Baseline characteristics
| All patients (n=2525) | Crowding level 1, normal (n=662) | Crowding level 2, high (n=1409) | Crowding level 3, very high (n=454) | P value | |
| Age (years) | 64 (18–101) | 64 (18–100) | 65 (18–100) | 62 (18–101) | 0.386 |
| Male, sex | 1465 (58.0%) | 361 (54.5%) | 852 (60.5%) | 252 (55.5%) | 0.019 |
| Presenting symptom | |||||
| Chest pain | 1164 (46.1%) | 322 (48.6%) | 645 (45.8%) | 197 (43.4%) | 0.21 |
| Dyspnoea | 335 (13.3%) | 91 (13.7%) | 187 (13.3%) | 57 (12.6%) | 0.847 |
| Atypical | 1021 (40.4%) | 247 (37.3%) | 575 (40.8%) | 199 (43.8%) | 0.085 |
| Else or missing | 5 (0.2%) | 2 (0.3%) | 2 (0.1%) | 1 (0.2%) | 0.742 |
| Final diagnoses | |||||
| UA | 280 (11.1%) | 48 (7.3%) | 182 (12.9%) | 50 (11.0%) | <0.001 |
| NSTEMI | 330 (13.1%) | 108 (16.3%) | 169 (12.0%) | 53 (11.7%) | 0.015 |
| STEMI* | 133* | 42* | 66* | 25* | 0.361 |
| Non-ACS | 1915 (75.8%) | 506 (76.4%) | 1058 (75.1%) | 351 (77.3%) | 0.577 |
| Risk factors | |||||
| Arterial hypertension | 1652 (65.4%) | 433 (65.4%) | 943 (66.9%) | 276 (60.8%) | 0.058 |
| Hypercholesterolaemia | 1135 (45.0%) | 303 (45.8%) | 633 (44.9%) | 199 (43.8%) | 0.815 |
| Diabetes mellitus | 535 (21.2%) | 151 (22.8%) | 305 (21.6%) | 79 (17.4%) | 0.077 |
| Active smoker | 551 (21.8%) | 155 (23.4%) | 287 (20.4%) | 109 (24.0%) | 0.135 |
| Family history | 665 (26.3%) | 180 (27.2%) | 373 (26.5%) | 112 (24.7%) | 0.633 |
| History | |||||
| Coronary artery disease | 827 (32.8%) | 222 (33.5%) | 476 (33.8%) | 129 (28.4%) | 0.093 |
| Myocardial infarction | 430 (17.0%) | 131 (19.8%) | 236 (16.7%) | 63 (13.9%) | 0.033 |
| Coronary angiography | 1039 (41.1%) | 272 (41.1%) | 605 (42.9%) | 162 (35.7%) | 0.024 |
| Percutaneous coronary intervention | 655 (25.9%) | 179 (27.0%) | 378 (26.8%) | 98 (21.6%) | 0.065 |
| Coronary bypass surgery | 166 (6.6%) | 40 (6.0%) | 97 (6.9%) | 29 (6.4%) | 0.759 |
| High-sensitivity troponin T at baseline(ng/L) | 10 (<3–4085) | 9 (<3–3379) | 10 (<3–4085) | 10 (<3–2776) | 0.065 |
| Renal function | |||||
| Serum creatinine (mg/dL) | 0.89 (0.28–5.71) | 0.87 (0.44–5.71) | 0.90 (0.38–4.62) | 0.86 (0.28–4.32) | <0.001 |
| eGFR (mL/min/1.73 m2) | 83.3 (7.5–151.1) | 84.1 (7.5–141.9) | 81.7 (12.4–151.1) | 86.6 (12.6–148) | 0.006 |
| GRACE score (n=2497): | 98 (17–241) | 98 (23–212) | 98 (17–241) | 95 (17–204) | 0.207 |
| Low | 1562/2525 (61.9%) | 415/662 (62.7%) | 839/1409 (59.5%) | 308/454 (67.8%) | 0.006 |
| Intermediate | 670/2525 (26.5%) | 158/662 (23.9%) | 406/1409 (28.8%) | 106/454 (23.3%) | 0.014 |
| High | 265/2525 (10.5%) | 82/662 (12.4%) | 147/1409 (10.4%) | 36/454 (7.9%) | 0.058 |
| Not determinable | 28/2525 (1.1%) | 7/662 (1.1%) | 17/1409 (1.2%) | 4/454 (0.9%) | 0.838 |
Data are median (minimum–maximum) or number of patients (%).
*Patients with STEMI were registered but excluded for the analysis.
ACS, acute coronary syndrome; eGFR, estimated glomerular filtration rate; NSTEMI, non-ST-segment elevation myocardial infarction; STEMI, ST-segment elevation myocardial infarction; UA, unstable angina.