| Variable | 
        Overall study
            population
          (n=2,791) | 
        (+) POAF
           
           
          (n =    901) | 
        (-) POAF
           
            
          (n =    1,890) | 
        P value | 
      
      
        Aortic cross clamp time  
          (minutes) | 
        63.8  ± 33.5 | 
        66.2 ± 34.3 | 
        62.8 ± 33 | 
        0.0124 | 
      
      
        | Cardiopulmonary bypass (CPB) time    (minutes) | 
        102  ± 49.4 | 
        104.4 ± 45.5 | 
        101 ± 51.2 | 
        0.015 | 
      
      
        Venous    grafts
            Number of vein grafts  
            (mean ± SD) | 
        2372 (85%)
          1.76 ± 0.78 | 
        772 (85.7%)
          1.79 ± 0.77 | 
        1600 (84.7%)
          1.74 ± 0.79 | 
        0.53
          0.13 | 
      
      
        Right    Internal  
          Mammary artery graft | 
        130 (4.7%) | 
        28 (3.1%) | 
        102 (5.4%) | 
        0.009 | 
      
      
        Left Internal Mammary  
          Artery    graft | 
        2461 (88.2%) | 
        778 (86.3%) | 
        1683 (89%) | 
        0.045 | 
      
      
        | Number of arterial    grafts (mean ± SD) | 
        1.12 ± 0.4 | 
        1.07 ± 0.34 | 
        1.14 ± 0.43 | 
        <0.0001 | 
      
      
        | Intraoperative    IABP | 
        54 (1.9%) | 
        18 (2%) | 
        36 (1.9%) | 
        0.97 |