High-sensitivity cardiac troponin T and copeptin assays to improve diagnostic accuracy of exercise stress test in patients with suspected coronary artery disease.
BACKGROUND
The average diagnostic sensitivity of exercise stress tests (ESTs) is lower than that of other non-invasive cardiac stress tests. The aim of the study was to examine whether high-sensitivity cardiac troponin T (hs-cTnT) or copeptin concentrations rise in response to inducible myocardial ischaemia and may improve the diagnostic accuracy of ESTs.


RESULTS
An EST was performed stepwise on a bicycle ergometer by 383 consecutive patients with suspected or progression of coronary artery disease (CAD). In addition venous blood samples for measurement of hs-cTnT and copeptin were collected prior to EST, at peak exercise, and 4 h after EST. Coronary angiography was assessed for all patients. Patients with significant CAD (n = 224) were more likely to be male and older compared to patients with non-significant CAD (n = 169). Positive EST was documented in 125 (55.8%) patients with significant CAD and in 69 (43.4%) patients with non-significant CAD. Copeptin and hs-cTnT concentrations at baseline were higher in patients with significant CAD (copeptin: 10.8 pmol/l (interquartile range (IQR) 8.1-15.6) vs 9.4 pmol/l (IQR 7.1-13.9); p = 0.04; hs-cTnT: 3.0 ng/l (IQR <3.0-5.4) vs <3.0 ng/l (IQR <3.0); p = 0.006). Hs-cTnT improved sensitivity (61.6% vs 55.8%), specificity (67.7% vs 56.6%) and the positive predictive value (PPV) (72.3% vs 64.4%) and negative (55.2% vs 47.6%) predictive value (NPV) of EST. Copeptin could not improve sensitivity (55.4% vs 55.8%) and reduced specificity, PPV and NPV.


CONCLUSIONS
The measurement of hs-cTnT during EST improves sensitivity, specificity, and positive and negative predictive values. In contrast, measurement of copeptin does not improve diagnostic sensitivity and reduces specificity.
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany c.liebetrau@kerckhoff-klinik.de.
Christoph
C
Liebetrau
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Luise
L
Gaede
Division of Cardiology, Justus Liebig University Giessen, Germany.
Oliver
O
Dörr
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Jedrzej
J
Hoffmann
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Jan S
JS
Wolter
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Michael
M
Weber
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Andreas
A
Rolf
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Christian W
CW
Hamm
Division of Cardiology, Justus Liebig University Giessen, Germany.
Holger M
HM
Nef
Department of Cardiology, Kerckhoff Heart and Thorax Centre, Germany.
Helge
H
Möllmann
D000367:Age Factors; D000368:Aged; D019540:Area Under Curve; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006020:Glycopeptides / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012737:Sex Factors; D020107:Troponin T / Q000097:blood*; D015854:Up-Regulation
D015415:Biomarkers; D006020:Glycopeptides; C545568:TNNT2 protein, human; D020107:Troponin T; C048197:copeptins
Coronary artery disease; cardiac troponin T; copeptin; exercise stress test; myocardial ischaemia