Diagnosis: Cardiac biomarkers
• The molecular forms of troponin T in blood are free troponin T, a troponin I–troponin T complex, and a troponin I–troponin C–troponin T complex.
• Although there are many molecular forms of troponin T in blood, only one immunochemical method, which uses one set of antibodies, is currently available to measure troponin T. Therefore, the troponin T results from different hospitals should be essentially the same because the same species of troponin T is being measured.
• The general protocol used for evaluating patients admitted to the emergency department with chest pain is to measure troponin T on admission and at 3- to 6-hour intervals.
• Elevated levels of troponin T are usually detected in serum by 4 to 6 hours after an acute myocardial infarction.
• The sensitivity of the troponin T assay for detecting an acute myocardial infarction is approximately 98%. The specificity of the troponin T assay for detecting an acute myocardial infarction is approximately 95%.
