title: Preoperative sCD40L levels predict risk of atrial fibrillation after off-pump coronary artery bypass graft surgery.
abstract: BACKGROUND
  The risk of atrial fibrillation (AF) after coronary bypass surgery has been related to redox state, inflammation, and ischemia. Platelet activation is common to all of these pathways. We investigated the relation between AF and preoperative soluble CD40 ligand (sCD40L), a proinflammatory marker released by activated platelets. Furthermore, we studied the role of inflammation, endothelial function, and redox state in this relation.
  
  
  RESULTS
  sCD40L levels were measured in 144 patients in sinus rhythm the day before off-pump coronary artery surgery. Systemic inflammation was assessed from levels of C-reactive protein and soluble intercellular adhesion molecule-1, and endothelial function was assessed from the brachial artery flow-mediated dilatation response. Graft samples were collected during surgery to assess vascular redox state. AF occurred in 33% of patients after surgery, with 3% still in AF after 6 weeks. Preoperative sCD40L levels were significantly higher in those who developed in-hospital AF (odds ratio for a 1-SD increase in log[sCD40L]=1.97; 95% CI, 1.21 to 3.22; P=0.007; after adjustment for age, sex, Euroscore, and total duration of operation). sCD40L and vascular superoxide levels were higher in patients still in AF at 6 weeks, and endothelial function was lower, although the small number of events precluded statistical analysis in this group. Systemic endothelial function, redox state, and preoperative markers of systemic inflammation were not associated with in-hospital postoperative AF.
  
  
  CONCLUSIONS
  Preoperative platelet activation, as assessed by sCD40L levels, is a novel predictor of postoperative AF, independent of systemic endothelial function, vascular redox state, and systemic inflammation.
authors.affiliation: Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, UK.
authors.forename: Charalambos
authors.initials: C
authors.lastname: Antoniades
authors.forename: Tim
authors.initials: T
authors.lastname: Van-Assche
authors.forename: Cheerag
authors.initials: C
authors.lastname: Shirodaria
authors.forename: Jonathan
authors.initials: J
authors.lastname: Diesch
authors.forename: Alexios S
authors.initials: AS
authors.lastname: Antonopoulos
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
authors.forename: Colin
authors.initials: C
authors.lastname: Cunnington
authors.forename: Dimitris
authors.initials: D
authors.lastname: Tousoulis
authors.forename: Christodoulos
authors.initials: C
authors.lastname: Stefanadis
authors.forename: Barbara
authors.initials: B
authors.lastname: Casadei
authors.forename: David
authors.initials: D
authors.lastname: Taggart
authors.forename: Keith M
authors.initials: KM
authors.lastname: Channon
authors.forename: Paul
authors.initials: P
authors.lastname: Leeson
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood / Q000209:etiology*; D002097:C-Reactive Protein / Q000032:analysis; D023201:CD40 Ligand / Q000097:blood*; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D015539:Platelet Activation; D012307:Risk Factors; D013481:Superoxides / Q000378:metabolism
chemical_list: D013481:Superoxides; D018799:Intercellular Adhesion Molecule-1; D023201:CD40 Ligand; D002097:C-Reactive Protein; D019331:NG-Nitroarginine Methyl Ester