Baseline characteristics of patients with confirmed STEMI
| Characteristic | No supplemental oxygen exposure N=128 | Low supplemental oxygen exposure N=105 | Moderate supplemental oxygen exposure N=104 | High supplemental oxygen exposure N=104 | p Value |
|---|---|---|---|---|---|
| Age in years, mean (SD) | 61 (12) | 63 (13) | 63 (12) | 64 (12) | 0.23 |
| Males, n (%) | 103 (80.5) | 76 (72.4) | 83 (79.8) | 86 (82.7) | 0.28 |
| History and risk factors, n (%) | |||||
| Diabetes mellitus | 18 (14.1) | 25 (23.8) | 21 (20.2) | 14 (13.5) | 0.13 |
| Hypertension | 64 (50.0) | 66 (62.9) | 59 (56.7) | 64 (61.5) | 0.18 |
| Dyslipidaemia | 59 (46.1) | 64 (61.0) | 49 (47.1) | 67 (64.4) | 0.008 |
| Current or ex-smoker | 95 (74.8) | 74 (70.5) | 65 (63.7) | 72 (69.2) | 0.34 |
| Peripheral vascular disease | 4 (3.1) | 4 (3.8) | 1 (1.0) | 6 (5.8) | 0.29 |
| Stroke | 9 (7.0) | 9 (8.6) | 3 (2.9) | 5 (4.8) | 0.31 |
| Ischaemic heart disease | 22 (17.2) | 23 (21.9) | 14 (13.5) | 19 (18.3) | 0.46 |
| Previous PCI | 14 (10.9) | 15 (14.3) | 8 (7.7) | 13 (12.5) | 0.49 |
| Previous CABG | 2 (1.6) | 2 (1.9) | 1 (1.0) | 2 (1.9) | 0.94 |
| Medication only | 7 (5.5) | 6 (5.7) | 3 (2.9) | 4 (3.8) | 0.71 |
| Creatinine >120 µmol/L | 7 (5.5) | 9 (8.6) | 9 (8.7) | 11 (10.6) | 0.55 |
| Status on arrival of paramedics | |||||
| Heart rate, median (IQR) | 76 (64, 84) | 72 (61, 84) | 76 (60, 88) | 70 (60, 83) | 0.63 |
| Systolic blood pressure, median (IQR) | 140 (120, 159) | 130 (105, 150) | 130 (110, 150) | 130 (101, 150) | 0.09 |
| Oxygen saturation, median (IQR) | 98 (87, 99) | 98 (96, 99) | 98 (97, 99) | 98 (97, 99) | 0.15 |
| Pain score, median (IQR) | 7 (5, 8) | 6 (5, 8) | 7 (5, 9) | 8 (5, 9) | 0.04 |
CABG, coronary artery bypass grafting; PCI, percutaneous coronary intervention; STEMI, ST-elevation myocardial infarction.