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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 2, March/April 2016
AFRICA
111
Valvular heart disease in pregnancy
John Anthony, Ayesha Osman, Mahmoud U Sani
Abstract
Valvular heart disease may be a pre-existing complication of
pregnancy or it may be diagnosed for the first time during
pregnancy. Accurate diagnosis, tailored therapy and an
understanding of the physiology and pathophysiology of
pregnancy are necessary components of management, best
achieved through the use of multidisciplinary clinics. This
review outlines the management of specific lesions, with
particular reference to post-rheumatic valvular heart disease.
Keywords:
valvular, heart disease, pregnancy
Submitted 9/2/16, accepted 14/4/16
Cardiovasc J Afr
2016;
27
: 111–118
www.cvja.co.zaDOI 10.5830/CVJA-2016-052
Heart disease is one of the most common medical disorders
in pregnancy. Pregnancy is associated with significant
haemodynamic changes that may aggravate valvular heart
disease and increase the risk of thrombo-embolic events. Valvular
heart disease accounts for approximately a quarter of the cardiac
diseases complicating pregnancy and is an important cause of
maternal mortality, posing many challenges in management.
1
In developing countries, valvular disease is almost exclusively
the consequence of childhood rheumatic fever, although valvular
dysfunction may also develop in some patients who have a
prolapse of the mitral valve leaflets (Barlow’s syndrome), or
ventricular dilation due to elevated afterload or cardiomyopathy.
2
This review will be directed to the main source of valvular disease
in developing countries, which is post-rheumatic disorders.
Epidemiology of rheumatic heart disease
Rheumatic fever and its cardiac sequelae remain prevalent in
developing countries.
3
Although the Global Burden of Disease
study demonstrated an overall reduction in deaths due to
rheumatic heart disease (RHD) over a 20-year period, much
of the change occurred in North America and Europe.
4
The
condition remains prevalent in other parts of the world, with an
estimated global incidence of 282 000 new cases per year.
5
On a global scale, the years lived with disability due to
rheumatic fever, valvular heart disease caused by rheumatic
disease, and heart failure related to valvular rheumatic heart
disease are less encouraging, with increased rates of heart
failure evident.
6
This epidemiology is significant because it
defines a condition that is preventable within the context of
socio-economic upliftment, limiting overcrowding and giving
sufficient access to medical care; it is also a significant cause
of premature mortality. The cited estimates of mortality reflect
institutional rates due to clinical disease and take no account of
the pre-clinical incidence of the disease.
It has been projected that more than 15 million people
suffer from RHD worldwide, which is likely a significant
underestimation, according to the increasing data on subclinical
RHD.
7,8
RHD accounts for a major proportion of all
cardiovascular disease (CVD) in children and young adults in
African countries and for 17–43% of all cardiovascular disease
in sub-Saharan Africa (SSA).
9
The disease causes 400 000 deaths
annually, mainly among children and young adults living in
developing countries.
10
The recently published Global Rheumatic Heart Disease
registry (REMEDY) enrolled 3 343 patients (median age 28
years, 66.2% female) presenting with RHD at 25 hospitals in
12 African countries, India and Yemen. The majority (63.9%)
had moderate-to-severe multi-valvular disease complicated
by congestive heart failure (33.4%), pulmonary hypertension
(28.8%), atrial fibrillation (AF) (21.8%), stroke (7.1%), infective
endocarditis (4%) and major bleeding (2.7%). Among 1 825
women of childbearing age (12–51 years), only 3.6% were using
contraception.
11
In general, RHD accounts for about 8% of the clinical disease
documented in an urban South African black population but
is the presenting cardiac disease in a far higher proportion of
pregnant women accessing maternity care in an African setting.
12
In South Africa, cardiac disease in pregnancy is the most
common medical disorder leading to maternal mortality and
about 26% of those deaths have been attributed to complications
arising from valvular heart disease.
The physiological changes of pregnancy can precipitate
symptoms of cardiac disease in women who were previously
asymptomatic. The management of pregnant women with
valvular heart disease combines and sometimes conflicts with
obstetric management of the pregnancy. Perinatal outcome
becomes an additional consideration superimposed on the need
for good-quality medical care. These competing interests are best
managed through collaborative, combined care in a high-risk
clinic attended by both obstetricians and cardiologists.
13
Physiology of pregnancy and heart disease
Pregnancy results in the development of a hyperdynamic
circulation. Increased circulating blood volume and increased
cardiac output are necessary adaptations, allowing increased
uterine and placental perfusion, combined with augmented
perfusion of maternal organs, which is important in pregnancy
homeostasis, especially for the kidneys and skin.
14
The changes
that take place are progressive and largely determined by
placental endocrine function.
Division of Obstetrics and Gynaecology, Groote Schuur
Hospital, University of Cape Town, Cape Town, South Africa
John Anthony, MB ChB, FCOG, MPhil,
john.anthony@uct.ac.zaAyesha Osman, MB ChB, FCOG, MMed
Department of Medicine, Bayero University Kano and
Aminu Kano Teaching Hospital, Kanu, Nigeria
Mahmoud U Sani, MB BS, FWACP