Table 1.
Baseline patient characteristics. Descriptive data stratified by preoperative chronotropic incompetence (defined as chronotropic index [CI] <0.6). Data are presented as n (%) or mean (standard deviations; sd). Continuous data are reported to one decimal place, and categorical data are rounded to the nearest whole number.
| Whole cohort | CI <0.6 | CI ≥0.6 | |
|---|---|---|---|
| Number of cases, n | 1324 | 396 | 928 |
| Mean age (sd) | 64.2 (10.4) | 64.8 (10.5) | 64.0 (10.3) |
| Age ≥70 yr (%) | 447 (33.8) | 149 (37.6) | 298 (32.1) |
| Male sex (%) | 817 (61.7) | 236 (59.6) | 581 (62.6) |
| Co-morbid disorder (%) | |||
| Atrial fibrillation | 50 (3.8) | 23 (5.8) | 27 (2.9) |
| Diabetes mellitus | 243 (18.4) | 90 (22.7) | 153 (16.5) |
| Hypertension | 725 (54.8) | 238 (60.1) | 487 (52.5) |
| Diagnosis of congestive cardiac failure | 16 (1.2) | 10 (2.5) | 6 (0.7) |
| Coronary artery disease | 153 (11.6) | 72 (18.2) | 81 (8.7) |
| Peripheral vascular disease | 39 (3.0) | 18 (4.6) | 21 (2.3) |
| Previous stroke or transient ischaemic attack | 52 (3.9) | 25 (6.3) | 27 (2.9) |
| Chronic obstructive pulmonary disease | 163 (12.3) | 74 (18.7) | 89 (9.6) |
| Preoperative estimated glomerular filtration rate <60 ml min−1 (1.73 m2)−1 | 108 (8.2) | 45 (11.4) | 63 (6.8) |
| Surgical procedure type (%) | |||
| Vascular | 23 (1.7) | 12 (3.0) | 11 (1.2) |
| Intraperitoneal or retroperitoneal | 29 (2.2) | 5 (1.3) | 24 (2.6) |
| Urological or gynaecological | 437 (33.0) | 131 (33.1) | 306 (33.0) |
| Intra-thoracic | 306 (23.3) | 107 (27.0) | 199 (21.4) |
| Orthopaedic | 398 (30.1) | 106 (26.8) | 292 (31.5) |
| Head and neck | 87 (6.6) | 23 (5.8) | 64 (6.9) |
| Other | 39 (3.0) | 11 (2.8) | 28 (3.0) |
| High-risk surgery (%) | 756 (57.1) | 221 (55.8) | 535 (57.7) |
| ASA physical status (%) | |||
| 1 | 99 (7.5) | 24 (6.1) | 75 (8.1) |
| 2 | 772 (58.4) | 207 (52.3) | 565 (61.0) |
| 3 | 433 (32.8) | 159 (40.2) | 274 (29.6) |
| 4 | 18 (1.4) | 6 (1.5) | 12 (1.3) |
| Preoperative medication (%) | |||
| Beta blockers | 213 (16.1) | 137 (34.6) | 76 (8.2) |
| Diltiazem or verapamil | 25 (1.9) | 11 (2.8) | 14 (1.5) |
| Haemodynamic variables | |||
| Resting heart rate (beats min−1) | 77 (14.3) | 75 (15.2) | 78 (3.7) |
| Resting systolic blood pressure (mm Hg) | 129 (18.1) | 127 (9.0) | 130 (17.6) |
| Resting pulse pressure (mm Hg) | 51 (16.5) | 51 (17.9) | 52 (15.8) |