Definition of Variables
The binary endpoints: middle-term mortality, first confirmed occurrence of all cause death and cardio-death in relation to LVEF were evaluated. Major cardiovascular disease included heart failure, angina, myocardial infarction, atrial fibrillation and revascularization. Postoperative respiratory failure was defined as prolonged ventilation for more than 72h resulting from respiratory causes, newly developed pulmonary edema, adult respiratory distress syndrome, re-intubation due to respiratory causes and tracheostomy.