Absolute and relative kinetic changes of high-sensitivity cardiac troponin T in acute coronary syndrome and in patients with increased troponin in the absence of acute coronary syndrome

TY - JOUR

T1 - Absolute and relative kinetic changes of high-sensitivity cardiac troponin T in acute coronary syndrome and in patients with increased troponin in the absence of acute coronary syndrome

AU - Mueller, Matthias

AU - Biener, Moritz

AU - Vafaie, Mehrshad

AU - Doerr, Susanne

AU - Keller, Till

AU - Blankenberg, Stefan

AU - Katus, Hugo A

AU - Giannitsis, Evangelos

PY - 2012/1

Y1 - 2012/1

N2 - BACKGROUND: We evaluated kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) in patients with acute coronary syndrome (ACS) and patients with hs-cTnT increases not due to ACS to rule in or rule out non-ST-segment elevation myocardial infarction (STEMI).METHODS: hs-cTnT was measured serially in consecutive patients presenting to the emergency department. Patients with ACS who had at least 2 hs-cTnT measurements within 6 h and non-ACS patients with hs-cTnT concentrations above the 99th percentile value (14 ng/L) were enrolled to compare absolute and relative kinetic changes of hs-cTnT.RESULTS: For discrimination of non-STEMI (n=165) in the entire study population (n=784), the absolute δ change with the ROC-optimized value of 9.2 ng/L yielded an area under the curve of 0.898 and was superior to all relative δ changes (P<0.0001). The positive predictive value for the absolute δ change was 48.7%, whereas the negative predictive value was 96.5%. In a specific ACS population with exclusion of STEMI (n=342), the absolute δ change with the ROC-optimized value of 6.9 ng/L yielded a positive predictive value of 82.8% and a negative predictive value of 93.0%. In comparison to the ≥20% relative δ change, the ROC-optimized absolute δ change demonstrated a significantly added value for the entire study population and for the ACS cohort (net reclassification index 0.331 and 0.499, P<0.0001).CONCLUSIONS: Absolute δ changes appear superior to relative δ changes in discriminating non-STEMI. A rise or fall of at least 9.2 ng/L in the entire study population and 6.9 ng/L in selected ACS patients seems adequate to rule-out non-STEMI. However, δ-values are useful to rule-in non-STEMI only in a specific ACS population.

AB - BACKGROUND: We evaluated kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) in patients with acute coronary syndrome (ACS) and patients with hs-cTnT increases not due to ACS to rule in or rule out non-ST-segment elevation myocardial infarction (STEMI).METHODS: hs-cTnT was measured serially in consecutive patients presenting to the emergency department. Patients with ACS who had at least 2 hs-cTnT measurements within 6 h and non-ACS patients with hs-cTnT concentrations above the 99th percentile value (14 ng/L) were enrolled to compare absolute and relative kinetic changes of hs-cTnT.RESULTS: For discrimination of non-STEMI (n=165) in the entire study population (n=784), the absolute δ change with the ROC-optimized value of 9.2 ng/L yielded an area under the curve of 0.898 and was superior to all relative δ changes (P<0.0001). The positive predictive value for the absolute δ change was 48.7%, whereas the negative predictive value was 96.5%. In a specific ACS population with exclusion of STEMI (n=342), the absolute δ change with the ROC-optimized value of 6.9 ng/L yielded a positive predictive value of 82.8% and a negative predictive value of 93.0%. In comparison to the ≥20% relative δ change, the ROC-optimized absolute δ change demonstrated a significantly added value for the entire study population and for the ACS cohort (net reclassification index 0.331 and 0.499, P<0.0001).CONCLUSIONS: Absolute δ changes appear superior to relative δ changes in discriminating non-STEMI. A rise or fall of at least 9.2 ng/L in the entire study population and 6.9 ng/L in selected ACS patients seems adequate to rule-out non-STEMI. However, δ-values are useful to rule-in non-STEMI only in a specific ACS population.

KW - Acute Coronary Syndrome/blood

KW - Aged

KW - Aged, 80 and over

KW - Biomarkers/blood

KW - Chest Pain/blood

KW - Female

KW - Humans

KW - Kinetics

KW - Male

KW - Middle Aged

KW - Myocardial Infarction/blood

KW - Sensitivity and Specificity

KW - Troponin T/blood

U2 - 10.1373/clinchem.2011.171827

DO - 10.1373/clinchem.2011.171827

M3 - SCORING: Journal article

C2 - 22134520

VL - 58

SP - 209

EP - 218

JO - CLIN CHEM

JF - CLIN CHEM

SN - 0009-9147

IS - 1

ER -