The Incremental Value of Copeptin for the Early Rule-Out of Non-ST Elevation Myocardial Infarction in the Emergency Department.

Background/Objectives: Copeptin, a marker of endogenous stress, has been used for the early detection of non-ST elevation myocardial infarction (NSTEMI) in combination with conventional cardiac troponin. However, its incremental diagnostic value, when combined with high-sensitivity troponin, is not well defined. This study seeks to assess the diagnostic performance for NSTEMI of a Dual Marker Strategy (DMS) [copeptin and high-sensitivity cardiac troponin T (hs-cTnT)] measured upon presentation to the Emergency Department (ED) and compare it to the hs-cTnT 0h/1h and 0h/2h algorithms recommended by the European Society of Cardiology (ESC). Methods: This prospective observational study enrolled 102 patients presenting to the ED with chest pain of <6 h duration; patients with ST elevation myocardial infarction (STEMI) were excluded. Copeptin and hs-cTnT were measured upon patient presentation (time 0 h, DMS) in the whole cohort. hs-cTnT was subsequently repeated either at 1 h (n = 51) or 2 h (n = 51). The diagnostic performance of the DMS, assessed in terms of sensitivity, specificity, and negative (NPV) and positive predictive value (PPV), was compared to that of the ESC-recommended hs-cTnT algorithms 0h/1h and 0h/2h for NSTEMI. Results: Of the total population, 59.8% were men, with a mean age of 57.7 ± 18.4 years; 8.8% of the patients were eventually di agnosed with NSTEMI. The DMS (cut-offs: copeptin < 10 pmol/L and hs-cTnT < 14 ng/L) demonstrated a sensitivity of 88.9% (95% CI: 51.75-99.72) and an NPV of 98.5% (90.94-99.76). On the other hand, the hs-cTnT 0h/1h algorithm showed a sensitivity of 60% (14.66-94.73) and an NPV of 95.6% (88.06-98.45), while the hs-cTnT 0h/2h algorithm exhibited a sensitivity of 75% (19.41-99.37) and an NPV of 95.8% (85.22-98.93). In ROC analysis, copeptin yielded an AUC of 0.702 (p = 0.046) and hs-cTnT at 0h showed an AUC of 0.736 (p = 0.02), whereas their combination demonstrated an AUC of 0.730 (p = 0.023) for the detection of NSTEMI. Conclusions: The copeptin/hs-cTnT DMS has comparable diagnostic performance to the hs-cTnT 0h/1h and 0h/2h algorithms for the early rule-out of NSTEMI.