GSTM1 and chronic kidney disease: Higher proportions of male sex (41.2% vs 26.2%, P = .074), CKD stage ≥ 3 (41.2% vs 25.1%, P = .054), and low preoperative Hb < 12 g/dL (85.3% vs 70.7%, P = .077) with a borderline significance were noted in the non-survival group (Table 3).