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AFRICA
S9
CVJAFRICA • Volume 26, No 2, H3Africa Supplement, March/April 2015
Discussion
The most prominent finding in this study was that the
age-standardised mortality rate for CVD has not declined in
SSA, in sharp contrast to the dramatic declines that have been
documented in other world regions, especially in the high-income,
developed world. It is of concern that the age-standardised
mortality rate for CVD in SSA women, which was lower than the
corresponding rate in women in developing countries in 1990,
is now higher than in developing countries, and substantially
higher than corresponding rates in the developed world. In fact,
a previous analysis of the GBD 2013 data on demographic and
epidemiological drivers of global CVD mortality suggested that
age-specific death rates for western sub-Saharan Africa may
have increased.
16
These findings have significant implications for
effective prevention and treatment of CVD in SSA.
A second important observation from this study was that
although most CVD deaths occur in developing countries, the
overall number of CVD deaths in SSA is substantially lower
than seen in the rest of the developed and developing world,
and amounts to 5.5% of global CVD deaths. In addition, these
CVD deaths in SSA constitute 38.3% of non-communicable
disease deaths and 11.3% of deaths from all causes in that
region.
1
Therefore the assertion that CVD deaths represent an
emerging epidemic may be unwarranted. Importantly, however,
the approximately one million deaths in 2013 in SSA represent
a near doubling of the deaths a decade earlier. Roth
et al
.
16
have
showed that population growth and ageing accounted for the
increase in the number of global deaths due to CVD between
1990 and 2013, despite an overall decrease in age-specific death
rates for most regions.
16
A careful analysis of the data from SSA to determine the
role that population growth, ageing and health transitions
play in these deaths is needed. Uniformly however, component
CVD deaths increased by a range from 7% for RHD to nearly
a three-fold increase in atrial fibrillation and peripheral arterial
disease. The good news from the data is the relative decline in the
age-standardised mortality rates for RHD, haemorrhagic stroke
and endocarditis.
This study has several limitations. Some cardiovascular causes
of death are less commonly reported as an underlying cause
of death. These diseases include rheumatic heart disease, atrial
fibrillation, peripheral vascular disease, endocarditis and aortic
aneurysms. Changes over time in the detection and reporting
of these conditions most likely reflect not just epidemiological
changes but changes in diagnostics and the ways that these
diagnoses are attributed to deaths by physicians. Rheumatic
heart disease-related mortality may be particularly difficult to
attribute as a cause of death, which increases uncertainty for
estimates of this condition.
Importantly, data sources on disease burden in SSA are among
the most limited in the world, despite several comprehensive
networks for data collection related to maternal and child
mortality. Unfortunately a functioning vital records system can
only be built in a society with a functioning primary health
system that provides broad access – a concept that remains
a serious challenge for most of SSA within the foreseeable
future. Verbal autopsy and sample vital registration will likely
expand as countries expand their investment in health system
infrastructure.
Efforts should focus on improving comparability across
countries and regions within SSA. Increased attention to
non-communicable diseases will help highlight the important
role of routine surveillance, rather than one-off research studies,
as an important source of descriptive statistics related to CVD
in SSA.
Conclusions
SSA has seen no significant decline in age-standardised CVD
mortality rates, whereas these rates continue to fall dramatically
in most of the high- and middle-income world. Without further
investment in the prevention and treatment of CVD and other
NCDs and their risk factors in SSA, the continent risks being left
behind at a time when improved detection, prevention, treatment
and control of these diseases and risk factors are leading to
longevity and improved quality of life in other world regions.
These decisions should be informed ideally by reliably accurate,
directly enumerated data, rather than estimates such as those
presented in this study.
The relative lack of directly enumerated epidemiological data,
coupled with the absence of vital registration systems in 42 of
the 46 SSA countries, presents major challenges in mortality
and burden of disease data for this region. The estimates of
mortality presented here must therefore be interpreted with
caution. Nevertheless, we found no evidence to support a rapidly
rising epidemic or an impending pandemic of CVD in SSA.
However, the consistency of the directional changes in CVD
deaths, disability and risk-factor trends observed in GBD 2010,
and the mortality trends seen in GBD 2013, together with the
young average age at time of death from CVDs in SSA, compel
attention to aggressive efforts at CVD risk-factor prevention,
treatment and control in both women and men. Coordinated
partnerships between ministries of health, other government
agencies, non-governmental organisations, and the private sector
will be essential in order to mount a targeted response to the
observed challenges.
Interventions at the individual and population levels as
well as improved systems of healthcare will be required. In
addition, investments to improve local-level directly enumerated
epidemiological data and refinement of the quantitation of risk
exposure, death certification and burden of disease assessment
will be crucial. Further research is needed to identify ideal
dissemination and implementation strategies for CVD risk
reduction in the SSA setting.
Until then, finding ways to implement interventions that
are feasible, affordable and acceptable to the local population
and are appropriate to implement in low-resource settings
for the prevention and control of CVD in Africa should be a
priority.
17
This strategy is particularly relevant for the clinical and
public health approaches for addressing hypertension, diabetes,
unhealthy diet, physical inactivity and tobacco use. Improving
access to directly enumerated epidemiological data for the
region would also go a long way towards appropriately informed
healthcare policy and practice.
The views expressed in this article are those of the authors and do not neces-
sarily represent the views of the National Heart, Lung, and Blood Institute,
National Institutes of Health, or the US Department of Health and Human
Services.