Table 1. Patient characteristics.

Continuous data are presented as mean ± standard deviation, and categorical data as number (percentage).

LVEF: left ventricular ejection fraction; sCr: serum creatinine; eGFR: estimated glomerular filtration rate; CPB: cardiopulmonary bypass; CABG: coronary artery bypass grafting; ACE-I: angiotensin-converting enzyme inhibitor; ARB: angiotensin receptor blocker; ASA-PS: American Society of Anesthesiologists physical status; EuroSCORE: European System for Cardiac Operative Risk Evaluation.

* eGFR was calculated by the equation devised by the Japanese Society of Nephrology [23].

Variable	All patients (n = 50)	No AKI (n = 38)	AKI (n = 12)	P value
Age (years)	68 ± 11	69 ± 12	67 ± 8.7	0.53
Gender (male, %)	28 (56%)	18 (47%)	10 (83%)	0.03
Weight (kg)	59 ± 13	56 ± 11	67 ± 15	0.02
Height (cm)	158 ± 10	154 ± 10	160 ± 9.2	0.36
Body Mass Index (kg/m2)	23 ± 3.6	23 ± 5.8	26 ± 6.7	0.01
Preoperative LVEF (%)	58 ± 15	59 ± 15	55 ± 16	0.39
Preoperative sCr (mg/dL)	0.73 ± 0.12	0.69 ± 0.12	0.79 ± 0.11	0.03
Preoperative eGFR* (ml/min/1.73 m2)	74 ± 13	73 ± 14	72 ± 10	0.61
Type of surgery
CABG	27 (54%)	21 (55%)	6 (50%)	1.00
Valve surgery	19 (38%)	14 (37%)	5 (42%)
Thoracic aortic surgery	4 (8.0%)	3 (7.9%)	1 (8.3%)
Comorbidity
Diabetes mellitus	20 (40%)	14 (37%)	6 (50%)	0.50
Preoperative insulin	3 (6.0%)	2 (5.3%)	1 (8.3%)	1.00
Hypertension	38 (76%)	27 (71%)	11 (92%)	0.25
Preoperative ACE-I or ARB	17 (34%)	13 (34%)	4 (33%)	1.00
Dyslipidemia	26 (52%)	18 (47%)	8 (67%)	0.32
Smoking history	26 (52%)	20 (53%)	6 (50%)	1.00
Chronic lung disease	5 (10%)	5 (13%)	0 (0%)	0.31
Cerebrovascular disease	16 (32%)	8 (21%)	8 (67%)	0.01
ASA-PS classification (3, %)	50 (100%)	38 (100%)	12 (100%)	1.00
Logistic EuroSCORE (%)	5.3 ± 4.1	4.9 ± 4.4	5.7 ± 3.0	0.79