Obesity and coronary bypass.

To the Editor,

We have read with great interest the article entitled “Obesity is still a risk factor in coronary artery bypass surgery” published in Anatol J Cardiol 2014; 14: 631-7 (1). The authors aimed to document the effects of obesity on surgical outcomes in patients undergoing coronary artery bypass surgery. They concluded that obesity was still a risk factor for occurrence of adverse events in cardiac surgery and the mortality rates were similar in obese and non-obese patients. We congratulate the authors for these valuable results.

There are several reports regarding the effect of obesity on postoperative mortality and morbidity after cardiac operations. Some of them concluded that obesity is a risk factor for both mortality and morbidity, and some concluded that obesity is a risk factor only for morbidity (2). This result is partially supported again with this article. However, the design of the article does not confirm the hypothesis of the manuscript because there is a statistical difference between the parameters which affect the operative mortality and morbidity, such as female gender, smoking, diabetes mellitus, and hypertension; even the result of the article is compatible with the literature (Table 3). We expect equality between the parameters which affect the prognosis. We assume that obesity is a risk factor not only for morbidity but also for mortality after coronary bypass surgery and after many other operations. There is a need to more detailed studies about the clarification of this difference between obese patients.

Furthermore, postoperative atrial fibrillation is a common complication after cardiac surgery and predicts increased morbidity and mortality. There are many studies in the literature which propose that atrial fibrillation is a risk factor for obese patients compared with that for non-obese patients (3). We believe that mortality resulting from obesity disagree with the results of postoperative atrial fibrillation which is more often seen in BMI <30 group, as shown Table 5. There is a need for further studies on this issue.