Comparison of glucose-insulin-potassium and insulin-glucose as adjunctive therapy in acute myocardial infarction: a contemporary meta-analysis of randomised controlled trials

Background There is conflicting evidence regarding two different insulin regimens for acute myocardial infarction (AMI), one focusing on delivering insulin ('insulin focus', glucose-insulin-potassium (GIK)) and one focusing on tight glycaemic control ('glycaemia focus', insulin-glucose). A longstanding controversy has focused on which strategy provides the greatest reduction in mortality. The aim of this study was to perform a meta-analysis of randomised controlled trials (RCTs) comparing GIK or insulin-glucose therapy versus standard therapy for AMI in the reperfusion era. Methods A MEDLINE/EMBASE/CENTRAL search was conducted of RCTs evaluating GIK or insulin-glucose as adjunctive therapy for AMI. The primary endpoint was all-cause mortality. The data were analysed with a random effect model. Results A total of 11 studies (including 23 864 patients) were identified, eight evaluating insulin focus with GIK and three evaluating glycaemia focus with insulin-glucose. Overall, insulin focus with GIK was not associated with a statistically significant effect on mortality (RR 1.07, 95% CI 0.89 to 1.29, p=0.487). Before the use of reperfusion, GIK also had no clear impact on mortality (RR 0.92, 95% CI 0.70 to 1.20, p=0.522). Pooled data from the three studies evaluating glycaemia focus showed that insulin-glucose did not reduce mortality in the absence of glycaemia control in patients with AMI with diabetes (RR 1.07, 95% CI 0.85 to 1.36, p=0.547). Conclusions Current evidence suggests that GIK with insulin does not reduce mortality in patients with AMI. However, studies of glycaemia are inconclusive and it remains possible that glycaemic control is beneficial.