To examine the extent of change in Troponin T levels in patients with non-ST-elevation myocardial infarction (NSTEMI).
Changes in cardiac troponin levels are required for the diagnosis of NSTEMI, according to the new universal definition of acute myocardial infarction. A relative change of 20-230 % and an absolute change of 7- 9 ng/L have been suggested as cut-off points.
In 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-sensitive cTnT (hs-cTnT) assay, and 37 clinical parameters were evaluated in 1178 patients with a final diagnosis of NSTEMI presenting <24h after symptom onset.
After six hours 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 <20% was linked to higher long-term mortality across quartiles (p=0.002) and in multivariate analyses (HR 1.61 (1.17-2.21) p=0.004), whereas 30-day mortality was similar across quartiles of relative hs-cTnT change
Because stable hs-TnT levels are common in patients with a clinical diagnosis of NSTEMI in our hospital, a small hs-cTnT change may not be useful to exclude NSTEMI, particularly as these patients show both short-term and long-term mortality at least as high as patients with large changes in hs-cTnT.
2013. Vol. 62, no 14, 1231-1238 p.