Oxidative stress after reperfusion with primary coronary angioplasty: Lack of effect of glucose-insulin-potassium infusion

Abstract

Objective: To evaluate the oxidative stress status and the modification with glucose-insulin-potassium (GIK) therapy in patients with acute myocardial infarction undergoing primary percutaneous transluminal coronary angioplasty. Design: Prospective, randomized, double-blinded, placebo-controlled study. Setting: Cardiac intensive care unit at the university hospital. Patients: Twenty patients were randomized to GlK solution (30% glucose in water with insulin 50 IU/L, and KCI 40 mM) vs. placebo (normal saline) at 1.5 mL/kg/hr for 24 hrs. The control group was 15 healthy volunteers with no heart disease. Interventions: Eligible patients were randomized by a blinded pharmacist, patients with acute myocardial infarction were treated by primary percutaneous transluminal coronary angioplasty and randomized to GlK or placebo (saline solution). Primary angioplasty was successful in nine of ten patients (90%) and ten of ten patients (100%) in the GlK and placebo groups, respectively. Nine (100%) and six (60%) patients from GlK and placebo groups, respectively, underwent stent implantation. Measurements and Main Results: We determined plasma levels of lipid peroxidation estimated by the malondialdehyde assay, superoxide dismutase, glutathione peroxidase, and catalase erythrocyte activities at admission and 0.5 and 24 hrs after angioplasty. Baseline determinations were compared with a control group (n = 15). Baseline clinical characteristics and time to treatment (4.5 +/- 3.5 hrs) were similar between groups. Angioplasty success rate (Thrombolysis in Myocardial Infarction [TIMI] 3 flow with residual stenosis less than or equal to30%) was 90% and 100% in GIK and placebo groups, respectively. Patients with acute myocardial infarction had an increase of malondialdehyde at baseline (2.9 +/- 1.7 vs. 1.1 +/- 0.3 muM, p <.01) and lower enzymatic activities of superoxide dismutase (0.5 +/- 0.5 vs. 1.3 +/- 0.4 U/mg hemoglobin, p <.01) and catalase (147 +/- 73 vs. 198 +/- 31 U/g hemoglobin, p <.01). These measurements did not change significantly after angioplasty and no differences were observed between GlK and placebo groups. Conclusion: Patients with acute myocardial infarction had increased levels of oxidative stress associated with a reduction in enzymatic antioxidant reserve. Administration of GIK solution did not improve these abnormalities among patients undergoing primary angioplasty.