Table. Baseline Demographic, Clinical, and Procedural Characteristics by Presence of Acute Kidney Injurya.
| Characteristic | Total (N = 1 349 612) |
AKI (n = 94 584) |
No AKI (n = 1 255 028) |
|---|---|---|---|
| Demographic Variables | |||
| Age, mean (SD) | 64.9 (12.2) | 68.3 (12.4) | 64.6 (12.1) |
| Sex, No. (%) | |||
| Male | 908 318 (67.3) | 57 310 (60.6) | 851 008 (67.8) |
| Female | 441 294 (32.7) | 37 274 (39.4) | 404 020 (32.2) |
| Race/ethnicity, No. (%) | |||
| White | 1 191 488 (88.3) | 80 492 (85.1) | 1 110 996 (88.5) |
| Black or African American | 107 778 (8.0) | 10 368 (11.0) | 97 410 (7.8) |
| BMI, mean (SD) | 30.1 (12.8) | 30.5 (13.4) | 30.1 (12.7) |
| No insurance, No. (%) | 91 743 (6.8) | 5843 (6.2) | 85 900 (6.8) |
| Length of stay, mean (SD) | 2.2 (4.3) | 5.7 (8.1) | 2.0 (3.8) |
| AKI Variables | |||
| Creatinine level, mean (SD), mg/dL | |||
| Before procedure | 1.1 (0.5) | 1.3 (0.8) | 1.1 (0.5) |
| After procedure | 1.1 (0.6) | 2.1 (1.5) | 1.0 (0.4) |
| New requirement for dialysis, No. (%) | 4185 (0.3) | 4185 (4.4) | 0 (0.0) |
| AKI stage, No. (%)b | |||
| No AKI | 1 255 028 (93.0) | 0 (0.0) | 1 255 028 (100.0) |
| Stage I | 80 547 (6.0) | 80 547 (85.2) | 0 (0.0) |
| Stage II | 6412 (0.5) | 6412 (6.8) | 0 (0.0) |
| Stage III | 3440 (0.3) | 3440 (3.6) | 0 (0.0) |
| New dialysis | 4185 (0.3) | 4185 (4.4) | 0 (0.0) |
| GFR and contrast volume | |||
| GFR by MDRD equation, mean (SD), mL/min/1.73 m2,c | 73.0 (22.6) | 64.1 (28.7) | 73.7 (22.0) |
| GFR level, No. (%), mL/min/1.73 m2 | |||
| Normal: >60 | 957 136 (70.9) | 48 945 (51.9) | 908 191 (72.4) |
| Mild: >45-60 | 229 427 (17.0) | 18 539 (19.7) | 210 888 (16.8) |
| Moderate: 30-45 | 123 017 (9.1) | 16 111 (17.1) | 106 906 (8.5) |
| Severe: <30 | 39 790 (2.9) | 10 747 (11.4) | 29 043 (2.3) |
| Contrast volume level, mL, No. (%) | |||
| 0-50 | 23 171 (1.7) | 1849 (2.0) | 21 322 (1.7) |
| 51-100 | 139 388 (10.4) | 9922 (10.5) | 129 466 (10.3) |
| 101-150 | 306 762 (22.8) | 19 967 (21.2) | 286 795 (22.9) |
| 151-200 | 350 100 (26.0) | 22 835 (24.2) | 327 265 (26.2) |
| 201-250 | 240 920 (17.9) | 16 441 (17.4) | 224 479 (17.9) |
| 251-300 | 141 460 (10.5) | 10 563 (11.2) | 130 897 (10.5) |
| 301-350 | 68 966 (5.1) | 5572 (5.9) | 63 394 (5.1) |
| 351-400 | 37 563 (2.8) | 3297 (3.5) | 34 266 (2.7) |
| >400 | 36 926 (2.7) | 3795 (4.0) | 33 131 (2.6) |
| Contrast volume, mean (SD), mL | 197.7 (90.5) | 205.7 (100.4) | 197.1 (89.6) |
| History, No. (%) | |||
| Diabetes | 486 687 (36.1) | 46 727 (49.4) | 439 960 (35.1) |
| Hypertension | 1 104 205 (81.9) | 81 899 (86.6) | 1 022 306 (81.5) |
| Dyslipidemia | 1 073 707 (79.6) | 73 186 (77.5) | 1 000 521 (79.8) |
| Family history of premature CAD | 330 477 (24.5) | 18 746 (19.8) | 311 731 (24.8) |
| Myocardial infarction | 404 299 (30.0) | 30 777 (32.6) | 373 522 (29.8) |
| Heart failure | 158 706 (11.8) | 21 782 (23.0) | 136 924 (10.9) |
| Valve surgery/procedure | 20 002 (1.5) | 1977 (2.1) | 18 025 (1.4) |
| PCI | 538 899 (39.9) | 34 524 (36.5) | 504 375 (40.2) |
| CABG | 249 692 (18.5) | 20 060 (21.2) | 229 632 (18.3) |
| Currently undergoing dialysis | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Cerebrovascular disease | 166 297 (12.3) | 17 664 (18.7) | 148 633 (11.8) |
| Peripheral arterial disease | 165 465 (12.3) | 17 414 (18.4) | 14 8051 (11.8) |
