Table 1.
Baseline characteristics of unselected patients and patients selected for cardiac troponin testing in UK and US. Values are numbers (percentages) unless stated otherwise
| Characteristics | Unselected patients (n=1054) | Selected patients (UK) (n=5815) | Selected patients (US) (n=1631) |
|---|---|---|---|
| Female sex | 549/1054 (52.0) | 2552 (43.9) | 720/1631 (44.1) |
| Mean (SD) age, years | 54 (23) | 64 (16) | 57 (15) |
| Chest pain | 183/1042 (17.6) | 4825/5813 (83.0) | 835/1572 (51.2) |
| Risk factors | |||
| Smoker | 299/902 (33.1) | 1105/3615 (30.6) | 592/1631 (36.3) |
| Hypertension | 337/1041 (32.4) | 1969/5233 (37.6) | 1074/1631 (65.9) |
| Hyperlipidaemia | 299/1041 (28.7) | 1611/5232 (30.8) | 696/1631 (42.7) |
| Past medical history | |||
| Ischaemic heart disease | 193/1042 (18.5) | 1846/5240 (35.2) | 337/1631 (20.7) |
| Myocardial infarction | 109/1041 (10.5) | 1082/5235 (20.7) | 190/1629 (11.7) |
| Cerebrovascular disease | 99/1041 (9.5) | 475/5340 (9.1) | 153/1631 (9.4) |
| Diabetes mellitus | 106/1047 (10.1) | 842/5233 (16.1) | 505/1631 (31.0) |
| PCI | 52/1046 (5.0) | 611/5233 (11.7) | 150/1621 (9.2) |
| CABG | 32/1046 (3.1) | 330/5228 (6.3) | 73/1620 (4.5) |
| Drugs at presentation | |||
| Aspirin | 180 (17.5) | 1344 (33.7) | 627 (38.4) |
| Clopidogrel | 81 (7.9) | 468 (11.8) | 76 (4.7) |
| β blockers | 149 (14.5) | 1082 (27.2) | 589 (36.1) |
| ACE-I/ARB | 189 (18.3) | 1311 (32.9) | 578 (35.4) |
| Statin | 249 (24.2) | 1578 (39.6) | 556 (34.1) |
| Warfarin | 44 (4.3) | 278 (7.0) | 115 (7.1) |
| Haemodynamics | |||
| Mean (SD) systolic blood pressure, mm Hg | 130.5 (22.2) | 137.5 (26.0) | 143.7 (28.5) |
| Mean (SD) heart rate, beats/min | 86.9 (22.3) | 81.2 (22.9) | 90.2 (34.3) |
| Killip class | |||
| I | 930/1037 (89.7) | 4847/5336 (90.8) | - |
| II | 85/1037 (8.2) | 408/5336 (7.6) | - |
| III | 15/1037 (1.4) | 75/5336 (1.4) | - |
| IV | 1/1037 (0.1) | 6/5336 (0.1) | - |
| Baseline electrocardiography | |||
| ST elevation* | 13/656 (2.0) | 218/5157 (4.2) | 304/1631 (18.6) |
| ST depression | 21/653 (3.2) | 397/5156 (7.7) | 212/1631 (13.0) |
| T wave inversion | 58/653 (8.9) | 726/5154 (14.1) | 316/1631 (19.4) |
| Diagnosis | |||
| Type 1 myocardial infarction | 17/1054 (1.6) | 843/5815 (14.5) | 68/1631 (4.2) |
| Type 2 myocardial infarction | 13/1054 (1.2) | 229/5815 (3.9) | 102/1631 (6.3) |
| Myocardial injury | 114/1054 (10.8) | 341/5815 (5.9) | 245/1631 (15.0) |
ACE-I/ARB=angiotensin converting enzyme inhibitor/angiotensin receptor blocker; CABG=coronary artery bypass grafting; PCI=percutaneous coronary intervention.
*
In the selected US population, ST segment elevation was defined as an increase >0.5 mm in any lead.