Baseline characteristics of 7286 patients in the SIRS kidney substudy,*† by treatment group
| Characteristic | No. (%) of patients‡ | |
|---|---|---|
| Methylprednisolone n = 3647 | Placebo n = 3639 | |
| Age, yr, mean ± SD | 68 ± 14 | 68 ± 14 |
| Sex, female | 1461 (40.1) | 1423 (39.1) |
| Body mass index, mean ± SD | 27 (6) | 27 (5) |
| Ethnic origin†§ | n = 3404 | n = 3399 |
| White | 2097 (61.6) | 2070 (60.9) |
| Asian (including South Asian) | 904 (26.6) | 894 (26.3) |
| Hispanic | 233 (6.8) | 235 (6.9) |
| Middle Eastern | 144 (4.2) | 156 (4.6) |
| African | 21 (0.6) | 39 (1.2) |
| Aboriginal | 5 (0.2) | 5 (0.2) |
| Year of randomization | ||
| 2007–2010 | 293 (8.0) | 298 (8.2) |
| 2011 | 735 (20.2) | 709 (19.5) |
| 2012 | 1426 (39.1) | 1438 (39.5) |
| 2013 | 1193 (32.7) | 1194 (32.8) |
| Location | ||
| North America | 1617 (44.3) | 1603 (44.1) |
| Asia | 882 (24.2) | 878 (24.1) |
| Europe | 511 (14.0) | 511 (14.0) |
| South America | 282 (7.7) | 282 (7.8) |
| Australia | 220 (6.0) | 222 (6.1) |
| Middle East | 135 (3.7) | 143 (3.9) |
| Medical history | ||
| Hypertension | 2408 (66.0) | 2385 (65.5) |
| Congestive heart failure | 970 (26.6) | 993 (27.3) |
| Diabetes | 932 (25.6) | 939 (25.8) |
| Atrial fibrillation | 816 (22.4) | 848 (23.3) |
| Previous cardiac surgery | 579 (15.9) | 550 (15.1) |
| CABG | 195 (5.4) | 188 (5.2) |
| Valve | 340 (9.3) | 313 (8.6) |
| Other | 110 (3.0) | 118 (3.2) |
| Peripheral artery disease | 352 (9.7) | 392 (10.8) |
| Smoking (within 12 mo) | 453 (12.4) | 466 (12.8) |
| Stroke | 292 (8.0) | 301 (8.3) |
| Left ventricular ejection fraction† | n = 3618 | n = 3600 |
| ≥ 50% | 2281 (63.0) | 2313 (64.3) |
| < 50% | 1337 (37.0) | 1287 (35.8) |
| eGFR¶ | ||
| eGFR, mL/min/1.73m2, mean ± SD | 73 ± 22 | 73 ± 22 |
| eGFR ≥ 60 mL/min/1.73m2 | 2563 (70.3) | 2589 (71.2) |
| Mean ± SD, mL/min/1.73m2 | 84 ± 17 | 83 ± 17 |
| eGFR < 60 mL/min/1.73m2 | 1084 (29.7) | 1050 (28.9) |
| Mean ± SD, mL/min/1.73m2 | 47 ± 10 | 47 ± 10 |
| eGFR ≤ 45 mL/min/1.73m2 | 395 (10.8) | 393 (10.8) |
| eGFR ≤ 30 mL/min/1.73m2 | 81 (2.2) | 80 (2.2) |
| Pre-randomization medication use | ||
| Statin | 2058 (56.4) | 2018 (55.5) |
| ACE inhibitor or ARB | 2016 (55.3) | 1983 (54.5) |
| ACE inhibitor† | n = 3404 1341 (39.4) | n = 3399 1304 (38.4) |
| ARB† | n = 3404 593 (17.4) | n = 3399 594 (17.5) |
| Diuretic | 2016 (55.3) | 2007 (55.2) |
| Acetylsalicylic acid | 1681 (46.1) | 1623 (44.6) |
| Surgery | ||
| Evidence of non-elective surgery** | 711 (19.5) | 693 (19.0) |
| Preoperative use of inotropes or vasopressors | 300 (8.2) | 308 (8.5) |
| Preoperative use of IABP or VAD | 53 (1.5) | 69 (1.9) |
| Previous MI within 30 d of surgery | 439 (12.0) | 395 (10.9) |
| Surgery type | ||
| Isolated CABG | 797 (21.9) | 737 (20.3) |
| Isolated valve | 1195 (32.8) | 1216 (33.4) |
| CABG and valve | 878 (24.1) | 913 (25.1) |
| Other†† | 777 (21.3) | 773 (21.2) |
Note: ACE = angiotensin-converting enzyme, ARB = angiotensin receptor blocker, CABG = coronary artery bypass graft, eGFR = estimated glomerular filtration rate, IABP = intra-aortic balloon pump, MI = myocardial infarction, SD = standard deviation, SIRS = Steroids in Cardiac Surgery, VAD = ventricular assist device.
↵* All baseline characteristics (except surgical data) were assessed before randomization (surgical data [i.e., preoperative use of inotropes or vasopressors, or IABP or VAD, and surgery type] were assessed at the time of surgery; the median time from randomization to surgery was 17 [interquartile range 3–26] hours; time of randomization was missing for all 483 pilot patients; time of surgery was missing for 2 patients from the main study).
↵† All patients in the pilot study (methylprednisolone [n = 243] and placebo [n = 240]) were missing data on prerandomization body mass index, ethnicity, and prerandomization use of ACE inhibitors or ARBs (however, information on combined ACE/ARB use was available). Data on left ventricular ejection fraction were missing in 68 patients (methylprednisolone [n = 29], placebo [n = 39]). Data on the remaining variables were missing for < 2% of patients. For missing data on categorical variables, the condition/medication/procedure was considered absent; for calculating eGFR, patients missing ethnicity were assumed to be white. Pilot patients who answered “yes” to taking a statin or a nonstatin lipid-lowering agent were assumed to be taking a statin.
↵‡ Unless stated otherwise.
↵§ Data on self-reported ethnic origin were collected and recorded by a research assistant using prespecified categories (black or white ethnic origin is needed for the calculation of eGFR).
↵¶ Calculated using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration equation).14
↵** Evidence of nonelective surgery was defined by preoperative use of inotropes, vasopressors, an IABP or a VAD, or history of an MI in the 30 days before surgery.
↵†† Surgery type “other” includes patients who had an aorta surgery (patch enlargement, Bentall procedure, ascending aortic replacement, arch replacement, and/or descending thoracic aortic replacement) or cardiac ablation surgery, or some type of “other cardiac procedure.” Patients in this category may have had one of CABG or valve surgery, but not both; if a patient had both CABG and valve as well as aorta surgery and/or cardiac ablation surgery, they are included in the “CABG and valve” category.