Diazoxide may protect endothelial glycocalyx integrity during coronary artery bypass grafting

Abstract

OBJECTIVES: Plasma hyaluronan and syndecan-1 levels represent shedding of the endothelium glycocalyx during ischemia and edema. Diazoxide, a K(ATP)-channel opener, has been shown to decrease myocardial edema during coronary artery bypass grafting (CABG). We evaluated whether diazoxide exerts an impact on plasma hyaluronan and syndecan-1 levels during CABG. DESIGN: Representative blood samples for hyaluronan and syndecan-1, before, during and after surgery, were obtained in 13 out of 16 patients that had a history of stable coronary artery disease undergoing CABG with or without diazoxide. Electron microscopy from biopsies procured from the right atrium in 9 patients was performed to confirm ultrastructural differences among patients before and during CABG. RESULTS: Ultrastructural differences were apparent between individual patients already before operation at base line reflecting differences in the severity of myocardial ischemia and edema. A significant decrease of hyaluronan and syndecan-1 values was observed in patients with diazoxide after surgery (p < 0.04). Significant correlation of plasma hyaluronan and syndecan-1 levels was observed in patients with diazoxide but not in controls (p < 0.005, Spearman rank rho). CONCLUSION: Diazoxide may have an impact on levels of peripheral plasma hyaluronan and syndecan-1 after CABG, suggesting decreased shedding of the endothelial glycocalyx layer.