Preparing the United States for high-sensitivity cardiac troponin assays

It is only a matter of time before the use of high-sensitivity cardiac troponin assays (hs-cTn) becomes common throughout the United States. In preparation for this inevitability, this article raises a number of important issues regarding these assays that deserve consideration. These include: the need for the adoption of a universal nomenclature; the importance of defining uniform criteria for reference populations; the challenge of discriminating between acute and nonacute causes of hs-cTn elevations, and between type 1 and type 2 acute myocardial infarction (AMI); factors influencing the analytical precision of hs-cTn; ascertaining the optimal duration of the rule-out period for AMI; the need for further evaluation to determine the causes of a positive hs-cTn in non-AMI patients; and the use of hs-cTn to risk-stratify patients with disease conditions other than AMI. This review elaborates on these critical issues as a means of educating clinicians and researchers about them.