title: Preoperative C-reactive protein and atrial fibrillation after off-pump coronary bypass surgery.
abstract: OBJECTIVE
  The purpose of the present study was to investigate the association between preoperative C-reactive protein (CRP) and atrial fibrillation (AF) after isolated off-pump coronary bypass surgery.
  
  
  METHODS
  Of 683 consecutive patients undergoing isolated coronary bypass surgery by a single surgeon between January 2002 and March 2009, 552 were retrospectively analyzed after excluding the following 131 cases: on-pump surgery (n = 6), chronic AF (n = 14), pacemaker rhythm (n = 7), and preoperative CRP of ≥ 10 mg l(-1) (n = 104). We analyzed the correlation on a continuous basis per 1 SD increase in the logarithmically transformed value of CRP and on a group basis CRP level categorized into three groups: <1.0 mg l(-1), n = 196; 1.0-3.0 mg l(-1), n = 220; and 3.0-10.0 mg l(-1), n = 136.
  
  
  RESULTS
  AF occurred in 121 patients (21.9%, 121/552) of patients after surgery. The median value (interquartile range) of preoperative CRP (mg l(-1)) was significantly higher in patients who developed AF than in those who did not (2.2 (1.0-4.2) vs 1.3 (0.6-2.5), p = 0.001). The rate of 7-day survival free from AF was 65.4% in patients with CRP of 3.0-10.0 mg l(-1), 79.9% in those with CRP of 1.0-3.0 mg l(-1), and 85.7% in those with CRP of <1.0 mg l(-1) (log-rank test: p = 0.001). The unadjusted hazard ratio (95% confidence interval) for the association between CRP and postoperative AF was 1.65 (1.32-2.06) per 1 SD increase and 3.17 (1.86-5.40) for patients with CRP of 3.0-10.0 mg l(-1) versus those with levels of <1.0 mg l(-1). This association persisted after adjustment for the univariate predictors (1.43 (1.22-1.97) per 1 SD increase; 2.88 (1.67-4.97) for patients with CRP of 3.0-10.0 mg l(-1) vs <1.0 mg l(-1)) or the known risk factors (1.34 (1.18-1.86) per 1 SD increase; 2.52 (1.54-4.36) for patients with CRP of 3.0-10.0 mg l(-1) vs <1.0 mg l(-1)). The area under the receiver operating characteristic curve (95% confidence interval) for preoperative CRP as a predictor of postoperative AF was 0.68 (0.62-0.74) (p = 0.001).
  
  
  CONCLUSIONS
  Preoperative CRP is independently associated with the occurrence of AF after isolated off-pump coronary bypass surgery.
authors.affiliation: Division of Cardiovascular Surgery, Shiga University of Medical Science, Otsu, Japan. kinotakekinotake@yahoo.co.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Tohru
authors.initials: T
authors.lastname: Asai
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Takashima
authors.forename: Soh
authors.initials: S
authors.lastname: Hosoba
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kambara
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsubayashi
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis* / Q000378:metabolism; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D003327:Coronary Disease / Q000097:blood* / Q000601:surgery; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein