Duchenne J, Mestres S, Dublanchet N, et al. Diagnostic accuracy of copeptin sensitivity and specificity in patients with suspected non-ST-elevation myocardial infarction with troponin I below the 99th centile at presentation. BMJ Open 2013;4:e004449.

The email address for the corresponding author of this paper was published incorrectly; the correct email is: j.duchenne@ch-aurillac.fr

In addition, during the proofing stage of this article the abbreviations of different troponins (high-sensitive cardiac troponin I: hs-cTnI; high-sensitive cardiac troponin T: hs-cTnT; the generic term high-sensitive cardiac troponin: hs-cTn) were incorrectly replaced in the text and figures 1 and 2 by ‘hs-cTnT’. The correct abbreviations are as follows (in bold):

Abstract/Objective: ‘To determine whether copeptin-us can rule out diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) without prolonged monitoring and serial blood sampling in patients with high-sensitive cardiac troponin I (hs-cTnI) below the 99th centile at presentation to the emergency department (ED).’

Abstract/Interventions: ‘Hs-cTnI was measured using an assay with Dimension VISTA, Siemens.’

Abstract/Conclusions: ‘In this study, copeptin does not add a diagnostic value at admission to ED for patients with suspected acute coronary syndrome without ST-segment elevation and with hs-cTnI below the 99th centile.’

Introduction/Last paragraph: ‘The aim of this study was to determine whether copeptin-us can rule out diagnosis of acute MI without prolonged monitoring and serial blood sampling in patients with suspected NSTEMI and high-sensitive cardiac troponin I (hs-cTnI) below the 99th centile at presentation to ED.’

Methods/Population/Last sentence of first paragraph: ‘After the result of the first blood sample, patients with hyponatraemia <135 mmol/L or hs-cTnI >0.045 µg/L were released of the study.’

Methods/Study protocol/First sentence: ‘On admission, all patients underwent an initial clinical assessment, including medical history, temperature, respiratory rate, cardiac frequency, blood pressure, pulse oxymetry, 18-lead ECG, chest X-ray and screening blood test including C reactive protein, natraemia, creatinine, hs-cTnI and creatine kinase (CK).’

Methods/Study protocol/Third sentence: ‘Blood samples were collected for hs-cTnI and CK analysis and 18-lead ECG was performed after 2, 4, 6 and 12 h.’

Methods/Study protocol/Third paragraph: ‘The hs-cTnI was measured using a chemiluminescence test (Dimension VISTA, Siemens Healthcare Diagnostics). The limit of blank of hs-cTnI was 0.015 µg/L, the 99th centile concentration was 0.045 µg/L and the lowest concentration measurable with a CV <10% was 0.040 µg/L according to the manufacturer.’

Methods/Outcomes/Third sentence: ‘The diagnosis of NSTEMI, in these patients showing suspected symptoms of ACS, was defined by a rise and/or fall of hs-cTnI with at least one value above the 99th centile and with the following criteria: imaging evidence of new loss of viable myocardium or new regional wall motion abnormality or identification of an intracoronary thrombus by angiography.’

Results/Patient characteristics/Second sentence: ‘Nine presented 1 or more exclusion criteria, 6 did not give their informed consent for participation, 26 were released after the results of the first blood sample because they had hyponatraemia <135 mmol/L (n=3) or hs-cTnI >0.045 µg/L (n=23).’

Results/Main results/Troponin: ‘According to the inclusion criteria, all patients had hs-cTnI ≤99th centile at admission.’

Limitations of the study/First sentence: ‘Despite the bicentric inclusions on a 1-year period, only eight patients with NSTEMI and hs-cTnI below the 99th centile at presentation were included.’

Limitations of the study/Fourth paragraph: ‘Twelve hours after admission, there was no significant difference between the two groups (NSTEMI vs non-NSTEMI) for myoglobin and CK. This may be due to the low infarcts size observed (hs-cTnI <99th centile at admission in the 6 h after the pain onset) but also due to the lack of 12 h blood samples for two patients with NSTEMI.’

Discussion/Third paragraph: ‘Bahrmann et al²⁵ and Lotze et al¹⁴ found a NPV of 100%, but each of these studies included only one patient with NSTEMI with hs-cTn below the cut-off defined.’

Discussion/Sixth paragraph: ‘This observation is consistent with the precautionary statements of the Study Group on Biomarkers in Cardiology of the European Society of Cardiology Working Group on Acute Cardiac Care, advocating additional blood sampling in patients strongly suspected of having an AMI but no significant hs-cTn increase after 3 h.’

Discussion/Seventh paragraph: ‘A recent study suggests that undetectable Roche highsensitive cardiac troponin T at admission could be considered to rule out patients with AMI.38 This algorithm could not be envisaged in our study population and the hs-cTnI used; three patients with NSTEMI had hs-cTnI undetectable at admission.’

Discussion/Last paragraph: ‘In conclusion, our study did not show a relevant diagnostic value of copeptin in patients with suspected ACS without ST-elevation and with hs-cTnI below the 99th centile at admission. Measurements of hs-cTn at presentation and after 3 h, and after 6 h if necessary, remain the biochemical gold standard for NSTEMI diagnosis.’

Figure 1/At admission section: ‘hs-cTnI’

Figure 2/y axis: ‘hs-cTnI’.