Subgroup analysis by pre-existing chronic kidney disease: effect of methylprednisolone versus placebo on the risk of acute kidney injury (4 secondary definitions)
| Variable | No. of events/no. of patients (%) | Adjusted relative risk (95% CI)* | p value (interaction)* | |
|---|---|---|---|---|
| Methylprednisolone | Placebo | |||
| Acute kidney injury or death† | ||||
| Chronic kidney disease‡ | ||||
| Yes | 521/1084 (48.1) | 507/1050 (48.3) | 1.00 (0.88 to 1.13) | 0.5 |
| No | 991/2563 (38.7) | 952/2589 (36.8) | 1.06 (0.97 to 1.16) | 0.5 |
| Stage 2 or higher acute kidney injury§ | ||||
| Chronic kidney disease‡ | ||||
| Yes | 119/1084 (11.0) | 134/1050 (12.8) | 0.87 (0.68 to 1.11) | 0.1 |
| No | 241/2563 (9.4) | 222/2589 (8.6) | 1.10 (0.92 to 1.33) | 0.1 |
| Stage 3 acute kidney injury¶ | ||||
| Chronic kidney disease‡ | ||||
| Yes | 71/1084 (6.6) | 83/1050 (7.9) | 0.83 (0.60 to 1.14) | 0.5 |
| No | 74/2563 (2.9) | 78/2589 (3.0) | 0.96 (0.70 to 1.32) | 0.5 |
| Acute dialysis within 30 days of surgery | ||||
| Chronic kidney disease‡ | ||||
| Yes | 54/1084 (5.0) | 48/1050 (4.6) | 1.09 (0.74 to 1.62) | 0.9 |
| No | 41/2563 (1.6) | 40/2589 (1.5) | 1.03 (0.67 to 1.60) | 0.9 |
Note: CI = confidence interval.
↵* Analyzed using modified Poisson regression; models were adjusted for 9 prespecified covariates: age (yr); sex; left ventricular function < 50%; diabetes; prerandomization use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, statins, or diuretics; surgery type (isolated valve [referent], isolated coronary artery bypass grafting [CABG], CABG and valve, or other); and evidence of nonelective surgery (defined as preoperative use of inotropes or vasopressors, preoperative use of an intra-aortic balloon pump or ventricular assist device, or evidence of myocardial infarction in the 30 days before surgery).
↵† Met the primary definition of acute kidney injury (i.e., an increase in serum creatinine concentration of ≥ 0.3 mg/dL [≥ 26.5 μmol/L] or ≥ 50% (from the preoperative value) within 14 days of surgery, or receipt of dialysis within 30 days of surgery) or died within 48 hours of surgery.
↵‡ Chronic kidney disease was defined as a preoperative estimated glomerular filtration rate < 60 mL/min/1.73m2, calculated using CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration equation).14
↵§ Defined as (i) a postoperative percentage increase in serum creatinine concentration of 100% or more (from the preoperative value) within 14 days of surgery, (ii) an increase in postoperative serum creatinine concentration to an absolute value of ≥ 4.0 mg/dL (≥ 353.6 μmol/L) (while meeting the primary definition) within 14 days of surgery, or (iii) receipt of dialysis within 30 days of surgery.
↵¶ Defined as (i) a postoperative percentage increase in serum creatinine concentration of ≥ 200% from the preoperative value within 14 days of surgery, (ii) an increase in postoperative serum creatinine concentration of ≥ 0.3 mg/dL (≥ 26.5 μmol/L) to an absolute value of ≥ 4.0 mg/dL (≥ 353.6 μmol/L) (while meeting the primary definition) within 14 days of surgery, or (iii) receipt of dialysis within 30 days of surgery.