Background: The aim of the present study was to identify, using proteomics, changes in the expression of proteins and protein isoforms mainly associated with inflammation and vascular damage in the coronary sinus of patients undergoing off-pump coronary artery bypass (OPCAB) surgery.
Methods: Plasma from the coronary sinus of 18 patients undergoing OPCAB was obtained before the ischemic procedure and after revascularization of the left anterior descending artery (LAD) with an internal thoracic artery graft. The mean LAD ischemic time was 11.1+/-0.7 min. For the proteomic study, two-dimensional gel electrophoresis was performed.
Results: A significant decrease in the expression of three fibrinogen gamma-chain (FGC) isoforms, three vitamin D-binding protein (DBP) isoforms, six haptoglobin (HPT) isoforms, two apolipoprotein (apo)-AI isoforms, one ceruloplasmin (CP) isoform and apoAIV was found after revascularization. Before anastomosis, negative correlations between blood flow and FGC isoforms 2 and 3 and positive correlations between blood flow and apoAI isoform 5 were observed. After anastomosis, we observed positive correlations between haptoglobin isoform 3 and DBP isoform 2 and blood flow. Before anastomosis, positive correlation between DBP isoform 2 and troponin I was observed. After LAD grafting, positive correlations between troponin I and HPT isoform 6, CP isoform 1 and apoAI isoforms 2 and 4 were observed. After the procedure, positive correlations between creatine kinase-MB and coronary sinus expression of FGC isoforms 1, 2 and 3 and HPT isoforms 1 and 2 were also observed. conclusions: In blood from coronary sinus the expression of a number of proteins and protein isoforms associated with inflammation and vascular protection was modified after OPCAB.