title: The relevance of the association between inflammation and atrial fibrillation.
abstract: BACKGROUND
  The relevance of the association between inflammation and atrial fibrillation (AF) is not firmly established. The clinical importance is considerable because inflammation is usually not targeted as a treatment option, minimizing a probable benefit.
  
  
  METHODS
  We have used a case-control study with a Mendelian randomization rationale to assess whether proposed risk factors that have a genetic component and are readily detected in circulating blood are causally related to AF. The studied variables were C-reactive protein (CRP) and a representative of the chemokine system, the monocyte chemoattractant protein-1 (CCL2).
  
  
  RESULTS
  Plasma CRP and CCL2 concentrations were significantly higher in AF patients than in the unaffected population. However, when segregated between paroxysmal and permanent, the difference for CRP was only observed in patients with a permanent condition. Plasma CCL2 was raised in both subgroups. Confounding factors were carefully considered, and multivariable analyses revealed that circulating CCL2 was significant and CRP was negligible to explain the presence of AF. The duration of the episode also bore a significant predictive value. Odd ratios for AF as a function of genotype did not differ from 1·0 for any of the individual CRP and CCL2 polymorphisms, or any combinations.
  
  
  CONCLUSIONS
  Elevated plasma CRP concentration per se does not increase atrial fibrillation risk. Values obtained for CCL2 suggest that inflammation is probably a consequence of AF. Our data also suggest that the effect of the duration of the episode should be further studied in the assessment of the actual role of inflammation.
authors: Secció de Cardiologia, Hospital Universitari de Sant Joan, IISPV, Universitat Rovira i Virgili, Reus, Spain. jmalegret@grupsagessa.cat
authors: Josep M
authors: JM
authors: Alegret
authors: Gerard
authors: G
authors: Aragonès
authors: Roberto
authors: R
authors: Elosua
authors: Raúl
authors: R
authors: Beltrán-Debón
authors: Anna
authors: A
authors: Hernández-Aguilera
authors: César
authors: C
authors: Romero-Menor
authors: Jordi
authors: J
authors: Camps
authors: Jorge
authors: J
authors: Joven
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000097:blood* / Q000235:genetics; D002097:C-Reactive Protein / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D018932:Chemokine CCL2 / Q000097:blood* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012044:Regression Analysis; D012307:Risk Factors
chemical_list: D018932:Chemokine CCL2; D002097:C-Reactive Protein