title: Predictive value of aortic knob width for postoperative atrial fibrillation in coronary artery bypass surgery.
abstract: OBJECTIVE
  The aim of our study was determine whether aortic knob width (AKW) is associated with the development of atrial fibrillation (AF) after isolated coronary artery bypass surgery (CABG).
  
  
  METHODS
  In this retrospective observational cohort study, we evaluated 135 patients without hemodynamically significant valvular problems. AKW was measured on chest X-ray by digital system. Multiple logistic regression analysis was used to find independent associates of postoperative AF (POAF). The diagnostic value of AKW was assessed using ROC analysis.
  
  
  RESULTS
  POAF occurred in 43 (31.8%) of all patients. The age, AKW, left atrial (LA) diameter and C-reactive protein (CRP) were significantly higher in patients with POAF than without POAF (67.2 ± 8.6 vs 61.3 ± 9.8 years, p=0.004; 45.6 ± 5.8 vs 36.1 ± 3.8 mm, p<0.001; 37.9 ± 3.5 vs 35.8 ± 3.1mm, p=0.002 and 10.6 ± 8.5 vs 5.6 ± 6.5 mg/L, p=0.001 respectively). Multiple logistic regression analysis demonstrated that AKW, LA diameter and CRP were independently associated with POAF (OR=4.527, 95% CI=1.315 -15.588, p=0.017; OR=2.834, 95% CI=1.091-7.360, p=0.032 and OR=1.300, 95% CI=1.038-1.628, p=0.022 respectively). ROC analysis has demonstrated that aortic knob of 36.5 mm constitutes the cut-off value for the occurrence of POAF with 84.4% sensitivity and 64.6% specificity (AUC=0.84, 95% CI=0.75-0.94, p<0.001).
  
  
  CONCLUSIONS
  We have demonstrated a significant association between the AKW and AF development after isolated CABG. PA chest radiography is a cheap and readily available clinical tool and it can be examined easily by every cardiovascular surgeons.
authors.affiliation: Departments of Cardiovascular Surgery Faculty of Medicine, Abant İzzet Baysal University; Bolu-Turkey. drkemalettincvs@yahoo.com.
authors.forename: Kemalettin
authors.initials: K
authors.lastname: Erdem
authors.forename: Serkan
authors.initials: S
authors.lastname: Oztürk
authors.forename: Selim
authors.initials: S
authors.lastname: Ayhan
authors.forename: Onursal
authors.initials: O
authors.lastname: Buğra
authors.forename: Orhan
authors.initials: O
authors.lastname: Bozoğlan
authors.forename: Ümit Yaşar
authors.initials: ÜY
authors.lastname: Tekelioğlu
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yazıcı
authors.forename: Bahadır
authors.initials: B
authors.lastname: Dağlar
mesh_terms: D001011:Aorta / Q000473:pathology*; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D006801:Humans; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D012372:ROC Curve; D013902:Radiography, Thoracic; D012189:Retrospective Studies