Cardiovascular disease is the leading cause of death worldwide. The role of cardiac markers in the diagnosis, risk stratification, and treatment of patients with chest pain is vital. Patients with elevated cardiac troponin levels but negative CK-MB who were formerly diagnosed with unstable angina or minor myocardial injury are now reclassified as non–ST-segment elevation MI (NSTEMI) even in the absence of diagnostic ECG changes. CK-MB is both a sensitive and specific marker for myocardial infarction. Cardiac troponin T is a cardio-specific, highly sensitive marker for myocardial damage. Cardiac troponin I is a contractile protein exclusively present in the cardiac muscle. The absolute cardiospecificity of cTnI allows the diagnosis of myocardial infarction distinct from muscle lesions and non-cardiac surgery. In 2000, the European Society of Cardiology and the American College of Cardiology redefined AMI with a particular advocacy on troponin. The 2002/2007 American College of Cardiology (ACC) and the American Heart Association (AHA) Guideline Update for the management of these patients strongly recommend to include cTnI. Specifically, with rare exception, the diagnosis cannot be made in the absence of elevated biomarkers of cardiac injury.
Part of the book: Myocardial Infarction