Table 1. Baseline characteristics of the overall cohort.
| All patients | SIMA | BIMA | |
| Number of patients | 49702 | 49143 | 559 |
| Percent of study population | 100 | 98.9 | 1.1 |
| Age, mean (SD), years | 66.7 (9.2) | 66.7 (9.2) | 64.4 (11.1) |
| Female sex (%) | 21.0 | 21.0 | 25.9 |
| Estimated GFR, mean (SD), mL/min/1.73 m2 | 75 (21) | 75 (21) | 75 (22) |
| Diabetes mellitus (%) | 22.7 | 22.8 | 13.7 |
| Hypertension (%) | 56.1 | 56.1 | 51.3 |
| Hyperlipidemia (%) | 57.6 | 58.5 | 57.6 |
| Peripheral vascular disease (%) | 7.3 | 7.3 | 13.6 |
| Current smoking (%) | 18.9 | 19.1 | 18.9 |
| Chronic obstructive pulmonary disease (%) | 4.6 | 4.6 | 4.3 |
| Prior myocardial infarction (%) | 42.9 | 42.9 | 42.8 |
| Prior stroke (%) | 4.3 | 4.3 | 3.9 |
| Heart failure (%) | 3.7 | 3.7 | 2.7 |
| Left ventricular function | |||
| Ejection fraction >50% (%) | 73.5 | 73.6 | 70.4 |
| Ejection fraction 30–50% (%) | 23.3 | 23.3 | 25.3 |
| Ejection fraction <30% (%) | 3.2 | 3.2 | 4.3 |
| Surgery within 7 days of decision (%) | 28.2 | 28.2 | 32.4 |
| CABG without cardiopulmonary bypass (%) | 6.3 | 6.2 | 18.6 |
| No. of grafted coronary arteries, mean (SD) | 3.5 (0.95) | 3.5 (0.95) | 3.1 (0.90) |
| Radial artery used (%) | 5.7 | 5.5 | 16.2 |
| Acute perioperative kidney injury (%) | 13.2 | 13.2 | 9.2 |
BIMA = bilateral internal mammary artery, GFR = glomerular filtration rate, CABG = coronary artery bypass grafting, SD = standard deviation, SIMA = single internal mammary artery. Acute perioperative kidney injury was defined as a >0.3 mg/dL (26 µmol/L) increase in postoperative creatinine values.