title: C-reactive protein elevation in patients with atrial arrhythmias: inflammatory mechanisms and persistence of atrial fibrillation.
abstract: BACKGROUND
  Atrial fibrillation (AF) may persist due to structural changes in the atria that are promoted by inflammation. C-reactive protein (CRP), a marker of systemic inflammation, predicts cardiovascular events and stroke, a common sequela of AF. We hypothesized that CRP is elevated in patients with atrial arrhythmias.
  
  
  RESULTS
  Using a case-control study design, CRP in 131 patients with atrial arrhythmias was compared with CRP in 71 control patients. Among arrhythmia patients, 6 had frequent atrial ectopy or tachycardia, 86 had paroxysmal AF, 39 had persistent AF lasting >30 days, and 70 had lone arrhythmias. CRP was higher in arrhythmia than in control patients (median, 0.21 versus 0.096 mg/dL; P<0.001). Arrhythmia patients in AF within 24 hours before sampling had higher CRP than those in sinus rhythm (0.30 versus 0.15 mg/dL; P<0.001). CRP in controls was not different than in patients with atrial ectopy or tachycardia. Lone arrhythmia patients had a CRP of 0.21 mg/dL, which was not significantly lower than arrhythmia patients with structural heart disease (CRP, 0.23 mg/dL) but higher than controls (P=0.002). Persistent AF patients had a higher CRP (0.34 mg/dL) than paroxysmal AF patients (0.18 mg/dL; P=0.008); both groups had higher CRP levels than controls (P</=0.005).
  
  
  CONCLUSIONS
  CRP is elevated in AF patients. This study is the first to document elevated CRP in non-postoperative arrhythmia patients. These findings are reinforced by stepwise CRP elevation with higher AF burden. Although the cause of elevated CRP levels in AF patients remains unknown, elevated CRP may reflect an inflammatory state that promotes the persistence of AF.
authors.affiliation: Department of Cardiovascular Medicine, the Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA. chungm@ccf.org
authors.forename: M K
authors.initials: MK
authors.lastname: Chung
authors.forename: D O
authors.initials: DO
authors.lastname: Martin
authors.forename: D
authors.initials: D
authors.lastname: Sprecher
authors.forename: O
authors.initials: O
authors.lastname: Wazni
authors.forename: A
authors.initials: A
authors.lastname: Kanderian
authors.forename: C A
authors.initials: CA
authors.lastname: Carnes
authors.forename: J A
authors.initials: JA
authors.lastname: Bauer
authors.forename: P J
authors.initials: PJ
authors.lastname: Tchou
authors.forename: M J
authors.initials: MJ
authors.lastname: Niebauer
authors.forename: A
authors.initials: A
authors.lastname: Natale
authors.forename: D R
authors.initials: DR
authors.lastname: Van Wagoner
mesh_terms: D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000378:metabolism*; D001281:Atrial Fibrillation / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006325:Heart Atria / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D008875:Middle Aged
chemical_list: D002097:C-Reactive Protein