Introduction
Materials and methods
Results
Study population and CTPA scans
Patient characteristics | All patients (n = 250) | Subgroup comparison | ||
---|---|---|---|---|
CTPA positive (n = 74) | CTPA negative (n = 175) |
p value | ||
Origins | ||||
ER Hospital Outpatient clinic | 155 (62 %) 87 (34.8 %) 8 (3.2 %) | 49 (66.2 %) 24 (32.4 %) 1 (1.4 %) | 105 (60 %) 63 (36 %) 7 (4 %) | 0.543 |
Demographics | ||||
Sex (women) | 134 (53.4 %) | 40 (54.1 %) | 93 (53.1 %) | 1.000 |
Age (years) | 64 (49–73) | 66 (52.5–77) | 62 (46–71) | 0.044* |
Clinical risk factors | ||||
Immobilisation (yes) | 40 (16 %) | 12 (16.2 %) | 28 (16 %) | 1.000 |
Paresis/paralysis legs or cast in the past 4 weeks (yes) | 10 (4 %) | 3 (4.1 %) | 7 (4 %) | 1.000 |
Surgery past 4 weeks (yes) | 25 (10 %) | 11 (14.9 %) | 14 (8 %) | 0.110 |
Trauma (yes) | 6 (2.4 %) | 0 (0 %) | 6 (3.4 %) | 0.183 |
History of DVT (yes) | 21 (8.4 %) | 11 (14.9 %) | 9 (5.1 %) | 0.019* |
History of PE (yes) | 14 (5.6 %) | 5 (6.8 %) | 9 (5.1 %) | 0.564 |
COPD (yes) | 30 (12 %) | 4 (5.4 %) | 26 (14.9 %) | 0.053** |
Heart failure under treatment (yes) | 20 (8 %) | 5 (6.8 %) | 15 (8.6 %) | 0.800 |
Pacemaker (yes) | 3 (1.2 %) | 0 (0 %) | 3 (1.7 %) | 0.557 |
Active malignancy (yes) | 64 (25.6 %) | 17 (23 %) | 47 (26.9 %) | 0.634 |
Central venous catheter (yes) | 2 (0.8 %) | 1 (1.4 %) | 1 (0.6 %) | 0.507 |
Oestrogen use women (yes) |
n = 134 women 3 (2.2 %) |
n = 40 women 1 (2.5 %) |
n = 93 women 2 (2.2 %) | 1.000 |
Pregnant women (yes) |
n = 134 women 7 (5.2 %) |
n = 40 women 0 (0 %) |
n = 93 women 7 (7.5 %) | 0.102 |
Clinical factors | ||||
Dyspnea (yes) | 182 (72.8 %) | 54 (73 %) | 128 (73.1 %) | 1.000 |
Chest pain (yes) | 116 (46.4 %) | 31 (41.9 %) | 84 (48 %) | 0.406 |
Signs of DVT (yes) | 30 (12 %) | 15 (20.3 %) | 15 (8.6 %) | 0.017* |
Haemoptysis (yes) | 11 (4.4 %) | 3 (4.1 %) | 8 (4.6 %) | 1.000 |
Syncope (yes) | 12 (4.8 %) | 3 (4.1 %) | 9 (5.2 %) | 1.000 |
Hypotension (syst < 100) (yes) | 8 (3.2 %) | 3 (4.1 %) | 5 (2.9 %) | 0.698 |
Tachycardia (>100/bpm) (yes) | 80 (32 %) | 29 (39.2 %) | 51 (29.1 %) | 0.138 |
Tachypnea (>30/min) (yes) | 10 (4 %) | 4 (5.4 %) | 6 (3.4 %) | 0.489 |
Hypoxaemia (Sp/aO2 < 90 %) (yes) | 44 (17.6 %) | 14 (18.9 %) | 30 (17.1 %) | 0.720 |
Hypothermia (<36gr centigrade) (yes) | 2 (0.8 %) | 0 (0 %) | 2 (1.1 %) | 1.000 |
