Baseline characteristics, stratified by type of surgery*
| Variable | No. (%) of patients† | ||||
|---|---|---|---|---|---|
| Isolated CABG n = 52 546 | Single valve‡ n = 10 368 | Multiple valves§ n = 1309 | CABG + single valve‡ n = 7936 | CABG + multiple valves§ n = 665 | |
| Age, yr, mean ± SD | 65.9 ± 9.8 | 67.5 ± 11.2 | 68.3 ± 11.4 | 72.6 ± 9.0 | 72.5 ± 9.1 |
| 40–64 | 22 925 (43.6) | 3969 (38.3) | 458 (35.0) | 1460 (18.4) | 129 (19.4) |
| 65–74 | 18 626 (35.4) | 3197 (30.8) | 395 (30.2) | 2795 (35.2) | 216 (32.5) |
| 75–84 | 10 220 (19.4) | 2801 (27.0) | 388 (29.6) | 3128 (39.4) | 269 (40.5) |
| ≥ 85 | 775 (1.5) | 401 (3.9) | 68 (5.2) | 553 (7.0) | 51 (7.7) |
| Rural residence | 8204 (15.6) | 1756 (16.9) | 203 (15.5) | 1457 (18.4) | 143 (21.5) |
| Income quintile | |||||
| 1 (lowest) | 10 003 (19.0) | 1728 (16.7) | 245 (18.7) | 1370 (17.3) | 102 (15.3) |
| 2 | 10 724 (20.4) | 1959 (18.9) | 257 (19.6) | 1608 (20.3) | 148 (22.3) |
| 3 | 10 627 (20.2) | 2117 (20.4) | 249 (19.0) | 1609 (20.3) | 157 (23.6) |
| 4 | 10 714 (20.4) | 2214 (21.4) | 257 (19.6) | 1705 (21.5) | 127 (19.1) |
| 5 (highest) | 10 184 (19.4) | 2310 (22.3) | 292 (22.3) | 1617 (20.4) | 129 (19.4) |
| Missing | 294 (0.6) | 40 (0.4) | 9 (0.7) | 27 (0.3) | ≤ 5** |
| Hypertension | 46 111 (87.8) | 7954 (76.7) | 1007 (76.9) | 7185 (90.5) | 595 (89.5) |
| Atrial fibrillation | 2373 (4.5) | 1343 (13.0) | 304 (23.2) | 990 (12.5) | 155 (23.3) |
| Recent MI | 20 684 (39.4) | 422 (4.1) | 55 (4.2) | 1659 (20.9) | 132 (19.8) |
| Remote MI | 9432 (17.9) | 679 (6.5) | 91 (7.0) | 1295 (16.3) | 108 (16.2) |
| Previous PCI | 8773 (16.7) | 617 (6.0) | 70 (5.3) | 1004 (12.7) | 68 (10.2) |
| Heart failure | 10 126 (19.3) | 4729 (45.6) | 848 (64.8) | 3714 (46.8) | 430 (64.7) |
| LVEF, % | |||||
| ≥ 50 | 32 237 (61.4) | 8843 (85.3) | 1040 (79.4) | 5630 (70.9) | 435 (65.4) |
| 35–50 | 12 762 (24.3) | 967 (9.3) | 176 (13.4) | 1398 (17.6) | 145 (21.8) |
| 20–35 | 4911 (9.3) | 346 (3.3) | 67 (5.1) | 654 (8.2) | 66 (9.9) |
| < 20 | 905 (1.7) | 43 (0.4) | 13 (1.0) | 139 (1.8) | 13 (2.0) |
| Missing | 1731 (3.3) | 169 (1.6) | 13 (1.0) | 115 (1.4) | 6 (0.9) |
| Cerebrovascular disease | 5132 (9.8) | 970 (9.4) | 163 (12.5) | 1073 (13.5) | 82 (12.3) |
| Peripheral arterial disease | 6424 (12.2) | 1079 (10.4) | 139 (10.6) | 1389 (17.5) | 108 (16.2) |
| COPD or asthma | 14 702 (28.0) | 3301 (31.8) | 439 (33.5) | 2726 (34.3) | 251 (37.7) |
