The prognostic impact of the controlling nutritional status (CONUT) score in patients undergoing cardiovascular surgery

Background Various postoperative predictive markers following cardiovascular surgery have been examined for use in the current aging population. The controlling nutritional status (CONUT) score, which is advocated not only as a screening tool for poor nutritional status, but also as an immunonutritional assessment, has started to attract attention in several clinical settings, such as in cancer and heart failure patients. The aim of this study was to evaluate the value of the CONUT score as a postoperative prognostic marker in patients who underwent cardiovascular surgery. Methods A total of 75 patients who underwent elective cardiovascular surgery between January 2015 and October 2017 were retrospectively analyzed. The patients were divided into two groups according to their preoperative CONUT score (i.e., CONUT < 2 or CONUT >= 2), and their clinicopathological characteristics, surgical outcomes, and overall survival were compared. The median follow-up period was 23 months (range 0-43 months) after surgery. Results The high CONUT group (CONUT >= 2), which consisted of 30 (40.0%) patients, had a significantly worse prognosis than the low CONUT group with regard to overall survival (p = 0.0007). On multivariate analyses, the CONUT score was identified as the only independent prognostic factor for overall survival (hazard ratio 1.47 per 1 CONUT score increase, 95% confidence interval 1.05-2.06, p < 0.026). Conclusions The CONUT score is a reliable and independent preoperative predictor of overall survival after cardiovascular surgery.