Copeptin is stable and detectable,so it could be an alternative of arginine vasopressin.Copeptin combined with troponin T (TnT) contributes to the diagnosis of coronary syndrome.Copeptin is an independent predictor in adverse events of non-ST segment elevation acute myocardial infarction.Combined detection of copeptin and brain natriuretic peptide(BNP) can predict the prognosis of heart failure.