title: Active or passive bio-coating: does it matters in extracorporeal circulation?
abstract: BACKGROUND
  Two types of surface coating for cardiopulmonary bypass (CPB) are used: bioactive (heparin, nitric oxide) and biopassive (albumin, polyethyleneoxide (PEO), phosphorylcholine). When haemocompatible coatings are combined with the separation of pleuro-pericardial aspiration, attenuation of both the coagulation and complement cascades, as well as better platelet preservation, has been demonstrated. This study wants to investigate if the combination of a bioactive with a biopassive coating (unfractionated heparin embedded in a phosphorylcholine matrix) combines the beneficial effects of both approaches.
  
  
  METHODS
  Thirty patients undergoing elective CABG were prospectively randomized into two groups of 15 patients. The sole exclusion criterion was an ejection fraction of less than 40%. In the control group (PC), the whole CPB circuit was coated with phosphorylcholine (PC). In the study group (XPC), unfractionated heparin was embedded in the PC matrix of the oxygenator and arterial line filter.
  
  
  RESULTS
  No differences were found for haemolytic index, thrombin-anti-thrombin complex (TAT), IL-6, IL-10 and blood loss. PF4 plasma concentration increased from 27.6±22.0 IU/mL to 165.7±43.9 IU/mL (p<0.001) at 15 minutes of CPB in the PC and from 16.0±9.7 IU/mL to 150.9 ± 61.3 IU/mL (p<0.001) in the XPC group. Terminal complement complex (TCC) increased over time in both groups until the end of CPB (Figure 2A). Within each group, TCC generation was statistically significantly higher after the release of the aortic cross-clamp (p<0.001) and at the end of CPB (p<0.001). Total TCC generation was statistically significantly higher in the XPC group compared to the PC group (p=0.026). The difference was statistically significant after the release of the aortic cross-clamp (p=0.005) and at the end of CPB (p=0.001).
  
  
  CONCLUSIONS
  Based on our results, there is no additional benefit in combining phosphorylcholine with unfractionated heparin in elective patients undergoing coronary artery bypass grafting (CABG). Massive haemodilution leads to enhanced complement activation.
authors: Department of Anaesthesia, University Hospital Gent, Gent, Belgium.
authors: S
authors: S
authors: Jacobs
authors: F
authors: F
authors: De Somer
authors: G
authors: G
authors: Vandenplas
authors: Y
authors: Y
authors: Van Belleghem
authors: Y
authors: Y
authors: Taeymans
authors: G
authors: G
authors: Van Nooten
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000378:metabolism*; D003167:Complement Activation; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D006461:Hemolysis; D006493:Heparin / Q000378:metabolism*; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D010106:Oxygenators; D010767:Phosphorylcholine / Q000378:metabolism*; D011446:Prospective Studies
chemical_list: D020099:Coated Materials, Biocompatible; D015850:Interleukin-6; D010767:Phosphorylcholine; D016753:Interleukin-10; D006493:Heparin