Diagnosis of Acute Myocardial Infarction Using Highly Sensitive Cardiac Troponin Assays

Abstract

Acute myocardial infarction (AMI) is a major cause of morbidity and mortality worldwide. Determining the level of cardiac troponins (cTn), structural proteins unique to the heart, is a cornerstone of AMI diagnosis. One important limitation of standard cTn assays is a sensitivity deficit at presentation due to a delayed increase of circulating cTn levels. Recent multicentre studies have shown that novel, more sensitive and more precise cTn assays improve the early diagnosis of AMI. cTn must be interpreted as a quantitative variable. ‘Detectable’ levels will become the standard and must be clearly differentiated from ‘elevated’ levels. The differential diagnosis of a small amount of cardiomyocyte necrosis and, therefore, mild elevation of cTn, is broad and includes acute and chronic disorders. The differential diagnosis of more extensive cardiomyocyte necrosis, and therefore substantial elevation of cTn, is much smaller and largely restricted to AMI, myocarditis and Tako-Tsubo cardiomyopathy.