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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 2, March/April 2021
AFRICA
63
profile and echocardiographic findings in 84 subjects with
rheumatic MR. In contrast to previous findings,
14,15
Meel and
colleagues’ subjects with MR were older, with greater associated
co-morbidities and less evidence of acute rheumatic fever (ARF).
16
The echocardiographic features revealed signs of chronic disease
with leaflet thickening and/or calcification in subjects with
isolated rheumatic MR.
16
Rheumatic MR is an under-studied condition in the KZN
population compared to the rest of the country. In this study we
examined the clinical profile of subjects with rheumatic MR in
KZN and evaluated their surgical findings to determine whether
the pattern of disease involvement is similar to that of the rest
of the country. Our aim was to document the demographics,
clinical presentation and outcomes of patients with rheumatic
MR who had presented to our tertiary/quaternary unit over
the last 10 years. In order to make a comparison with previous
studies, Meel’s exclusion criterion was used as part of the sample
selection.
16
Methods
All patients seven years and older with moderate to severe
rheumatic MR, confirmed at echocardiography, in the
Department of Cardiology at Inkosi Albert Luthuli Central
Hospital (IALCH) over a 10-year period (2006–2015) were
eligible for inclusion in the study.
Ethical approval was obtained from the Biomedical Research
Ethics Committee affiliated to the University of KwaZulu-Natal
(BREC No 083/17). HIV status of the patients was obtained
from medical records. Informed consent was obtained from all
patients when they were admitted for cardiac evaluation with a
view to surgery.
Two-dimensional directed m-mode and colour Doppler
echocardiography was performed on all patients using a Siemens
Sequoia machine (Acuson, Germany) with a phased-array
transducer and an emission frequency of 3.0 MHz, with the
patient in the left decubitus position. Images were obtained
according to a standardised protocol. The left ventricular (LV)
end-systolic and end-diastolic dimensions (ESD and EDD), LV
wall thickness and left atrial (LA) dimensions were measured
according to the American Society of Echocardiography (ASE)
chamber guidelines.
17
Ejection fraction (EF) was assessed using
the Simpson’s method.
17
The World Heart Federation (WHF) criteria were used to
diagnose MR that was rheumatic in aetiology.
18
To describe leaflet
motion, the Carpentier classification was used.
19
The morphological characteristics of the valve were determined
using the Wilkins criteria for descriptive purposes,
20
such as leaflet
thickening, leaflet mobility, leaflet calcification and subvalvular
apparatus involvement. Acute or recurrent rheumatic carditis was
diagnosed using the modified Jones and WHO criteria.
21,22
Clinical evaluation of the severity of MR in this unit was
supported by colour Doppler estimation of the regurgitant jet
into the LA, the Doppler intensity of the regurgitant envelope,
and the LA size using qualitative and semi-quantitative methods
as per ASE and European Society of Cardiology (ESC) valvular
regurgitation guidelines.
23,24
Calculation of the effective regurgitant
orifice using proximal isovelocity surface area (PISA) was not
done because in most cases the regurgitant flow into the LA was
characterised by an eccentric jet.
The patients’ records were identified using the ICD 10 code
for rheumatic MR (I05-I09) accessed via the Speedminer software
program (Speedminer, Malaysia), which is a Data Warehouse
Management software package used at IALCH to record
and categorise patients’ medical details. Data were extracted
from the first visit on the demographics, clinical presentation,
co-morbidities, laboratory and echocardiographic findings, as well
as the surgical findings on those who underwent surgery. Data
were entered into Microsoft excel software and transferred for
statistical analyses.
Patients were excluded from the study if they met Meel’s
exclusion criteria: significant aortic valve disease, concurrent
mitral stenosis (MS) with a valve area of less than 2.0 cm
2
(as
assessed by planimetry), documented ischaemic heart disease,
pre-existing non-valvular cardiomyopathy, prior cardiac surgery,
congenital or pericardial disease, pregnancy and severe systemic
disorders such as renal failure, uncontrolled hypertension
[systolic blood pressure (SBP) > 140 mmHg and diastolic blood
pressure (DBP) > 90 mmHg on medication] or severe anaemia
(haemoglobin < 10 g/dl).
16
Statistical analysis
Statistical Package for the Social Sciences (SPSS version 23.0)
[International Business Machine (IBM), Los Angeles] was utilised
in the analysis of data for the study. A 95% confidence interval (CI)
was estimated, and a global significance level of
ά
= 5% was chosen,
to test for the assumptions of the null hypothesis.
Simple descriptive analysis was used to highlight clinical
characteristics and results are presented as frequencies, means
and percentages. Continuous variables are expressed as means ±
standard deviation (SD). The Student’s
t
-test and the chi-squared
test were used to compare continuous and categorical variables,
respectively. A
p
-value of < 0.05 was taken as statistically significant
for the variables being measured.
Results
Using the ICD 10 code for rheumatic MR, 2 986 records were
retrieved. Patients withmixedmitral valve disease who had dominant
MS (
n
= 613) were excluded, as well as those who presented to other
medical disciplines (
n
= 1 106), leaving 1 267 who were referred
directly to the Department of Cardiology and underwent a full
evaluation. Of these, 947 patients were further excluded based on
Meel’s exclusion criteria (Fig. 1). We excluded 277 subjects with
uncontrolled hypertension so that we could study the rheumatic
process unconfounded by the effects of elevated blood pressure
on cardiac function and resultant hypertrophy with fibrosis. This
left us with 320 patients with isolated rheumatic MR for analysis,
approximately 100 subjects in each of the three age groups (Table 1).
The mean patient age was 22.2 ± 15.8 years. The male:female
ratio was 1:2 and the ethnic composition was predominantly
black African (94.1%), followed by Asian (4.1%), white (0.9%)
and coloured (0.3%) subjects. Of the 320 patients, 116 were in the
paediatric age group (mean age 9.7 ± 1.7 years) (Fig. 1, Table 1),
all of whom were black subjects from rural areas and a poor socio-
economic environment characterised by overcrowding and/or single,
absent or unemployed parents.
Most patients presented with dyspnoea; effort tolerance was
graded as New York Heart Association (NYHA) class II in 54.1%,