Mortality risk prediction in infective endocarditis surgery: reliability analysis of specific scores

We assessed the prognostic utility of risk scores in surgery for infective endocarditis (IE) to evaluate their reliability in mortality risk prediction.

An observational retrospective study was developed to include all patients who underwent surgery for active IE from 2002 to 2016. Classical and endocarditis-specific risk scores were calculated.

A total of 180 patients were included in the study. The 30-day mortality rate was 26.82% [95% confidence interval (CI) 20.26-33.20%]. Classical risk scores were confirmed to have a suboptimal prognostic ability. Therefore, 4 IE-specific risk scores were calculated. Discrimination was evaluated using the area under the receiver operating characteristic curve. It was 0.76 (95% CI 0.68-0.82) for the Society of Thoracic Surgeons-IE (STS-IE) score; 0.68 (95% CI 0.58-0.76) for the De Feo-Cotrufo score; 0.73 (95% CI 0.66-0.79) for the PALSUSE score and 0.65 (95% CI 0.57-0.72) for the Costa score. The STS-IE score had higher discrimination when compared with the De Feo-Cotrufo score (P = 0.055) and the Costa score (P = 0.024); however, there was no significant difference when we compared the STS-IE score with the PALSUSE score (P = 0.58). Calibration was assessed using the Hosmer-Lemeshow test; an adequate calibration was confirmed in all 4 scores.

Specific risk scores had better prognostic performance than classical risk scores. The STS-IE score had the highest discrimination and was adequately calibrated. The PALSUSE score also showed optimal discrimination and calibration. The De Feo-Cotrufo score had a lower discrimination in our sample; however, the De Feo-Cotrufo score is recommended in the current guidelines. The Costa score had the lowest discrimination.