Predicting 30-day mortality of aortic valve replacement by the AVR score

Objectives The objective of this study is to develop a simple risk score to predict 30-day mortality of aortic valve replacement (AVR). Methods In a development set of 673 consecutive patients who underwent AVR between 1990 and 1993, four independent predictors for 30-day mortality were identified: body mass index (BMI) ≥30, BMI <20, previous coronary artery bypass grafting (CABG) and recent myocardial infarction. Based on these predictors, a 30-day mortality risk score-the AVR score-was developed. TheAVR score was validated on a validation set of 673 consecutive patients who underwent AVR almost two decennia later in the same hospital. Results Thirty-day mortality in the development set was ≤2% in the absence of any predictor (class I, low risk), 2-5% in the solitary presence of BMI ≥30 (class II, mild risk), 5-15% in the solitary presence of previous CABG or recent myocardial infarction (class III, moderate risk), and >15% in the solitary presence of BMI <20, or any combination of BMI ≥30, previous CABG or recent myocardial infarction (class IV, high risk). The AVR score correctly predicted 30-day mortality in the validation set: observed 30-day mortality in the validation set was 2.3% in 487 class I patients, 4.4% in 137 class II patients, 13.3%in 30 class III patients and 15.8%in 19 class IV patients. Conclusions The AVR score is a simple risk score validated to predict 30-day mortality of AVR.