| Diabetes mellitus | 25 267 (48.1) | 3218 (31.0) | 422 (32.2) | 3639 (45.9) | 266 (40.0) |
| Severe obesity | 20 490 (39.0) | 3951 (38.1) | 563 (43.0) | 3106 (39.1) | 281 (42.3) |
| Hypothyroidism | 969 (1.8) | 206 (2.0) | 40 (3.1) | 186 (2.3) | 18 (2.7) |
| Liver disease | 351 (0.7) | 153 (1.5) | 37 (2.8) | 81 (1.0) | 11 (1.7) |
| Anemia | 4918 (9.4) | 977 (9.4) | 203 (15.5) | 1113 (14.0) | 136 (20.5) |
| Venous thromboembolism | 173 (0.3) | 57 (0.5) | 10 (0.8) | 46 (0.6) | ≤ 5** |
| Dialysis | 1047 (2.0) | 195 (1.9) | 34 (2.6) | 233 (2.9) | 22 (3.3) |
| Baseline creatinine, μmol/L | |||||
| < 120 | 43 934 (83.6) | 8538 (82.3) | 1038 (79.3) | 6158 (77.6) | 522 (78.5) |
| 120–179 | 4487 (8.5) | 855 (8.2) | 163 (12.5) | 1037 (13.1) | 93 (14.0) |
| ≥ 180 | 1698 (3.2) | 261 (2.5) | 63 (4.8) | 381 (4.8) | 32 (4.8) |
| Missing | 2427 (4.6) | 714 (6.9) | 45 (3.4) | 360 (4.5) | 18 (2.7) |
| Chronic renal disease | 2109 (4.0) | 399 (3.8) | 66 (5.0) | 516 (6.5) | 43 (6.5) |
| Dementia | 98 (0.2) | 27 (0.3) | ≤ 5** | 41 (0.5) | 6 (0.9) |
| Depression | 733 (1.4) | 157 (1.5) | 37 (2.8) | 149 (1.9) | 13 (2.0) |
| Psychosis | 102 (0.2) | 33 (0.3) | 6 (0.5) | 17 (0.2) | ≤ 5** |
| Primary tumour | 2486 (4.7) | 601 (5.8) | 96 (7.3) | 539 (6.8) | 48 (7.2) |
| Metastatic cancer | 248 (0.5) | 72 (0.7) | 10 (0.8) | 40 (0.5) | ≤ 5** |
| Charlson score, median (IQR) | 2 (0–3) | 1 (0–2) | 1 (0–2) | 2 (0–3) | 2 (1–3) |
| Frailty¶ | 8623 (16.4) | 1204 (11.6) | 213 (16.3) | 1491 (18.8) | 154 (23.2) |
| No. of CABG grafts, median (IQR) | 3 (3–4) | – | – | 2 (1–3) | 2 (1–3) |
Note: CABG = coronary artery bypass grafting, COPD = chronic obstructive pulmonary disease, IQR = interquartile range, LVEF = left ventricular ejection fraction, MI = myocardial infarction, PCI = percutaneous coronary intervention, SD = standard deviation.
↵* Comparisons between surgery type yielded p < 0.001 for most variables, with the exception of severe obesity (p = 0.004), psychosis (p = 0.025) and metastatic cancer (p = 0.03).
↵† Unless otherwise stated.
↵‡ Mitral, aortic or tricuspid valve surgery.
↵§ Mitral, aortic or tricuspid valve surgery.
↵¶ According to the Johns Hopkins Adjusted Clinical Groups frailty-defining diagnoses indicator.28–33
↵** Small cells with values ≤ 5 were not reported as per ICES policy, where back calculation may occur.