Prognostic performance of kinetic changes of high-sensitivity troponin T in acute coronary syndrome and in patients with increased troponin without acute coronary syndrome.

Background: We sought to evaluate the prognostic impact of absolute and relative kinetic changes of high-sensitivity cardiac Troponin T (hs-cTnT) in comparison to baseline hs-cTnT elevations for risk stratification in acute coronary syndrome (ACS) and non-ACS conditions with increased hs-cTnT.
Methods: hs-cTnT was measured serially in patients presenting with acute symptoms to our emergency department. We assessed the prognostic performance of baseline and serial hs-cTnT concentrations in all consecutive patients with ACS (n=406) or hs-cTnT increases not due to ACS (n=442) within 3-6h after admission.
Results: Mortality rates were higher, albeit not statistically, in non-ACS (53/442=12.0%) than ACS patients (36/406=8.9%). In ACS patients, receiver operating characteristics (ROC) revealed optimized cut-off values of 12.2 ng/L for absolute δ-change (AUC=0.66, p<0.001), 31.2 ng/L for baseline hs-cTnT (AUC=0.71, p<0.001) and 45.2 ng/L for maximal hs-cTnT (AUC=0.68, p<0.001). C-statistics showed superiority of absolute δ-changes (p=0.0003), baseline hs-cTnT (p=0.04) and maximal hs-cTnT (p=0.02) compared to relative δ-changes. However, the combination of baseline hs-cTnT values with either absolute or relative δ-changes did not improve risk prediction compared to baseline hs-cTnT alone (p=n.s.). In non-ACS conditions, the ROC-optimized cut-off value of 46.2 ng/L for baseline hs-cTnT (AUC=0.661, p<0.001) was superior to absolute (p=0.007) and relative δ-changes regarding prognostication (p=0.045).
Conclusions: Our data suggest that the magnitude of baseline hs-cTnT, and not acute dynamic changes, convey superior long-term prognostic information in ACS and non-ACS conditions. Moreover, absolute and relative kinetic δ-changes of hs-cTnT do not add significant incremental value in risk assessment in both conditions.
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