Table 5.
Logistic regression assessment of postoperative in-hospital AKI and peak postoperative biomarker levels (independent variables) with the development of postoperative MAKE (dependent variable)
| Odds ratio (95% CI) | P | Odds ratio (95% CI) | P | |
|---|---|---|---|---|
| Clinical model | ||||
| Postoperative AKI | 3.60 (1.17–11.09) | 0.026 | ||
| Biomarkers | Postoperative 6 h–POD 1 | Postoperative 6 h–POD 4 | ||
| Serum cystatin C | 1.47 (0.57–3.76) | 0.42 | 2.31 (0.95–5.60) | 0.065 |
| Urine NGAL/Cr | 1.14 (0.91–1.44) | 0.26 | 1.28 (0.99–1.65) | 0.060 |
| Urine KIM-1/Cr | 1.76 (1.10–2.83) | 0.019 | 1.72 (1.09–2.72) | 0.020 |
| Combination 1 Serum cystatin C + urine NGAL/Cr | 1.08 (0.36–3.24) | 0.89 | 3.96 (1.06–14.86) | 0.041 |
| Combination 2 Serum cystatin C + urine NGAL/Cr | 2.40 (0.77–7.48) | 0.13 | 10.29 (3.14–33.69) | <0.001 |
| Combination 1 Serum cystatin C + urine KIM-1/Cr | 1.91 (0.57–6.39) | 0.29 | 4.30 (1.29–14.36) | 0.018 |
| Combination 2 Serum cystatin C + urine KIM-1/Cr | 2.10 (0.68–6.49) | 0.20 | 5.40 (1.59–18.37) | 0.007 |
| Biomarkers adjusted by postoperative AKI | ||||
| Serum cystatin C | 1.06 (0.38–2.92) | 0.92 | 1.63 (0.60–4.42) | 0.33 |
| Urine NGAL/Cr | 1.10 (0.87–1.41) | 0.43 | 1.22 (0.93–1.58) | 0.15 |
| Urine KIM-1/Cr | 1.63 (1.00–2.68) | 0.052 | 1.53 (0.94–2.49) | 0.090 |
| Combination 1 Serum cystatin C + urine NGAL/Cr | 0.77 (0.24–2.51) | 0.66 | 2.91 (0.71–11.86) | 0.14 |
| Combination 2 Serum cystatin C + urine NGAL/Cr | 1.90 (0.58–6.24) | 0.29 | 8.65 (2.34–32.05) | 0.001 |
| Combination 1 Serum cystatin C + urine KIM-1/Cr | 1.40 (0.39–5.00) | 0.61 | 3.32 (0.93–11.83) | 0.064 |
| Combination 2 Serum cystatin C + urine KIM-1/Cr | 1.50 (0.45–5.04) | 0.51 | 3.63 (0.84–15.65) | 0.084 |
AKI, acute kidney injury; CI, confidence interval; Cr, creatinine; KIM-1, kidney injury molecule 1; MAKE, major adverse kidney events as defined in the Methods section; NGAL, neutrophil gelatinase-associated lipocalin; POD, postoperative day.
Clinical model consisted of postoperative in-hospital AKI. Duplets of biomarkers were combined as follows: (i) at least 1 biomarker above the cutoff value (combination 1), or (ii) both biomarkers above the cutoff value (combination 2). MAKE was defined as postoperative death (n = 2, 1 required renal replacement therapy (RRT) before death and 1 met estimated glomerular filtration rate (eGFR) criterion before death), alive with need for RRT during the 30 days following surgery (n = 1), or alive but having ≥25% reduction in postoperative eGFR in reference to preoperative eGFR (n = 13, determined by the post–hospital discharge routine clinical care serum Cr (SCr) value available closest to 30 days after surgery). If no postdischarge SCr value was available, the last SCr measured during primary surgical hospitalization was used.