Table 1.
Pre- and Postoperative characteristics in the analyzed cohort.
| n = 94 | No AKI | AKI | p-value | Missing data (n) | |
|---|---|---|---|---|---|
| Age (years)—median (IQR) | 74 (70–78) | 71 (66–75) | 0.12 | 0 | |
| Sex (female)—n (%) | 11 (11.7%) | 6 (6.38%) | 0.29 | 0 | |
| Ethnic (Caucasian)—n (%) | 49 (52.13%) | 43 (45.74%) | 0.23 | 0 | |
| BMI | 30.8 (27.6–33.4) | 30.8 (25.5–37.3) | 0.87 | 0 | |
| Sildenafil intervention | 25 (26.6%) | 20 (21.28%) | 0.54 | 0 | |
| Diabetes—n (%) | 14 (14.89%) | 22 (23.4%) | 0.06 | 0 | |
| Stroke/Transient Ischaemic Attack—n (%) | 0 (0%) | 1 (1.08%) | 0.48 | 1 | |
| Chronic obstructive pulmonary disease—n (%) | 4 (4.26%) | 3 (3.19%) | 1 | 0 | |
| Renal disease—n (%) | 7 (7.29%) | 0 (0%) | 1 | 0 | |
| Myocardial infarction—n (%) | 19 (19.79%) | 0 (0%) | 0.35 | 0 | |
| Pulmonary hypertension—n (%) | 12 (12.5%) | 0 (0%) | 0.59 | 0 | |
| Anemia n (%) | 21 (22.83%) | 24 (26.09%) | 0.4 | 2 | |
| Surgery type | CABG—n (%) | 18 (19.15%) | 17 (18.09%) | 0.87 | 0 |
| Valve—n (%) | 12 (12.77%) | 14 (14.89%) | |||
| CABG & Valve—n (%) | 15 (15.96%) | 11 (11.7%) | |||
| other—n (%) | 4 (4.26%) | 3 (3.19%) | |||
| NYHA | Class I—n (%) | 6 (6.67%) | 5 (5.56%) | 0.95 | 4 |
| Class II—n (%) | 33 (36.67%) | 29 (32.22%) | |||
| Class III, IV—n (%) | 8 (8.89%) | 9 (10%) | |||
| CCS | Asymptomatic—n (%) | 17 (18.89%) | 11 (12.22%) | 0.7 | 4 |
| Class I—n (%) | 13 (14.44%) | 14 (15.56%) | |||
| Class II—n (%) | 14 (15.56%) | 16 (17.78%) | |||
| Class III, IV—n (%) | 3 (3.33%) | 2 (2.22%) | |||
| Left Ventricular Ejection Fraction | Good(> 49%)—n (%) | 38 (40.86%) | 28 (30.11%) | 0.13 | 1 |
| Fair(30–49%)—n (%) | 9 (9.68%) | 13 (13.98%) | |||
| Poor(< 30%)—n (%) | 1 (1.08%) | 4 (4.3%) | |||
| Extent of coronary disease | Normal/ 1VD—n (%) | 21 (22.58%) | 23 (24.73%) | 0.46 | 1 |
| 2VD—n (%) | 5 (5.38%) | 7 (7.53%) | |||
| 3VD—n (%) | 22 (23.66%) | 15 (16.13%) | |||
| Pre-operative PaO2/FiO2 ratio—median (IQR) | 457.14 (409.5–533.3) | 457.14 (409.5–533.3) | 0.7 | 2 | |
| Pre-operative Serum Creatinine (umol/L)—median (IQR) | 83 (72–97) | 92 (79–111) | 0.07 | 0 | |
| Pre-operative eGFR—mean (STD) | 76 (63.5–88) | 69.6 (59–80) | 0.27 | 0 | |
| eGFR < 60—n (%) | 8 (8.51%) | 14 (14.89%) | 0.14 | 0 | |
| Pre-operative Serum Troponin (ng/mL)—median (IQR) | 10 (7.8–20.4) | 20 (10–36) | 0.01 | 14 | |
| Pre-operative Serum NT-proBNP (pg/mL)—median (IQR) | 6 (5.9–12.2) | 10 (10.1–25.9) | 0.31 | 4 | |
| Pre-operative MODS—median (IQR) | 0 (0–1) | 1 (0–1) | 0.05 | 5 | |
| Pre-operative Lactate—median (IQR) | 1 (0.8–1.5) | 1.35 (1–1.63) | 0.09 | 7 | |
| Pre-operative mean arterial pressure—median (IQR) | 95.5 (91–105.5) | 96.5 (88–104) | 0.68 | 0 | |
| Post-operative Lactate (at return to ICU)—median (IQR) | 1.9 (1.58–2.6) | 2.6 (2.02–3.58) | < 0.01 | 3 | |
| Post-operative acute lung injury—mean (SD) | 10 (10.64%) | 19 (20.21%) | 0.03 | 0 | |
| CBP time—median (IQR) | 102 (72–122) | 102 (86–134) | 0.22 | 0 | |
| Cross-clamp time—median (IQR) | 65 (46–80) | 63 (52–85) | 0.67 | 0 | |
ACE angiotensin-converting enzyme, AKI acute kidney injury, CABG coronary artery bypass grafting, CCS Canadian Cardiovascular Society, Hct Hematocrit, FiO2 fraction of inspired oxygen, KDIGO the kidney disease improving global outcomes, MODS multiple organ dysfunction score, NYHA New York Heart Association, PO2 partial pressure of oxygen, RBC red blood cells, VD vessel disease.
(*) Tests between groups were conducted by exact test for categorical variables and ANOVA or non-parametric Kruskal–Wallis test for continuous variables. Data are presented as n (%) for categorical variables and mean (standard deviation, STD) or median (interquartile range, IQR) for continuous variables.
Significant values are given in bold.