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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 4, July/August 2016
AFRICA
207
Acquired von Willebrand syndrome (AVWS) is a rare clinical
condition characterised by prolonged bleeding time and
decreased levels of factor VIII and von Willebrand factor. It has
been reported to occur in patients with severe aortic stenosis and
other cardiac conditions associated with high shear stress, such
as para-valvar leaks after prosthetic valve replacement surgery.
First reported decades ago, the mechanism was initially unclear
but it has now become known. In this issue, Binneto
ğ
lu and
colleagues (page 222) report on a prospective series of children
with aortic and pulmonary stenosis, and describe the frequency
of occurrence and underlying pathophysiology.
There is general agreement on the considerable variation in
the prevalence of various cardiac diseases among the different
ethnic groups in Africa and there may also be differences in the
manner in which the diseases express themselves. There is less
clarity about the contributions of intrinsic ‘genetic’ differences to
that variability compared to acquired or environmental factors.
Sirtuin 1 (SIRT1) has been identified as a candidate molecule
affecting the epigenetic mechanisms of cardiovascular disease
(CVD). Previous studies have shown that some SIRT1 single-
nucleotide polymorphisms (SNPs) are associated with body
mass index, diabetes, blood pressure, cholesterol metabolism
and coronary artery calcification. An investigation conducted by
Ramkaran and co-workers (page 213) in young South African
Indians with coronary disease concluded that SNP variant alleles
occurred more frequently in South African Indians than in black
South Africans. The study is not large enough to definitively
assess whether these variants may serve as risk factors that
contribute to Indians developing early-onset CVD but the results
are intriguing and warrant further investigation.
Technological advances in many aspects of the management
of CVD continue to amaze those of us who have been privileged
to witness their evolution and development. Left ventricular
assist devices (LVADs) and two- and three-dimensional
echocardiography were the stuff of dreams when many of us
were training but now are part of routine care in some parts
of the world. Demirozu and co-workers (page 208) elegantly
demonstrate how the use of advanced imaging techniques of
echocardiography can be used to fine-tune the functioning of
LVADs.
Intravascular stenting was equally unthinkable only a few
decades ago but has now revolutionised much of the management
of CVD. The way in which a new generation of biodegradable
stents promises to advance this area even further is described by
Tiryakioglu
et al
. (page 238).
Cardiologists and physicians trained in an era prior to the
introduction of the technological advances mentioned above
will be pleased to see that the old stalwart, electrocardiography
(ECG) continues to be widely used. Some consider it does not
receive the recognition it deserves as a cheap, non-invasive
adjunct to the clinical examination. A cross-sectional study
carried out on adults in Nigeria examined the ECGs of 100
HIV-infected patients on highly active anti-retroviral therapy
(HAART), 100 HIV-infected HAART-naïve patients and 100
HIV-negative controls (Njoko
et al
., page 252). The clinical
relevance of these findings and that of similar findings reported
by others and discussed by the authors, remains unclear and
requires long-term follow up studies accompanied by imaging,
either by echocardiography or perhaps more helpfully, by cardiac
magnetic resonance imaging.
PJ Commerford
Editor-in-Chief
From the Editor’s Desk
Professor PJ Commerford