title: Effect of minimized perfusion circuit on brain injury markers carnosinase and brain-type fatty binding protein in coronary artery bypass grafting patients.
abstract: A minimized perfusion circuit (MPC) has proven to be superior to the conventional circulatory perfusion bypass (CCPB) as it reduces the blood-material interaction and hemodilution. Until now not much is known about impact these different perfusion systems have on the brain. The objective of this study is to determine carnosinase and brain-type fatty binding protein (BFABP) activity as novel specific biomarkers for ischemic brain tissue damage and how their activity differs during and after MPC and CCPB as well as to compare the inflammatory response of both perfusion systems. In a prospective pilot study, 28 patients undergoing coronary artery bypass grafting were randomly divided into an MPC group (n = 14) and a CCPB group (n = 14). Blood samples were taken before, during, and after operation until the fifth postoperative day. The brain biomarker carnosinase was determined by measuring the rate of histidine production from the substrate homocarnosine, whereas BFABP and interleukin-6 were determined by enzyme-linked immunosorbent assay (ELISA). C-reactive protein (CRP) and endothelin-1 were determined by enzyme immunoassay. The mean serum carnosinase activity was significantly higher in MPC (0.57 ± 0.34 nM histidine/mL/min) as compared with the CCPB group (0.36 ± 0.13 nM histidine/mL/min) at the end of operation (P = 0.02). The BFABP did not show any difference between the two groups in the immediate postoperative period until the second postoperative day. From that time point onward, it showed a steep increase in the CCPB group (581.3 ± 157.11 pg/mL) as compared with the concentrations in the MPC group (384.6 ± 39 pg/mL) (P = 0.04). The inflammation markers interleukin-6 and CRP showed a similar pattern in both groups without significant difference. In contrast, the leukocyte count on operation day and endothelin-1 on the first postoperative day were significantly higher in the CCPB group (P = 0.01, P = 0.03, respectively). MPC showed a significant higher and stable serum carnosinase activity during extracorporeal circulation as compared with the CCPB due to less hemodilution and a better preserved oxygen capacity. As a consequence, the antioxidant stress during MPC is limited as compared with CCPB, which means less brain tissue damage reflected by a lower BFABP release. Except endothelin-1 and leukocyte count, the inflammatory response of the MPC and CCPB was equal.
authors.affiliation: Department of Cardiothoracic and Vascular Surgery, Städtisches Klinikum Braunschweig, Braunschweig, Germany. dipak.pahari@gmx.de
authors.forename: Dipak R
authors.initials: DR
authors.lastname: Pahari
authors.forename: Y John
authors.initials: YJ
authors.lastname: Gu
authors.forename: Willem
authors.initials: W
authors.lastname: van Oeveren
authors.forename: Aschraf
authors.initials: A
authors.lastname: El-Essawi
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Harringer
authors.forename: René M H
authors.initials: RM
authors.lastname: Brouwer
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D002097:C-Reactive Protein / Q000378:metabolism; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002352:Carrier Proteins / Q000097:blood*; D001026:Coronary Artery Bypass; D004150:Dipeptidases / Q000097:blood*; D019332:Endothelin-1 / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D000071438:Fatty Acid-Binding Protein 7; D005260:Female; D005858:Germany; D006801:Humans; D007124:Immunoenzyme Techniques; D018836:Inflammation Mediators / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D010477:Perfusion / Q000009:adverse effects / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D025521:Tumor Suppressor Proteins / Q000097:blood*
chemical_list: D015415:Biomarkers; D002352:Carrier Proteins; D019332:Endothelin-1; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D025521:Tumor Suppressor Proteins; D002097:C-Reactive Protein; D004150:Dipeptidases; C019673:aminoacyl-histidine dipeptidase