Troponin—Keep Up or Be Left Behind

The dawn of the new millennium ushered in a new era for cardiac marker testing. The European Society of Cardiology (ESC) and the American College of Cardiology (ACC) redefined myocardial infarction (MI) as “myocardial necrosis caused by ischemia” and designated troponin (Tn) as the “preferred” biomarker (1). The upper reference limit (URL) of Tn was specified to be at the 99th centile of a reference population, and the assay imprecision at this level should be 10% or less. Furthermore, the National Academy of Clinical Biochemistry (NACB) and the International Federation of Clinical Chemists (IFCC) recommend that Tn results should be available within 60 minutes (2). The ESC/ACC reiterated this position in their “universal definition of myocardial infarction” (3). The American Heart Association published a monograph on “Biomarkers in Heart Disease” in 2008 (4).