Baseline characteristics
| Variables | Total (n=643) | Missing data (%) | CI-AKI (n=96) | non-CI-AKI (n=547) | P value |
| Age, years | 69.88±9.67 | 0 (0) | 74.47±8.45 | 69.07±9.65 | <0.001 |
| Age >75 years, n (%) | 234 (36.39) | 0 (0) | 54 (56.25) | 180 (32.91) | <0.001 |
| Female sex, n (%) | 181 (28.15) | 0 (0) | 37 (38.54) | 144 (26.33) | 0.014 |
| Weight, kg | 63.63±10.27 | 8 (1.24) | 60.37±9.87 | 64.21±0.24 | <0.001 |
| SBP, mm Hg | 129.61±23.81 | 2 (0.31) | 128.16±28.67 | 129.87±22.87 | 0.579 |
| DBP, mm Hg | 74.16±12.48 | 2 (0.31) | 73.47±13.95 | 74.28±12.21 | 0.593 |
| HR, bpm | 76.58±15.12 | 3 (0.47) | 81.43±18.31 | 75.72±14.33 | 0.004 |
| Medical history | |||||
| Chronic heart failure, n (%) | 468 (73.01) | 2 (0.31) | 77 (80.21) | 391 (71.74) | 0.085 |
| Hypotension, n (%) | 25 (3.91) | 4 (0.62) | 12 (12.77) | 13 (2.39) | <0.001 |
| % | 53.52±13.63 | 74 (11.51) | 51.20±13.08 | 53.95±13.69 | 0.072 |
| LVEF <40%, n (%) | 100 (17.57) | 74 (11.51) | 18 (20.22) | 82 (17.08) | 0.475 |
| Hypertension, n (%) | 475 (73.87) | 0 (0) | 74 (77.08) | 401 (73.31) | 0.438 |
| Hyperlipidaemia, n (%) | 85 (13.22) | 0 (0) | 14 (14.58) | 71 (12.98) | 0.669 |
| Hypoalbuminaemia, n (%) | 356 (65.32) | 98 (15.24) | 53 (75.14) | 303 (63.79) | 0.05 |
| Anaemia, n (%) | 301 (47.55) | 10 (1.56) | 56 (58.33) | 245 (44.79) | 0.011 |
| AMI, n (%) | 263 (41.22) | 5 (0.78) | 62 (64.58) | 201 (37.08) | <0.001 |
| Diabetes, n (%) | 207 (32.19) | 0 (0) | 33 (34.38) | 174 (31.81) | 0.62 |
| CAD, n (%) | 610 (96.06) | 8 (1.24) | 95 (98.96) | 515 (95.55) | 0.154 |
| CKD stages | <0.001 | ||||
| CKD G3a, n (%) | 397 (61,74) | 0 (0) | 43 (44.79) | 354 (64.72) | |
| CKD G3b, n (%) | 177 (27.53) | 0 (0) | 28 (29.17) | 149 (27.24) | |
| CKD G4, n (%) | 59 (9.18) | 0 (0) | 22 (22.92) | 37 (6.76) | |
| CKD G5, n (%) | 10 (1.56) | 0 (0) | 3 (3.13) | 7 (1.28) | |
| Laboratory examination | |||||
| LDL-C, mmol/L | 2.68±0.89 | 149 (23.17) | 2.81±1.05 | 2.66±0.86 | 0.281 |
| HDL-C, mmol/L | 0.95±0.28 | 149 (23.17) | 0.98±0.26 | 0.95±0.29 | 0.471 |
| Lpa, mg/dL | 34.53±37.56 | 78 (12.13) | 31.69±32.30 | 35.02±38.41 | 0.402 |
| Scr, μmol/L | 145.39±70.94 | 0 (0) | 157.42±63.14 | 143.28±72.07 | 0.05 |
| eGFR, mL/min/1.73 mm2 | 45.71±11.40 | 0 (0) | 40.76±12.88 | 46.58±10.91 | <0.001 |
| Serum urea nitrogen, mg/dL | 7.79±4.02 | 5 (0.78) | 8.56±4.40 | 7.65±3.94 | 0.062 |
| Haemoglobin, g/L | 125.43±17.65 | 84 (13.06) | 116.40±20.20 | 126.76±16.86 | <0.001 |
| HbA1c, % | 6.77±1.39 | 147 (22.86) | 6.79±1.34 | 6.77±1.40 | 0.912 |
| Medications | |||||
| ACEI/ARB, n (%) | 551 (85.69) | 0 (0) | 72 (75.00) | 479 (87.57) | <0.001 |
| β-blocker, n (%) | 504 (78.50) | 1 (0.16) | 60 (62.50) | 444 (81.92) | <0.001 |
| Statin, n (%) | 616 (95.80) | 0 (0) | 91 (94.79) | 525 (95.98) | 0.581 |
| Diuretics, n (%) | 240 (37.33) | 0 (0) | 51 (53.13) | 189 (34.55) | <0.001 |
| Procedure | |||||
| PCI, n (%) | 386 (69.30) | 86 (13.37) | 61 (85.92) | 325 (66.87) | 0.001 |
| Emergency procedure | 165 (25.66) | 0 (0) | 41 (42.71) | 124 (22.67) | <0.001 |
| Hydration volume, mL | 1091.42±669.98 | 22 (3.42) | 1325.13±875.55 | 1050.25±618.81 | 0.004 |
| Contrast volume, mL | 136.10±64.72 | 1 (0.16) | 145.36±60.08 | 134.47±65.42 | 0.108 |
| Mehran Score | 8.37±5.28 | 17 (2.64) | 11.82±8.45 | 7.77±9.65 | <0.001 |
| Periprocedure IABP, n (%) | 64 (9.95) | 0 (0) | 22 (22.92) | 42 (7.68) | <0.001 |
ACEI, ACE inhibitors ; AMI, acute myocardial infarction; ARB, angiotensin-receptor blockers; CAD, coronary artery disease; CI-AKI, contrast-induced acute kidney injury; CKD, chronic kidney disease; DBP, diastolic blood pressure; eGFR, estimate glomerular filtration rate; HDL-C, high density lipoprotein-C; HR, heart rate; IABP, intra-aortic balloon pump; LDL-C, low density lipoprotein-C; Lpa, lipoprotein a; LVEF, left ventricular ejection fraction; PCI, percutaneous coronary intervention; SBP, systolic blood pressure; Scr, serum creatinine.