Table 1.
Baseline patient characteristics
| Regular hours (n=18 452) | Off-hours (n=24 225) | P value | |
| Age (SD), years | 64.52 (12.95) | 62.86 (12.92) | <0.001 |
| Gender—female (n (%)) | 4801 (26.02) | 6093 (25.15) | 0.042 |
| Deprivation, most deprived decile (n (%)) | 2623 (14.22) | 3498 (14.44) | 0.536 |
| Medical history | |||
| Previous AMI (n (%)) | 2187 (11.85) | 2927 (12.08) | 0.468 |
| Previous angina (n (%)) | 2170 (11.76) | 2815 (11.62) | 0.655 |
| History of hypertension (n (%)) | 7503 (40.66) | 9598 (39.62) | 0.030 |
| History/present PVD (n (%)) | 465 (2.52) | 552 (2.28) | 0.105 |
| History of stroke/CVD (n (%)) | 809 (4.38) | 921 (3.80) | 0.003 |
| History of asthma or COPD (n (%)) | 1867 (10.12) | 2414 (9.96) | 0.602 |
| History of chronic renal failure (n (%)) | 377 (2.04) | 346 (1.43) | <0.001 |
| History/present hypercholesterolemia (n (%)) | 5733 (31.07) | 7450 (30.75) | 0.483 |
| Previous PCI (n (%)) | 1522 (8.25) | 1878 (7.75) | 0.061 |
| Previous CABG (n (%)) | 343 (1.86) | 494 (2.04) | 0.183 |
| Family history of premature CHD (n (%)) | 6169 (33.43) | 8106 (33.46) | 0.951 |
| Current smoker (n (%)) | 6725 (36.45) | 10 050 (41.49) | <0.001 |
| Diabetes (n (%)) | 2290 (12.41) | 3018 (12.46) | 0.883 |
| Clinical presentation | |||
| Heart rate b.p.m (IQR) | 75 (64–87) | 75 (64–88) | 0.016 |
| Systolic BP mmHg (SD) | 131.98 (27.49) | 132.88 (27.82) | 0.001 |
| Elevated cardiac markers (n (%)) | 17 016 (92.22) | 22 097 (91.22) | <0.001 |
| Cardiac arrest (n (%)) | 1804 (9.78) | 2459 (10.15) | 0.202 |
| Creatinine umol/L(IQR) | 85 (72–100) | 85 (73–101) | 0.015 |
| Loop diuretic (n (%)) | 2428 (13.16) | 3424 (14.13) | 0.004 |
| Adjusted mini-GRACE score (SD) | 118.43 (30.63) | 115.29 (30.71) | <0.001 |
AMI, acute myocardial infarction; BP, blood pressure; CABG, coronary artery bypass surgery; CHD, coronary heart disease; COPD, chronic obstructive pulmonary disease; CVD, cerebrovascular disease; GRACE, Global Registry of Acute Coronary Events; PCI, percutaneous coronary intervention; PVD, peripheral vascular disease.