Objective. The prognosis of patients with acute Myocardial Infarction (MI), according to the new criteria for Impaired Fasting Glucose (IFG) (FG: 100 to 126 mg/dl) has not been evaluated.

Research Design and Methods. 2353 patients with acute MI and surviving at day 5 after admission were analysed for short term morbidity and mortality. FG was obtained at day 4 and 5. Patients were classified as diabetics (DM) (known diabetes or FG126 mg/dl), high IFG (110 FG <126 mg/dl), low IFG (100 FG<110 mg/dl) and normal fasting glucose (NFG) (FG< 100 mg/dl).

Results. Among the 2353 patients, 968 (41%) had DM, 262 (11%) had high IFG, 332 (14%) had low IFG and 791 (34%) had NFG. Compared to NFG patients, 30-day CV mortality was increased in high but not in low IFG subjects. In-hospital heart failure was increased in high IFG subjects (42% vs. 20% for NFG, p<0.0001), but not in low IFG subjects (21% vs. 20%). High IFG, but not low IFG, was an independent factor associated with 30-day CV mortality (OR: 2.33 [1.55-3.47]) and in-hospital heart failure (OR: 1.70 [1.36-2.07]). The optimal threshold levels of FG on the ROC curves were 114 mg/dl and 112 mg/dl to predict mortality and in-hospital heart failure, respectively.

Conclusion. The present study, based on non-selected cohort of MI patients, underscores the high prevalence of IFG (25%) and highlights the clinical relevance of 110 mg/dl, but not of 100 mg/dl, as a cut-off value to define the risk for worse outcome.