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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 4, July/August 2017
216
AFRICA
followed by transthoracic echocardiography. The assessment of
previous heart failure (HF) was made based on a combination
of the patient’s prior history, as well as available clinical records.
Acute or recurrent rheumatic carditis was diagnosed using the
modified Jones and World Health Organisation criteria.
7,8
The
HIV status was available on all patients from prior medical
records.
Transthoracic echocardiography was performed on all patients
in the left lateral position using a S5-1 transducer on a Philips iE33
system (Amsterdam, the Netherlands). Images were obtained
according to a standardised protocol. Data were transferred and
analysed offline using the Xcelera workstation (Philips).
All linear chamber measurements were performed according
to the American Society of Echocardiography (ASE) chamber
guidelines.
9
Left atrial (LA) volume was measured using the
biplane area length method (apical four- and two-chamber
for LA) and was indexed to body surface area (BSA).
9
Left
ventricular (LV) end-diastolic volume (EDV), end-systolic
volume (ESV) and ejection fraction (EF) were assessed using
the Simpsons method.
9
LV mass was calculated according to
ASE recommendations and was indexed to BSA.
9
LV diastolic
function measurements were performed in accordance with the
ASE guidelines on diastolic function and included pulse-wave
Doppler at the mitral tips and tissue Doppler of both medial
and lateral mitral annuli.
10
Measurements relating to the right
ventricle (RV) were based on the ASE guidelines for the RV.
11
MR severity was assessed using qualitative, semi-quantitative
and quantitative methods as per European Association of
Echocardiography valvular regurgitation guidelines.
12
In
equivocal cases, the echocardiographic data were integrated
with the clinical evaluation by an experienced cardiologist to
distinguish moderate from severe MR.
MR was considered of rheumatic aetiology when the
morphology of the valve satisfied the proposed World Heart
Federation (WHF) criteria for the diagnosis of chronic rheumatic
heart disease (RHD).
13
The Carpentier classification was used to
assess leaflet motion.
14
The extent of morphological abnormality
of the valve was determined using the Wilkins score.
15
TheWilkins score was used to characterise the mitral valve due
to the absence of an alternate scoring system. Although it was
originally designed for prediction of success for balloon mitral
valvotomy in mitral stenosis (MS), its systematic classification
of structural changes to the mitral valve was considered useful
to characterise the morphology of chronic rheumatic valve
disease and therefore was used in this study. The Wilkins score
is divided into four components: (1) leaflet thickening, (2) leaflet
mobility, (3) leaflet calcification, and (4) subvalvular apparatus
involvement. The individual components are then graded from 0
(absent) to 4 (severe), depending on the extent of involvement,
ranging from none to severe.
15
Statistical analysis
Statistical analysis was performed with Statistica version 12.5
series 0414 for Windows. Continuous variables are expressed
as mean
±
SD or median (IQR). The Student’s
t
-test or Mann–
Whitney
U
-test was used to compare continuous variables.
Categorical variables were evaluated by the chi-squared and
Fishers exact test when necessary. A
p
-value of
<
0.05 was
recognised as statistically significant.
Results
The baseline characteristics of the study patients are listed in
Table 1. All patients were black South Africans, predominantly
from Soweto. MR was moderate in 59 (68%) and severe in
25 (32%) patients. The mean age of patients was 44
±
15.3
years with 84% females. Two-thirds of patients were in New
York Heart Association (NYHA) II or III, with 26% having
been hospitalised for heart failure (HF) in the preceding year.
Only one patient presented with features of acute rheumatic
carditis two years prior to this study. No patients had recurrent
rheumatic carditis despite only 6% being on penicillin for
secondary prophylaxis for ARF. Four (5%) patients were in atrial
fibrillation (AF).
Table 1. Baseline clinical and echocardiographic characteristics
*
Characteristics
Number
=
84
Clinical
Age (years)
44
±
15.3
Females (%)
84
Systolic blood pressure (mmHg)
124.1
±
11.4
Diastolic blood pressure (mmHg)
77.2
±
8.8
Heart rate (beats/min)
78.2
±
12.7
Body mass index (kg/m
2
)
27.1
±
6.1
Body surface area (m
2
)
1.7
±
0.2
NYHA functional class (I/II/III/IV) (%)
34/42/24/0
Hypertension
52
Diabetes mellitus type 2
3
Human immunodeficiency virus
26
Medication (%)
Highly active antiretroviral therapy
19
Diuretics
71
Spironolactone
21
Angiotensin converting enzyme inhibitor
40
Beta-receptor antagonists
25
Calcium channel antagonists
29
Aspirin
12
Warfarin
5
Digoxin
5
Amiodarone
1
Left ventricle
Left ventricular end-diastolic diameter (mm)
55.3
±
9.5
Left ventricular end-systolic diameter (mm)
41.4
±
10.3
Interventricular septal diameter (mm)
8.9
±
3.5
Posterior wall diameter (mm)
8.6
±
1.6
End-diastolic volume indexed (ml/m
2
)
†
93.8
±
31.4
End-systolic volume indexed (ml/m
2
)
†
39.7
±
22.3
Left ventricular mass (g)
175.7
±
64.2
Left ventricular mass indexed (g/m
2
)
†
77.9
±
22.5
Left ventricular ejection fraction (%)
58.8
±
12.8
Average E/E
′
(cm/s)
18
±
10.0
Deceleration time (cm/s)
214.2
±
63.3
E
′
(cm/s)
8.6
±
3.3
E/A ratio
1.5
±
0.7
Left atrium
Left atrial volume indexed (ml/m
2
)
†
69.5
±
50.7
Right ventricle
Right ventricle S
′
(cm/s)
12.8
±
11.0
Pulmonary artery systolic blood pressure (mmHg)
36.2
±
18.9
Tricuspid regurgitation (none/mild/moderate or
severe) (%)
36/33/31
*Data are presented as mean
±
SD or %.
†
Values are indexed to body surface
area. NYHA: New York Heart Association.