Patient demographic and clinical characteristics
| Overall | On-pump CABG cohort (n=10 109) | Off-pump CABG cohort (n=11 757) | |||||
| First procedure (n=8480) | Non-first procedure (n=1629) | P value* | First procedure (n=8279) | Non-first procedure (n=3478) | P value* | ||
| Age, mean (SD), years | 61.2 (8.6) | 60.8 (8.5) | 60.5 (8.5) | 0.33 | 61.7 (8.8) | 61.2 (8.6) | 0.005 |
| Female, n (%) | 4975 (22.8) | 1893 (22.3) | 388 (23.8) | 0.19 | 1887 (22.8) | 807 (23.2) | 0.63 |
| BMI, mean (SD), kg/m2† | 25.7 (3.0) | 25.8 (3.0) | 25.7 (3.1) | 0.94 | 25.6 (3.0) | 25.6 (3.1) | 0.65 |
| Smoking, n (%) | 12 117 (55.4) | 4578 (54.0) | 866 (53.2) | 0.54 | 4683 (56.6) | 1990 (57.2) | 0.51 |
| Diabetes, n (%) | 4952 (22.6) | 2017 (23.8) | 353 (21.7) | 0.06 | 1820 (22.0) | 762 (21.9) | 0.93 |
| Hypertension, n (%) | 13 957 (63.8) | 5418 (63.9) | 1069 (65.6) | 0.18 | 5291 (63.9) | 2179 (62.7) | 0.20 |
| Hyperlipidaemia, n (%) | 16 128 (73.8) | 6178 (72.9) | 1176 (72.2) | 0.58 | 6172 (74.6) | 2602 (74.8) | 0.76 |
| Prior COPD, n (%) | 139 (0.6) | 44 (0.5) | 10 (0.6) | 0.63 | 57 (0.7) | 28 (0.8) | 0.50 |
| Prior MI, n (%) | 8189 (37.5) | 3209 (37.8) | 633 (38.9) | 0.44 | 3085 (37.3) | 1262 (36.3) | 0.32 |
| Prior stroke, n (%) | 1684 (7.7) | 632 (7.5) | 122 (7.5) | 0.96 | 648 (7.8) | 282 (8.1) | 0.61 |
| Prior PCI, n (%) | 1233 (5.6) | 433 (5.1) | 89 (5.5) | 0.55 | 523 (6.3) | 188 (5.4) | 0.06 |
| Prior cardiac surgery, n (%) | 828 (3.8) | 322 (3.8) | 59 (3.6) | 0.73 | 309 (3.7) | 138 (4.0) | 0.54 |
| Angina, n (%) | 18 491 (84.6) | 7032 (82.9) | 1352 (83.0) | 0.94 | 7061 (85.3) | 3046 (87.6) | 0.001 |
| NYHA Ⅲ/Ⅳ, n (%) | 6923 (31.7) | 2367 (27.9) | 502 (30.8) | 0.017 | 2809 (33.9) | 1245 (35.8) | 0.05 |
| eGFR, median (IQR), mL/min/1.73 m2‡ | 91.6 (78.1–107.0) | 92.0 (78.4–107.5) | 91.2 (78.4–106.6) | 0.41 | 91.5 (77.8–106.5) | 91.2 (78.4–107.2) | 0.40 |
| PAD, n (%) | 2790 (12.8) | 881 (10.4) | 146 (9.0) | 0.08 | 1194 (14.4) | 569 (16.4) | 0.007 |
| LM disease, n (%) | 4145 (19.0) | 1580 (18.6) | 284 (17.4) | 0.25 | 1633 (19.7) | 648 (18.6) | 0.17 |
| Three-vessel disease, n (%) | 13 296 (60.8) | 5692 (67.1) | 1116 (68.5) | 0.27 | 4507 (54.4) | 1981 (57.0) | 0.012 |
| Preoperative LVEF, mean (SD) | 61.1 (7.4) | 60.9 (7.6) | 60.6 (7.8) | 0.16 | 61.3 (7.2) | 61.5 (6.9) | 0.17 |
| Aortic calcification, n (%) | 1774 (8.1) | 437 (5.2) | 110 (6.8) | 0.009 | 863 (10.4) | 364 (10.5) | 0.95 |
| EuroSCORE >3, n (%) | 4990 (22.8) | 1727 (20.4) | 304 (18.7) | 0.33 | 2075 (25.1) | 884 (25.4) | 0.69 |
*The χ2 test is used for categorical variables and the Kruskal-Wallis test is used for continuous variables between first and non-first procedure groups in specific CABG cohorts. Those achieving a statistically significant level of 0.05 are in bold.
†BMI=weight (kg)/(height [m])2.
‡eGFR (mL/min/1.73 m2)=186×(serum creatinine level [mg/dL])−1.154×(age [years])−0.203.
BMI, body mass index; CABG, coronary artery bypass grafting; COPD, chronic obstructive pulmonary disease; eGFR, estimated glomerular filtration rate; EuroSCORE, European System for Cardiac Operative Risk Evaluation; LM, left main; LVEF, left ventricular ejection fraction; MI, myocardial infarction; NYHA, New York Heart Association; PAD, peripheral artery disease; PCI, percutaneous coronary intervention.