Application of High-Sensitivity Troponin in Suspected Myocardial Infarction
Clinical question: What is the cutoff for high-sensitivity troponin concentration at emergency department presentation, what is the dynamic change in concentration during serial sampling, and what is the time between the obtaining of samples that can help provide a flexible method to determine the probability of myocardial infarction and 30-day outcomes?
What is already known: Previous studies have shown a strong association of high-sensitivity troponin concentrations and cardiovascular risk among patients with acute coronary syndrome and in the general population.
Methods: The COMPASS-MI (Calculation of Myocardial Infarction Risk Probabilities to Manage Patients With Suspicion of Myocardial Infarction) study combined data from 15 different international cohorts of patients (n = 22,651) presenting to the emergency department with symptoms suggestive of MI who had serial hs-Tn (Tn I or T) measurements. Patients with ST-segment elevation MI were excluded.
Results/Implications: Of 22,651 patients, 3,455 (15.3%) presented with acute MI. The authors present the data by grouping patients according to negative predictive value/positive predictive value categories derived from combinations of hs-Tn cut-offs, absolute change in levels and resampling times (early 45-120 minutes vs. late 120-210 minutes).. The authors provide risk-assessment diagrams and an online interactive risk calculator at http://www.compass-mi.com.
Bottom line: For patients with suspected myocardial infarction who present to the ED, the authors developed a tool that integrated the high-sensitivity troponin I or troponin T concentration at presentation, its dynamic change during serial sampling, and the time between the obtaining of samples to allow for the estimation of both the probability of myocardial infarction on emergency department presentation and 30-day outcomes and also provided estimates of long-term risk on the basis of the initial concentration of high-sensitivity troponin at presentation among patients in whom MI was ruled out.