The association between systemic inflammatory response index and contrast-associated acute kidney injury in patients undergoing elective percutaneous coronary intervention

Figures & data

Figure 1. Flow chart of the participants.

Table 1. Baseline variables in groups with high or low levels of SIRI.

	Total	SIRI ≤ 1.39	SIRI > 1.39	P. overall
	N = 5685	N = 3765	N = 1920
Demographics
Age, median (IQR), years	66.00 (59.00–73.00)	65.00 (58.00–72.00)	67.00 (60.00–74.00)	<0.001
Sex(female), n (%)	1235 (21.72%)	933 (24.78%)	302 (15.73%)	<0.001
Smoke, n (%)	2425 (48.47%)	1544 (46.60%)	881 (52.13%)	<0.001
Medical history, n (%)
Diabetes	2026 (35.64%)	1364 (36.23%)	662 (34.48%)	0.203
Hypertension	3867 (68.02%)	2514 (66.77%)	1353 (70.47%)	0.005
Atrial fibrillation	369 (6.49%)	220 (5.84%)	149 (7.76%)	0.007
Congestive heart failure	243 (4.27%)	124 (3.29%)	119 (6.20%)	<0.001
Acute myocardial infarction	1817 (31.96%)	856 (22.74%)	961 (50.05%)	<0.001
History of myocardial infarction	748 (13.16%)	510 (13.55%)	238 (12.40%)	0.241
Anemia	2866 (50.41%)	1779 (47.25%)	1087 (56.61%)	<0.001
Procedure performed
Number of stents, mean ± SD,	1.64 ± 0.88	1.64 ± 0.88	1.63 ± 0.88	0.725
Stent length, mean ± SD, mm	44.59 ± 26.95	44.49 ± 26.98	44.79 ± 26.90	0.691
Contrast volume > 150mL, n (%)	3937 (72.36%)	2620 (72.54%)	1317 (72.01%)	0.704
Radial approach, n (%)	5553 (97.6%)	3644 (97.9%)	1909 (97.3%)	0.269
Periprocedural complication
Stroke, n (%)	6 (0.10%)	4 (0.11%)	2 (0.10%)	0.999
Bleeding Academic Research Consortium ≥2, n (%)	115 (2.00%)	54 (1.45%)	61 (3.11%)	<0.001
Medication use
Antiplatelet, n (%)	5668 (99.7%)	5304 (99.74%)	364 (99.18%)	0.093
Statin, n (%)	5628 (98.9%)	5265 (99.00%)	363 (98.91%)	0.785
ACEI/ARB, n (%)	4677 (82.2%)	4365 (82.08%)	312 (85.01%)	0.176
Beta-blocker, n (%)	4703 (82.7%)	4386 (82.47%)	317 (86.38%)	0.066
Calcium channel blockers, n (%)	2109 (35.5%)	1886 (35.46%)	133 (36.24%)	0.807
Laboratory measurements
White blood cell count, mean ± SD, 109/L	6.97 (5.80–8.44)	6.40 (5.42–7.49)	8.60 (7.20–10.36)	<0.001
Platelet, mean ± SD, 109/L	213.00 (181.00–254.0)	209.00 (178.00–249.00)	219.00 (186.00–264.00)	<0.001
Hemoglobin, mean ± SD, g/L	138.00 (127.00–148.0)	138.20 (129.00–148.00)	137.00 (125.00–148.00)	<0.001
Cholesterol, mean ± SD, mmol/L	4.05 (3.43–4.89)	4.04 (3.41–4.90)	4.08 (3.46–4.88)	0.527
High-density lipoprotein-C, mean ± SD, mmol/L	1.00 (0.84–1.19)	1.00 (0.85–1.20)	0.98 (0.82–1.18)	0.011
Low-density lipoprotein-C, mean ± SD, mmol/L	2.58 (2.00–3.28)	2.55 (1.98–3.28)	2.62 (2.05–3.29)	0.055
D-dimer, mean ± SD, mg/L FEU	0.34 (0.20–0.66)	0.31 (0.19–0.58)	0.41 (0.22–0.82)	<0.001
ALT, mean ± SD, U/L	23.00 (16.00–35.00)	22.00 (15.00–32.00)	25.00 (17.00–40.00)	<0.001
AST, mean ± SD, U/L	22.00 (17.00–31.00)	21.00 (17.00–27.00)	25.00 (18.00–52.00)	<0.001
NT-proBNP, mean ± SD, pg/mL	209.65 (70.95–802.92)	145.90 (57.80–477.68)	532.95 (143.07–1644.2)	<0.001
Left ventricular ejection fraction, mean ± SD, %	59.00 (56.00–62.00)	60.00 (57.00–62.00)	58.00 (54.00–61.00)	<0.001
Estimated glomerular filtration rate, mean ± SD, mL/min/1.73m^2	89.7 ± 24.11	90.60 ± 22.57	88.08 ± 26.79	<0.001
Serum creatinine, median (IQR), mg/dL	0.88 (0.76-1.02)	0.87 (0.75-1.00)	0.90 (0.77-1.07)	<0.001
CA-AKI, n (%)	352 (6.19%)	170 (4.52%)	182 (9.48%)	<0.001

N-terminal pro-B-type natriuretic peptide; ALT: Alanineaminotransferase; AST: Aspartate transaminase; ACEI: Angiotensin converting enzyme inhibitors; ARB: Angiotensin II receptor blocker; CCB: Calcium channel blockers, CA-AKI: contrast-associated acute kidney injury.

Figure 2. Restricted cubic spline curve with logistic regression between SIRI score and CA-AKI.

Figure 3. Subgroup analysis stratified by risk factors for contrast-associated acute kidney injury. CI, confidence interval.

Table 2. Relationship of SIRI with CA-AKI and long-term mortality.

Models	Relationship between SIRI and CA-AKI					Relationship between SIRI and long-term mortality
	Odds ratio	95% CI		P value		Hazard ratio	95% CI		P value
		Lower	Upper				Lower	Upper
Unadjusted	2.214	1.783	2.752	<0.001		1.734	1.454	2.067	<0.001
Model 1	2.260	1.813	2.819	<0.001		1.572	1.317	1.878	<0.001
Model 2	2.147	1.719	2.681	<0.001		1.472	1.231	1.761	<0.001
Model 3	1.580	1.253	1.993	<0.001		1.400	1.164	1.684	<0.001

Model 1: adjusted for age > 75 years and gender.

Model 2: adjusted for variables incorporated in Model 1 plus diabetes, hypertension, anemia, history of myocardial infarction, eGFR, contrast volume > 150 mL.

Model 3: adjusted for variables incorporated in Model 2 plus acute myocardial infarction.

CI: confidence interval; CA-AKI: contrast-induced nephropathy; SIRI: systemic inflammatory response index; eGFR: estimated glomerular filtration rate.

Figure 4. Associations between SIRI and long-term mortality. Solid lines indicate survival probability; shaded areas indicate confidence interval.

Data availability statement

The datasets used and/or analyzed in this study are available from the corresponding author upon reasonable request.