Table 1.
Baseline characteristics of the low-risk group at the primary care emergency clinic
|
OUT-ACS total n = 1711 (100%) |
Not admitted to hospital n = 1485 (86.8%) |
Admitted to hospital n = 226 (13.2%) |
|
|---|---|---|---|
| Male sex, n (%) | 895 (52.3) | 764 (51.4) | 131 (58.0) |
| Age, median (IQR) | 56 (45–68) | 55 (44–66) | 63.5 (51–73) |
| Risk factors for CVD, n (%) | |||
| Current/history of smoking | 449 (26.2) | 387 (26.1) | 62 (27.4) |
| Previous coronary artery disease | 317 (18.5) | 262 (17.6) | 55 (24.3) |
| Hypertension | 448 (26.2) | 379 (25.5) | 69 (30.5) |
| Dyslipidaemia | 422 (24.7) | 369 (24.8) | 53 (23.5) |
| Other CVDa | 288 (16.8) | 228 (15.4) | 60 (26.5) |
| Diabetes mellitus | 171 (10.0) | 143 (9.6) | 28 (12.4) |
| COPD | 80 (4.7) | 58 (3.9) | 22 (9.7) |
| Family history of CVD | 691 (40.4) | 603 (40.6) | 87 (38.5) |
| Presenting acute symptoms (%) | |||
| Chest pain | 1486 (86.8) | 1301 (87.6) | 184 (81.4) |
| Constricting | 1239 (72.4) | 1082 (72.9) | 157 (69.5) |
| Sharp | 404 (23.6) | 358 (24.1) | 46 (20.4) |
| Tearing | 64 (3.7) | 58 (3.9) | 6 (2.7) |
| Burning | 208 (12.2) | 183 (12.3) | 25 (11.1) |
| Respiratory dependent | 302 (17.7) | 251 (16.9) | 51 (22.6) |
| Chest wall tenderness | 205 (12.0) | 184 (12.4) | 21 (9.3) |
| Movement dependent | 219 (12.8) | 197 (13.3) | 21 (9.3) |
| Other pain (abdomen, back, neck) | 48 (2.8) | 39 (2.6) | 9 (4.0) |
| No pain | 177 (10.3) | 144 (9.7) | 33 (14.6) |
| Pain radiation | 972 (56.8) | 865 (58.2) | 135 (59.7) |
| Dyspnea | 901 (52.7) | 768 (51.7) | 133 (58.8) |
| Palpitations | 637 (37.2) | 558 (37.6) | 79 (35.0) |
| Syncope/pre-syncope | 460 (26.9) | 391 (26.3) | 69 (30.5) |
| Acute fatigue | 571 (33.4) | 488 (32.9) | 83 (36.7) |
| Nausea and/or vomiting | 732 (42.8) | 641 (43.2) | 91 (40.3) |
| Diaphoresis | 561 (32.8) | 490 (33.0) | 71 (31.4) |
| First ECG, n (%) | |||
| Normal | 1515 (88.5) | 1332 (89.7) | 183 (81.0) |
| Non-specific changesb | 196 (11.5) | 153 (10.3) | 43 (19.0) |
| Symptom onset to first hs-cTnT, n (%) | |||
| < 3 h | 182 (10.6) | 161 (10.8) | 21 (9.3) |
| 3 – 5.99 h | 609 (35.6) | 532 (35.8) | 77 (34.1) |
| 6 – 11.99 h | 409 (23.9) | 336 (22.6) | 73 (32.3) |
| > 12 h | 511 (29.9) | 456 (30.7) | 55 (24.3) |
| According to the 0/1-h algorithm | |||
| Rule-out (0/1 h) | 1311 (76.6) | 1232 (83.0) | 79 (35.0) |
| Observation group (0/1 h) | 334 (20.5) | 243 (16.4) | 91 (40.3) |
| Rule-in (0/1 h) | 66 (3.9) | 10 (0.7) | 56 (24.8) |
| HEART risk score | |||
| Low risk (0–3 points) | 871 (50.9) | 805 (54.2) | 66 (29.2) |
| Intermediate risk (4–6 points) | 760 (44.4) | 633 (42.6) | 127 (56.2) |
| High risk (7–10 points) | 80 (4.7) | 47 (3.2) | 33 (14.6) |
| Endpoints | |||
| Myocardial infarctions at index | 61 (3.6) | 1 (0.1) | 60 (26.5) |
| Myocardial infarctions after 30 days | 3 (0.2) | 3 (0.2) | 0 (0.0) |
| Myocardial infarctions after 90 days | 2 (0.1) | 1 (0.1) | 1 (0.4) |
| Deaths after 30 days | 5 (0.3) | 1 (0.1) | 4 (1.8) |
| Deaths after 90 days | 4 (0.2) | 1 (0.1) | 3 (1.3) |
All values are presented as n (%) or median (IQR). As the low-risk hospital cohort was obtained from administrative data only, we do not have additional baseline characteristics for these patients. However, for the purpose of this analysis, we consider the non-hospitalised OUT-ACS cohort comparable to the low-risk patients at Drammen hospital
COPD Chronic obstructive pulmonary disease, CVD Cardiovascular disease, ECG Electrocardiogram, hs-cTnT High-sensitivity cardiac troponin T, IQR Interquartile range; One hoUr Troponin in a low-prevalence of Acute Coronary Syndrome
aIncludes atrial fibrillation, other arrhythmias, cardiomyopathies, cerebral stroke, heart failure, or valvular disease
bNon-specific changes in either the ST-segment, T-inversions, Q-waves, atrial fibrillation, pacemaker or left/right bundle branch block of unknown clinical significance