Preoperative blood urea nitrogen-to-left ventricular ejection fraction ratio is an independent predictor of long-term major adverse cardiac events in patients undergoing coronary artery bypass grafting surgery

Abstract

Background: Long-term mortality rate following coronary artery bypass grafting (CABG) procedure is still considered to be high despite advances in surgical techniques and perioperative management. Identifying high-risk patients by using cost-effective and clinically useful parameters is needed. Methods: Patients who were admitted to our cardiology clinic with the diagnosis of coronary artery disease and underwent CABG between January 2008 and August 2010 were included. Study patients were followed-up for 112.6 +/- 17.8 months for major adverse cardiac events (MACE) which were defined as all-cause mortality and new-onset decompensated heart failure (HF). Results: Patients in MACE (+) group were older (p < 0.001), had higher additive Euroscore (p < 0.001), and lower left ventricular ejection fraction (p < 0.001). Multivariate Cox regression analysis showed that additive Euroscore [odds ratio (OR) = 1.601; 95% confidence interval (CI) = 1.374-1.864; p < 0.001)] and blood urea nitrogen-to-left ventricular ejection fraction ratio (BUNEFr; OR = 1.028; 95% CI = 1.006-1.050; p = 0.011) independently predicted MACE. Receiver operating characteristic curve analysis demonstrated that BUNEFr had an area under curve of 0.794 and BUNEFr >33 had a sensitivity and specificity of 74% and 64%, respectively. Conclusion: BUNEFr is a clinically useful and cost-effective parameter for the prediction of long-term mortality and new-onset decompensated HF in patients undergoing CABG.