A lower preoperative Hb (below 13.2 g/dL) was associated with increased in-hospital mortality and at 12 months and more likely to require inotropic drugs and suffer acute renal failure, cerebrovascular events, high-grade ventricular arrhythmias, and require RBC transfusion in the postoperative period. Here, GSTM1 is linked to Ventricular arrhythmia.