Introduction The aim of the study was to analyse the incremental usefulness of high blood glucose level for non-ST elevation acute coronary syndrome (ACS) diagnosis in patients admitted to the emergency department (ED) for chest pain and suspected ACS.

Methods A post hoc analysis of a prospective, observational study of 11 months duration was carried out. Initial glucose levels were analysed in 672 consecutive patients admitted to the ED with chest pain and suspected non-ST elevation ACS. A cut-off glucose level (>140 mg/dl) for high glucose level diagnosis was defined. Based on hospital diagnostic test results, patients were classified as having non-ST elevation ACS by two independent physicians. The association and performance of high glucose level for ACS diagnosis were studied by univariate and multivariate analysis and receiver operator characteristic (ROC) curves.

Results Out of the 672 eligible patients who were recruited, 181 (26.9%) had a confirmed non-ST elevation ACS. The independent factors associated with a diagnosis of ACS were age, previous coronary artery disease, hyperlipidaemia, smoking status and glucose level >140 mg/dl (OR 1.98 95% CI 1.14 to 3.45). In addition to a predictive model that included the usual diagnostic tools for non-ST elevation ACS management, a glucose level >140 mg/dl added significant incremental information (p=0.03). However, the addition of blood glucose level >140 mg/dl to the conventional diagnostic tool resulted in small increases in the ability to classify ACS, as measured by the c-statistic (0.82, 95% CI 0.79 to 0.85).

Conclusion An initial serum glucose level >140 mg/dl is associated with non-ST elevation ACS in patients admitted to an ED for chest pain but added moderately to conventional tools used for ACS diagnosis.

Clinical trial number NCT00714298.