An infusion of glucose, insulin, and potassium (GIK) could be an important adjuvant for the immediate treatment of patients with acute myocardial infarction. In a placebo-controlled, randomised trial of 407 patients from six South American countries, a combination of traditional reperfusion therapy and GIK (given over 24 hours) reduced mortality after acute myocardial infarction from 15·2% to 5·2%.
"If these results are confirmed by larger clinical trials, GIK might become a promising therapy", says Leopoldo Piegas (Instituto Dante Pazzanese de Cardiologia, São Paulo, Brazil), one of researchers involved in the trial.
GIK infusion was first proposed as a metabolic way to protect the ischaemic myocardium in 1962, but since then no conclusion has been reached about the efficacy of the approach.
In the current study, patients were given either 2·4 L GIK solution (containing 25% glucose, 50 IU insulin, and 80 mmol/L potassium chloride ), 1·8 L GIK solution, or no GIK. Because of the small number of patients, there were no significant differences in adverse effects or benefits between the high and low-dose groups, and the trialists reported their results as a comparison between GIK therapy and no GIK (Circulation 1998; 98: 222734).
As Piegas notes, the trial was designed to investigate the safety of the method. However, the trialists reported a significant reduction in mortality (relative risk in patients given GIK compared with controls was 0·34 [95% CI 0·150·78]). Side-effects were rare and minor.
The Estudios Cardiólogicos Latinoamérica Collaborative Group is now doing a 10 000-patient study of GIK infusion. Piegas, a member of the group, says that if the treatment proves to be an effective adjuvant option for treatment of acute myocardial infarction, it will have an impact on survival in both developed and developing countries, since it requires few human or technological resources. "And it's very cheap, probably less than US$5 per patient", he adds.
Claudio Csillag
