This study was designed to assess the prognostic significance of hyperglycemia in acute myocardial infarction (AMI) in the thrombolytic era using contemporary criteria for hyperglycemia.

Most studies that have examined this issue were performed before the widespread use of disease-modifying therapies and varied in their definition of hyperglycemia, assessment of risk factors, and reported outcomes.

There were 1,664 consecutively hospitalized patients with AMI between October 1997 and October 1998 from a disease-specific, population-based registry. Patients were stratified according to history of diabetes mellitus and, further, according to whether they had a blood glucose >198 mg/dl (11 mmol/l). The influences of cardiac risk factors, medications, and interventions were analyzed, and multivariate logistic regression was used to determine the influence of blood glucose on mortality.

In patients without a history of diabetes, glucose levels were ≤198 mg/dl in 1,078 patients (Group 1) and >198 mg/dl in 135 (Group 2). Of those with diabetes, glucose levels were ≤198 mg/dl in 169 patients (Group 3) and >198 mg/dl in 282 (Group 4). Compared with Group 1 patients, the odds ratios (95% confidence interval) for in-hospital mortality among those in Groups 2, 3, and 4 were 2.44 (1.42 to 4.20; p = 0.001), 1.87 (1.05 to 3.34; p = 0.035), and 1.91 (1.16 to 3.14; p = 0.011), respectively. These groups also had greater 12-month mortality.

Hyperglycemia in AMI is associated with poor outcome even among patients without known diabetes. This finding underlines the need for aggressive glucose management in this setting and may support a more vigorous screening strategy for early recognition of diabetes.