To examine the characteristics of FGF 21 in patients with acute myocardial infarction (AMI), we measured the dynamic change in circulating FGF21 levels in 100 Chinese patients (55 AMI patients and 45 non-AMI patients) and analyzed the association of FGF21 levels with a cluster of metabolic parameters and clinical end points. Here, FGF21 is linked to myocardial infarction.