Fig. 1: Adjusted mortality over time (with 95% confidence intervals). For patients less than 80 years old, p for linear trend < 0.001; for those 80 years of age and older, p for linear trend < 0.001. The rates were adjusted for the following variables: centre, sex, urgency, presence of diabetes, preoperative renal failure, ejection fraction, hypertension, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, heart failure, previous myocardial infarcation, redo surgery, left main disease; age and year of surgery were excluded.