Table 1.

Clinical characteristics of University of Chicago cardiac surgery study subjects (n = 123)

CharacteristicNo AKI (n = 77)AKIN Stage 1 to 2 (n = 37)AKIN Stage 3 (n = 9)
Age
    median years687272
    IQR56.5 to 7761 to 8159 to 79.3
Gender, male/female (%)66.2/33.862.2/37.866.7/33.3
Race
    Caucasian54326
    African American1843
    other510
    Hispanic, n (%)5 (6.5)2 (5.4)1 (11.1)
Baseline GFR (MDRD), ml/min per 1.73 m2 (mean ± SEM)72.3 ± 3.273.1 ± 5.464.4 ± 9.4
Baseline creatinineb
    median mg/dl1.041.091.40
    IQR0.87 to 1.330.90 to 1.201.20 to 1.67b
Diabetes mellitus, n (%)21 (27.2)10 (27.0)3 (33.3)
COPD, n (%)19 (27.5)7 (18.9)3 (33.3)
Ejection fraction
    n59295
    mean ± SEM4.4 ± 2.249.5 ± 3.251.0 ± 4.0
Preoperative medications, n (%)
    beta blockers32 (41.6)9 (24.3)5 (55.5)
    ACEI/ARBs23 (29.9)11 (29.7)4 (44.4)
    calcium channel blockers12 (15.6)4 (14.8)2 (22.2)
    diuretics28 (36.4)8 (21.6)6 (66.6)
    statins27 (35.1)11 (29.7)5 (55.5)
Operative factors
    surgery type
        CABG alone2482
        valve alone10111
        CABG + valve20115
        CABG + other300
        valve + other1751
        other320
    previous CT surgery, n (%)18 (23.4)5 (13.5)2 (22.2)
    CPB timec
        median minutes162160.5250.5
        IQR126 to 213128 to 214182 to 345.5
    off-pump surgery, n (%)8 (10.4)3 (8.1)1 (11.1)
    crossclamp time, minutes (mean ± SEM)b126.2 ± 5.6129.3 ± 10.9156.1 ± 16.6
    no crossclamp, n (%)14 (18.2)3 (8.1)1 (11.1)
Outcomes
    ICU days, median (IQR)a,d3 (2 to 5)3 (2 to 5)9 (5.75 to 16)d
    postoperative hospital days, mean ± SEMc7 (6 to 9.3)7 (6 to 10.3)19 (8.5 to 30.3)c
    in-hospital mortality, na,d014
  • COPD, chronic obstructive pulmonary disease; ACEI, angiotensin converting enzyme inhibitor; ARB, angiotensin receptor blocker; CABG, coronary artery bypass graft; MDRD, Modification of Diet in Renal Disease.

  • No AKI versus AKI aP < 0.05; stage 3 versus all others

  • b P < 0.05,

  • c P < 0.01, and

  • d P < 0.001; all other P = NS.