| Chronic lung disease | 206 002 (15.3) | 19 336 (20.5) | 186 666 (14.9) |
| Anemia | 51 402 (3.9) | 10 521 (11.4) | 40 881 (3.3) |
| Current/recent smoker (within 1 y) | 376 391 (27.9) | 22 162 (23.5) | 354 229 (28.2) |
| Catheterization Laboratory Visit | |||
| CAD presentation, No. (%) | |||
| No presentation documented | 116 285 (8.6) | 6492 (6.9) | 109 793 (8.8) |
| Other symptoms | 36 897 (2.7) | 2285 (2.4) | 34 612 (2.8) |
| Stable angina | 216 050 (16.0) | 8240 (8.7) | 207 810 (16.6) |
| Unstable angina | 501 711 (37.2) | 27 500 (29.1) | 474 211 (37.8) |
| Non-STEMI | 262 515 (19.5) | 26 448 (28.0) | 236 067 (18.8) |
| STEMI | 215 727 (16.0) | 23 594 (25.0) | 192 133 (15.3) |
| Heart failure within 2 wk, No. (%) | 136 967 (10.2) | 23 815 (25.2) | 11 3152 (9.0) |
| Cardiomyopathy or left ventricular systolic dysfunction, No. (%) | 137 706 (10.2) | 17 223 (18.2) | 120 483 (9.6) |
| Left ventricular ejection fraction before PCI, mean (SD), % | 52.3 (12.5) | 46.8 (15.0) | 52.6 (12.3) |
| Cardiogenic shock within 24 h, No. (%) | 25 553 (1.9) | 8573 (9.1) | 16 980 (1.4) |
| IABP used during admission, No. (%) | 34 421 (2.6) | 10 861 (11.5) | 23 560 (1.9) |
| IABP used before PCI, No. (%) | 3439 (0.3) | 1141 (1.2) | 2298 (0.2) |
| Cardiac arrest within 24 h, No. (%) | 25 400 (1.9) | 5829 (6.2) | 19 571 (1.6) |
| Fluoroscopy time, mean (SD), min | 14.8 (11.7) | 17.1 (13.6) | 14.6 (11.5) |
| Outcomes, No. (%) | |||
| Death in hospital | 16 019 (1.2) | 9340 (9.9) | 6679 (0.5) |
| Myocardial infarction (biomarker positive) | 29 184 (2.2) | 3518 (3.7) | 25 666 (2.0) |
| Cardiogenic shock | 13 838 (1.0) | 5965 (6.3) | 7873 (0.6) |
| Heart failure | 14 705 (1.1) | 6101 (6.5) | 8604 (0.7) |
| CVA/stroke | 3305 (0.2) | 1033 (1.1) | 2272 (0.2) |
| Other vascular complications requiring treatment | 6271 (0.5) | 1395 (1.5) | 4876 (0.4) |
| Received RBCs/whole blood transfusion | 38 809 (2.9) | 14 714 (15.6) | 24 095 (1.9) |
| Bleeding event within 72 h | 25 247 (1.9) | 6465 (6.8) | 18 782 (1.5) |
Abbreviations: AKI, acute kidney injury; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CABG, coronary artery bypass grafting; CAD, coronary artery disease; CVA, cerebrovascular accident; GFR, glomerular filtration rate; IABP, intra-aortic balloon pump; MDRD, Modification of Diet in Renal Disease Study; PCI, percutaneous coronary intervention; RBCs, red blood cells; Scr, serum creatinine; STEMI, ST-elevation myocardial infarction.
P < .001 for all comparisons between the AKI and no AKI groups. Continuous variables were compared using unpaired, 2-tailed t test; categorical variables, using the χ2 or Fisher exact test.
Classification/staging system for AKI is as follows: Stage 1: increase in serum creatinine of more than or equal to 0.3 mg/dL (≥26.4 μmol/L) or increase to more than or equal to 150% to 200% (1.5- to 2-fold) from baseline. Stage 2: increase in serum creatinine to more than 200% to 300% (>2-fold to 3-fold) from baseline. Stage 3: increase in serum creatinine to more than 300% (>3-fold) from baseline (or serum creatinine of more than or equal to 4.0 mg/dL [≥354 μmol/L] with an acute increase of at least 0.5 mg/dL [44 μmol/L]).
The MDRD equation is as follows: GFR (mL/min/1.73 m2) = 175 × (Scr)−1.154 × (Age)−0.203 × (0.742 if female) × (1.212 if African American).