Table 1.
Baseline characteristics of training and validation groups.
| Variables | Training group (n = 15,701) | Validation group (n = 6647) |
|---|---|---|
| Age, years | 47.0 ± 14.2 | 47.0 ± 14.2 |
| Male | 7711 (49.1%) | 3239 (48.7%) |
| LVEF, % | 62.9 ± 9.4 | 62.8 ± 9.4 |
| LVEF | ||
| LVEF > 60% | 11426 (72.8%) | 4813 (72.4%) |
| 40% < LVEF ≤ 60% | 3851 (24.5%) | 1649 (24.8%) |
| LVEF ≤ 40% | 424 (2.7%) | 185 (2.8%) |
| Baseline serum creatinine, µmol/l | 75.5 ± 17.3 | 75.5 ± 17.2 |
| eGFR, ml/min/1.73m2 | 94.2 ± 19.3 | 94.1 ± 19.0 |
| Comorbidities | ||
| Hypertension | 3184 (20.3%) | 1319 (19.8%) |
| Diabetes mellitus | 791 (5.0%) | 309 (4.6%) |
| Coronary heart disease | 1504 (9.6%) | 644 (9.7%) |
| COPD | 227 (1.4%) | 83 (1.2%) |
| Infectious endocarditis | 848 (5.4%) | 376 (5.7%) |
| Cerebrovascular disease | 686 (4.4%) | 305 (4.6%) |
| Peripheral vascular disease | 65 (0.4%) | 30 (0.5%) |
| Atrial fibrillation | 4073 (25.9%) | 1749 (26.3%) |
| PCI history | 159 (1.0%) | 69 (1.0%) |
| Previous cardiac surgery | 454 (2.9%) | 188 (2.8%) |
| History of transfusion | 35 (0.2%) | 16 (0.2%) |
| Recent contrast media exposure | 3543 (22.6%) | 1529 (23.0%) |
| Preoperative drugs use | ||
| Renin-angiotensin system inhibitors | 5261 (33.5%) | 2219 (33.4%) |
| NSAID | 2202 (14.0%) | 903 (13.6%) |
| Aminoglycoside antibiotics | 911 (5.8%) | 364 (5.5%) |
| Stain | 1945 (12.4%) | 810 (12.2%) |
| Proton pump inhibitors | 6458 (41.1%) | 2745 (41.3%) |
| Erythrocyte transfusion, U | 0.0 (0.0, 0.0) | 0.0 (0.0, 0.0) |
| Procedure | ||
| CABG | 729 (4.6%) | 312 (4.7%) |
| Valve | 9790 (62.4%) | 4166 (62.7%) |
| Aortic | 1111 (7.1%) | 486 (7.3%) |
| CHD | 3391 (21.6%) | 1393 (21.0%) |
| CABG + valve | 456 (2.9%) | 183 (2.8%) |
| Others | 224 (1.4%) | 107 (1.6%) |
| Laboratory Findings | ||
| Hemoglobin, g/l | 134.1 ± 19.1 | 134.2 ± 19.2 |
| Platelet (×109/l) | 205.1 ± 65.2 | 205.6 ± 65.1 |
| Blood leucocytes (×109/l) | 7.2 ± 2.6 | 7.2 ± 2.7 |
| Natremia, mmol/l | 139.0 ± 2.7 | 138.9 ± 2.7 |
| Potassium, mmol/l | 3.8 ± 0.4 | 3.8 ± 0.4 |
| Magnesemia, mmol/l | 0.9 ± 0.1 | 0.9 ± 0.1 |
| Hypomagnesemia | 3395 (21.6%) | 1399 (21.0%) |
| Alanine aminotransferase, U/l | 26.1 ± 28.9 | 27.8 ± 47.3 |
| Uric acid, μmol/l | 390.8 ± 113.4 | 390.2 ± 115.9 |
| Albumin, g/l | 37.9 ± 4.9 | 37.8 ± 4.9 |
| International Normalized Ratio | 1.2 ± 0.5 | 1.2 ± 0.4 |
| Low density lipoprotein, mmol/l | 3.0 ± 0.9 | 3.0 ± 1.0 |
| Total bilirubin, μmol/l | 19.1 ± 10.8 | 19.2 ± 10.8 |
CABG: coronary artery bypass grafting; CHD: congenital heart disease; COPD: chronic obstructive pulmonary disease; eGFR: estimated glomerular filtration rate; LVEF: left ventricular ejection fraction; NSAID: non-steroidal anti-inflammatory drugs; PCI: percutaneous coronary intervention.