Prognostic interpretation of serial high-sensitivity cardiac troponin in patients presenting with suspected acute coronary syndrome

Diagnostic and prognostic interpretation of serial measurement of high-sensitivity cardiac troponin. The figure illustrates the complexity and overlapping nature of current probabilistic algorithms such as the ESC 0/1 h algorithm,8 purely diagnostic criteria such as the Fourth Universal Definition of MI14 based on the 99th percentile upper reference limit (URL), and focused prognostic assessment that considers both mortality and other cardiovascular events.9 The green and red zones reflect higher confidence regarding the definitive exclusion of myocardial injury or identification of acute or chronic myocardial injury, respectively. The yellow zone reflects intermediate probability and criteria that can overlap with the green or red zone depending on the concentration. aVery low probabilistic threshold to exclude myocardial infarction (MI) (e.g. from the ESC 0/1 h algorithm). bValues <99th percentile URL do not meet criteria for acute myocardial injury but can establish a gradient of risk for future events, with patients overlapping the ESC ‘observe’ zone having intermediate probability of a final diagnosis of MI. cESC ‘observe’ zone includes values both above and below the 99th percentile URL but below the ESC ‘rule in’ threshold, and identifies patients with an intermediate probability of a final diagnosis of MI (prevalence 22.5%5) and cardiovascular events through 30 days. dThis cohort of patients meet diagnostic criteria for myocardial injury but may overlap with the ESC observe zone. The diagnosis of myocardial infarction is made when acute myocardial injury is in the setting of myocardial ischaemia.