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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 5, September/October 2020
226
AFRICA
Is the prevalence of congenital heart disease in
Africa less than elsewhere?
The increasing prevalence of congenital heart since the 1950s is
ascribed to better recognition of less-severe disease. Worldwide,
data are consistent, and it would be surprising if the prevalence
of a congenital condition is truly half that of the rest of the
world. As indicated above, the global burden of disease data
would suggest that data from Africa are equivalent to the rest
of the world. More recent studies, some of which are spin-offs
from screening studies for rheumatic heart disease, would suggest
that this is the case. Ekure
et al
., for example, documented a
prevalence of 9.410/1 000 in school-going children in Nigeria,
10
with a median age of 11 years.
How can better data be obtained?
Prospective patient registries (as suggested by Mahzani
et al
.)
may offer a good solution. In a small country such as Botswana
with one major referral hospital, it may be easier to link the data
in a registry to birth data and get a better idea of prevalence.
The performance of prospective prevalence studies in newborns
(ideally as regional research projects) would be the best way of
showing the community of paediatricians that children with
congenital heart disease are not rare.
References
1.
Mahzani T, Steenhoff AP, Tefera E, David T, Patel Z, Sethomo W,
et al
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Clinical spectrum and prevalence of congenital heart disease in children
in Botswana.
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2.
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56,109 births. Incidence and natural history.
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Wren C. The epidemiology of cardiovascular malformations.
Pediatric
Cardiovascular Medicine.
Moller JH, Hoffman JIE (eds). Wiley Online
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4.
Zimmerman MS, Smith AGC, Sable CA, Echko MM, Wilner LB, Olsen
HE,
et al.
Global, regional, and national burden of congenital heart
disease, 1990–2017: a systematic analysis for the Global Burden of
Disease Study 2017.
Lancet Child Adolescent Health
2020;
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(3): 185–200.
5.
Liu Y, Chen S, Zuhlke L, Black GC, Choy MK, Li N,
et al
. Global birth
prevalence of congenital heart defects 1970-2017: updated systematic
review and meta-analysis of 260 studies.
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6.
Van der Linde D, Konings EE, Slager MA, Witsenburg M, Helbing
WA, Takkenberg JJ,
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J Am Coll Cardiol
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Hoffman J. The global burden of congenital heart disease.
Cardiovasc J
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Edwin F, Zuhlke L, Farouk H, Mocumbi AO, Entsua-Mensah K,
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. Status and challenges of care in Africa for adults
with congenital heart defects.
World J Pediatr Congenit Heart Surg
2017;
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Chaix MA, Andelfinger G, Khairy P. Genetic testing in congenital heart
disease: A clinical approach.
World J Cardiol
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10. Ekure EN, Sokunbi O, Kalu N, Olusegun-Joseph A, Kushimo O, Amadi
C,
et al
. Congenital heart disease in school children in Lagos, Nigeria:
Prevalence and the diagnostic gap.
Am J Med Genet C Semin Med Genet
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Cocoa may improve walking in people with peripheral artery disease: small study
In a small study of 44 peripheral artery disease patients
over age 60 years, those who drank a beverage containing
flavanol-rich cocoa three times a day for six months were able
to walk up to 42.6 metres further in a six-minute walking test,
compared to those who drank the same number and type of
beverages without cocoa. Those who drank the flavanol-rich
cocoa also had improved blood flow to their calves and some
improved muscle function compared to the placebo group.
Peripheral artery disease or PAD, a narrowing of the
arteries that reduces blood flow from the heart to the legs,
affects over 8.5 million people 40 years of age and older in
the USA. The most common symptoms are pain, tightness,
cramping, weakness or other discomfort in leg muscles while
walking.
‘Few therapies are available for improving walking
performance in people with PAD,’ said lead study author
Dr Mary McDermott, the Jeremiah Stamler professor of
medicine and preventive medicine at the Feinberg School
of Medicine at Northwestern University in Chicago. ‘In
addition to reduced blood flow to the legs, people with
peripheral artery disease have been shown to have damaged
mitochondria in their calf muscles, perhaps caused by
the reduced blood flow. Mitochondria are known as the
powerhouse of the cell, converting food to energy. Previous
research has shown that better mitochondrial health and
activity are associated with better walking performance and
improving the health of damaged mitochondria could lead to
walking improvements.’
Researchers hypothesised that epicatechin, a major
flavanol component of cocoa, may increase mitochondrial
activity and muscle health in the calves of patients with
lower-extremity PAD, potentially improving patient walking
ability. Epicatechins and flavanols also have the potential to
improve blood flow.
Study participants were randomly assigned to drink
milk or water mixed with the contents of a powder packet
containing flavanol-rich cocoa (15 g of cocoa and 75 mg of
epicatechin daily) or a placebo powder packet without cocoa
or epicatechin, three times daily over six months. Walking
performance was measured at the beginning of the study and
at six months, with a six-minute walking measured test twice:
2.5 and 24 hours after drinking the beverage.
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