Outcomes Following On-Pump Versus OffPump CABG: Apprising the “Bypassed”

Insights into the Molecular Mechanism of Endothelial Glycocalyx Dysfunction during Heart Surgery

“…A quiescent heart and a bloodless surgical area are made possible by CPB, which also maintains adequate oxygenation and systemic perfusion. Roller and centrifugal pumps are common components of CPB machines, which offer non-pulsatile flow [14]. While pulsatile flow is recommended in adult open-heart surgery by the 2019 EACTS/EACTAIC/EBCP guidelines, the evidence for its superiority over non-pulsatile flow remains unclear, although pulsatile flow is a more natural option [56,58].…”

“…Under pressure and shear stress, the endothelium glycocalyx goes through a dynamic process of ongoing breakdown and repair [75]. Magoon et al highlight the role of a healthy glycocalyx in mechanotransduction, the process by which cells convert mechanical stimuli into biochemi-cal signals [14]. Changes in the glycocalyx that disrupt these interactions can exacerbate disease, emphasizing the importance of the glycocalyx in vascular health [19,20,71].…”

“…The glycocalyx acts as a mechanosensor, converting mechanical forces exerted by the blood flow into biochemi-cal signals, especially in downstream signaling pathways. Recent research suggests that the EGC has an important mechanosensing function [1,[14][15][16][17]. Components of the EGC participate in mechanotransduction, as they participate in the translation of shear stress into electrical, functional, and genetic changes inside endothelial cells by connecting the cytoskeleton and cell membrane.…”

“…PECAM-1 plays a multifaceted role in endothelial mechanotransduction by detecting mechanical signals, mediating intercellular communication, regulating focal-adhesion dynamics, and modulating intracellular signaling pathways as well as inflammatory modulation. Mechanical forces generated during leukocyte adhesion and migration can influence PECAM-1-mediated signaling, regulating the inflammatory phenotype of endothelial cells [1,[14][15][16][17][18].…”

“…The interaction of plasma proteins (enzymes and cofactors, xanthine-oxidoreductase, superoxide dismutase, and thrombomodulin) with EGC is crucial in maintaining endothelial structure and function [24]. Proteins such as factor H, the C1 inhibitor, and antithrombin III, which bind to heparan sulfate domains within the glycocalyx, participate in vasodilatation and regulate coagulation, preserving vascular hemostasis and health [14].There is a dynamic balance between the layer of soluble EGC components and the circulating blood, which constantly affects the composition and thickness of the glycocalyx, and at the capillary level, they even slow down the blood flow due to their volume [26]. Therefore, the composition, structure, and dimensions of the EGC are quite variable [27].…”