Skip to main content

Table 1 Univariate analysis of perioperative factors and acute kidney injury for the whole cohort

From: Acute kidney injury increases the risk of end-stage renal disease after cardiac surgery in an Asian population: a prospective cohort study

Variables Whole cohort (n = 2666) No AKI (n = 1889) AKIN 1 (n = 608) AKIN 2 and 3 (n = 169) p-value
Pre-operative
 Age (years) 59.3 ± 10.5 58.0 ± 10.5 62.3 ± 9.6 62.4 ± 10.6 <0.001
 Gender: male 2143 (80.4) 1534 (81.2) 486 (79.9) 123 (72.8) 0.029
 Ethnicity Chinese 1912 (71.7) 1390 (73.6) 414 (68.1) 108 (63.9) <0.001
Malay 425 (15.9) 271 (14.3) 126 (20.7) 28 (16.6)
Indian 329 (12.3) 228 (12.1) 68 (11.2) 33 (19.5)
 Body mass index (kg/m2) 25.0 ± 4.1 24.9 ± 4.0 25.4 ± 4.3 24.9 ± 4.7 0.032
 Diabetes mellitus 1205 (45.2) 793 (42.0) 294 (48.4) 118 (69.8) <0.001
 Hypertension 1998 (74.9) 1348 (71.4) 503 (82.7) 147 (87) <0.001
 Myocardial infarction 1559 (58.5) 1072 (56.7) 379 (62.3) 108 (63.9) 0.017
 Congestive cardiac failure 435 (16.3) 260 (13.8) 130 (21.4) 45 (26.6) <0.001
 Renal impairment 225 (8.4) 90 (4.8) 99 (16.3) 36 (21.3) <0.001
 Beta-blocker 1998 (74.9) 1377 (73.1) 482 (79.3) 139 (82.2) 0.001
 ACE-inhibitor 1300 (48.8) 905 (48.0) 306 (50.3) 89 (52.7) 0.365
 Calcium channel blocker 521 (19.5) 331 (17.6) 144 (23.7) 46 (27.2) <0.001
 Statin 2159 (81.0) 1526 (81.0) 494 (81.7) 139 (82.2) 0.881
 Diuretic 480 (18.0) 276 (14.6) 149 (24.5) 55 (32.5) <0.001
 Ejection fraction (<30%) 185 (6.9) 110 (5.9) 58 (9.6) 17 (10.2) 0.002
 Pre-operative creatinine (μmol/L) 91.0 ± 42.7 85.7 ± 34.6 103.5 ± 51.5 98.7 ± 35.5 <0.001
 Pre-operative eGFR (ml/min/1.73 m2) 81.0 ± 21.6 84.8 ± 19.3 71.9 ± 23.9 71.7 ± 23.9 <0.001
 Pre-operative haemoglobin (g/dL) 13.5 ± 1.7 13.8 ± 1.6 13.1 ± 1.8 12.7 ± 1.8 <0.001
 EuroSCORE logistic 3.6 ± 4.6 3.1 ± 3.7 4.8 ± 6.0 4.9 ± 6.2 <0.001
Surgical variables
 Coronary artery bypass graft surgery 2191 (82.2) 1546 (82.2) 506 (83.4) 139 (82.2) 0.802
 Valvular surgery 622 (23.3) 433 (22.9) 148 (24.3) 41 (24.3) 0.733
 Cardiopulmonary bypass 2578 (96.7) 1820 (96.3) 595 (97.9) 163 (96.4) 0.188
 IABP 249 (9.3) 130 (6.9) 89 (14.7) 30 (17.9) <0.001
 Cardiopulmonary bypass time (min) 113.5 ± 49.0 107.0 ± 43.4 125.7 ± 56.2 137.3 ± 64.7 <0.001
 Aortic cross clamp time (min) 67.2 ± 36.4 63.5 ± 32.8 74.1 ± 42.5 79.5 ± 46.0 <0.001
 Inotrope use 1652 (62.0) 1120 (59.9) 409 (67.7) 123 (72.8) <0.001
Haemodilution
 Prebypass haematocrit (%) 37.8 ± 4.9 38.3 ± 4.6 36.9 ± 5.3 35.8 ± 4.8 <0.001
 Lowest haematocrit during bypass (%) 24.4 ± 3.9 24.9 ± 3.9 23.4 ± 3.7 22.3 ± 3.8 <0.001
 RBC transfusion 746 (28.0) 426 (22.6) 238 (39.1) 82 (48.5) <0.001
Intensive care unit variables
 Inotrope use 1228 (46.1) 780 (41.3) 336 (55.4) 112 (66.3) <0.001
 New need for dialysis 59 (2.2) 12 (0.6) 21 (3.5) 26 (15.4) <0.001
 Lowest haemoglobin in 1st 24 h (g/dL) 9.7 ± 1.6 9.9 ± 1.5 9.2 ± 1.4 8.8 ± 1.4 <0.001
 RBC transfusion 1010 (37.9) 608 (32.2) 303 (49.9) 99 (58.6) <0.001
 Total length of hospitalization (days) 11.0 ± 10.6 9.2 ± 5.6 13.2 ± 9.6 22.0 ± 30.2 <0.001
Outcomes
 End-stage renal disease 24 (0.9) 6 (0.3) 12 (2.0) 6 (3.6) <0.001
 5-year mortality 128 (4.8) 68 (3.6) 41 (6.7) 19 (11.2) <0.001
  1. Data represent number (percent) or mean ± standard deviation
  2. AKI Acute Kidney Injury, AKIN Acute Kidney Injury Network, EuroSCORE European System for Cardiac Operative Risk Evaluation, eGFR estimated glomerular filtration rate, IABP intra-aortic balloon pump, RBC red blood cell