined – a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Eur Heart J. 2000; 21: 1502-1513]
Patients with an increased troponin concentration must be regarded as patients at high risk of death or myocardial infarction (MI), and must receive specific treatment. Troponins have assumed a central role in risk stratification and therapeutic decision-making in professional guidelines published by the ACC/AHA and the ESC.
However, serial measurements are recommended. During the first 6 hours after the onset of chest pain, the combination of myoglobin and troponin is considered most useful for the diagnosis of acute myocardial infarction (AMI). For patients admitted more than 6 hours after onset of symptoms, troponin alone is the best cardiac marker (Figure 8).
Figure 8. Kinetics of cardiac markers
[Wu A.H. et al., National Academy of Clinical Biochemistry – Standards of laboratory practice: recommendations for the use of cardiac markers in coronary artery diseases. Clin. Chem. 1999; 45: 1104-1121]
[Myocardial infarction redefined – a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Eur Heart J. 2000; 21: 1502-1513]
Patients with an increased troponin concentration must be regarded as patients at high risk of death or myocardial infarction (MI), and must receive specific treatment. Troponins have assumed a central role in risk stratification and therapeutic decision-making in professional guidelines published by the ACC/AHA and the ESC.
However, serial measurements are recommended. During the first 6 hours after the onset of chest pain, the combination of myoglobin and troponin is considered most useful for the diagnosis of acute myocardial infarction (AMI). For patients admitted more than 6 hours after onset of symptoms, troponin alone is the best cardiac marker (Figure 8).
Figure 8. Kinetics of cardiac markers
[Wu A.H. et al., National Academy of Clinical Biochemistry – Standards of laboratory practice: recommendations for the use of cardiac markers in coronary artery diseases. Clin. Chem. 1999; 45: 1104-1121]
Often, a blood test is performed for cardiac troponins 12 hours after onset of chest pain. If this is positive, coronary angiography is typically performed on an urgent basis, as a positive troponin result is highly predictive of re-infarction.
Troponin is also valuable for the detection of minor myocardial injury in the absence of overt ischemic heart disease associated with other clinical situations, such as percutaneous coronary artery intervention, cardiovascular surgery, non-cardiac surgery, heart failure, renal failure, trauma, burns, acute myocarditis, acute pericarditis, pulmonary embolism and sepsis.
Source: Biomerieux-diagnostics.com
Troponin is also valuable for the detection of minor myocardial injury in the absence of overt ischemic heart disease associated with other clinical situations, such as percutaneous coronary artery intervention, cardiovascular surgery, non-cardiac surgery, heart failure, renal failure, trauma, burns, acute myocarditis, acute pericarditis, pulmonary embolism and sepsis.
Source: Biomerieux-diagnostics.com
