CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 2, March 2012
AFRICA
103
Review Article
A systematic overview of prospective cohort studies of
cardiovascular disease in sub-Saharan Africa
ANDRE PASCAL KENGNE, LUCAS M NTYINTYANE, BONGANI M MAYOSI
Abstract
Background:
Cardiovascular diseases (CVDs) are becom-
ing increasingly significant in sub-Saharan Africa (SSA).
Reliable measures of the contribution of major determinants
are essential for informing health services and policy solu-
tions.
Objective:
To perform a systematic review of all longitudi-
nal studies of CVDs and related risk factors that have been
conducted in SSA.
Data source:
We searched electronic databases from 1966
to October 2009. Published studies were retrieved from
PubMed and Africa EBSCO. Reference lists of identified
articles were scanned for additional publications.
Study selection:
Any longitudinal study with data collection
at baseline on major cardiovascular risk factors or CVD,
including 30 or more participants, and with at least six
months of follow up were included.
Data extraction:
Data were extracted on the country of study,
year of inception, baseline evaluation, primary focus of the
study, outcomes, and number of participants at baseline and
final evaluation.
Results:
Eighty-one publications relating to 41 studies from
11 SSA countries with a wide range of participants were
included. Twenty-two were historical/prospective hospital-
based studies. These studies focused on risk factors, particu-
larly diabetes mellitus and hypertension, or CVD including
stroke, heart failure and rheumatic heart disease. The rate of
participants followed through the whole duration of studies
was 72% (64–80%), with a significant heterogeneity between
studies (for heterogeneity,
p
<
0.001). Outcomes monitored
during follow up included trajectories of risk markers and
mortality.
The George Institute for International Health, University of
Sydney, Sydney, Australia
ANDRE PASCAL KENGNE, MD, PhD
Department of Medicine, Groote Schuur Hospital and
University of Cape Town, Cape Town, South Africa
ANDRE PASCAL KENGNE, MD, PhD
LUCAS M NTYINTYANE, MB ChB, PhD
BONGANI M MAYOSI, MB ChB, Dphil,
National Collaborative Research Programme on
Cardiovascular and Metabolic Disease, Medical Research
Council, Cape Town, South Africa
ANDRE PASCAL KENGNE, MD, PhD
Conclusions:
Well-designed prospective cohort studies are
needed to inform and update our knowledge regarding the
epidemiology CVDs and their interactions with known risk
factors in the context of common infectious diseases in this
region.
Keywords:
cohort studies, cardiovascular diseases, risk factors,
outcomes, sub-Saharan Africa
Submitted 3/7/10, accepted 15/8/11
Cardiovasc J Afr
2012;
23
: 103–112
DOI: 10.5830/CVJA-2011-042
The pattern of disease occurrence in sub-Saharan Africa (SSA)
is changing constantly, both at the level of and within broad
categories of disease entities. Over the past few decades, the
significance of chronic diseases and principally cardiovascular
diseases (CVD) has grown consistently in SSA. Within the
broad category of cardiovascular diseases, a double burden of
infectious and post-infectious diseases (i.e. rheumatic valve
disease, post-tuberculosis cor pulmonale and pericardial tuber-
culosis) co-exists, with a rising burden of hypertension and its
related complications of stroke, heart failure and chronic kidney
disease.
1-3
According to the global burden of disease estimates,
4
in 2001,
cerebrovascular diseases and ischaemic heart diseases (IHD)
were the eighth and ninth leading causes of death in SSA, and
contributed 3.3 and 3.2%, respectively, of total deaths recorded
in that year. Overall, in 2001, 10% of all deaths in SSA occurred
as a result of CVD, and 4% of disability-adjusted life years
(DALYs) were related to a CVD. CVDs and chronic diseases are
compounding an under-resourced and understaffed public care
system in SSA, and there is a huge financial burden as well.
SSA is a poor region with major socio-economic challenges.
Projections indicate that by 2030, IHD and cerebrovascular
diseases will overtake HIV/AIDS as the leading causes of death
in this region. By then, the two CVD constituents will contribute
over 20% of total deaths and 7% of DALYs in SSA. Diabetes
mellitus will feature among the top 10 leading causes of death.
5
A short window of opportunity still exists, during which it
might be possible to introduce measures that would prevent the
full development of this epidemic of cardiovascular diseases
in SSA. Reliable information about the distribution of known
risk factors, how they change with time and how they relate to
cardiovascular outcomes is of major importance but still lacking
in Africa.
6
Without such reliable data it is impossible to devise
effective, long-term disease-prevention strategies to combat the
double burden.
