Is blood glucose an independent predictor of mortality in acute myocardial infarction in the thrombolytic era?

Abstract

Objectives: 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.

Background: 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.

Methods: 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.

Results: In patients without a history of diabetes, glucose levels were < or =198 mg/dl in 1,078 patients (Group 1) and >198 mg/dl in 135 (Group 2). Of those with diabetes, glucose levels were < or =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.

Conclusions: 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.