Objectives: Patients with diabetes are known to have a worse prognosis after an acute myocardial infarction (AMI) compared with non-diabetic patients. The primary aim of this study was to investigate the effect of glucometabolic status on long-term prognosis in non-diabetic patients with an AMI. The second aim was to evaluate the extent to which blood glucose levels at admission depended on acute stress, assessed as serum cortisol, previous glucometabolic status, measured as haemoglobin A1c (HbA1c), or both.
Design: In a prospective study of patients with an AMI, blood glucose, HbA1c and cortisol were measured at admission. Fasting blood glucose was determined before discharge and also afterwards, if necessary, for classification. Patients were followed-up for 5.5 years.
Subjects: Of the 305 consecutive patients 24% were diagnosed as diabetic and 76% as non-diabetic.
Main outcome measures: Death or non-fatal myocardial re-infarction.
Results: In non-diabetic patients, a Cox regression model was used. With death or re-infarction as endpoint, the following prognostic factors had an impact on event-free survival: age (P<0.001), HbA1c (P=0.002), cortisol (P<0.001) and thrombolytic treatment (P=0.001). There was a correlation between cortisol and blood glucose at admission (r=0.44, P<0.001). Fasting blood glucose day 5 showed no association with event-free survival.
Conclusions: In non-diabetic patients with AMI, admission HbA1c and cortisol were predictors for 5.5-year survival without recurrent non-fatal myocardial infarction. The glucometabolic status of importance for prognosis was detected by HbA1c but not by fasting blood glucose or admission blood glucose, of which the latter was influenced by cortisol.