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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 6, November/December 2017
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AFRICA
notable that D-dimer, troponin and BNP tests were positive
in all our patients with available results. However, there were
no D-dimers and cardiac biomarkers measured in more than
50% of our patients, a higher percentage than that found in
the SWIVTER register,
25
in which 30% of patients with PE had
no cardiac biomarkers or echocardiograms done.
25
This result
may reflect under-utilisation of these tests, or it may just be
unavailability of records of the laboratory tests performed.
The ABG, chest radiography, electrocardiogram, echocardio-
gram and Doppler ultrasound of the limbs were performed in
more than 75% of our patients. In 54% of these patients, there
were deviations from normal in the ABG, and the most frequent
was hypoxaemia. Bova
et al
. described hypoxaemia as an
independent predictor of PE mortality at three months.
26
Abnormal chest radiography was documented in 50% of
our patients. These results are similar to those found in the
EMEP study (45.8%).
14
According to these authors, inter-
observer variability and subjectivity in the interpretation of chest
radiography may have influenced the results.
Electrocardiographic (ECG) changes were identified in 56%
of patients; however, isolated use of ECG has low sensitivity
and specificity to exclude PE. ECG is an important test for the
evaluation of diseases with similar presentation to that of PE in
the acute phase and can be included in some risk-stratification
strategies.
27
In the 48% of patients with abnormalities on the
echocardiogram, changes in the right chambers were the most
frequent. This examination is often used in the evaluation
of patients with PE and has the advantage of not being
invasive or expensive. Although there is inter-observer variability
and different evaluation criteria, the echocardiogram allows
identification of RV dysfunction, which is described as one
of the main predictors of early mortality in patients with
sub-massive PE.
It is estimated that about 30 to 40% of normotensive PE
patients at admission have RV dysfunction, identifiable by
echocardiography. These patients have in-hospital mortality rates
between 11.8 and 23%, substantially higher than the rates of
normotensive patients without RV dysfunction (0–9.6%).
28
Lower-limb Doppler ultrasound in symptomatic patients
with deep-vein thrombosis (DVT) has a sensitivity of 96% and
specificity of 99%. It is an important examination considering
that about 70% of patients with PE have lower-limb DVT.
29
In our study, 20% of the patients presented with DVT.
The inter-observer variability and limitations of ultrasound in
identifying thrombi in the pelvis and in small vessels of the leg
may have influenced this result.
PCTA is the imaging test of choice for diagnosis and
exclusion of PE, considering its high sensitivity and specificity.
30
The correlation of its changes with haemodynamic stability at
admission showed that most of our patients with massive PE had
haemodynamic instability, as previously described.
31
Additionally,
we found a statistically significant rate of haemodynamic
stability at admission for patients with sub-massive PE.
A meta-analysis to assess the prognostic value of the embolic
load for short-term mortality showed that the presence of emboli
centrally located in a pulmonary artery was associated with
twice the risk of mortality within 30 days.
32
On the other hand,
assessment of RV function by pulmonary CT angiography has
diagnostic and prognostic value in PE.
30,33
In this study, 28% of patients presented with sub-massive
PE, despite haemodynamic stability at admission. The presence
of RV dysfunction and centrally located pulmonary artery
thrombus predicts a higher mortality rate in normotensive
patients.
30
Low-risk 30-day-mortality PE was identified in 36%
of patients and all were stable at admission. Studies show that
these patients have a lower risk of adverse events and may be
candidates for home treatment.
34,35
The treatment of PE in the acute phase, based on
anticoagulation with heparin or NOAC, prevents the extension
of thrombi and recurrence of thromboembolic events. We
found that most of our patients received low-molecular-weight
heparins and warfarin. Out-patient anticoagulation depends on
the clinical context and existing risk factors, and its duration in
PE is still controversial.
In our study, thrombolytic therapy was used in 18% of
patients, however 28% presented with haemodynamic instability.
These results may suggest an underuse of thrombolytic therapy.
Similar results were found in the EMEP study
14
in which 20%
of the patients were hypotensive but thrombolytic therapy
was used in only 15% of them. Thrombolysis allows early
pulmonary reperfusion, and despite increasing the risk of major
bleeding, is indicated in unstable patients. Furthermore, it
benefits normotensive patients with sub-massive PE, preventing
haemodynamic instability, as demonstrated in the PEITHO
study.
35
The in-hospital mortality rate of 20% in our study was
similar to that described in the EMEP study (22%) and higher
than the rate described in other PE studies.
7,14,22,36
Conducting
the study in the ICU on more severely ill patients with a rate
of 38% complications may have contributed to the higher
mortality rate. Moreover, we found that 67% of the complicating
events occurred in the PCTA sub-group of massive PE; 30% of
patients had a very high risk of 30-day mortality, according to
the admission PESI score; and a third of the deaths occurred
within the first 24 hours of hospitalisation, which may reflect the
severity of PE since admission.
Some limitations of this study relate to its retrospective nature
and the lack of data. In addition, using health professionals from
different schools may have favoured some variability in clinical
practice during the study period.
Conclusions
Our results confirm that PE does not seem to be a rare disease
in African populations. The clinical characteristics of the study
sample were similar to those described in the literature, although
black patients were more prevalent. In diagnostic examinations,
the use of pulmonary CT angiography in all patients allowed
consistent diagnosis and assessment of the prognosis. Most
patients were treated with low-molecular-weight heparin and
warfarin. The intra-hospital mortality rate was relatively higher
than that described in other studies. The high prevalence of
patients with very high risk of mortality at admission highlights
the need to investigate the cause of worst cardiovascular disease
outcomes in Africans.
The authors acknowledge the Studies Office and Arquive Staff of Girassol
Clinic for general support and technical assistance.