Cardiovascular Journal of Africa: Vol 32 No 3 (MAY/JUNE 2021)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 3, May/June 2021 AFRICA 149
Effect of mitral valve replacement on left ventricular
function in subjects with severe rheumatic mitral
regurgitation
Sharen Maharaj, Somalingum Ponnusamy, Datshana Naidoo
Abstract
Introduction: This study describes the effects of mitral valve
replacement (MVR) on left ventricular (LV) function in
patients with severe rheumatic mitral regurgitation (MR).
Methods: This was a retrospective analysis over a nine-year
period (2005–2013). Clinical and echocardiographic parame-
ters were recorded pre-operatively and at two weeks, six weeks
to three months and six months following MVR.
Results: Of the 132 patients included in the study, 66%
were in New York Heart Association (NYHA) class III–IV
and 38% presented with clinical features of heart failure.
Pre-operatively, 28% of subjects had impaired LV func-
tion [ejection fraction (EF) < 60%] and the majority had
advanced chamber dilatation [left ventricular end-diastolic
diameter (LVEDD) 60.7 ± 7.9 mm (n = 132), left ventricular
end-systolic diameter (LVESD) 39.9 ± 7.2 mm (n = 118) and
left atrial size 61.2 ± 12.6 mm (n = 128)]. Paired analysis of
83 patients revealed that the EF was > 55% in 87% (n = 72)
pre-operatively, decreasing to 20% (n = 17) of patients at two
weeks postoperatively (p < 0.001); thereafter an EF > 55%
was recorded in 60% (n = 50) at the six-month follow-up visit
( p < 0.001). On multivariate analysis, only LVESD emerged
as a significant predictor of postoperative LV dysfunction.
Conclusion: In this study, most patients with severe MR
presented late with significant impairment of LV function
and chamber dilatation that often did not recover fully after
surgery. This study emphasises early comprehensive evalua-
tion of severe MR followed by timeous surgery in order to
preserve LV function.
Keywords: mitral regurgitation, mitral valve replacement, left
ventricular function, heart failure
Submitted 13/3/20, accepted 1/12/20
Published online 12/2/21
Cardiovasc J Afr 2021; 32: 149–155
DOI: 10.5830/CVJA-2020-056
Recent hospital-based studies in South Africa (SA) reveal an
incidence of congestive heart failure secondary to rheumatic
heart disease (RHD) of 25 cases per 100 000 per year.1,2 Mitral
regurgitation (MR) is one of the commonest causes of heart
failure in subjects with RHD. Subjects with MR may remain
asymptomatic for several years. Symptoms occur late in the
natural history of chronic MR since the left atrium dilates to
accommodate large volumes of blood without a significant rise
in left atrial (LA) pressure.3
As the lesions of MR progress, left ventricular (LV) volume
overload ensues as a result of the increase in the regurgitant
orifice area.4 Long-standing severe MR eventually leads to
impaired LV function with increasing end-systolic volumes and
pulmonary congestion. Although there may be underlying LV
dysfunction, ejection fraction (EF) is maintained until late in the
disease process.4
At the point when the end-systolic diameter (ESD) increases
to above 40 mm, the EF falls below 60%.4 International
guidelines therefore recommend surgical intervention when the
patient develops dyspnoeic symptoms, and/or echocardiography
demonstrates evidence of LV dysfunction (EF < 60%) and/or
dilatation (ESD > 45mm).4,5 However, not much is known about
the outcome of surgery in subjects with overt impairment of LV
function.6
We hypothesised that in these subjects, recovery of contractile
function is slow, with persistence of heart-failure symptoms.
Since these subjects are known to have a poorer prognosis7 and
reduced survival rates,8 we examined the early surgical outcome
in those with impaired LV function, and evaluated the response
of the LV after corrective surgery.
Methods
This retrospective study was conducted in subjects with
severe rheumatic MR confirmed by echocardiography in the
Department of Cardiology at Inkosi Albert Luthuli Central
Hospital (IALCH) over a nine-year period (2005–2013). Patients
were selected using the common procedural terminology
(CPT) code for mitral valve replacement (33 430) via the
Speedminer software program 3 (Speedminer, Malaysia), which
is the Data Warehouse Management software package used
at IALCH to record and categorise patients’ medical details.
Patient demographics, HIV status, New York Heart Association
(NYHA) classification, presence of atrial fibrillation, chronic
medication and echocardiographic parameters were recorded at
their most recent pre-operative visit and subsequent to mitral
valve replacement (MVR) at two-week, six-week to three-month,
and six-month follow-up intervals. Data were collected and
grouped according to pre-operative EF in each case: EF < 40%,
EF = 40–49%, EF = 50–59% and EF > 60%.
Patients with isolated, pure rheumatic MR were included.
Patients with ischaemic and functional MR, concomitant mitral
stenosis with mitral valve area (MVA) < 2.5 cm², aortic valve
Department of Cardiology, Inkosi Albert Luthuli Central
Hospital, University of KwaZulu-Natal, Durban, South Africa
Sharen Maharaj, MB ChB, MMed, FCP (SA),
Somalingum Ponnusamy, MB ChB, FCP (SA), Cert Cardiol
(Physicians) (SA)
Datshana Naidoo, MD (UKZN), FRCP,