Effects of glucose-insulin-potassium solution on acute myocardial infarction outcome in patients received streptokinase according to Killip classes.

Acute myocardial infarction (AMI) is associated with a high mortality rate and a large number of complications (1). The AMI mortality rate is directly related to the severity of hemodynamic deterioration and can be reduced by rapid reperfusion with chemical agents or mechanical procedures (2). The main mechanism of improvement is myocardial salvage (3). However, restoration of myocardial function does not depend only on the success of reperfusion therapy. Glucose-insulinpotassium solution (GIK) was proposed for the first time as a polarizing agent promoting electrical stability and protecting heart during AMI (4). Although a meta-analysis of subsequent randomized trials found a 28% reduction of in hospital mortality rates (5), there are controversial reports about the GIK effect in AMI management. The present study aimed to evaluate the effects of GIK on AMI patients received streptokinase and compare its effects on patients with different Killip classes (KC I vs. II /III). Present single-blind clinical trial evaluated the effects of GIK on AMI patients admitted to Tabriz Shahid Madani Hospital, Feb 2006-Jul 2007. Study protocol was approved by the ethic committee of Tabriz University of Medical Sciences. Patients who had symptoms consistent with AMI 20 minutes in duration, presented within 12 hours of symptom onset, and had ST elevation ≥1 mm in two contiguous electrocardiographic leads were enrolled. Exclusion criteria were serum creatinine ≥3 mg/dl, hyperkaliemia, and severe heart failure (KC IV). Patients with diabetes mellitus or plasma glucose level ≥300 mg/ dl were also excluded. One hundred AMI cases were enrolled; 50 patients into KC-I group and remainder into KC-II/III. The patients underwent streptokinase thrombolytic therapy after admission during at least 12 hours after onset of the symptoms. B group was divided into two subgroups including 25 patients (GIK vs. Placebo group). All included patients received standard therapies for AMI according to European Society Guidelines. The GIK (25 % glucose, 50 IU insulin and 80 mmol/lit potassium chloride) infused with 1mg/kg/h speed for 24 hours simultaneously with streptokinase (1.5 MU during 30-60 minutes). Left ventricle ejection fraction (LVEF) was determined using transthoracic echocardiography by Simpson's method. Post AMI recurrent MI, mechanical complications, cardiogenic shock, arrhythmia, heart failure (HF), mortality and revascularization were surveyed during hospitalization period, at 1st, 3rd and 12th months after discharge. Statistical analyses were performed using SPSS software 13.0. Statistical significance between groups of evaluation was estimated using one-way repeated measures ANOVA and Chisquare tests. The p value <0.05 was considered significant. There were no significant differences between groups in demographic characteristics and clinical manifestation of AMI. Table 1 shows infarct locations and primary LVEF in the study’s groups. Considering study design, subjects of KC-I group have high LVEF (p=0.024). The outcome of GIK infusion during follow up period is presented in Table 2. During hospitalization. Only three subjects from KC-I 's placebo subgroup complicated with HF (p=0.022), while there were