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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 6, November/December 2017
AFRICA
359
median ages between 60 and 68.9 years.
7,12-14
According to
Memtsoudis,
15
in a retrospective and multicentre study of
patients with PE after arthroplasty, the regressive multivariate
analysis suggested that there is a higher risk of PE in the age
group 45 to 64 years, but age alone was not identified consistently
as a risk factor.
Black patients were predominant (86.9%) in our study. The
fact that the study was conducted in an African country may
have contributed to this result. In the EMPEROR study,
11
conducted in a population with multiple ethnic groups, they
found a prevalence of 25.6% Afro-American patients with
PE. Evidence suggested that non-Caucasian origin could be
predictive of worse clinical outcomes for acute cardiovascular
disease.
11,16
The most common symptoms in our study were dyspnoea,
chest pain and cough. These results are similar to those found in
the JASPER study.
12
However tachypnoea and tachycardia have
been reported at higher prevalences compared to our results.
7,14,17
The clinical manifestations of PE are often unspecific, which
represents a diagnostic challenge. Dyspnoea and chest pain are
symptoms that may constitute the sole or first manifestation
of a broad spectrum of diseases. The observation of sudden
dyspnoea may suggest PE. However, few studies describe a
correlation between the degree of dyspnoea perceived by the
patient and the degree observed by physicians.
18
Chest pain
associated with PE may have pleuritic or anginal characteristics
in cases of RV ischaemia.
14
In a cohort study conducted in primary healthcare, the most
common differential diagnoses in patients referred for suspected
PE were chest pain/non-specific dyspnoea, pneumonia, myalgia,
asthma/COPD, hyperventilation anxiety disorders, heart failure,
pericarditis and lung cancer. In these patients, although PE was
excluded, there was a greater probability of clinically relevant
illness in the presence of sudden dyspnoea, tachycardia, cough
and haemoptysis.
18
The most prevalent risk factor in our study was immobilisation
for more than 72 hours in 48% of patients. Similar results
were found in the ICOPER
7
and EMEP
14
studies in 28 and
38.5% of patients, respectively. The effect of the muscle pump
in maintaining venous return is considered one of the main
promotional mechanisms of blood stasis in immobilised
patients.
14
The prevalence of patients over 40 years of age was 72%
in our study. The incidence of venous thromboembolic events
increases after 40 years and it is estimated that the risk doubles
with each subsequent decade.
19
The prevalence of patients with cancer (10%) was lower than
the range of 24.3 to 18.3% reported in other studies.
7,12,14,20
This
result may have been influenced by the prevalence of cancer in
the different populations studied. In a retrospective study in
cancer patients, PE was an accidental imaging found in 69.4% of
patients. Cancer increases the risk of venous thromboembolism,
mainly by activation of the coagulation system. Some authors
suggest a systematic investigation for cancer in patients with PE
of undetermined aetiology, and the prevention of thrombosis in
patients with cancer.
21
In the RIETE registry,
22
predictors for PE were found to be
increased mortality rate, type of venous thromboembolism,
advanced age, cancer and immobilisation due to neurological
disease.
22
In 6% of our patients, no risk factors or co-morbidity
were identified. It was recognised that in some patients, aetiology
of PE may not be determined, suggesting the existence of
unknown risk factors associated with the heterogeneity of
individual susceptibility.
23,24
The majority of patients in our study had moderate/
intermediate PE probability. Although the Wells score includes
subjective criteria, overall accuracy as a clinical prediction rule is
similar to the Geneva score, as previously reported.
8
In our study,
the frequency of intermediate and high-probability PE groups
was similar for both scoring systems. Of note, only 10 to 14% of
the patients had a low probability.
Since requesting D-dimer blood tests is less likely in patients
with higher PE probability, there was a low frequency of
realisation and positivity rates of D-dimer blood tests. It is
Table 5. Pulmonary embolism classification according to pulmonary
computed tomography angiography and correlation
with haemodynamic stability at admission
CT angiography
classification
Haemodynamically
stable patients,
n
(%)
Haemodynamically
unstable patients,
n
(%)
Sub-total
p
-value
Massive PE
4 (8)
10 (20)
14 (28)
0.109
Sub-massive PE
14 (28)
4 (8)
18 (36)
0.018
Low-risk PE
18 (36)
–
18 (36)
–
Total
36 (72)
14 (28)
50
Table 6. Stratification of patients according to the
pulmonary embolism severity index
30-day mortality risk classes
Number (%)
I: Very low risk (0–1.6%)
17 (34)
II: Low risk (1.7–3.5%)
10 (20)
III: Moderate risk (3.2–7.1%)
5 (10)
IV: High risk (4.0–11.4%)
3 (6)
V: Very high risk (10.0–24.5%)
15 (30)
Total
50
Table 7. Treatment of pulmonary embolism
Treatment
Number (%) Median duration (days)
±
SD
Thrombolytic therapy
9 (18)
–
Unfractionated heparin
16 (32)
5.4
±
2.1
Low-molecular-weight heparins
22 (44)
6.2
±
3.7
Warfarin
35 (70)
Continuous use after discharge
New oral anticoagulants
3 (6)
Continuous use after discharge
Elastic compression bandage
3 (6)
Continuous use after discharge
Unavaible treatment information 12 (24)
–
Table 8. Complicating events in patients with pulmonary embolism
Complications
Massive
PE
Sub-massive
PE
Low-
risk PE
Number
(%)
Respiratory failure requiring
mechanical ventilation
12
3
–
15 (37)
Cardiogenic shock
4
3
–
7 (18)
Sepsis and pulmonary infection
2
2
1
5 (13)
Cardiorespiratory arrest (reversed)
3
1
–
4 (10)
AKI or chronic kidney disease
agudisation
3
1
–
4 (10)
Acute myocardial infaction
2
–
–
2 (5)
Heart failure
1
1
2 (5)
Hyperglycaemia
>
200 mg/dl
(11.1 mmol/l) in non-diabetic patients
–
–
1
1 (2)
Sub-total
27 (67) 11 (28)
2 (5)
40
AKI, acute kidney injury.