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.