Background and goal. The endothelial glycocalix (EG) system is an important protective regulator of vascular integrity, permeability, and endothelial activation. The perioperative EG shedding can be associated with capillary leak, hemodynamic disturbances, and increased postoperative morbidity. The goal of this study was to assess the EG response to elective on-pump valve surgery.
Methods. Twenty-six adult patients scheduled for elective valvular interventions on cardiopulmonary bypass were enrolled into a single-centre prospective observational study. The components of EG including Heparan Sulfate Proteoglycan (HSPG) and Syndecan-1 (S1) were measured after the induction of anaesthesia, and at 6 and 24 hrs postoperatively (ELISA Kits SEA565Hu and SEB966Hu, Cloud-Clone Corp., USA). The hemodynamic variables, blood gases, pro-B-type natriuretic peptide (NT-proBNP), and biochemical parameters were measured perioperatively. The statistical analysis was performed using Mann–Whitney U-test, ANOVA, Spearman’s rho, and ROC-analysis. Data are presented as median (25th–75th percentiles). p values < 0.05 were regarded as statistically significant.
Results. At 6 hrs after surgery, we observed a decrease in HSPG concentration from 6.13 (4.20–9.04) ng/ml to 5.08 (4.18–7.21) ng/ml (p < 0.01), while S1 increased from 0.80 (0.56–1.13) ng/ml to 1.25 (1.04–1.41) ng/ml (p < 0.001). At 24 hrs, HSPG and S1 returned to values close to baseline. The baseline HSPG correlated with systemic vascular resistance index (rho = –0.55 p = 0.004), postoperative cardiac index (rho = 0.43–0.46, p = 0.03) , pulse pressure variation (rho = –0.76, p = 0.003), and glucose concentration (rho = –0.50, p =0.02). In addition, the baseline HSPG concentrations above 5.1 ng/mL predicted postoperative hyperlactatemia (> 2 mmol/l) with AUC 0.75, sensitivity 100% and specificity 58% (p = 0.02). The baseline NT-proBNP demonstrated weak correlation with HSPG concentration at 6 hrs after surgery (rho = 0.42, p = 0.04). The values of HSPG at all stages and the baseline S1 concentration correlated with duration of mechanical ventilation (rho = 0.46–0.49, p < 0.02).
Conclusion. At the selected perioperative time-points, the EG system demonstrated relatively minor shedding to the elective on-pump cardiosurgical interventions and moderate associations with hemodynamics, metabolic response, and the duration of respiratory support.

Acknowledgements: The authors appreciate the invaluable help of Drs. Tatyana V. Chernova, Maria M. Sokolova, Eugenia V. Fot, and Aleksey A. Smetkin.


05 / The endothelial glycocalix changes are associated with hemodynamic and metabolic responses in on-pump valve repair surgery