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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 4, July/August 2021
190
AFRICA
Discussion
In this study, the findings of 139 patients with IE were evaluated
to determine recent epidemiological features in southern Turkey
during a 10-year period. Compared with previous studies from
Turkey, a shift can be seen over the years in terms of patient age,
predisposing factors and causative micro-organisms.
6-9
Consistent with recent trends in IE epidemiology, the median
age of our study patients was higher compared with older data.
3,10
The mean age (55 ± 16 years) of this study population is the
highest ever reported for IE in Turkey, although it remains below
the mean age in European countries.
6-9,11,12
The older age of the IE
population can be explained by a decrease in incidence of RHD,
an increase in incidence of valvular degenerative disease due
to longer life expectancy, and a larger number of patients with
intracardiac prosthetic material.
The average diagnosis time of three (five) days was extremely
short compared with a previous case series, where a period of
18 days (range, 1–30 days) was reported.
13
This indicates an
improved IE diagnostic process.
Supportingpreviousdata,feverwasthemostfrequentsymptom
in the current study, detected in more than half of the patients.
6-9,14
Conflicting with medical teaching, Roth spots were detected in
only one patient and membranoproliferative glomerulonephritis
in one patient. However, in 2006, Leblebicioglu
et al
. reported a
50% incidence rate of immunological phenomenona.
11
The low
rates in our series may have been due to prompt diagnosis of IE
before the emergence of immunological signs.
Diagnostic imaging for IE should begin with TTE. However,
in the case of intracardiac devices or prostheses, or unclear results
with high clinical suspicion of IE, TEE should be performed.
Moreover, even if the diagnosis is clear on TTE, TEE should also
be applied to investigate complications such as abscess.
15
While in the current study, TTE examinations had a sensitivity
of 64.7%, which is lower than expected (75%), TEE examinations
were more sensitive, supporting the findings of previous studies.
16
This high rate of sensitivity of TEE cannot be attributed to only
the presence of prosthetic heart valves in one-third of the study
population because 20 of 44 patients who showed a vegetation
on TEE and not on TTE had prosthetic heart material. It must
be kept in mind that TEE should be the modality of choice in
cases with prosthetic heart valves, intracardiac devices, or if there
are complications such as a fistula, abscess or leaflet perforation.
RHD-related endocarditis was very rare in this study
population, with an incidence of 3.5%, which is lower compared
to previous reports from Turkey.
7-9,11,17
Elbey
et al
. reported RHD
as the most common underlying heart disease, with a prevalence
of 28%, in a study from 2005 to 2012 in 13 tertiary-care centres.
7
In a study by Yavuz
et al
. published in 2015, covering the
previous 14 years, patients with RHD comprised 33.9% of the
IE population.
9
Due to the successful treatment of streptococcal
tonsillitis, there has been a decrease in patients with RHD over
the years.
Culture-negative endocarditis was seen in this study at the
rate of 21.6%, which is in the expected range of 20.6 to 36.1%
in Turkey, and five to 34% worldwide.
3,6-8,18
Culture-negative
endocarditis could have been a result of previous antibiotic
therapy because 17 (12.2%) patients had been referred to our
hospital from other peripheral centres where empirical antibiotic
therapy had possibly been given.
It was confirmed in this study that staphylococci seem to
have replaced streptococci as the major cause of IE. This could
be attributed to the fact that the incidence of dialysis and other
intravascular access is increasing, and the number of patients
with RHD is decreasing throughout the world.
3,19-21
In the current series, the surgery rate (65.5%) is higher than
previously reported (40–50%).
22
It is also higher than rates
(27.8–60%) in previous reports from Turkey.
6-8
This may be a
result of the study being done in a tertiary referral centre and
the high incidence of prosthetic valve endocarditis in the study
population.
Unlike recent data, the most common indication for surgery in
the current study population was persistent infection (enlarging
vegetation or persistent bacteraemia despite appropriate
antibiotic therapy), whereas previous reports have shown valvular
dysfunction causing heart failure.
1,23
This may be a result of
antibiotic-resistant micro-organisms. Therefore, early surgical
management should be kept in mind, because antibiotics alone
may not be sufficient to eradicate the disease.
24
Consequently,
postponing surgery until after the completion of a course of
antibiotics is not recommended.
25
Tugcu
et al
. reported in 2007 that the median time between
diagnosis and surgery was 11 days.
8
In our study population, the
median time from diagnosis to surgery was seven (18) days. This
trend is consistent with recent recommendations supporting early
surgery in IE.
19,22
In the current study, the most frequent complication was
systemic embolism (39.6%), which is in the expected range
reported by recent guidelines (20–50%).
5
It should be kept in
mind that a cerebral embolic event can be a presenting symptom
of IE on admission.
Table 5. Complications of IE and indications for surgery
Complications
Number (%)
Systemic embolism
Brain
30 (21.6)
Spleen
22 (15.8)
Lungs
6 (4.3)
Renal
5 (3.5)
Multiple locations
8 (5.7)
Acute renal failure
11 (7.9)
Heart failure
31 (22.3)
Spondylodiscitis
10 (7.2)
Heart block
0
Cause of surgery
Persistent infection
39 (28.1)
Valvular dysfunction with heart failure
32 (23)
Recurrent embolism on antibiotic therapy
13 (9.4)
Paravalvular invasion or abscess
7 (5)
Table 6. Regression analysis of co-morbidities for mortality
Co-morbidities
β
p-value
Hypertension
–0.069
0.450
Diabetes mellitus
0.111
0.175
Chronic renal disease
0.239
0.008
Smoking
0.022
0.789
Congestive heart failure
0.198
0.017
Chronic dialysis
0.222
0.009
White blood cell level
0.095
0.266
C-reactive protein
0.222
0.009
Creatinine
0.201
0.018