IJCS | Volume 32, Nº6, November / December 2019

589 Table 3 - Intra- and postoperative variables of patients with (n = 72) and without (n = 72) postoperative atrial fibrillation With POAF (n = 72) Without POAF (n = 72) p-value Type of surgery, n(%) Coronary artery bypass grafting 36 (50.0) 35 (48.7) 1.000* Valvular surgery 32 (44.4) 32 (44.4) Both 4 (5.6) 5 (6.9) ECC, n (%) 68 (94.4) 65 (90.2) 0.346† Time of ECC, in hours, mean (SD) 1.4 (0.5) 1.5 (0.8) 0.726‡ Time of anesthesia, in hours, mean (SD) 7.2 (1.3) 7.3 (1.8) 0.640‡ Use of VAD in IPO, n (%) 71 (98.6) 72 (100.0) 1.000* Total length of stay, in days, mean (SD) 17.8 (13.3) 12.6 (12.4) 0.018‡ Death, n (%) 3 (4.1) 10 (13.8) 0.042† POAF: postoperative atrial fibrillation; SD: standard deviation; ECC: extracorporeal circulation; IPO: immediate postoperative period; VAD: vasoactive drug; (*) Fisher's exact test; (†)Pearson's chi-squared test; (‡) Student’s t-test. Chart 1 - Cut-off values for discrimination of patients with and without postoperative atrial fibrillation according to the CHADS 2 (A) and CHA 2 DS 2 -VASc (B) scores and left atrial size. LA size LA size With AF With AF With AF With AF With AF With AF Without AF Without AF Without AF Without AF Without AF Without AF Silva & Butcher Scores for prediction of AF after cardiac surgery Int J Cardiovasc Sci. 2019;32(6):585-593 Original Article Tables 5 and 6 show logistic regression models of the CHADS 2 and CHA 2 DS 2 VASc scores alone and in association with left atrial size. Chart 2 shows the ROC curve area for the scores alone or in association with LA size. Discussion The present study described the prediction capacity of the CHADS 2 and CHA 2 DS 2 VASc scores, alone or in association with LA size, to determine the onset of POAF