Postoperative cognitive dysfunction markers in coronary artery surgery.

To the Editor,

We congratulate Özturk et al. (1) on their study entitled “Effect of the type of cardiopulmonary bypass pump flow on postoperative cognitive function in patients undergoing isolated coronary artery surgery” published for the Anatolian Journal of Cardiology 2016 May 9 as an Epub ahead of print. We believe that we can offer the authors some points that will contribute to their study in which they compared use of pulsatile and non-pulsatile pumps in terms of post-operative cognitive dysfunction (POCD). Firstly, although the study is prospective, not very many data about the patients were analyzed. Some factors that are predictors of POCD should have been compared between the 2 groups. For example, we see that the authors did not analyze hypertension, diabetes mellitus, duration of operation, period of anesthesia, preoperative low ejection fraction, low effort capacity, or preoperative European system for cardiac operative risk evaluation levels, which are described as predictor factors for POCD in several studies (2, 3). In order to compare the 2 groups, it should have been reported that there was no difference on the basis of these parameters. The authors, inspired by some previous studies, analyzed levels of S100β and neuron-specific enclose biomarkers, which they thought might be associated with POCD. However, one of the most-used biomarkers in the literature associated with POCD is serum cortisone level (4). We are of the opinion that if the authors provide us with their ideas on this subject and if they can share any available data for these parameters, it will surely add value to their study.