Effect of 5% albumin on endothelial glycocalyx degradation during off-pump coronary artery bypass

Abstract

Purpose: The integrity of the endothelial glycocalyx (EG), a critical player in vascular homeostasis, reportedly influences the outcomes of critically ill patients. We investigated the effect of 5% albumin, which preserved EG integrity in preclinical studies, vs balanced crystalloid solution on EG degradation in patients undergoing off-pump coronary surgery. Methods: Patients were randomized to receive either 5% albumin (N = 51) or balanced crystalloid solution (Plasma-Lyte [Baxter Incorporated, Seoul, Republic of Korea]; N = 53) for intravenous volume replacement during surgery (double-blinded). The primary outcome was plasma syndecan-1 concentration, a marker of EG degradation, measured after anesthetic induction (baseline), completion of grafting, and sternal closure. Secondary outcomes were atrial natriuretic peptide (ANP), tumour necrosis factor (TNF)-α, soluble thrombomodulin, and perioperative fluid balance. Results: The mean (standard deviation) fluid requirements were 833 (270) mL and 1,323 (492) mL in the albumin and Plasma-Lyte group, respectively (mean difference, −489 mL; 95% confidence interval [CI], −643 to −335; P < 0.001). Plasma syndecan-1 concentration increased after completion of grafting (median difference, 116 ng·mL−1; 95% CI, 67 to 184; P < 0.001) and sternal closure (median difference, 57 ng·mL−1; 95% CI, 36 to 80; P < 0.001) compared with those at baseline, without any intergroup differences. Atrial natriuretic peptide, TNF-α, and soluble thrombomodulin concentrations were similar between the two groups. The amount of chest tube drainage was greater in the albumin group than that in the Plasma-Lyte group (median difference, 190 mL; 95% CI, 18 to 276; P = 0.03). Conclusion: Off-pump coronary surgery was associated with significant EG degradation. Yet, intraoperative fluid therapy with 5% albumin could not ameliorate EG degradation when compared with balanced crystalloid solution. Trial registration: ClinicalTrials.gov (NCT03699462); first posted 9 October 2018.