Ultra-Sensitive Copeptin and Cardiac Troponin in Diagnosing Non-ST-Segment Elevation Acute Coronary Syndromes—The COPACS Study

OBJECTIVES: We tested the noninferiority of a fast-track rule-out protocol for the diagnosis of non-ST-segment elevation myocardial infarction vs noncoronary chest pain based on the single-sampling combined assessment of medium-sensitivity cardiac troponin I and ultra-sensitive copeptin compared with the serial assessment of medium-sensitivity cardiac troponin I. METHODS: Ultra-sensitive copeptin and medium-sensitivity cardiac troponin I levels were measured at presentation in 196 consecutive patients admitted to the emergency department for acute nontraumatic chest pain within 6 hours from symptoms onset and without ST-segment elevation on a 12-lead electrocardiogram. The diagnostic performance for non-ST-segment elevation myocardial infarction diagnosis of the dual-marker single-sampling strategy with medium-sensitivity cardiac troponin I and ultra-sensitive copeptin on admission was compared with that of the serial 0- and 3-hour medium-sensitivity cardiac troponin I sampling in reference to the adjudicated postdischarge diagnosis, using both the comparison of area under the curve (AUC) receiver operating characteristic and the McNemar chi-square test. RESULTS: The diagnosis of non-ST-segment elevation myocardial infarction was adjudicated in 29 patients (14.8%). The combination of medium-sensitivity cardiac troponin I and ultra-sensitive copeptin generated an AUC of 0.87 (95% confidence interval, 0.82-0.91), which was noninferior with respect to the 3-hour interval medium-sensitivity cardiac troponin I serial sampling (P = .194 for AUC difference). The combination of medium-sensitivity cardiac troponin I and ultra-sensitive copeptin also yielded a numerically higher diagnostic sensitivity (100% vs 89.7%; P = not significant). CONCLUSIONS: A single-sampling strategy of combined ultra-sensitive copeptin and medium-sensitivity cardiac troponin I is noninferior to a 0- and 3-hour serial medium-sensitivity cardiac troponin I sampling in ruling out non-ST-segment elevation myocardial infarction and thus may allow an earlier discharge of patients who are ruled out for non-ST-segment elevation myocardial infarction (ClinicalTrials.gov Identifier NCT01962506).