Diazoxide may protect endothelial glycocalyx integrity during coronary artery bypass grafting.

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.