High-sensitivity Troponins – Difficult Friends in Acute Coronary Syndromes

The introduction of novel high-sensitivity cardiac troponin (hs-cTn) assays has made it possible to measure cardiac troponin levels that are up to 10-fold lower than those detectable by conventional cardiac troponin (cTn) assays. With such novel assays, an elevated risk of major adverse cardiovascular events was noted across the continuum of cTn levels, with an incremental risk of increasing levels even in healthy individuals, but also in patients with stable coronary artery disease, congestive heart failure or acute coronary syndrome (ACS). The rapid triage of patients presenting to the accident and emergency department with chest pain is critical to ensure optimal management, and the novel hs-cTn assays provide a valuable tool for a more rapid exclusion of acute myocardial infarction (AMI), with a higher sensitivity, negative predictive value and diagnostic accuracy compared with conventional cTn assays. The associated decrease in specificity and positive predictive value for the diagnosis of AMI can be overcome by serial measurements to assess the absolute and relative increases in cTn levels. This article provides a contemporary overview of the role of hs-cTn in the detection of individuals with subclinical disease, diagnosis of ACS, risk stratification and clinical management. Furthermore, aspects of uncertainty, such as cut-offs, and the role of hs-cTn for clinical decision-making are addressed.