Evaluation of serum cysteine-rich protein 61 and cystatin C levels for assessment of acute kidney injury after cardiac surgery

Figures & data

Table 1. A summary of clinical data of the patients.

	Non-AKI	AKI	p
Number of patients and gender (male/female)	24 (12/12)	26 (18/8)	0.409
Age (years)	79.8 ± 10.9	70.1 ± 13.4	0.770
BMI (kg/m)	27.2 ± 4.4	27.3 ± 4,7	0.841
Diabetes mellitus (non/oral/insulin)	20/2/2	15/7/4	0.448
Arterial hypertension (y/n)	18/6	24/2	0.520
Left ventricular ejection fraction (%)	59.7 ± 16.1	59.2 ± 7.3	0.718
Pre-operative eGFR (mL/min/1.73 m^2)	95.1 ± 22.1	93.7 ± 34.1	0.531
eGFR ≤ 60 mL/min/1.73 m^2 (number of patients)	1	6	–
CPB time (min)	97 ± 33	101 ± 37	0.053

Data are represented as mean ± SD; BMI: Body Mass Index; eGFR: Estimated Glomerular Filtration Rate; CPB: Cardiopulmonary bypass.

Figure 1. Serum creatinine values (mean and SD) at five time-points: before surgery, at the end of CPB and 2, 24, and 48 h after the end of CPB.

Table 2. Serum creatinine levels (μmol/L) in AKI and non-AKI groups at different points.

Measured parameters	Non-AKI (N = 24)	AKI (N = 26)	p
Creatinine pre (μmol/L)	64.8 ± 17.9	74.0 ± 43.3	<0.001
Creatinine 0 h (μmol/L)	62.0 ± 16.4	83.3 ± 28.1	<0.001
Creatinine 2 h (μmol/L)	69.7 ± 14.3	93.3 ± 38.7	<0.001
Creatinine 24 h (μmol/L)	68.1 ± 20.8	111.9 ± 55.6	<0.001
Creatinine 48 h (μmol/L)	64.6 ± 22.4	124.6 ± 67.2	<0.001

Data are represented as mean ± SD. Significance at p ≤ 0.05. Pre: before surgery; 0 h: at the end of CPB; 2, 24, and 48 h: hours after the end of CPB.

Figure 2. Serum CysC values (mean and SD) at five time-points: before surgery, at the end of CPB and 2, 24, and 48 h after the end of CPB.

Table 3. Serum CysC levels (μg/L) in AKI and non-AKI groups at different points.

Measured parameters	Non-AKI (N = 24)	AKI (N = 26)	p
CysC pre (μg/L)	747 ± 276	856 ± 400	<0.001
CysC 0 h (μg/L)	724 ± 177	932 ± 480	<0.001
CysC 2 h (μg/L)	700 ± 170	949 ± 557	<0.001
CysC 24 h (μg/L)	770 ± 261	1070 ± 430	<0.001
CysC 48 h (μg/L)	910 ± 422	1421 ± 739	<0.001

CysC: Cystatin C. Data are represented as mean ± SD. Significance at p ≤ 0.05. Pre: before surgery; 0 h: at the end of CPB; 2 h, 24, and 48 h: hours after the end of CPB.

Figure 3. Serum CYR61 values (median and interquartile ranges) at five time-points: before surgery, at the end of CPB and 2, 24, and 48 h after the end of CPB.

Figure 4. The correlation (r = −0.465; p < 0.01) between serum CYR61 levels (μg/L) 48 h after the end of CPB and age of the patients (years).

Figure 5. ROC curve for serum creatinine, CysC and CYR61 values 2 h after the end of CPB.

Table 4. Serum CYR61 levels (μg/L) in AKI and non-AKI groups at different points.

Measured parameters	Non-AKI (N = 24)	AKI (N = 26)	p
CYR61 pre (μg/L)	20.3	12.4	0.47
Q1–Q3	7.9–51.7	3.7–42.8
CYR61 0 h (μg/L)	5.7	4.0	0.82
Q1–Q3	1.8–19.8	2.4–13.9
CYR61 2 h (μg/L)	12.4	8.9	0.88
Q1–Q3	4.8–24.9	6.0–45.2
CYR61 24 h (μg/L)	10.4	14.2	0.39
Q1–Q3	1.2–24.6	4.2–28.2
CYR61 48 h (μg/L)	11.8	15.9	0.62
Q1–Q3	4.0–29.9	4.0–54.9

CYR61: Cysteine-rich protein 61. Data are represented as mean ± SD. Significance at p ≤ 0.05. Pre: before surgery; 0 h: at the end of CPB; 2, 24, and 48 h: hours after the end of CPB.