Altered consciousness (yes) | 2 (0.8 %) | 0 (0 %) | 2 (1.1 %) | 1.000 |
Wells score | 4 (3–4.5) | 4.5 (3–6) | 4 (3–4.5) | 0.008* |
Wells category (>4) | 124 (49.6 %) | 44 (59.5 %) | 79 (45.1 %) | 0.052** |
D-dimer - <0.5 - ≥0.5 |
n = 159 12 (7.5 %) 147 (92.5 %) |
n = 50 0 (0 %) 50 (100 %) |
n = 109 12 (11 %) 97 (89 %) | 0.019* |
Pulmonary infiltrate (yes) |
n = 249 37 (14.9 %) | 7 (9.5 %) | 30 (17.1 %) | 0.171 |
Atelectasis (yes) |
n = 249 52 (20.9 %) | 13 (17.6 %) | 39 (22.3 %) | 0.496 |
Consolidation (yes) |
n = 249 34 (13.7 %) | 13 (17.6 %) | 21 (12 %) | 0.312 |
Groundglass (yes) |
n = 249 18 (7.2 %) | 9 (12.2 %) | 9 (5.1 %) | 0.062** |
Pulmonary embolism | All patients (n = 249 CTPA scans) | |||||
---|---|---|---|---|---|---|
- None | 175 (70.3 %) | |||||
- Proximal | 64 (25.7 %) | |||||
- Subsegmental | 10 (4 %) | |||||
Pulmonary embolism | Wells low | Wells high | ||||
n = 126 (50.6 %) |
n = 123 (49.4 %) | |||||
- None | 96 (76.2 %) | 79 (64.2 %) | ||||
- Proximal | 27 (21.4 %) | 37 (30.1 %) | ||||
- Subsegmental | 3 (2.4 %) | 7 (5.7 %) | ||||
D-dimer low | D-dimer unknown | D-dimer high | D-dimer low | D-dimer unknown | D-dimer high | |
n = 7 (5.6 %) |
n = 29 (23 %) |
n = 90 (71.4 %) |
n = 5 (4.1 %) |
n = 61 (49.6 %) |
n = 57 (46.3 %) | |
Pulmonary embolism | ||||||
- None | 7 (100 %) | 26 (89.7 %) | 63 (70 %) | 5 (100 %) | 40 (65.6 %) | 24 (59.6 %) |
- Proximal | - | 3 (10.3 %) | 24 (26.7 %) | - | 17 (27.9 %) | 20 (35.1 %) |
- Subsegmental | - | - | 3 (3.3 %) | - | 4 (6.6 %) | 3 (5.3 %) |
Univariate logistic regression | |||
---|---|---|---|
β |
p value | OR (95 % CI) | |
Origins | |||
Total | − | 0.463 | − |
Hospital Outpatient clinic | −0.203 −1.184 | 0.493 0.274 | 0.816 (0.457–1.458) 0.306 (0.031–2.557) |
Demographics | |||
Sex (women) | 0.037 | 0.895 | 1.037 (0.601–1.789) |
Age (years) | 0.017 | 0.054** | 1.017 (1.000–1.034) |
Clinical risk factors | |||
Immobilisation (yes) | 0.016 | 0.966 | 1.016 (0.486–2.127) |
Paresis/paralysis legs or cast in the past 4 weeks (yes) | 0.014 | 0.984 | 1.014 (0.255–4.034) |
Surgery past 4 weeks (yes) | 0.697 | 0.105 | 2.008 (0.865–4.659) |
History of DVT (yes) | 1.170 | 0.013* | 3.220 (1.274–8.142) |
History of PE (yes) | 0.290 | 0.614 | 1.337 (0.432–4.132) |
COPD (yes) | –1.116 | 0.045* | 0.327 (0.110–0.974) |
