Table 2.
Characteristics of the Patients in the Derivation Cohort
| Entire Cohort (N=6081) | No AKI (N=3922) | AKI (N=2159) | P Value | |
|---|---|---|---|---|
| Preoperative | ||||
| Male | 3767 (61.9%) | 2254 (57.5%) | 1513 (70.1%) | <0.01 |
| Age, y | 58 (48, 65) | 57 (46, 65) | 60 (52, 67) | <0.01 |
| Kidney function | ||||
| Serum creatinine, μmol/L | 77 (65, 89) | 73 (63, 86) | 81 (70, 97) | <0.01 |
| eGFR, mL/min per 1.73 m2 | 88.7 (72.3, 101.9) | 92.0 (76.7, 104.6) | 81.7(65.5, 96.3) | <0.01 |
| >60 mL/min | 5373 (88.3%) | 3635 (92.7%) | 1738 (80.5%) | <0.01 |
| 30< eGFR ≤60 mL/min | 659 (10.8%) | 273 (6.9%) | 386 (17.9%) | <0.01 |
| ≤30 mL/min | 49 (0.9%) | 14 (0.4%) | 35 (1.6%) | <0.01 |
| Comorbidities | ||||
| Hypertension | 2012 (33.1%) | 1164 (29.7%) | 848 (39.3%) | <0.01 |
| DM | 763 (12.5%) | 471 (12.0%) | 292 (13.5%) | 0.09 |
| COPD | 43 (0.7%) | 2 (0.1%) | 41 (1.9%) | <0.01 |
| CVD | 83 (1.4%) | 15 (0.4%) | 68 (3.1%) | <0.01 |
| Kidney disease without RRT | 217 (3.6%) | 90 (2.3%) | 127 (5.9%) | <0.01 |
| Cardiac function | ||||
| NYHA classification >2 | 3428 (56.4%) | 2075 (52.9%) | 1353 (62.7%) | <0.01 |
| NYHA classification ≤2 | 2653 (43.6%) | 1847 (47.1%) | 806 (37.3%) | <0.01 |
| LVEF >50% | 5030 (82.7%) | 3412 (87.0%) | 1618 (74.9%) | <0.01 |
| 35< LVEF ≤50 | 968 (15.9%) | 482 (12.3%) | 486 (22.5%) | <0.01 |
| LVEF ≤35% | 83 (1.3%) | 28 (0.7%) | 55 (2.5%) | <0.01 |
| Previous cardiac surgery | 84 (1.4%) | 42 (1.2%) | 42 (1.9%) | 0.008 |
| CM exposure | 2464 (40.5%) | 1600 (40.8%) | 864 (40.0%) | 0.567 |
| Intraoperative | ||||
| Emergency | 11 (0.2%) | 8 (0.2%) | 3 (0.2%) | 0.06 |
| Procedure | ||||
| Valve | 3975 (65.4%) | 2642 (67.4%) | 1333 (61.7%) | <0.01 |
| CABG | 1527 (25.1%) | 1109 (28.3%) | 418 (19.4%) | <0.01 |
| OPCAB | 286 (4.7%) | 23 (0.6%) | 263 (12.2%) | <0.01 |
| Valve and CABG | 293 (4.8%) | 148 (3.8%) | 145 (6.7%) | <0.01 |
| CPB | 4083 (67.1%) | 2550 (65.0%) | 1533 (71.0%) | <0.01 |
| Erythrocyte transfusion, U | 1 (0, 2) | 1 (0, 2) | 1 (0, 2) | <0.01 |
| Postoperative | ||||
| LCOS | 158 (2.6%) | 19 (0.5%) | 139 (6.4%) | <0.01 |
| CVP, cm H2O | 9 (7, 11) | 8 (6, 11) | 10 (8, 12) | <0.01 |
| Prognosis | ||||
| 28‐day mortality | 170 (2.8%) | 31 (0.8%) | 139 (6.4%) | <0.01 |
AKI indicates acute kidney injury; CABG, coronary artery bypass grafting; CM, contrast media; COPD, chronic obstructive pulmonary disease; CPB, cardiopulmonary bypass; CVD, cerebral vascular disease; CVP, central venous pressure by ICU admittance; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate, as was calculated based on the CKD‐EPI formulas; LCOS, low cardiac output syndrome; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association; OPCAB, off‐pump coronary artery bypass.