Additional diagnostic and prognostic value of copeptin ultra-sensitive for diagnosis of non-ST-elevation myocardial infarction in older patients presenting to the emergency department¹⁾

BACKGROUND: Identifying older patients with non-ST- elevation myocardial infarction (NSTEMI) within the very large proportion with elevated high-sensitive cardiac troponin T (hs-cTnT) is a diagnostic challenge because they often present without clear symptoms or electrocardiographic features of acute coronary syndrome to the emergency department (ED). We prospectively investigated the diagnostic and prognostic performance of copeptin ultra-sensitive (copeptin-us) and hs-cTnT compared to hs-cTnT alone for NSTEMI at prespecified cut-offs in unselected older patients. METHODS: We consecutively enrolled 306 non-surgical patients ≥70 years presenting to the ED. In addition to clinical examination, copeptin-us and hs-cTnT were measured at admission. Two cardiologists independently adjudicated the final diagnosis of NSTEMI after reviewing all available data. All patients were followed up for cardiovascular-related death within the following 12 months. RESULTS: NSTEMI was diagnosed in 38 (12%) patients (age 81±6 years). The combination of copeptin-us ≥14 pmol/L and hs-cTnT ≥0.014 µg/L compared to hs-cTnT ≥0.014 µg/L alone had a positive predictive value of 21% vs. 19% to rule in NSTEMI. The combination of copeptin-us <14 pmol/L and hs-cTnT <0.014 µg/L compared to hs-cTnT <0.014 µg/L alone had a negative predictive value of 100% vs. 99% to rule out NSTEMI. Hs-cTnT ≥0.014 µg/L alone was significantly associated with outcome. When copeptin-us ≥14 pmol/L was added, the net reclassification improvement for outcome was not significant (p=0.809). CONCLUSIONS: In unselected older patients presenting to the ED, the additional use of copeptin-us at predefined cut-offs may help to reliably rule out NSTEMI but may not help to increase predicted risk for outcome compared to hs-cTnT alone.