Rheoparin-coated Tubing System for Minimized Extracorporeal Circulation (MECC) (RheoMECC)

Coagulation, Inflammation and Cerebral Embolism Using a Rheoparin-coated Tubing System for Minimized Extracorporeal Circulation (MECC): Differences to the Conventional MECC System

In this study, the investigators would like to compare a heparin-coated tubing system for minimized extracorporeal circulation (MECC) with the conventional tubing system for MECC, which does not contain heparin coating. The MECC system has been used since 14 years in the investigators' hospital as an extracorporeal system to support circulation and provide oxygen to the tissues during coronary artery bypass grafting. Until today, the investigators performed more than 5000 MECC procedures in their department.

Background The investigators would like to investigate a new composition of their MECC system in patients receiving coronary artery bypass surgery. Normally, the MECC system induces complement system activation and coagulation cascade, which could have a negative impact on postoperative outcome. A tubing system containing heparin (rheoparin) could contribute to a better biocompatibility in terms of a diminished activation of inflammatory reactions and a reduction of cerebral embolic load, which is a regular issue during extracorporeal circulation due to formation of solid and gaseous microemboli in the tubing system. Objective The aim is to investigate biocompatibility (coagulation, inflammation) and influence on cerebral embolic load of the rheoparin-coated MECC system and to compare the results with the current MECC system containing a rheoparin-free tubing system. Methods Patients undergoing elective coronary artery surgery are randomized to receive extracorporeal circulation using the MECC system with or without rheoparin coating. All procedures are performed according to the institutional standards.

Biocompatibility will be assessed by measuring different coagulatory and inflammatory parameters as determined in comparable studies. Especially, hte investigators assess in their central laboratory the thrombin-antithrombin complex and the d-dimer as measures of the activity of the coagulation/fibrinolysis system and furthermore the complement factors C3a-C5a, the interleukins IL 6, IL8, IL10, the tumor-necrosis factor alpha (TNF-alpha), platelet factor 4 and the syndecan-1 activity as an expression of the inflammatory response to the different coating used for minimized extracorporeal circulation system.

Inclusion Criteria: Written informed consent Elective cardiac surgery Coronary artery bypass grafting Exclusion Criteria Re do Usage of antiplatelets, antithrombotic drugs Coagulopathy Persistent foramen ovale Infection Heparin-induced thrombocytopenia (HIT)