Heart failure under treatment (yes) | –0.258 | 0.631 | 0.773 (0.270–2.210) |
Active malignancy (yes) | –0.208 | 0.522 | 0.812 (0.430–1.535) |
Central venous catheter (yes) | 0.869 | 0.541 | 2.384 (0.147–38.623) |
Oestrogen use women (yes) | 0.154 | 0.901 | 1.167 (0.103–13.247) |
Clinical factors | |||
Dyspnea (yes) | –0.009 | 0.978 | 0.991 (0.537–1.829) |
Chest pain (yes) | –0.247 | 0.377 | 0.781 (0.451–1.352) |
Signs of DVT (yes) | 0.998 | 0.012* | 2.712 (1.249–5.889) |
Haemoptysis (yes) | –1.126 | 0.856 | 0.882 (0.227–3.422) |
Syncope (yes) | –0.249 | 0.715 | 0.779 (0.205–2.964) |
Hypotension (syst <100) (yes) | 0.362 | 0.626 | 1.437 (0.334–6.173) |
Tachycardia (>100/bpm) (yes) | 0.449 | 0.122 | 1.567 (0.887–2.769) |
Tachypnea (>30/min) (yes) | 0.476 | 0.471 | 1.610 (0.441–5.879) |
Hypoxaemia (Sp/aO2 <90 %) (yes) | 0.120 | 0.737 | 1.128 (0.559–2.276) |
Wells score | 0.219 | 0.005* | 1.245 (1.067–1.453) |
Wells category (>4) | 0.578 | 0.040* | 1.782 (1.027–3.093) |
CT findings | |||
Pulmonary infiltrate (yes) | –0.683 | 0.125 | 0.505 (0.211–1.208) |
Atelectasis (yes) | –0.297 | 0.404 | 0.743 (0.370–1.491) |
Consolidation (yes) | 0.447 | 0.245 | 1.563 (0.736–3.317) |
Groundglass (yes) | 0.938 | 0.057** | 2.554 (0.971–6.720) |
Diagnostic accuracy
CTPA-diagnosed PE | |||
---|---|---|---|
Yes | No | ||
Wells category | |||
Wells >4 | 44 | 79 |
123 (PPV, 38.8 %)
|
Wells ≤4 | 30 | 96 |
126 (NPV, 76.2 %)
|
Total | 74 (SE, 59.5 %) | 175 (SP, 54.9 %) | |
D-dimer category (n = 159) | |||
D-dimer high | 50 | 97 |
147 (PPV, 34 %)
|
D-dimer low | 0 | 12 |
12 (NPV, 100 %)
|
Total | 50 (SE, 100 %) | 109 (SP, 11 %) | |
History of DVT | |||
History of DVT (yes) | 11 | 9 |
20 (PPV, 55 %)
|
History of DVT (no) | 63 | 166 |
172 (NPV, 72.5 %)
|
Total | 74 (SE 14.9 %) | 175 (SP, 94.9 %) | |
Signs of DVT
| |||
Signs of DVT(yes) | 15 | 15 |
30 (PPV, 50 %)
|
Signs of DVT (no) | 59 | 160 |
219 (NPV, 73.1 %)
|
74 (SE, 20.3 %) | 175 (SP, 91.4 %) |
Comparison with previous results
Walen et al. 2014 [7] | Present study | Difference (%) | |||||
---|---|---|---|---|---|---|---|
n
| % | 95 % CI |
n
| % | 95 % CI | ||
Positive | 224 | 23 % | 20.5 -25.8 % | 74 | 29.6 % | 24.3-35.5 % |
6.6 %
|
Undiagnostic | 38 | 4 % | 2.3-5.3 % | 1 | 0.4 % | 0.1–2.2 % |
−3.5 %
|
Negative | 712 | 73.1 % | 70.2-75.8 % | 175 | 70 % | 64.1–75.3 % |
−3.1 %
|
Total | 974 | 250 |