Table 2

Baseline characteristics

OUT-ACS study,
total19
n=1711
(100.0%)
Single hs-cTnT,
rule-out group
n=569
(33.3%)
Original HEART,
low-risk group
n=871
(50.9%)
Modified HEART,
low-risk group
n=639
(37.3%)
P value
Female sex, n (%)816 (47.7)340 (59.8)384 (44.1)306 (47.9)<0.001
Age, median (IQR)56 (45–68)47 (38–56)46 (38–55)43 (35–51)<0.001
Risk factors for CVD, n (%)
Current/history of smoking449 (26.2)156 (27.4)214 (24.6)141 (22.1)0.098
Previous coronary artery disease317 (18.5)40 (7.0)9 (1.0)5 (0.8)<0.001
Hypertension448 (26.2)83 (14.6)92 (10.6)48 (7.5)<0.001
Dyslipidaemia422 (24.7)94 (16.5)78 (9.0)50 (7.8)<0.001
Other CVD*288 (16.8)51 (9.0)71 (8.2)47 (7.4)0.59
Diabetes mellitus171 (10.0)44 (7.7)42 (4.8)21 (3.3)0.002
COPD80 (4.7)7 (1.2)10 (1.1)5 (0.8)0.71
Family history of CVD691 (40.4)253 (44.5)333 (38.2)245 (38.3)0.037
Presenting acute symptoms, n (%)
Chest pain1486 (86.8)525 (92.3)791 (90.8)588 (92.0)0.56
 Constricting1239 (72.4)439 (77.2)637 (73.1)475 (74.3)0.23
 Sharp404 (23.6)168 (29.5)263 (30.2)201 (31.5)0.76
 Tearing64 (3.7)19 (3.3)39 (4.5)30 (4.7)0.45
 Burning208 (12.2)81 (14.2)127 (14.6)99 (15.5)0.81
 Respiratory dependent302 (17.7)126 (22.1)215 (24.7)164 (25.7)0.34
 Chest wall tenderness205 (12.0)80 (14.1)135 (15.5)104 (16.3)0.56
 Movement dependent219 (12.8)93 (16.3)146 (16.8)115 (18.0)0.72
Other pain (abdomen, back or neck)48 (2.8)15 (2.6)15 (1.7)10 (1.6)0.34
No pain177 (10.3)29 (5.1)65 (7.5)41 (6.4)0.20
Pain radiation972 (56.8)369 (64.9)534 (61.3)401 (62.8)0.40
Dyspnoea901 (52.7)327 (57.5)489 (56.1)369 (57.7)0.80
Palpitations637 (37.2)232 (40.8)367 (42.1)278 (43.5)0.63
Syncope/presyncope460 (26.9)155 (27.2)259 (29.7)189 (29.6)0.55
Acute fatigue571 (33.4)188 (33.0)295 (33.9)223 (34.9)0.79
Nausea/vomiting732 (42.8)251 (44.1)377 (43.3)285 (44.6)0.87
Diaphoresis561 (32.8)184 (32.3)310 (35.6)221 (34.6)0.44
Symptom onset to first hs-cTnT, n (%)
<3 hours182 (10.6)0 (0.0)114 (13.1)80 (12.5)<0.001
3 to <6 hours609 (35.6)225 (39.5)316 (36.3)231 (36.2)0.38
6 to <12 hours409 (23.9)148 (26.0)186 (21.4)137 (21.4)0.081
12 to <24 hours224 (13.1)82 (14.4)104 (11.9)76 (11.9)0.31
≥24 hours287 (16.8)114 (20.0)151 (17.3)115 (18.0)0.42
  • All values are presented as n (%) and median (IQR). P values are calculated for comparisons across all three groups (single rule-out and the two low-risk HEART groups). The Pearson χ2 test or the Fisher exact test were used for the categorical variables and the Kruskal-Wallis test for the continuous variables.

  • *Includes atrial fibrillation, other arrhythmias, cardiomyopathies, cerebral stroke, heart failure or valvular disease.

  • COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; HEART, History, ECG, Age, Risk factors and Troponin; hs-cTnT, high-sensitivity cardiac troponin T; OAEOC, Oslo Accident and Emergency Outpatient Clinic.