INTRODUCTION
Despite recent advance in technology and surgical techniques, the perioperative and in-hospital mortality and morbidity rates of patients undergoing cardiac surgery remain high1-3. There are many factors that can cause this increase in risk. Left ventricular dysfunction, preoperative anemia, chronic renal failure, coronary artery diameter and advanced age are the most common causes4-8. Currently, various risk estimation algorithms are used to evaluate the surgical risk of patients planned for cardiac surgery. The most commonly used of these are the Society of Thoracic Surgeons (STS) score and the Euroscore9,10. While both scores take into account many variables belonging to the patient, they ignore the clinical nutritional status of the patient. On the other hand, the patient’s clinical nutritional status is an indirect indicator of the patient’s resistance and reservoir. This relationship has been demonstrated especially in patients undergoing gastrointestinal system and malignancy surgery11,12. Several different methods, including Mini Nutritional Assessment, Malnutrition Universal Screening Tool, Subjective Global Assessment, and Short Nutritional Assessment Questionnaire have been developed for the nutritional status of patients who undergo malignancy surgery. The prognostic nutritional index (PNI) is one of them, and it’s the most widely used method. The PNI, which was first designed by Buzby et al.11 in 1980 and simplified by Onodera et al.13, was calculated based on the serum albumin concentration and lymphocyte count of peripheral blood. On the other hand, there are very limited studies in the literature regarding this evaluation in patients undergoing cardiac surgery14. Thus the aim of this study was to assess the value of PNI as a predictor of in hospital mortality and morbidity in patients undergoing cardiac surgery.