Small Changes in Troponin T Levels Are Common in Patients With Non–ST-Segment Elevation Myocardial Infarction and Are Linked to Higher Mortality

ObjectivesThe purpose of this study was to examine the extent of change in troponin T levels in patients with non–ST-segment elevation myocardial infarction (NSTEMI).BackgroundChanges in cardiac troponin T (cTnT) levels are required for the diagnosis of NSTEMI, according to the new universal definition of acute myocardial infarction. A relative change of 20% to 230% and an absolute change of 7 to 9 ng/l have been suggested as cutoff points.MethodsIn a clinical setting, where a change in cTnT was not mandatory for the diagnosis of NSTEMI, serial samples of cTnT were measured with a high-sensitivity cTnT (hs-cTnT) assay, and 37 clinical parameters were evaluated in 1,178 patients with a final diagnosis of NSTEMI presenting <24 h after symptom onset.ResultsAfter 6 h of observation, the relative change in the hs-cTnT level remained <20% in 26% and the absolute change <9 ng/l in 12% of the NSTEMI patients. A relative hs-cTnT change