Relationship between hyperglycaemia at admission and prognosis in patients with acute myocardial infarction: a retrospective cohort study

Abstract

Background The optimal threshold of hyperglycaemia at admission for identifying high-risk individuals in patients with acute myocardial infarction (AMI) and its impact on clinical prognosis are still unclear. Methods We retrospectively reviewed 2027 patients with AMI admitted from June 2001 to December 2012 in the ‘Medical Information Mart for Intensive Care III’ database. The significant cut-off values of admission blood glucose (Glucose_0) for predicting hospital mortality in patients with AMI with and without diabetes were obtained from the receiver operating characteristic (ROC) curve, then patients were assigned to hyperglycaemia and non-hyperglycaemia groups based on corresponding cut-off values. The primary endpoints were the hospital and 1-year mortality. Results Among 2027 patients, death occurred in 311 patients (15.3%). According to the ROC curve, the significant cut-off values of Glucose_0 to predict hospital mortality were 224.5 and 139.5 mg/dL in patients with diabetes and without diabetes, respectively. The crude hospital and 1-year mortality of the hyperglycaemia subgroup were higher than the corresponding non-hyperglycaemia group (p< 0.01). After adjustment, regardless of the state of diabetes, hyperglycaemia at admission was related to significantly increased hospital mortality in patients with AMI. For patients with AMI without diabetes, hyperglycaemia at admission was positively correlated with the increase of 1-year mortality (HR, 1.47; 95% CI 1.18 to 1.82; p=0.001). Nevertheless, this trend disappeared in those with diabetes (HR, 1.35; 95% CI 0.93 to 1.95; p=0.113). Conclusion Hyperglycaemia at admission was an independent predictor for mortality during hospitalisation and at 1-year in patients with AMI, especially in patients without diabetes.