Table 1.
Comparison of preoperative and immediate postoperative clinical data of total cohort of patients by both AKI after cardiopulmonary bypass surgery exposure and long-term follow-up status
| Variable | CPB-AKI–Positive Patients, by Follow-Up Status (n=119) | AKI-Negative Patients, by Follow-Up Status (n=253) | |||||
|---|---|---|---|---|---|---|---|
| A: Follow-Up Positive (n=33) | B: Follow-Up Negative (n=86) | C: P Value (Column A versus Column B)a | D: Follow-Up Positive (n=18) | E: Follow-Up Negative (n=235) | F: P Value (Column D versus Column E)b | G: P Value (Column A versus Column D)c | |
| Age at surgery, yr | 0.51 (0.34, 1.38) | 0.54 (0.35, 0.99) | 0.14 | 0.57 (0.25, 3.15) | 2.8 (0.51, 5.9) | 0.01 | 0.79 |
| Male, n (%) | 16 (48.5) | 44 (51.2) | 1.00 | 8 (44.4) | 130 (55.3) | 0.46 | >0.99 |
| White, n (%) | 32 (100) | 73 (85) | 0.24 | 18 (100) | 201 (87) | 0.62 | >0.99 |
| No history of CPB, n (%) | 21 (63.6) | 59 (68.6) | 0.66 | 11 (61) | 125 (53) | 0.63 | >0.99 |
| Baseline serum creatinine, mg/dl | 0.3 (0.3, 0.4) | 0.3 (0.3, 0.4) | 0.90 | 0.4 (0.3, 0.6) | 0.4 (0.4, 0.6) | 0.19 | 0.02 |
| Baseline eCCL, ml/min per 1.73 m2 (14) | 97.5 (85.5, 134.75) | 99 (71.44, 140.63) | 0.94 | 96 (74.25, 116.6) | 112.2 (79.31, 132.92) | 0.11 | 0.36 |
| RACHS-1 score, n (%) (15) | 0.07 | 0.22 | 0.21 | ||||
| 1 | 0 | 6 (7) | 2 (11.1) | 28 (11.9) | |||
| 2 | 15 (45.5) | 46 (53.5) | 8 (44.4) | 107 (45.5) | |||
| 3 | 15 (45.5) | 28 (32.5) | 5 (27.8) | 87 (37) | |||
| 4 | 1 (3) | 3 (3.5) | 2 (11.1) | 7 (3) | |||
| 5 | 2 (6) | 0 | 1 (5.6) | 2 (0.9) | |||
| 6 | 0 | 3 (3.5) | 0 | 4 (1.7) | |||
| CPB time, min | 136 (104, 175) | 121 (84, 182) | 0.72 | 93.5 (82, 138) | 92 (68, 127) | 0.42 | 0.10 |
| Highest postoperative serum creatinine, mg/dl | 0.7 (0.5, 0.9) | 0.6 (0.5, 0.7) | 0.23 | 0.4 (0.4, 0.5) | 0.5 (0.4, 0.6) | 0.39 | 0.01 |
| Lowest postoperative eCCL, ml/min per 1.73 m2 | 45 (36.56, 59.09) | 52.65 (39.31, 70.82) | 0.26 | 75.38 (59.4, 102.44) | 106.7 (70.88, 131.31) | 0.07 | 0.003 |
| Change in serum creatinine, % | 100 (67.67, 133.33) | 75 (60, 100) | 0.14 | 22.5 (0, 33.33) | 0 (0, 25) | 0.15 | <0.001 |
| pRIFLE, n (%) | 0.22 | NA | NA | NA | |||
| R | 11 (33.2) | 44 (51.2) | |||||
| I | 14 (42.4) | 27 (31.4) | |||||
| F | 8 (24.2) | 15 (17.4) | |||||
| Duration of AKI, d | 2 (2, 3) | 2 (2, 3) n=79 | 0.94 | NA | NA | NA | NA |
| Inotrope score on postoperative d 2 | 3 (0, 7.5) | 0 (0, 12) n=83 | 0.33 | 0 (0, 0) | 0 (0, 7.5) | 0.13 | 0.03 |
