Use of copeptin in emergency patients with cardiac chief complaints

BACKGROUND: Combined testing of copeptin and troponin at presentation to the emergency department (ED) has been shown to possess a high negative predictive value (NPV) for ruling out acute myocardial infarction (AMI) in patients with suspected acute coronary syndrome. PURPOSE: The aim of this study was to evaluate the diagnostic performance of the combination of copeptin and troponin for the exclusion of AMI in emergency patients with acute cardiac chief complaints and to assess diagnoses and outcome in copeptin-positive patients. METHODS: In this prospective study, 537 consecutive patients with cardiac chief complaints were recruited from the ED. Blood samples were collected at admission. RESULTS: The overall incidence of AMI in the study sample was 14.2% (n=76). In troponin-negative patients, copeptin showed a sensitivity of 76.9% (95% confidence interval (CI) 46.2-95.0), a specificity of 64.2% (95% CI 59.2-69.0), a positive predictive value (PPV) of 6.9% (95% CI 3.3-12.2) and an NPV of 98.8% (95% CI 96.5-99.8). The highest copeptin values were observed in patients with chronic heart failure, followed by ST-elevation myocardial infarction (STEMI), acute heart failure (AHF), pneumonia and non-STEMI (NSTEMI). A copeptin-value of above 10 pmol/l increased the risk of death within three months significantly (hazard ratio (HR)=5.42 (1.81-16.21) p=0.003). CONCLUSION: Copeptin seems to be a promising biomarker for the initial evaluation of emergency patients with cardiac chief complaints. The study adds to the evidence that a single copeptin and troponin test at admission achieves a high NPV for ruling-out NSTEMI early in low-to-intermediate risk patients and thus--in combination with the clinical evaluation--seems to be of considerable relevance in emergency medicine.