Effects of Glucose-Insulin-Potassium Infusion on ST-Elevation Myocardial Infarction in Patients Treated With Thrombolytic Therapy

The role of glucose-insulin-potassium (GIK) infusion in the management of acute myocardial infarction is not well established. This prospective, randomized study comprised 120 patients who had ST-elevation myocardial infarction that was treated within 12 hours from symptom onset with a high dose of GIK (25% glucose, 50 IU of soluble insulin per liter, and 80 mmol of potassium chloride per liter at 1 ml/kg/hour over 24 hours) as adjunct to thrombolytic therapy (1.5 MU of streptokinase/30 to 60 minutes; GIK group) or thrombolytic therapy alone (control group). The primary end point of the study was the rate of major adverse cardiac events (MACEs) at 1 month, defined as a composite of cardiac death, reinfarction, serious arrhythmias (ventricular fibrillation and/or tachycardia), and severe heart failure. The secondary end points were the rate of MACEs at 1 year and improvement in left ventricular systolic function. The incidence of MACEs at 1 month was significantly lower in the GIK group (10% vs 32.5%, relative risk 0.24, 95% confidence interval 0.09 to 0.63, p = 0.0043). Patients in the GIK group had significant decreases in ventricular tachycardia and/or fibrillation (1.3% vs 15.0%, p = 0.003) and severe heart failure (3% vs 12.5%, p = 0.031). The rate of MACEs at 1 year was also significantly lower in the GIK group (13% vs 40.0%, relative risk 0.22, 95% confidence interval 0.09 to 0.55, p = 0.0012). After 1 year, there was a significant improvement in left ventricular ejection fraction in the GIK group (from 48 ± 8% to 51 ± 10%, p <0.01), which was not observed in the control group. In conclusion, high-dose GIK, used as an adjunct to thrombolytic therapy, was safe and improved clinical outcome at 1 month. The beneficial effect of GIK infusion was maintained up to 1 year.