Validation of age, creatinine and ejection fraction (ACEF) and Cockcroft-Gault ACEF scores in elective cardiac surgery.

The objective of this study was to evaluate the efficacy of age, creatinine and ejection fraction (ACEF) score and the modified ACEFCG model, incorporating creatinine clearance, to predict immediate operative mortality risk of patients undergoing elective cardiac surgery. A retrospective analysis was performed of prospectively collected data between 2012 and 2015, from a series of 1190 adult patients who underwent elective cardiac surgery. Operative risk mortality was assessed with ACEF, ACEFCG and EuroSCORE II. Overall mortality rate was 4.0% (48 cases), while mean mortality rates predicted by ACEF, ACEFCG, and EuroSCORE II were 2.3% (p = 0.014), 6.4% (p = 0.010) and 2.5% (p = 0.038), respectively. Overall observed/predicted mortality ratio was 1.8 for ACEF score, 0.6 for ACEFCG score and 1.6 for EuroSCORE II. The ACEF score demonstrated an adequate overall performance for the low- and intermediate-risk groups, but underestimated mortality for the high risk group. The ACEFCG score discriminatory power systematically improved the area under the ROC curve (AUC) obtained with the ACEF score; however, EuroSCORE II showed the best AUC. Overall accuracy was 56.1% for the ACEF score, 51.2% for the ACEFCG score and 75.9% for EuroSCORE II. For clinical use, the ACEF score seems to be adequate to predict mortality in low- and intermediate-risk patients. Though the ACEFCG score had a better discriminatory power and calibration, it tended to overestimate the expected risk. Since ideally, a simpler risk stratification score should be desirable for bedside clinical use, the ACEF model reasonably met the expected performance in our population.