Table 1 Perioperative characteristics and plasma RIP3 levels of patients (n = 80)
|  | No AKI (n = 27) | AKI stage 1 (n = 29) | AKI stage 2–3 (n = 24) | F or H or χ2 Value | P value |
|---|---|---|---|---|---|
Male sex | 20 (74.1) | 22 (75.9) | 16 (66.7) | 0.944 | 0.624 |
Age (years) | 52.2 ± 13.0 | 54.3 ± 9.6 | 56.4 ± 12.7 | 0.733 | 0.484 |
Body mass index (kg/m2) | 24.8 ± 3.9 | 25.9 ± 4.0 | 24.4 ± 4.0 | 2.000 | 0.377 |
Past medical history | |||||
 Hypertension | 16 (59.3) | 21 (72.4) | 13 (54.1) | 3.315 | 0.191 |
 Cardiovascular surgery | 3 (11.1) | 0 (0) | 2 (8.3) | 3.304 | 0.187 |
 Marfan syndrome | 2 (7.4) | 0 (0) | 1 (4.2) | 2.075 | 0.408 |
Preoperative items | |||||
 Left ventricular ejection fraction (%) | 64.7 ± 5.2 | 67.2 ± 4.2 | 60.8 ± 9.4 | 7.034 | 0.039 |
 Pericardial tamponade | 2 (7.4) | 3 (10.3) | 4 (16.7) | 1.142 | 0.613 |
 Hypotension (MAP < 75 mmHg) | 4 (14.8) | 5 (17.2) | 6 (25.0) | 1.117 | 0.591 |
  MAP: 60–75 mmHg | 3 (11.1) | 4 (13.8) | 2 (8.3) | 0.402 | 0.908 |
  MAP ≤ 50 mmHg | 1 (3.7) | 1 (3.4) | 4 (16.7) | 3.591 | 0.175 |
  Duration of hypotension (hours) | 4.8 ± 2.1 | 2.8 ± 0.8 | 6.8 ± 3.4 | 3.499 | 0.063 |
Serum creatinine (umol/L) | 85.5 (60.4–137.2) | 79.5 (68.2–114.2) | 68.7 (57.2–114.0) | 1.825 | 0.401 |
Serum creatinine > 135umol/L | 7 (25.9) | 3 (10.3) | 4 (16.7) | 2.446 | 0.341 |
Procalcitonin (ng/ml) | 0.10 (0.06–0.35) | 0.05 (0.03–0.15) | 0.12 (0.04–0.27) | 4.081 | 0.130 |
Interleukin-6 (pg/ml) | 54.9 (39.3–110.3) | 38.3 (31.2–49.3) | 55.4 (39.1–89.9) | 6.883 | 0.032 |
C-reactiveprotein (mg/L) | 6.8 (2.9–59.3) | 3.4 (2.2–9.0) | 10.3 (4.6–23.2) | 5.046 | 0.080 |
Malperfusion syndrome | 7 (25.9) | 9 (31.0) | 6 (25.0) | 0.472 | 0.813 |
Cerebral malperfusion | 2 (7.4) | 4 (13.8) | 4 (16.7) | 1.136 | 0.639 |
Extremity malperfusion | 2 (7.4) | 3 (10.3) | 2 (8.3) | 0.323 | 1.000 |
Renal malperfusion | 1 (3.7) | 2 (6.9) | 1 (4.2) | 0.570 | 1.000 |
 One sided | 0 (0) | 2 (6.9) | 2 (8.3) | 2.253 | 0.452 |
 Both sided | 1 (3.7) | 0 (0) | 0 (0) | 1.827 | 0.638 |
 A total obstruction | 0 (0) | 0 (0) | 2 (8.3) | 3.169 | 0.087 |
 A stenosis | 1 (3.7) | 2 (6.9) | 0 (0) | 1.537 | 0.771 |
Mesenteric malperfusion | 2 (7.4) | 1 (3.4) | 2 (8.3) | 0.773 | 0.731 |
