The ACEF II Risk Score for cardiac surgery: updated but still parsimonious

Area of Science:

• Cardiovascular Surgery
• Medical Risk Stratification
• Health Outcomes Research

Background:

• The Age, Creatinine, and Ejection Fraction (ACEF) score is a recognized tool for risk stratification in myocardial revascularization.
• Current guidelines incorporate the ACEF score for evaluating surgical and percutaneous revascularization procedures.
• There is a need for enhanced risk models that account for emergency procedures and pre-operative conditions like anemia.

Purpose of the Study:

• To introduce and validate an updated version of the ACEF score, termed ACEF II.
• To improve the accuracy of risk stratification for cardiac surgery patients.
• To incorporate emergency surgery and pre-operative anemia into the risk assessment model.

Main Methods:

• Development and validation of the ACEF II score using two independent cohorts of cardiac surgery patients (7011 and 1687 patients).
• Multivariable logistic regression was employed to identify independent predictors of operative mortality.
• The ACEF II score calculation incorporates age, ejection fraction, serum creatinine, emergency surgery status, and hematocrit levels.

Main Results:

• The ACEF II score demonstrated significantly better discrimination (c-statistic 0.814) compared to the original ACEF score (c-statistic 0.773).
• ACEF II showed comparable discrimination to the EuroSCORE II and maintained good calibration in external validation.
• The updated score effectively incorporates emergency surgery and anemia, enhancing its applicability.

Conclusions:

• The ACEF II score provides a more adequate and accurate risk stratification for the contemporary cardiac surgery landscape.
• Inclusion of emergency status and anemia improves the model's relevance and predictive power.
• ACEF II is a valuable tool for assessing operative mortality risk in diverse cardiac surgery patient populations.