title: Association of anti-heat shock protein 65 antibodies with development of postoperative atrial fibrillation.
abstract: BACKGROUND
  Atrial fibrillation (AF) is a frequently encountered arrhythmia after cardiac surgery, but its underlying mechanisms are still unclear. We hypothesize that autoimmune and inflammatory responses against heat shock protein 65 (HSP65) may be involved and hence examined the relationship between HSP65 autoantibodies and occurrence of postoperative AF.
  
  
  RESULTS
  A prospective study of 329 patients undergoing elective primary CABG was undertaken. Cardiovascular risk factors, ECG characteristics, medications, and intraoperative and postoperative features were documented. Anti-HSP65 antibodies and C-reactive protein levels were measured in all preoperative blood samples with ELISA. Postoperative AF was defined as the characteristic arrhythmia, lasting for at least 15 minutes and confirmed on 12-lead ECG and occurring within the first postoperative week. This occurred in 62 patients (19%). In univariate analysis, HSP65 antibodies were significantly higher in patients with postoperative AF (P=0.02). History of previous myocardial infarction, duration of bypass, number of distal anastomosis, and duration of ventilation were also associated with AF (P<0.05), but C-reactive protein levels were not (P=0.13). Multivariate analysis confirmed the positive association of HSP65 antibodies with postoperative AF (OR, 1.41; P=0.04) independent of age, sex, other cardiovascular risk factors, severity of coronary artery disease, duration of ventilation, duration of bypass, and left ventricular function.
  
  
  CONCLUSIONS
  We report a novel association between anti-HSP65 antibodies and occurrence of postoperative AF, indicating a possible role for antibody-mediated immune response in its pathogenesis.
authors.affiliation: Department of Cardiothoracic Surgery, St George's Hospital & Medical School, London, UK.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Mandal
authors.forename: Marjan
authors.initials: M
authors.lastname: Jahangiri
authors.forename: Michael
authors.initials: M
authors.lastname: Mukhin
authors.forename: Jan
authors.initials: J
authors.lastname: Poloniecki
authors.forename: A John
authors.initials: AJ
authors.lastname: Camm
authors.forename: Qingbo
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D002315:Cardiopulmonary Bypass; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D018834:Chaperonin 60; D024101:Mitochondrial Proteins
chemical_list: D001323:Autoantibodies; D006360:Heat-Shock Proteins; C060293:HSPD1 protein, human; D018834:Chaperonin 60; D024101:Mitochondrial Proteins