Impact of fasting glycemia on short-term prognosis after acute myocardial infarction.

Objective: The prognosis of patients with acute myocardial infarction (MI), according to the new criteria for impaired fasting glucose (IFG) (FG 100-126 mg/dl), has not been evaluated.

Research Design And Methods: A total of 2353 patients with acute MI and surviving at d 5 after admission were analyzed for short-term morbidity and mortality. FG was obtained at d 4 and 5. Patients were classified as diabetes mellitus (known diabetes or FG > or = 126 mg/dl), high IFG (110 < or = FG < 126 mg/dl), low IFG (100 < or = FG < 110 mg/dl), and normal fasting glucose (NFG) (FG < 100 mg/dl).

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

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