Prognostic value of admission plasma glucose and HbA in acute myocardial infarction.

OBJECTIVE: Stress hyperglycaemia increases the risk of mortality after acute myocardial infarction in diabetic and in non-diabetic patients. We aimed to determine the contribution of admission plasma glucose and HbA(1c) on post-acute myocardial infarction prognosis.

PATIENTS AND METHODS: Admission plasma glucose and HbA(1c) were simultaneously measured in all patients consecutively hospitalized for acute myocardial infarction. Patient survival was measured on 5 and 28 days after admission. Patients were defined as having 'previously diagnosed diabetes' (personal history of diabetes defined using ADA 1997 criteria), 'no diabetes', those without previously diagnosed diabetes and HbA(1c) below 6.5%, or 'possible diabetes', i.e. those without previously diagnosed diabetes and HbA(1c) above 6.5%.

RESULTS: Of the 146 patients included, four had died by day 5 and 14 by day 28. Admission plasma glucose was higher in patients who had died by day 28 (11.7 +/- 5.8 vs. 8.0 +/- 3.3 mmol/l, P = 0.002), whereas HbA(1c) was not (6.4 +/- 1.9 vs. 6.1 +/- 0.8%, NS). Admission plasma glucose was significantly higher in those who had died by day 28 after adjustment on HbA(1c). A multivariate analysis, including sex, age and heart failure prior to acute myocardial infarction, showed that admission plasma glucose concentration was an independent predictor of survival after acute myocardial infarction. Twenty-seven of the patients had previously diagnosed diabetes and 119 had no history of diabetes. Eleven were found to have possible diabetes. Admission plasma glucose was significantly higher in previously diagnosed diabetes (11.1 +/- 5.6) than in the other groups: 7.7 +/- 2.9 in non-diabetes, 8.2 +/- 2.1 in possible diabetes (P < 0.0001). The relationship between HbA(1c)-adjusted admission plasma glucose and mortality after acute myocardial infarction was also found in the non-diabetes group.

CONCLUSIONS: Admission plasma glucose, even after adjustment on HbA(1c), is a prognostic factor associated with mortality after acute myocardial infarction. Acute rather than the chronic pre-existing glycometabolic state accounts for the prognosis after acute myocardial infarction.