Is the European System for Cardiac Operative Risk Evaluation model valid for estimating the operative risk of patients considered for percutaneous aortic valve replacement?

Objective: The European System for Cardiac Operative Risk Evaluation has been used to define a particularly high-risk group of patients for aortic valve replacement in whom alternative procedures, such as stent-mounted percutaneous valve procedures, may be appropriate. Our objective was to assess the validity of this risk assessment at a large-volume, tertiary cardiac surgical center. Methods: From January 1, 2000, to December 30, 2006, a total of 1177 patients underwent isolated aortic valve replacement at the Mayo Clinic. Patient and operative demographics were recorded in a prospective database. Early mortality (<= 30 days) was obtained. Additive and logistic European System for Cardiac Operative Risk Evaluations were calculated for each patient. Results: The mean patient age was 68.0 years (+/- 14.7 years) at the time of surgery, and 36.8% were female. Variables used in the calculation of the European System for Cardiac Operative Risk Evaluation included chronic lung disease (15% of our cohort), extracardiac arteriopathy (13.8%), neurologic dysfunction (0.2%), previous cardiac surgery (23.2%), renal failure (6.5%), active endocarditis (3.1%), recent myocardial infarction (1.1%), unstable angina (0.1%), and severe pulmonary hypertension (6.5%). The ejection fraction was severely reduced (<= 30%) in 4.9% of patients and moderately reduced (<= 50%) in 12.7% of patients. One percent of patients were in a critical state, and operation was performed urgently in 3.4% of patients. Although mean mortality estimates were 6.9% +/- 3.4% (additive European System for Cardiac Operative Risk Evaluation) and 10.9% +/- 12.7% (logistic European System for Cardiac Operative Risk Evaluation), actual overall operative mortality in our patients was 2.5%. Additive and logistic European System for Cardiac Operative Risk Evaluations overestimated operative mortality in low, intermediate, and high-risk subgroups by up to 17.8%. Conclusions: The European System for Cardiac Operative Risk Evaluation should not be used to determine the operability of patients for isolated aortic valve replacement. Elevated European System for Cardiac Operative Risk Evaluations alone do not appropriately define a population for use of a percutaneous aortic valve.