Coronary malperfusion | 0 (0) | 0 (0) | 2 (8.3) | 0.472 | 0.813 |
Type of combined surgery | |||||
 Aortic valvuloplasty | 17 (63.0) | 16 (55.2) | 14 (58.3) | 0.397 | 0.820 |
 Bentall | 2 (7.4) | 3 (10.3) | 5 (20.8) | 1.809 | 0.397 |
 Coronary artery bypass grafting | 0 (0) | 0 (0) | 2 (8.3) | 2.974 | 0.096 |
 Mitral valve replacement | 0 (0) | 0 (0) | 1 (4.2) | 1.961 | 0.315 |
Intraoperative items | |||||
 Lowest Nasopharyngeal temperature (℃) | 23.0 (22.1–23.7) | 22.5 (22.0–22.8) | 22.9 (22.0–23.1) | 5.444 | 0.066 |
 Extracorporeal circulation time (min) | 131.5 (120.5–139.5) | 137.0 (117.7–155.0) | 153.0 (126.0–165.0) | 4.790 | 0.091 |
 Aortic crossclamp time (min) | 51.9 ± 14.4 | 55.9 ± 16.1 | 66.0 ± 19.7 | 4.426 | 0.015 |
 Moderate hypothermia circulation arrest time (min) | 16.0 ± 3.7 | 15.5 ± 4.7 | 16.0 ± 3.6 | 1.026 | 0.867 |
 Red blood cells transfused volume (U) | 4 (4–6) | 6 (4–6) | 6 (4–8) | 11.034 | 0.004 |
 Plasma transfused volume (ml) | 523.08 ± 230.85 | 603.84 ± 206.36 | 613.04 ± 294.34 | 0.981 | 0.430 |
Postoperative items | |||||
 Peak creatinine (umol/L) | 103.5 (75.1–141.2) | 130.5 (114.6–175.5) | 219 (143–474) | 23.458 | 0.000 |
 Peak procalcitonin (ng/ml) | 1.72 (0.85–3.78) | 1.01 (0.70–3.40) | 5.18 (1.91–12.60) | 14.870 | 0.001 |
 Peak interleukin-6 (pg/ml) | 163.4 (141.0–273.1) | 197.9 (166.4–249.9) | 284.2 (270.1–321.7) | 18.822 | 0.000 |
 Peak lactate (mmol/L) | 3.10 (2.50–4.30) | 3.70 (2.55–4.95) | 7.10 (3.68–9.73) | 12.095 | 0.002 |
 Peak C-reactiveprotein (mg/L) | 211.09 ± 59.42 | 229.28 ± 49.75 | 243.30 ± 59.5 | 1.943 | 0.151 |
 Extracorporeal membrane oxygenation | 0 (0) | 0 (0) | 2 (8.3) | 2.974 | 0.096 |
 Mechanical ventilation time (h) | 19.0 (14.5–39.7) | 21.0 (16.7–34.0) | 72.0 (33.2–112.0) | 18.172 | 0.000 |
 ICU stay time (h) | 55.0 (39.7–72.0) | 57.2 (41.5–89.5) | 122.5 (68.5–171.2) | 16.297 | 0.000 |
 In-hospital mortality | 0 (0) | 0 (0) | 3 (12.5) | 4.628 | 0.028 |
Plasma RIP3 levels (pg/ml) | |||||
 Preoperative RIP3 levels | 905.4 ± 183.9 | 877.7 ± 134.0 | 987.7 ± 223.7 | 2.820 | 0.138 |
 Postoperative RIP3 levels | 1007.4 ± 195.8 | 1101.3 ± 141.4 | 1394.5 ± 160.6 | 34.331 | 0.000 |
 Elevated RIP3 levels | 101.9 ± 66.7 | 223.6 ± 89.5 | 406.8 ± 159.1 | 44.947 | 0.000 |