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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 5, September/October 2014
228
AFRICA
Hypertensive retinopathy and its association with
cardiovascular, renal and cerebrovascular morbidity in
Congolese patients
Nelly N Kabedi, Jean-Claude Mwanza, François B Lepira, Tharcisse K Kayembe, David L Kayembe
Abstract
Background:
Signs indicating hypertensive retinopathy can
help determine the extent of hypertensive cardiovascular,
renal and cerebrovascular damage.
Objectives:
To study the association between hypertensive
retinopathy and cardiovascular, renal and cerebrovascular
changes, and to determine the predictors of hypertensive
retinopathy in Congolese patients.
Methods:
A total of 159 hypertensive subjects (mean age: 58.9
±
13.2 years) were enrolled from the cardiology out-patient
clinic. Retinopathy grade was assessed on direct ophthalmos-
copy. Hypertensive cardiovascular, renal and cerebrovascular
changes were indicated by left ventricular hypertrophy (LVH),
chronic kidney disease (CKD) and stroke, respectively.
Results:
Hypertensive retinopathy was present in 83.6% of
the patients (grade 1: 42.1%; grade 2: 11.3%; grade 3: 23.3%;
grade 4: 6.9%). There was no association between hyperten-
sive retinopathy and the presence or absence of LVH (86.5
vs 73.3%,
χ
2
=
1.53,
p
=
0.21), chronic kidney disease (89.3 vs
83.3%,
χ
2
=
0.12,
p
=
0.73) or stroke (85.7 vs 83.2%,
χ
2
>
0.001,
p
=
0.99). On multivariate logistic regression, CKD was the
most significant predictor of severe hypertensive retinopathy,
with an odds ratio of 4.4.
Conclusion:
No association was found between hypertensive
retinopathy and LVH, CKD or stroke. CKD was the most
significant predictor of hypertensive retinopathy and there
was a tendency toward increased risk of target-organ damage
among patients with advanced hypertensive retinopathy.
Keywords:
hypertension, hypertensive retinopathy, left ventricu-
lar hypertrophy, chronic kidney disease, stroke
Submitted 25/1/14, accepted 14/8/14
Cardiovasc J Afr
2014;
25
: 228–232
www.cvja.co.zaDOI: 10.5830/CVJA-2014-045
Hypertension is a major public health problem worldwide and
on the African continent.
1,2
The disease, once considered to be
rare outside Europe and North America, is now a leading cause
of disability and mortality in developing countries. Its prevalence
is projected to reach 30% worldwide by 2025.
2
Poor control of hypertension increases the likelihood of
complications affecting the cardiovascular and cerebrovascular
systems, kidney and retina, often labelled under the term target-
organ damage (TOD).
1
The development of subclinical TOD,
such as left ventricular hypertrophy (LVH), increased intima–
media thickness of the large vessels, microalbuminuria following
glomerular dysfunction, cognitive decline and hypertensive
retinopathy precedes the occurrence of major complications,
which include stroke, congestive heart failure and myocardial
infarction, renal failure and retinal vascular occlusions.
3-5
In
the Democratic Republic of Congo (DRC), the prevalence
of systemic hypertension has been reported to be over 25%,
6,7
whereas hypertension and associated complications account for
over 20% of deaths among adults.
8
Studies have demonstrated that TOD increases cardiovascular
risks over that already associated with elevated blood pressure
alone. For example, it has been shown that once LVH has
developed following long-standing systemic hypertension, it
behaves as an independent risk factor and a predictor of both
further cardiac complications,
9
and other incident vascular
events such as ischemic stroke and myocardial infarction.
10
Similarly, the presence of cerebrovascular and renal damage may
raise cardiovascular risk over that conferred by hypertension
itself.
11,12
In addition, hypertensive retinopathy has long been known
as a predictor of systemic morbidity and mortality. Both
epidemiological and clinical studies have provided evidence
that markers of hypertensive retinopathy are associated with
raised blood pressure, systemic vascular diseases, and subclinical
cerebrovascular and cardiovascular disease, and predict incident
clinical stroke, congestive heart failure and mortality due to
cardiovascular complications.
13
This association of hypertensive
retinopathy with other TOD has also been shown to be
independent of blood pressure and other risk factors, which
supports the recommendation that retinal vascular changes
should be assessed in individuals with systemic hypertension for
better extra-ocular TOD risk stratification.
13
While the number of reports on hypertensive TOD has been
on the rise on the African continent, the relationship between
Department of Ophthalmology, School of Medicine,
University of Kinshasa, Kinshasa, Democratic Republic
of Congo
Nelly N Kabedi, MD,
nelkabedi@yahoo.frDavid L Kayembe, MD, PhD
Department of Ophthalmology, School of Medicine,
University of North Carolina at Chapel Hill, Chapel Hill,
North Carolina, USA
Jean-Claude Mwanza, MD, MPH, PhD
Division of Nephrology, School of Medicine, Department
of Internal Medicine, University of Kinshasa, Kinshasa,
Democratic Republic of Congo
François B Lepira, MD, PhD
Department of Neurology, School of Medicine, University
of Kinshasa, Kinshasa, Democratic Republic of Congo
Tharcisse K Kayembe, MD, PhD