A risk factor analysis for in-hospital mortality after surgery for infective endocarditis and a proposal of a new predictive scoring system

Purpose Risk stratification is of utmost importance for patients with infective endocarditis (IE) who need surgery. However, for these critically ill patients, aspecific scoring systems are used to predict the risk of death after surgery. The aim of this study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE and to create a mortality risk score based on the results of this analysis. Methods Outcomes of 138 consecutive patients (mean age 60.6 ± 8.5 years) who had undergone surgery for IE in an Italian cardiac surgery center between 1999 and 2015 were reviewed retrospectively and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver-operating characteristic (ROC) curve analysis. Results Twenty-eight (20.3%) patients died in hospital following surgery. Anemia [odds ratio (OR) 11.0, p = 0.035), New York Heart Association class IV (OR 2.61, p = 0.09), critical state (OR 4.97, p = 0.016), large intracardiac destruction (OR 6.45, p = 0.0014), and surgery of the thoracic aorta (OR 7.51, p = 0.041) were independent predictors of hospital death. A new scoring system was devised to predict in-hospital death after surgery for IE (area under ROC curve, 0.828, 95% confidence interval, 0.754–0.887). The score outperformed six of seven scoring systems, for early death after cardiac surgery, that were considered. Conclusions A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk after surgery for IE. Prospective studies are needed for the score validation.