ROC curves for combined markers according to the time of chest pain onset in AMI patients. A combination of the three markers showed the highest ROC curves in all patient groups. Copeptin plus TnI showed better diagnostic performance than TnI plus CK-MB in the STEMI [(A)–(C)] and AMI [(G)–(I)] groups (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; copep, copeptin.