Comparison of contemporary risk scores for predicting outcomes after surgery for active infective endocarditis

Abstract

Decision making regarding surgery for acute bacterial endocarditis is complex given its heterogeneity and often fatal course. Few studies have investigated the utility of operative risk scores in this setting. Endocarditis-specific scores have recently been developed. We assessed the prognostic utility of contemporary risk scores for mortality and morbidity after endocarditis surgery. Additive and logistic EuroSCORE I, EuroSCORE II, additive Society of Thoracic Surgeon's (STS) Endocarditis Score and additive De Feo-Cotrufo Score were retrospectively calculated for patients undergoing surgery for endocarditis during 2005-2011. Pre-specified primary outcomes were operative mortality, composite morbidity and mortality during follow-up. A total of 146 patients were included with an operative mortality of 6.8% followed for 4.1±2.4years. Mean scores were additive EuroSCORE I: 8.0±2.5, logistic EuroSCORE I: 13.2±10.1%, EuroSCORE II: 9.1%±9.4%, STS Score: 32.2±13.5 and De Feo-Cotrufo Score: 14.6±9.2. Corresponding areas under curve (AUC) for operative mortality 0.653, 0.645, 0.656, 0.699 and 0.744; for composite morbidity were 0.623, 0.625, 0.720, 0.714 and 0.774; and long-term mortality 0.588, 0.579, 0.686, 0.735 and 0.751. The best tool for post-operative stroke was EuroSCORE II: AUC 0.837; for ventilation >24h and return to theatre the De Feo-Cotrufo Scores were: AUC 0.821 and 0.712. Pre-operative inotrope or intra-aortic balloon pump treatment, previous coronary bypass grafting and dialysis were independent predictors of operative and long-term mortality. In conclusion, risk models developed specifically from endocarditis surgeries and incorporating endocarditis variables have improved prognostic ability of outcomes, and can play an important role in the decision making towards surgery for endocarditis.