Usefulness of delta troponin for diagnosis and prognosis assessment of non-ST-segment elevation acute chest pain.

BACKGROUND: The additional diagnostic and prognostic information provided by delta high-sensitivity troponin T (hs-cTnT) in patients with acute chest pain and hs-cTnT elevation remains unclear.
METHODS: The study group consisted of 601 patients presenting at the emergency department with non-ST-segment elevation acute chest pain and hs-cTnT elevation after two determinations (admission and within the first six hours). Maximum hs-cTnT and delta hs-cTnT (absolute or percentage change between the two measurements) were considered. Cutoff values were optimized using the quartile distribution for the endpoints. The endpoints were diagnostic (significant stenosis in the coronary angiogram) and prognostic (death or recurrent myocardial infarction at one year).
RESULTS: Regarding the diagnostic endpoint, 114 patients showed a normal angiogram. Both maximum hs-cTnT ⩾80 ng/ml (OR 2.5, 95% CI 1.3-4.8, P=0.005) and delta hs-cTnT ⩾20 ng/l (OR 2.1, 95% CI 1.1-4.0, P=0.02) median value cutoffs were related to significant coronary stenosis. Furthermore, the combination of hs-cTn <80 ng/l and delta hs-cTn <20 ng/l showed the lowest probability of significant coronary stenosis (OR 0.3, 95% CI 0.1-0.4, P=0.001). During follow-up, 86 patients experienced the prognostic endpoint. After full adjustment for clinical data, maximum hs-cTnT ⩾30 ng/l, first quartile cutoff, was related to the outcome (HR 1.8, 95% CI 1.0-3.4, P=0.05), while delta hs-cTnT, either absolute or percentage change, lacked prognostic value.
CONCLUSIONS: Maximum hs-cTnT captures all the prognostic information provided by hs-cTnT in non-ST-segment elevation acute chest pain. Low maximum and low delta hs-cTnT are associated with a normal coronary angiogram, which could make the final diagnosis challenging in some cases. © The European Society of Cardiology 2015.