| Length of ICU stay, d | 9 (5, 20) | 8.5 (5, 19) | 0.90 | 6 (4, 22) | 5 (3, 8) | 0.13 | 0.23 |
| Death within 1 mo of original surgery, n (%) | NA | 5 (5.8) | NA | NA | 2 (1) | NA | NA |
| Preoperative urine biomarkers | |||||||
| NGAL/Cr, ng/mg | 18.18 (11.11–29.09); n=33 | 18.33 (10–27.78); n=86 | 0.70 | 12.91 (4.17–18.75); n=18 | 8.33 (3.57–15); n=234 | 0.12 | 0.06 |
| IL-18/Cr, pg/mg | 5.21 (0–24.67); n=15 | 0.59 (0–12.38); n=44 | 0.32 | 0 (0–4.12); n=10 | 2.59 (0–12.31); n=133 | 0.1 | 0.23 |
| KIM-1/Cr, pg/mg | 194.63 (168.05–235.03); n=13 | 284.2 (138.7–448.89); n=39 | 0.46 | 261.37 (215.42–505.73); n=10 | 243.1 (168.13–352.68); n=107 | 0.66 | 0.16 |
| L-FABP/Cr, ng/mg | 18.14 (5.21–49.63); n=15 | 8.08 (3.31–32.1); n=43 | 0.24 | 19.6 (0–58.33); n=11 | 12.75 (2.65–34.67); n=133 | 0.78 | 0.45 |
| 24-h postoperative urine biomarkers | |||||||
| NGAL/Cr, ng/mg | 220 (86.15–562.67); n=33 | 121.32 (39.53–304); n=86 | 0.02 | 18.46 (10–27.27); n=17 | 17.99 (6.67–34.29); n=234 | 0.73 | <0.001 |
| IL-18/Cr, pg/mg | 77.27 (36.67–170.67); n=15 | 64.23 (28.89–155.8); n=44 | 0.51 | 17.06 (0–40.67); n=10 | 12.5 (0–38.18); n=133 | 0.88 | 0.001 |
| KIM-1/Cr, pg/mg | 1861.29 (931.83–3881.82); n=15 | 1313.06 (644.06–2517.64); n=44 | 0.28 | 745.51 (245.9–1345.72); n=10 | 520.47 (227.92–972.61); n=125 | 0.38 | 0.01 |
| L-FABP/Cr, ng/mg | 876.86 (445.1–1190.38); n=14 | 301.66 (168.66–825.27); n=41 | 0.01 | 69.13 (18.69–360.49); n=10 | 107.97 (27.9–280.48); n=125 | 0.55 | 0.001 |
Unless otherwise noted, values are expressed as median (interquartile range). Level of significance: P<0.02. CPB, cardiopulmonary bypass surgery; eCCL, estimated creatinine clearance; NA, not applicable; RACHS-1, risk adjustment for congenital heart surgery; R, risk; I, injury; F, failure; ICU, intensive care unit; NGAL, neutrophil gelatinase-associated lipocalin; Cr, creatinine; KIM, kidney injury molecule; L-FABP, liver fatty acid–binding protein.
Column C: P values for comparisons between all patients who developed AKI after surgery using cardiopulmonary bypass (CPB-AKI), by long-term follow-up status: column A (follow-up) versus column B (no follow-up).
Column F: P values for comparisons between all patients who did not develop CPB-AKI, by long-term follow-up status: column D (follow-up) versus column E (no follow-up).
Column G: P values for comparisons between all patients who agreed to long-term follow-up, by CPB-AKI exposure status: column A (CPB-AKI positive) versus column D (CPB-AKI negative).