IJCS | Volume 32, Nº6, November / December 2019

595 1. Hernández-Leiva E, Alvarado P, Dennis RJ. Postoperative atrial fibrillation: evaluation of its economic impact on the costs of cardiac surgery. Braz J Cardiovasc Surg. 2019;34(2):179-86. 2. Dobrev D, Aguilar M, Heijman J, Guichard JB, Nattel S. Postoperative atrial fibrillation: mechanisms, manifestations and management. Nat Rev Cardiol. 2019;16(7):417-36. 3. Yadava M, Hughey AB, Crawford TC Postoperative atrial fibrillation: incidence, mechanisms, and clinical correlates. Cardiol Clin. 2014;32(4):627-36. Review. 4. Lee Sh, Kang DR, Uhm JS, Shim J, Sunq JH, Kim Jy, et al. New-onset atrial fibrillation predicts long-term newly developed atrial fibrillation after coronary artery bypass graft.Am Heart J. 2014;167(4):593-600. 5. Phan K, Ha HS, Phan S, Medi C, Thomas SP, Yan TD. New-onset atrial fibrillation following coronary bypass surgery predicts long-term mortality: a systematic review and meta-analysis. Eur J Cardiothorac Surg. 2015;48(6):817-24. Review. 6. Sareh S, ToppenW, Mukdad L, SatonN, Shemin R, Buch E, et al. CHADS 2 score predicts atrial fibrillation following cardiac surgery. J Surg Res. 2014;190(2):407-12. 7. Burgos L, Seoane L, Parodi J, Espinoza J, Brito V, Benzadón M, et al. Postoperative atrial fibrillation is associated higher with scores on predictive indices. J Thorac Cardiovasc Surg. 2019;157(6):2279-86. 8. Silva NA, Gengo RC, Butcher S. Left atrial size contribution to predictive capacity of two scores for atrial fibrillation in the postoperative period of cardiac surgeries. Int J Cardiovasc Sci. 2019 [online].ahead of print. PP.0-0. 9. Yamashita K, HuN, Ranjan R, Selzman C, Dosdall D. Clinical risk factors for postoperative atrial fibrillation among patients after cardiac surgery. Thorac Cardiovas Surg 2019;67(2):107-16. References Camanho & Santos Postoperative atrial fibrillation: risk prediction Int J Cardiovasc Sci. 2019;32(6):594-595 Editorial cohort study on 144 patients and tried to identify the cut-off values of the CHADS 2 and CHA 2 DS 2 VASc scores and LA size to calculate sensitivity, specificity, predictive value positive (PVP), and predictive value negative (PVN), in addition to regression models. In this population, half developed POAF. In the POAF group, patients were older, had reduced left ventricular ejection fraction and longer hospital length of stay. However, the CHADS 2 and CHA 2 DS 2 VASc score alone or in combination with LA size did not show good predictive capacity for POAF. The results of the study by Silva et al., 8 are in agreement with the findings observed in a recent meta-analysis 9 including 36,834 patients. The authors concluded that older age and history of heart failure were significant risk factors for POAF consistently, regardless of the design of the study included, i.e., whether prospective or retrospective. It is worth mentioning that the study has several limitations, since it is a retrospective, single-center study, with a relatively small sample and based on data analysis. However, left atrial size is an important marker of AF and a potential predictor of POAF and needs to be evaluated in future studies. This is an open-access article distributed under the terms of the Creative Commons Attribution License