According to the univariate regression analysis, age > 65 years, female gender, cor pulmonale complication, CKD stage, CCI score without renal disease, Hb level (according to the minimum values during hospital stay, < 6 g/dL, 6–8.9 g/dL, 9–11.9 g/dL and ≥ 12 g/dL) and AKI type were associated with in-hospital mortality (Table 4). This evidence concerns the gene GSTM1 and chronic kidney disease.