Age, creatinine and ejection fraction (ACEF) score: a simple risk-stratified method for infective endocarditis

Background: Older age, renal dysfunction and low left ventricular ejection fraction are accepted predictors of poor outcome in patients with infective endocarditis (IE). This study aimed to investigate the prognostic significance of the age, creatinine and ejection fraction (ACEF) score in IE. Methods: The study involved 1019 IE patients, who were classified into three groups according to the tertiles of ACEF score: low ACEF (<0.6, n = 379), medium ACEF (0.6-0.8, n = 259) and high ACEF (>0.8, n = 381). The ACEF score was calculated as follows: age (years)/ejection fraction (%)+1 (if serum creatinine value was >2 mg/dL). The relationship between ACEF score and adverse events was analyzed. Results: In-hospital mortality was 8.2%, which increased with the increase of ACEF score (4.2% vs. 5.0% vs. 14.4% for the low-, medium- and high-ACEF groups, respectively; P < 0.001). ACEF score had a good discriminative ability for predicting in-hospital death [areas under the curve (AUC), 0.706, P < 0.001]. The predictive value of ACEF score in surgical treatment was significantly higher than in conservative treatment for predicting in-hospital death (AUC, 0.812 vs. 0.625; P = 0.001). Multivariable analysis revealed that ACEF score was independently associated with in-hospital mortality (adjusted odds ratio, 2.82; P < 0.001) and long-term mortality (adjusted hazard ratio, 2.51; P < 0.001). Conclusion: ACEF was an independent predictor for in-hospital and long-term mortality in IE patients, and it could be considered as a useful tool for risk stratification. ACEF score was more suitable for surgical patients in terms of assessing the risk of in-hospital mortality.