Cardiovascular Journal of Africa: Vol 32 No 2 (MARCH/APRIL 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 2, March/April 2021

AFRICA

confirmed infective endocarditis at surgery and the nine treated

clinically yielded a 7.5% (24/320) complication rate of infective

endocarditis in subjects with chronic rheumatic MR.

Using surgery as the gold standard for macroscopic valve

morphology, echocardiographic findings were compared with

the surgical findings (Table 4). Although formal predictive

analysis was not performed, it is apparent that in our subjects

with MR, echocardiography over-diagnosed increased valve

thickening (99.7 vs 62.5%,

= 0.00), prolapse (63 vs 37%,

0.00) and chordal rupture (36 vs 19%,

= 0.00). Most cases of

valve prolapse at echocardiography were found to have chordal

elongation at surgery (

= 63, 29.2%).

To search for any change in the pattern and the severity of

valve disease, the clinical profile and echocardiographic findings

during the first five years (2006–2010) was compared with the

following five years (2011–2015). There was a decline in the

percentage of rheumatic MR presenting in the paediatric group

(seven to 12 years), from 40.7 to 31.4%, with a corresponding

increase in the percentage of new-onset RHD in the adults over

25 years in the latter five years (

= ns).

Of significance was the decline in the number of patients

presenting with severe dyspnoea (NYHA III), from 44.9

to 28.8%, with a corresponding increase in NYHA class II

symptoms during 2011–2015 (

= 0.00). This corresponded with

a decrease in the number of patients with severe MR from 85.6

to 66% (

= 0.00), with an accompanying decline in heart failure

from 46 to 26% (

= 0.00).

We also compared the surgical findings over the two five-

year periods. While the majority of valve morphology findings

remained unchanged, there was a significant increase in leaflet

thickening in the latter five years (38 to 97%,

= 0.00) and a

significant decline in chordal elongation (40.5 to 13%,

= 0.00).

Discussion

RHD remains a major public health burden in the province of

KZN in southern Africa, despite the previously reported decline

in other parts of SA.

25,26

In this study we screened 2 986 patients

with rheumatic MR over a 10-year period (2006–2015) and found

a 10.7% prevalence of isolated MR in this group. This condition

continues to impose an economic burden in our population since

the majority of our patients were young, with a mean age of 22.2 ±

15.8 years, and in need of chronic medical and surgical therapies.

In addition, the finding that all 116 (36.3%) patients in the

paediatric age group were young black Africans from poor

socio-economic circumstances suggests that RHD remains active

among those of lower socio-economic class. In contrast, among

the Indian race group in our study, there was only a single subject

in the 13–25-year age group, and the rest of the Indians were

adults above 25 years of age, suggesting that the socio-economic

circumstances have improved enough to eradicate rheumatic

fever in this group over the last decade. In other provinces in SA,

improvement in access to medical care for the general population

as well as the introduction of free healthcare to children under

the age of six years in 1994

has led to a dramatic decline in

the number of children younger than 14 years presenting to the

paediatric cardiology department with ARF and RHD.

The pattern of disease we describe in KZN most likely relates

to the low socio-economic burden in this province. Second to

Gauteng, KZN ranked highest in the provincial distribution

of population living in SA (Statistics SA between 2002 and

2014),

and is the third highest province affected by poverty,

following Eastern Cape and Limpopo.

Furthermore, the recent

census showed that the groups mostly affected by poverty within

these provinces were children below the age of 17 years, black

Africans, females, people living in rural areas, as well as those

with little or no education.

26,27

The relatively higher burden of

RHD in KZN affecting the predominantly younger African

female population may therefore be attributed to the increased

population burden, together with high levels of poverty when

compared to the rest of SA.

Although the majority of our patients presented for the first

time with RHD, 34 patients (10.6%) satisfied the modified Jones

criteria for ARF, and evidence of active rheumatic carditis was

confirmed in all at surgery. We postulate that the low rate of

ARF in the paediatric age group could be attributed to missed

diagnosis of ARF at the primary healthcare level, delayed

presentations, or failure to seek medical care at the onset of

disease due to socio-economic issues, resulting in patients

presenting at a later stage with more established disease. Also, a

few patients at our clinic have reported not receiving long-acting

penicillin for some time, as it had been out of stock in their base

hospitals, which may explain the recurrence of carditis in certain

cases. All these factors probably contributed to the failure of

implementing early secondary penicillin prophylaxis, which

resulted in disease progression. The REMEDY and other studies

have provided good clinical evidence that secondary penicillin

prophylaxis reduces the chance of recurrent carditis.

1,29-32

Our findings contrast with those of Meel

et al

whose

subjects were older than ours (mean age 44 vs 22 years) and had a

high prevalence of hypertension (Table 5). Meel

et al

. found only

one patient with active carditis, and echocardiography revealed

no chordal rupture or elongation, with minimal leaflet prolapse.

Instead, they showed marked leaflet thickening, calcification and

leaflet retraction with associated chordal thickening.

In contrast, we have shown a high prevalence of anterior

leaflet prolapse and chordal rupture, findings that were confirmed

in subjects undergoing surgery. This pattern of disease is quite

different from that found by Meel

et al

., who reported restrictive

(Carpentier type IIIa) leaflet dysfunction with annular dilatation

in the majority (80%) of their subjects, the remainder having a

combination of type 2 (excessive leaflet motion) and type IIIa.

After excluding uncontrolled hypertension, Meel

et al

found

Table 4. Comparison between echocardiographic and surgical findings

Valve morphology

Echocardiogram

(

= 216) (%)

Surgery

(

= 216) (%)

-value

Increased leaflet thickness

215 (99.7)

135 (62.5)

0.0000

Subvalvular apparatus thickness

42 (19.4)

37 (17)

0.3046

Calcification

19 (8.8)

1.0000

Prolapse

136 (63)

80 (37)

0.0000

Chordal rupture

77 (36)

41 (19)

0.0001

Chordal elongation

63 (29.2)

0.0000

Dilated annulus*

Not assessed

13 (6.0)

0.0003

Vegetations

25 (11.6)

14 (6.5)

0.0003

*Mitral annular measurements were not recorded at echocardiography.

Comments on annular dilatation were made in a few cases by the surgeon who

performed valve repair and inserted a mitral ring.

Echocardiography over-diagnosed leaflet/subvalvular thickness, chordal

rupture, valve prolapse as well as vegetations. About half of the subjects with

these diagnoses were confirmed at surgery. Surgery detected chordal elongation

in many subjects previously diagnosed with valve prolapse/chordal rupture.