Table 1:
Baseline Demographics, Primary Cohort
| Variable | ALL | No primary outcome |
Developed primary outcome |
P- value |
|
|---|---|---|---|---|---|
| (N=613) | (N=441) | (N=172) | |||
| Age at the time of surgery | 70.97 ± 8.84 | 70.68 ± 9.14 | 71.70 ± 8.01 | 0.20 | |
| Sex (female, %) | 168 (27.4%) | 113 (25.6%) | 55 (32.0%) | 0.11 | |
| Race (white, %) | 589 (96.1%) | 427 (96.8%) | 162 (94.2%) | 0.13 | |
| Diabetes | 256 (41.8%) | 173 (39.2%) | 83 (48.3%) | 0.03 | |
| Hypertension | 484 (79.0%) | 345 (78.2%) | 139 (80.8%) | 0.20 | |
| Congestive Heart Failure | 62 (10.1%) | 40 (9.1%) | 22 (12.8%) | 0.11 | |
| Left ventricular ejection fraction <40% | 48 (7.8%) | 29 (6.6%) | 19 (11.0%) | 0.048 | |
| Previous myocardial infarction | 173 (28.2%) | 123 (27.9%) | 50 (29.1%) | 0.26 | |
| eGFR, mL/min per 1.73m2 | 71.00 ± 18.23 | 70.79 ± 19.32 | 71.55 ± 15.12 | 0.64 | |
| eGFR, mL/min per 1.73m2 | >60 | 447 (72.9%) | 301 (68.3%) | 146 (84.9%) | <0.001 |
| <60 | 165 (26.9%) | 140 (31.7%) | 25 (14.4%) | ||
| Serum creatinine, mg/dL | 1.03 ± 0.31 | 1.04 ± 0.31 | 1.01 ± 0.32 | 0.25 | |
| Urine Microalbumin, pre-operative (>30 mg/g) | 365 (59.5%) | 248 (56.2%) | 117 (68.0%) | 0.027 | |
| STS Score32 | 9.08 ± 3.49 | 8.99 ± 3.52 | 9.33 ± 3.40 | 0.27 | |
| Elective surgery | 561 (91.5%) | 404 (91.6%) | 157 (91.3%) | 0.28 | |
| Isolated CABG or valve surgery | 480 (78.3%) | 347 (78.7%) | 133 (77.3%) | 0.75 | |
| Off-pump | 69 (11.3%) | 53 (12.0%) | 16 (9.3%) | 0.20 | |
| Reoperation | 6 (1.0%) | .. | .. | .. | |
| Perfusion time, min | 107.12 ± 57.93 | 106.93 ± 57.57 | 107.63 ± 59.02 | 0.89 | |
| Crossclamp time, min | 71.59 ± 43.86 | 71.89 ± 43.48 | 70.80 ± 44.97 | 0.78 | |
| AKIN Stage | 0 | 403 (65.7%) | 307 (69.6%) | 96 (55.8%) | 0.001 |
| 1 | 186 (30.3%) | 122 (27.7%) | 64 (37.2%) | ||
| 2 or 3 | 24 (3.9%) | 12 (2.7%) | 12 (7.0%) | ||
| AKI Duration (days) | 1 to 2 | 143 (23.3%) | 94 (21.3%) | 49 (28.5%) | 0.015 |
| 3 to 6 | 50 (8.2%) | 31 (7.0%) | 19 (11.0%) | ||
| >6 | 16 (2.6%) | 9 (2.0%) | 7 (4.1%) | ||
| Last serum Creatinine before discharge | 1.03 ± 0.45 | 1.01 ± 0.31 | 1.07 ± 0.67 | 0.15 | |
Mean (SD) and frequency (%) are presented for the continuous and categorical variables, respectively Ellipses (..) indicate small cell counts that cannot be presented due to privacy concerns
The primary outcome was a composite of CKD incidence or progression:
- CKD incidence (pre-operative eGFR ≥60): 25% reduction in eGFR and a fall below 60 mL/min/1.73m2
- CKD progression (pre-operative eGFR <60):50% reduction in eGFR or a fall below 15 mL/min/1.73m2
Abbreviations: eGFR: estimated glomerular filtration rate. STS: Society of Thoracic Surgeons. CABG: coronary artery bypass graft. AKI: acute kidney injury. AKIN: acute kidney injury network