13 / 60
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 2, March/April 2021
AFRICA
67
extensive fibrosis in isolated MR across her whole cohort, quite
different from the pattern in all our younger subjects, who
showed little evidence of advanced fibrosis.
It must be pointed out that our age comparisons reflect the
natural history of RHD, which is carditis being commoner in
the young, followed by a more fibrotic process in older age. Our
96 subjects in the older age group (> 25 years, mean age of 43
years) showed more evidence of a chronic fibrotic process with
subvalvular thickening and leaflet calcification, compared to
chordal rupture and valve prolapse in subjects under 25 years.
Of importance, our findings are suggestive of recent ongoing
carditis in young adults, diagnosed clinically and supported
by echocardiographic findings, as well as macroscopic surgical
findings.
In patients with active rheumatic carditis presenting with
overt heart failure, severe MR and its anatomical correlate of
annular dilation, chordal elongation and prolapse of the anterior
mitral leaflet is regarded as the hallmark of the disease.
12
We
feel the age comparison highlights this pattern of disease that is
still seen in developing countries and reflects a failure of proper
ongoing rheumatic fever prophylaxis.
Our finding of chordal elongation in 29% of subjects at
surgery is highly suggestive of ongoing rheumatic carditis in
young subjects (mean age 22 years) with isolated MR,
12,15
and it
fits the profile of rheumatic MR reported by Marcus
et al
., who
described active carditis in young subjects (mean age 19 years)
without any co-morbidities. In Marcus and colleagues’ study,
patients with pure MR had thin leaflets, elongated chordae,
dilated annuli and anterior leaflet prolapse, findings that were
corroborated at the time of surgery.
15
The prevalence of clinical
carditis in their study was also similar to that of ours (14 vs
10.6%).
Our finding of a 10.6% prevalence of active carditis in
patients with isolated MR is probably an underestimate of the
true prevalence since, similar to Marcus
et al
., we also showed
a significantly high prevalence of chordal elongation (29%),
ruptured chordae (19%) and leaflet prolapse (37%) in the absence
of infective endocarditis at surgery. It is clear that the pattern
of rheumatic MR in our study reflects the ongoing poor socio-
economic environment in many parts of KZN.
Another possible explanation for the discrepancy between
our findings and Meel and colleagues’ results is that we excluded
277 patients with uncontrolled hypertension because of the
confounding effects of hypertension on myocardial function.
This excluded a number of the middle-aged patients with RHD,
which probably accounted for the effects of co-morbidities on
the valve morphology in the study by Meel
et al
.,
16
as well as for
Sliwa and co-workers’ report on the increase in prevalence of
adult cases presenting with RHD in Soweto.
8
In our study, calcification was found in 8.8% and leaflet
thickening in two-thirds of subjects. Comparison of the surgical
findings over the two time periods in our study, however, did
reveal an increase in leaflet thickness and a decline in chordal
elongation in the latter five years of the study period, suggesting
that there is a gradual transition towards the pattern of disease
currently being seen in Soweto.
16
After the exclusion of those with
hypertension, the main co-morbidity encountered in our study
was HIV infection. We also compared the echocardiographic
and surgical findings of the patients with HIV infection to those
who were HIV negative, and found that HIV had no significant
influence on the pattern or progression of RHD.
There were 143 patients (44.6%) in our study who suffered 152
complications, in keeping with other hospital-based studies.
7,8
The commonest complication was heart failure, which occurred
in 117 patients (36.6%). This is not surprising since over half of
the subjects had an EF under 60% and, according to established
guidelines, should have undergone surgery at an earlier stage in
their illness.
33
Although we examined the clinical profile of our subjects
over the 10-year period and showed there was an improvement
in clinical presentation with a decline in heart failure, many
patients were lost to follow up and over a third of them had
died, according to the deaths registry. Factors that probably
contributed to the significant mortality rate in our study
included delay in surgical treatment, failure to refer patients
with severe MR to surgery, and/or clinician lethargy in referring
patients with severe MR to tertiary care until late in the disease.
Limitations and strengths
In addition to its retrospective design, our study has several other
limitations. Patients with ARF and MR who were stable and less
symptomatic may not have been referred for evaluation. However,
we captured the presentation of patients with significant MR
since all patients with moderate to severe rheumatic MR
managed in the public sector are usually referred for tertiary
care to IALCH. Although we have regular cardiac clinics two
days a week, long-term patient follow up was often not possible
because of difficulty of access to care from rural areas, resulting
in over half the patients presenting late with impaired ventricular
function (EF < 60%), or being lost to follow up with resultant
mortality, as revealed by the examination of the deaths registry.
Second, the retrospective nature of the study and the lack
of standardised echocardiographic assessment of patients
prior to surgery resulted in an incomplete dataset for analysis.
Measurements of the chords and mitral annulus were not
Table 5. Comparison of studies by Meel
et al
.
16
and Marcus
et al
.
14
with the current study (Zwane
et al
.)
Variables
Marcus
et al
.
(
n
= 219)
Meel
et al
.
(
n
= 84)
Zwane
et al.
(
n
= 320)
Age (years), mean ± SD
19 ± 11
44 ± 15.3 22.2 ± 15.8
Females (%)
Not specified
84
67.8
Black African (%)
100
100
93
Functional class (NYHA)
III–IV
II–III
II–IV
Active carditis (%)
14
1.2
10.6
Co-morbidities (%)
0
78
13.7
Mitral valve morphology (%)
Echo/surgery
Echo
Surgery
(
n
= 216)
Dilated annulus
95
84.5
6.0**
Thin, pliable leaflets
95
5
37.5
Thickened, non-pliable leaflets
59
41
20 *
Leaflet prolapse
84
20
37
Leaflet calcification (rigid)
5
27
8.8
Elongated chordae
92
0
29.2
Ruptured chordae
25
0
19
Commissural fusion
0
30
0
NYHA: New York Heart Association.
*Rigid posterior leaflet.
**The figure here reflects the comments on annular dilatation by the surgeon
who sized the annulus for insertion of a ring during mitral valve repair.
In contrast to the recent findings by Meel
et al
.,
16
our surgical findings (Zwane
et al
.) are similar to the profile of chronic MR described by Marcus
et al
.
15