title: The -174G/C interleukin-6 polymorphism influences postoperative interleukin-6 levels and postoperative atrial fibrillation. Is atrial fibrillation an inflammatory complication?
abstract: BACKGROUND
  It has been suggested that inflammation can have a role in the development of atrial arrhythmias after cardiac surgery and that a genetic predisposition to develop postoperative complications exists. This study was conceived to verify if a potential genetic modulator of the systemic inflammatory reaction to cardiopulmonary bypass (the -174 G/C polymorphism of the promoter of the Interleukin-6 gene) has a role in the pathogenesis of postoperative atrial fibrillation (AF). Patients and Results- In 110 primary isolated coronary artery bypass patients the -174G/C Interleukin-6 promoter gene variant was determined. Interleukin-6, fibrinogen and C-reactive protein plasma levels were determined preoperatively, 24, 48, and 72 hours after surgery and at discharge. Heart rate and rhythm were continuously monitored for the first 36 to 48 hours; daily 12-lead electrocardiograms were performed thereafter until discharge. GG, CT, and CC genotypes were found in 62, 38, and 10 patients, respectively. Multivariate analysis (which included genotype, age, sex, and classical risk factors for AF) identified the GG genotype as the only independent predictor of postoperative AF. The latter occurred in 33.9% of GG versus 10.4% of non-GG patients (hazard ratio 3.25, 95%CI 1.23 to 8.62). AF patients had higher blood levels of Interleukin-6 and fibrinogen after surgery (P<0.001 for difference between the area under the curve).
  
  
  CONCLUSIONS
  The -174G/C Interleukin-6 promoter gene variant appears to modulate the inflammatory response to surgery and to influence the development of postoperative AF. These data suggest an inflammatory component of postoperative atrial arrhythmias and a genetic predisposition to this complication.
authors.affiliation: Department of Cardiac Surgery, Cardiac Anaesthesiology, and Cardiology, Catholic University, Rome, Italy. mgaudino@tiscalinet.it
authors.forename: Mario
authors.initials: M
authors.lastname: Gaudino
authors.forename: Felicita
authors.initials: F
authors.lastname: Andreotti
authors.forename: Roberto
authors.initials: R
authors.lastname: Zamparelli
authors.forename: Augusto
authors.initials: A
authors.lastname: Di Castelnuovo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nasso
authors.forename: Francesco
authors.initials: F
authors.lastname: Burzotta
authors.forename: Licia
authors.initials: L
authors.lastname: Iacoviello
authors.forename: Maria Benedetta
authors.initials: MB
authors.lastname: Donati
authors.forename: Rocco
authors.initials: R
authors.lastname: Schiavello
authors.forename: Attilio
authors.initials: A
authors.lastname: Maseri
authors.forename: Gianfederico
authors.initials: G
authors.lastname: Possati
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000235:genetics; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011184:Postoperative Period; D011401:Promoter Regions, Genetic
chemical_list: D015850:Interleukin-6