ROC curves for CK-MB, TnI, and copeptin according to the time of chest pain onset in AMI patients. The ROC curve plots sensitivity on the Y-axis and (1-specificity) on the X-axis. The area under the curve (AUC) of each marker is presented in each graph. Copeptin as a single marker was superior to CK-MB within six hours [(A)–(C)] and to TnI within two hours [(A) & (B)] in the STEMI group (P<0.05). Copeptin showed better diagnostic performance than CK-MB within two hours [(G) & (H)] and TnI within one hour in the AMI group (G) (P<0.05).

Abbreviations: STEMI, ST elevation myocardial infarction; NSTEMI, non-ST elevation myocardial infarction; AMI, acute myocardial infarction; CK-MB, creatine kinase myocardial band; TnI, troponin I.