Glycometabolic State at Admission: Important Risk Marker of Mortality in Conventionally Treated Patients With Diabetes Mellitus and Acute Myocardial Infarction

Abstract

Background—The Diabetes and Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) study addressed prognostic factors and the effects of concomitant treatment and glycometabolic control in diabetic patients with myocardial infarction (AMI). Methods and Results—Of 620 diabetic patients with AMI, 306 were randomly assigned to a ≥24-hour insulin-glucose infusion followed by multidose subcutaneous insulin. Three hundred fourteen patients were randomized as controls, receiving routine antidiabetic therapy. Thrombolysis and β-blockers were administered when possible. Univariate and multivariate statistical analyses were applied to study predictors of long-term mortality. During an average follow-up of 3.4 years (range, 1.6 to 5.6 years), 102 patients (33%) in the intensive insulin group and 138 (44%) in the control group died (P=0.011). Old age, previous heart failure, diabetes duration, admission blood glucose, and admission Hb A_Ic were independent predictors of mortality in the total cohort, whereas previous AMI, hypertension, smoking, or female sex did not add independent predictive value. Metabolic control, mirrored by blood glucose and Hb A_Ic, improved significantly more in patients on intensive insulin treatment than in the control group. β-Blockers improved survival in control subjects, whereas thrombolysis was most efficient in the intensive insulin group. Conclusions—Mortality in diabetic patients with AMI is predicted by age, previous heart failure, and severity of the glycometabolic state at admission but not by conventional risk factors or sex. Intensive insulin treatment reduced long-term mortality despite high admission blood glucose and Hb A_Ic.