The aim of GLUTAMICS II is to evaluate whether intravenous glutamate infusion surgery reduces the risk of postoperative heart failure as measured by plasma NT-proBNP in patients undergoing moderate to high-risk coronary artery bypass graft surgery. Patients accepted for coronary artery bypass surgery of at least two vessel disease or left main stenosis with or without concomitant procedure and considered to be at moderate to high surgical risk preoperatively with regard to postoperative heart failure will be studied. The primary endpoint is postoperative increase of NT-proBNP from the day before surgery to the third postoperative day.