GIK does not reduce the progression of unstable angina to Myocardial Infarct

Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care (IMMEDIATE), has published the negative results of an intravenous administration of glucose-insulin-potassium (GIK) in patients with heart diseases. GIK´s effects were similar to placebo except the composite end point where GIK decreased infarcts sizes.

According the IMMEDIATE study, the out-of-hospital intravenous administration of GIK in patients suspected of having an Acute Coronary Syndrome (ACS) failed to provide any clinical benefit when compared with patients who received a glucose placebo. GIK, administered by emergency medical services (EMS) in the first hours of a suspected ACS event, failed to reduce the progression of unstable angina to Myocardial Infarct (MI) and was not associated with an improvement in 30 day survival rates.

Intravenous GIK solution was administered to 411 patients and a 5% glucose placebo was administered to 460 patients in the out-of-hospital setting and continued for 12 hours. The primary end point was the progression of ACS to MI. There was not significant difference in the rate of progression to MI in the two treatment groups (48.7% in the GIK-treated patients and 52.6% in the placebo-treated patients; p=0.28). In addition, there was no significant difference in the 30-day mortality rates (4.4% vs 6.1%, respectively; p=0.27

Differences appear in the composite end point. The results show 52% reduction in the composite end point of cardiac arrest or in-hospital mortality. The rate of cardiac arrest or in-hospital mortality was 4.4% in the GIK-treated patients and 8.7% in the placebo arm. Results were similar when investigators examined STEMI -segment elevation MI- patients alone.

In a relatively small cohort of 110 ACS patients who underwent imaging at 30 days, infarct size was reduced in the GIK-treated patients compared with those who received placebo and was also reduced in patients who presented at the hospital with STEMI. Left ventricular ejection fraction (LVEF) did not improve but there were significant reductions in the concentration of free fatty acids.

Dr Harry Selker, lead researcher, said end point supports the reduction in cardiac arrest observed in IMMEDIATE. “GIK as metabolic support is unlikely to unblock the coronary artery, so the infarction that had probably already started was not prevented. However, the size of the infarction was much smaller”, he asserted.

In addition, Selker told the results need to be validated in a larger clinical trial but said he would not consider it inappropriate if EMS began using GIK in the ACS setting. Asked about the future of GIK, Dr Selder said there is no patent or money to be made with GIK. He asseverates that most trials of this sort would be done quickly if there were a molecule to be sold, but that is not the case. “This is a public-interest issue”.

Written by Alejandro Balbuena for The All Results Journals.