OBJECTIVE There is uncertainty about the association between circulating concentrations of adiponectin and coronary heart disease risk, particularly in patients after acute myocardial infarction (AMI). The goal of this study was to determine whether plasma adiponectin levels could predict future cardiovascular events in patients after AMI, and to elucidate the role of adiponectin in cardioprotection. METHODS A total of 102 patients with AMI were enrolled. Plasma adiponectin levels were examined from blood samples collected 18 months after AMI. All subjects were followed-up for 43+/-12 months. The primary endpoint was the combined occurrence of major adverse cardiovascular events (MACE), including rehospitalization due to unstable angina, nonfatal MI, revascularization with percutaneous coronary intervention or coronary artery bypass grafting, ischemic stroke, and cardiovascular death. RESULTS A total of 30 MACE occurred, including one case of cardiovascular death, five cases of nonfatal MI, and nine cases of ischemic stroke. Patients with MACE had lower plasma adiponectin levels (p=0.013). In addition, adiponectin was positively associated with changes in left ventricular ejection fraction (p=0.005). All patients were divided into a high-adiponectin group (>or=6.46 microg/mL) and a low-adiponectin group (<6.46 microg/mL). The incidence of MACE was significantly reduced in the high-adiponectin group (p=0.021). In multivariate Cox regression analysis that included adiponectin, classical risk factors, and medications, adiponectin was an independent predictor of MACE in patients after AMI (HR, 0.821; 95% CI, 0.691 to 0.974; p=0.024). CONCLUSIONS The results indicate a potential association between plasma adiponectin levels and future cardiovascular events in patients after AMI. Moreover, plasma adiponectin concentrations appear to play a pivotal role in atherothrombosis and cardioprotection.