Glucose-insulin-potassium improves left ventricular performances after aortic valve replacement: A secondary analysis of a randomized controlled trial

Abstract

Background: Patients with left ventricular (LV) hypertrophy may suffer ischemia-reperfusion injuries at the time of cardiac surgery with impairment in left ventricular function. Using transesophageal echocardiography (TEE), we evaluated the impact of glucose-insulin potassium (GIK) on LV performances in patients undergoing valve replacement for aortic stenosis. Methods: In this secondary analysis of a double-blind randomized trial, moderate-to-high risk patients were assigned to receive GIK (20 IU insulin with 10 mEq KCL in 50 ml glucose 40%) or saline over 60 min upon anesthetic induction. The primary outcomes were the early changes in 2-and 3-dimensional left ventricular ejection fraction (2D and 3D-LVEF), peak global longitudinal strain (PGLS) and transmitral flow propagation velocity (Vp). Results: At the end of GIK infusion, LV-FAC and 2D- and 3D-LVEF were unchanged whereas Vp (mean difference [MD + 7.9%, 95% confidence interval [CI] 3.2 to 12.5%; P < 0.001) increased compared with baseline values. After Placebo infusion, there was a decrease in LV-FAC (MD -2.9%, 95%CI - 4.8 to - 1.0%), 2D-LVEF (MD -2.0%, 95%CI - 2.8 to - 1.3%, 3D-LVEF (MD -3.0%, 95%CI - 4.0 to - 2.0%) and Vp (MD - 4.5 cm/s, 95%CI - 5.6 to - 3.3 cm/s). After cardiopulmonary bypass, GIK pretreatment was associated with preserved 2D and 3D-LVEF (+ 0.4%, 95% 95%CI - 0.8 to 1.7% and + 0.4%, 95%CI - 1.3 to 2.0%), and PGLS (- 0.9, 95%CI - 1.6 to - 0.2) as well as higher Vp (+ 5.1 cm/s, 95%CI 2.9 to 7.3), compared with baseline. In contrast, in the Placebo group, 2D-LVEF (- 2.2%, 95%CI - 3.4 to - 1.0), 3D-LVEF (- 6.0%, 95%CI - 7.8 to - 4.2), and Vp (- 7.6 cm/s, 95%CI - 9.4 to - 5.9), all decreased after bypass. Conclusions: Administration of GIK before aortic cross-clamping resulted in better preservation of systolic and diastolic ventricular function in patients with LV hypertrophy undergoing aortic valve replacement. Trial registration: ClinicalTrials.gov: NCT00788242, registered on November 10, 2008.