Clinical implications of the change of cardiac troponin I levels in patients with acute chest pain — An evaluation with respect to the Universal Definition of Myocardial Infarction

BackgroundThe Universal Definition of Myocardial Infarction incorporates elevated cardiac troponin levels (> 99th percentile) together with a significant rise/fall of troponins as biochemical criterion. We sought to evaluate the clinical implications of the relative change of cardiac troponin I (cTnI) levels with respect to the Universal Definition in patients with acute chest pain.MethodscTnI (Stratus CS) was measured serially in 454 patients within 24 h from admission. Acute myocardial infarction (AMI) was defined using the criteria adapted to the ESC/ACC consensus document, or corresponding to the Universal Definition together with prespecified cTnI changes of ≥ 20%, ≥ 50% and ≥ 100%. Follow-up was completed after 5.8 years.ResultsA peak cTnI level above the 99th percentile together with a cTnI change of ≥ 20% was found in 160 patients of whom 25 did not have AMI according to the ESC/ACC criteria. These 160 patients had a significantly raised mortality (HR 2.5 [95% CI 1.7–3.8]). Higher cTnI deltas were not associated with higher mortalities but identified smaller patient cohorts at risk.ConclusionsThe Universal Definition of AMI together with a ≥ 20% cTnI change appears to improve the discrimination of acute from chronic causes of cTnI release, and allows a reliable identification of patients at risk.