CARDIOVASCULAR JOURNAL OF AFRICA • Vol 22, No 4, July/August 2011
AFRICA
193
of hypertension, particularly in urban communities, poor control,
and the larger contribution of hypertension to CVD in African
patients. The SHHS and the STEPS survey have reported preva-
lence rates of 20.1 and 20.4%, respectively for hypertension.
Also, the control of blood pressure in hypertensive patients
seems to be poor in Sudan.
Two outpatient surveys have been identified that assessed
this issue, both using cut-off points of
<
140/90 mmHg for good
control. The first was conducted in eastern Sudan and showed
control rates of 19.4%,
20
and the other was in Khartoum state
and showed a control rate of only 28.1%.
21
Both surveys showed
similar compliance rates with prescribed medication, of 59.6 and
59.4%, respectively. The commonest cause of non-compliance
was inability to purchase medication.
The prevalence of target-organ damage, mainly cardiac and
renal, in outpatient clinics in Sudan is relatively high, with at
least one-fifth of the hypertensive population showing evidence
of target-organ damage.
22,23
Hypertension itself, as shown in the
INTERHEART study, is a strong contributor to the hazards of
CVD in black Africans, with an odds ratio (OR) of 7.0 versus
2.3–3.9 in other ethnic groups (
p
=
0.0002).
24
This situation is not unique to Sudan and is seen throughout
the continent, where hypertension is the leading cardiovascular
disease and cause of heart failure.
17,25,26
However, this condition is
treatable and to some extent preventable.
4
Prevalence of rheumatic heart diseases
The highest prevalence of RHD is in sub-Saharan Africa, with a
prevalence of 5.7 per 1 000 people, compared with 1.8 per 1 000
in North Africa, and 0.3 per 1 000 in economically developed
countries with established market economies.
27
The epidemiological data on rheumatic valvular heart disease
in Sudan come from the WHO Global Rheumatic Fever/
Rheumatic Heart Disease Prevention Program in Sudan. This
project had two phases. Phase I was from 1986 to 1989, where
more than 13 000 schoolchildren aged five to 15 years in Sahafa
town were screened clinically. Sahafa was chosen because it had
well-marked houses and streets and most of its inhabitants were
low- and middle-income families that had moved to the capital
from all districts of the country following the drought in the
early 1980s. Prevalence of rheumatic heart disease in Sudan was
found to be 3/1 000 population,
28
as quoted by the World Health
Organisation.
29
Phase II of the programme was conducted from 1994 to
2003 in the state of Khartoum; 1 095 000 schoolchildren were
screened in this phase. Prevalence was found to be 0.3/1 000
after implementation of a primary and secondary prevention
programme. These data were presented by Dr N Kordofani at
the 2006 World Congress of Cardiology in Barcelona, Spain.
There are no data on other parts of the country. The 10-fold
drop in RHD prevalence over less than two decades, seen in the
capital state of Khartoum, due to screening and prevention is
not expected in other states where no formal programme exists.
However, the recent work by Marijon
et al
., which demon-
strated that the prevalence of RHD as detected by echocar-
diographic screening is 10 times that of clinical screening.
30
This raises a number of concerns for Sudan and the continent
regarding the true prevalence of RHD and the feasibility and
cost-effectiveness of echocardiographic screening.
Atherosclerotic heart diseases and risk
factors
Ischaemic heart disease is the leading cause of death worldwide,
both in high-income and low- and middle-income countries,
except in sub-Saharan Africa where HIV/AIDS and infectious
disease, mainly malaria, are the major causes of death. It is also
responsible for 10% of DALYs lost in low- and middle-income
countries and 18% in high-income countries.
31,32
The incidence
of ischaemic heart disease in Africa has risen greatly in the last
decade and it has been estimated that it ranked eighth in the
leading causes of death, and number one in those over 60 years
of age.
33-35
There has been only one population-based study in Sudan,
conducted by Khalil
et al
., which addressed the issue of coro-
nary event rates.
36
All coronary events occurring in Khartoum,
capital of Sudan, were registered during the calendar year 1989
using the diagnostic and classification criteria of the World
Health Organisation Monitoring of Trends and Determinants in
Cardiovascular Disease (MONICA) project.
37
The annual (1989)
coronary event rate was 112/100 000 with a total mortality of
36/100 000. The highest event rate of 364/100 000 occurred in
men aged 45 to 64 years. The event rates recorded in this study
were low compared to most other MONICA centres, e.g. Spain
(Catalonia) 187/100 000, Australia (Newcastle) 561/100 000 and
Canada (Halifax) 605/100 000.
38
However, these data are two decades old and it is believed that
during this time, many third-world countries, and Sudan is no
exception, have entered a period of epidemiological transition.
Greater urbanisation and economic development has led to a
shift in the major causes of death and disability, from infectious
diseases to chronic non-communicable diseases such as cardio-
vascular disease and cancer.
39
The WHO 2002 estimates for IHD in Sudan,
40
based on the
Global Burden of Disease study,
26
are an age-adjusted mortality
rate of 205/100 000 and an age-adjusted DALYs of 1185/100 000
population. Such estimates need to be validated by local surveys.
Table 3 presents age-standardised mortality rates for all-cause,
non-communicable diseases, cardiovascular diseases, IHD and
DALYs for IHD for Sudan and other African states from differ-
ent regions of the continent.
TABLE 3. SHOWS MORTALITY RATES FORALL-CAUSE,
CVDAND IHDANDYEARS OF LIFE LOST IN SUDAN
AND SELECTEDAFRICAN COUNTRIES FROM
DIFFERENT REGIONS OF THE CONTINENT
Country
Age-
standardised
all-cause
mortality
rates per
100 000
Age-
standardised
mortality
rate for
NCD per
100 000
Age-
standardised
mortality
rate for
CVD per
100 000
Age-
standardised
mortality
rate for
IHD per
100 000
Age-
standardised
DALYs
for IHD
per
100 000
Sudan
1495
902
499
204
1185
Egypt
1132
958
560
273
1781
Eritrea
1584
762
398
124
679
Ghana
1510
786
404
128
726
South
Africa
2011
808
406
124
758
Source: World Health Organisation. Death and DALY estimates by cause,
2002. Available at
-
dalyestimates.xls (accessed 06 December 2009). NCD, non-communicable
disease; CVD, cardiovascular disease; IHD, ischaemic heart disease; DALYs,
disability-adjusted life years.
