Table 1.
Baseline Characteristics and Risk Factors for the Primary Composite Outcome of Hospital Mortality or Initiation of Renal Replacement Therapy
| Outcome (–) | Outcome (+) | ||
|---|---|---|---|
| Baseline Characteristics and Outcomes | n = 578 | n = 25 | P |
| Demographics | |||
| Age | 65 (16) | 67 (14) | 0.63 |
| Male gender | 367 (63.5) | 13 (52.0) | 0.24 |
| Body mass index, kg/m2 | 27.8 (5.3) | 28.4 (5.9) | 0.66 |
| Preoperative risk factors | |||
| Left ventricular ejection fraction % | 53 (12) | 44 (19) | 0.03 |
| Unstable angina or recent myocardial infarction | 143 (24.7) | 6 (24.0) | 0.9 |
| Diabetes | 129 (22.3) | 10 (40.0) | 0.04 |
| Hypertension | 419 (72.5) | 18 (72.0) | 0.9 |
| Chronic obstructive pulmonary disease | 57 (9.9) | 2 (8.0) | 0.9 |
| Hyperlipidemia | 379 (65.6) | 13 (52.0) | 0.16 |
| Statin use | 310 (53.6) | 12 (48.0) | 0.58 |
| Smoker | 44 (7.6) | 0 (0.0) | 0.25 |
| Euroscorea | 6.8 (3.5) | 10.5 (3.1) | < 0.001 |
| Preoperative hemoglobin, g/dL | 12.9 (1.9) | 10.7 (2.1) | < 0.001 |
| Preoperative serum creatinine, mg/dL | 1.0 (0.3) | 1.6 (0.7) | < 0.001 |
| Preoperative eGFRb, mL/min/1.73 m2 | 76 (22) | 49 (24) | < 0.001 |
| Preoperative eGFR < 60 mL/min/1.73 m2 | 136 (23.5) | 16 (64.0) | < 0.001 |
| Intraoperative/postoperative risk factors | |||
| Reoperation | 123 (21.3) | 11 (44.0) | 0.01 |
| Surgical procedure | |||
| On-pump CABG | 105 (18.2) | 1 (4.0) | 0.16 |
| Off-pump CABG | 23 (4.0) | 0 (0.0) | |
| Valve ± other | 321 (55.5) | 15 (60.0) | |
| Aortic root ± other | 84 (14.5) | 5 (20.0) | |
| Ventricular assist device/extracorporeal membrane oxygenation/transplant/other | 45 (7.8) | 4 (16.0) | |
| Case urgency | |||
| Elective | 445 (77.0) | 11 (44.0) | < 0.001 |
| Nonelective | 133 (23.0) | 14 (56.0) | |
| Cardiopulmonary bypass duration | 106 (48) | 173 (78) | < 0.001 |
| Nadir intraoperative hemoglobin, g/dL | 8.3 (1.4) | 7.6 (0.9) | < 0.001 |
| Peak intraoperative glucose, mg/dL | 189 (47) | 226 (65) | 0.01 |
| pRBC transfusion, n (%) | 224 (38.8) | 20 (80.0) | < 0.001 |
| Transfused volume of pRBCs (mL) | |||
| Intraoperatively | 0 (0–250) | 750 (0–1,250) | < 0.001 |
| Within 48 hr postoperatively | 0 (0–0) | 0 (0–1,300) | < 0.001 |
| Outcomes | |||
| Acute kidney injuryc | |||
| Total | 134 (23.2) | 21 (84.0) | < 0.001 |
| Stage 1 | 108 (18.7) | 6 (24.0) | |
| Stage 2 | 18 (3.1) | 2 (8.0) | |
| Stage 3 | 8 (1.4) | 13 (52.0) | |
| Length of stay (d) | |||
| ICU | 2.3 (1.3–4.3) | 10.1 (6.1–21.5) | < 0.001 |
| Hospital | 8.5 (6.6–11.6) | 19.6 (10.8–23.6) | < 0.001 |
eGFR = estimated glomerular filtration rate, CABG = coronary artery bypass graft, pRBC = packed RBC.
a
Euroscore calculated from modified variables defined according to data available within the medical record and institutional usage to reasonably reflect Euroscore definitions.
b
eGFR calculated according to the Chronic Kidney Disease Epidemiology Collaboration equation.
c
Acute kidney injury defined over 7 days postoperatively according to creatinine-based Kidney Disease: Improving Global Outcomes practice guidelines.