OBJECTIVE: To investigate whether a relationship exists between admission plasma glucose level and long-term outcome in nondiabetic patients after an acute myocardial infarction. RESEARCH DESIGN AND METHODS: This was a retrospective study with prospective follow-up of 197 consecutive nondiabetic patients with acute myocardial infarction followed for 1.5-2.5 years at the Department of Cardiology at Karolinska Hospital. RESULTS: The mean admission plasma glucose level was 8.15 +/- 3.0 mmol/l. During follow-up, 60 (30%) patients died, 20 (10%) were rehospitalized for heart failure, 12 (6%) were rehospitalized for nonfatal reinfarction, and 79 (40%) had at least one of these events. In univariate analysis, admission plasma glucose level was significantly higher in patients who had any of the predefined events than in those without these events. In a multivariate Cox proportional hazard regression model that allowed for confounding baseline predictors, admission plasma glucose level was an independent predictor of nonfatal reinfarction (P = 0.006), hospitalization for heart failure (P = 0.0034), and a major cardiovascular event (P = 0.0042) and was of borderline significance for death during long-term follow-up (P = 0.09). CONCLUSIONS: Admission plasma glucose level in nondiabetic patients with acute myocardial infarction seems to be an independent predictor of long-term outcome. This indicates that an elevated admission plasma glucose level not only reflects acute stress, but also may be a marker of disturbed glucose metabolism that worsens the prognosis and requires intervention.