Copeptin improves the diagnostic performance of sensitive troponin I-Ultra but cannot rapidly rule out non-ST-elevation myocardial infarction at presentation to an emergency department.

Study Objective: We assess the performance of a single multimarker strategy, using a combination of sensitive troponin I-Ultra and copeptin assays to rule out non-ST-elevation myocardial infarction (NSTEMI) at presentation to an emergency department (ED).

Methods: A secondary analysis was carried out on 587 consecutive patients with chest pain who presented to the ED without ST elevation on ECG and were included in a single-site, prospective observational study. Samples for copeptin and combination of sensitive troponin I-Ultra assays were collected at presentation. The performance of the combination of copeptin and combination of sensitive troponin I-Ultra for NSTEMI was calculated in the whole cohort and after stratification by thrombosis in myocardial infarction (TIMI) risk score.

Results: NSTEMI was diagnosed in 87 patients (14.8%). The sensitivity and the negative predictive value of the combination of copeptin and combination of sensitive troponin I-Ultra were 96.6% (95% confidence interval [CI] 90.3% to 99.3%) and 99.1% (95% CI 97.4% to 99.8%), respectively, for a cutoff level of copeptin less than 12 pmol/L. Among the 243 patients with a low TIMI score, all 8 who had an NSTEMI were detected with the combination (sensitivity 100%; 95% CI 63.1% to 100%), and 158 were a combination of sensitive troponin I-Ultra and copeptin negative and had no NSTEMI (negative predictive value 100%; 95% CI 97.7% to 100%).

Conclusion: In this study, the combination of sensitive troponin and copeptin measurements had a high sensitivity and negative predictive value for NSTEMI diagnosis, especially among subjects with a low TIMI risk score. However, the sensitivity was too low to rule out NSTEMI with a single-draw strategy at ED presentation. Future studies are needed on the low-risk TIMI group to further investigate this preliminary finding.