Effects of cardiopulmonary bypass on new-onset atrial fibrillation.

To the Editor,

We read the article titled “SYNTAX score predicts postoperative atrial fibrillation in patients undergoing on-pump isolated coronary artery bypass grafting surgery” that is published in Anatolian J Cardiol October 18. Epub ahead of print (1), in which the authors described the effects of SYNTAX score on postoperative atrial fibrillation, with great interest. In this study, the groups are well balanced and standardized in many aspects, but there is no data revealing the duration of the on-pump procedures, which is very important and forms a basic variable in coronary artery bypass grafting. On the other hand, one should underline the two major causes of atrial fibrillation as cardiopulmonary bypass and oxidative stress/inflammatory response triggered by cross clamping (2–4). Many cellular and non-cellular elements are activated during cardiopulmonary bypass, particularly the triggering pro-inflammatory mechanisms (5). Thus, we strongly believe that the groups in this study should have been standardized considering the cardiopulmonary bypass and cross-clamp times if the SYNTAX score is a predictor of postoperative atrial fibrillation. We would deeply appreciate if the authors share their opinion or any data related to the matter.