Glucose-Insulin-Potassium in cardiac surgery – a meta-analysis

Objectives: Glucose-Insulin-Potassium therapy (GIK) has been suggested to reduce mortality and improve postoperative recovery after cardiac surgery. We performed a meta-analysis of all randomized studies using GIK in cardiac surgery. Material and Methods: A systematic MEDLINE search for all GIK studies in cardiac surgery was carried out. Randomized studies investigating the recovery of contractile function as a primary endpoint were included in the meta-analysis. Results: Thirtythree GIK trials were identified. Twentytwo studies were excluded because of lack of randomization, supplementary administration of other substances or due to other primary endpoints. Eleven studies were included with a total of 468 patients who underwent either coronary artery bypass grafting and/or heart valve replacement. Six studies noted a significant improvement in postoperative recovery. One study demonstrated no effect. In four studies, no comparable statistical analysis was available. GIK patients required similar or lesser doses of catecholamines. From the available data we estimated a weighted mean of relative improvement in postoperative recovery of cardiac index for GIK patients vs. controls of 11.4%. Five of the eleven studies reported the incidence of postoperative atrial fibrillation (AF). AF occurred in 28% (24/86) in GIK vs. 45% (39/86) in control patients (p=0.026). Conclusions: The findings indicate that GIK may considerably improve postoperative recovery of contractile function and reduce the incidence of atrial arrhythmias after cardiac surgery. However, several factors limit the power of this analysis and large, randomized multicenter trials are needed to fully assess the efficacy of GIK after cardiac surgery.