CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 3, April 2012
AFRICA
147
Prevalence of residual left ventricular structural changes
after one year of antihypertensive treatment in patients
of African descent: role of 24-hour pulse pressure
ELENA N LIBHABER, GAVIN R NORTON, CARLOS D LIBHABER, ANGELA J WOODIWISS,
GEOFFREY P CANDY, MOHAMMED R ESSOP, PINHAS SARELI
Abstract
Objectives:
One year of antihypertensive therapy may
normalise left ventricular (LV) structure in 51% of hyper-
tensive patients of European descent.Whether similar effects
can be achieved in patients of African descent, who have a
high prevalence of concentric LV hypertrophy (LVH) and
remodelling, is unknown.
Methods:
In 103 hypertensive patients in the Baragwanath
Hypertension study we evaluated the prevalence of residual
LV structural changes (echocardiography) after four and 13
months of stepwise antihypertensive therapy.
Results:
After 13 months of therapy, 24-hour blood pressure
control was achieved in 47% of patients. At baseline, 51.5%
of patients had concentric LVH, 19% eccentric LVH and
12% concentric LV remodelling. Despite changes in LV mass
index (
p
<
0.01) and relative wall thickness (
p
<
0.05) with
treatment, the proportion of patients with a normal LV mass
or geometry increased only from 17.5 to 25% (
p
>
0.05), while
26% remained with concentric LVH (
p
<
0.001 compared to
baseline), 25% with eccentric LVH and 23% with concentric
LV remodelling (
p
<
0.05 compared to baseline). Residual
structural changes were associated with 24-hour pulse pres-
sure (
p
=
0.02), but not with 24-hour systolic or diastolic
blood pressure or clinic blood pressure.
Conclusions:
Even after a year of antihypertensive therapy,
a high proportion (74%) of hypertensives of African ances-
try retained residual LV structural changes, an effect that
was associated with 24-hour pulse pressure but not systolic
or diastolic blood pressures or clinic blood pressure in this
ethnic group.
Keywords:
left ventricular geometry, antihypertensive therapy,
ambulatory blood pressure, pulse pressure
Submitted 6/9/11, accepted 11/1/12
Cardiovasc J Afr
2012;
23
: 147–152
DOI: 10.5830/CVJA-2012-001
Left ventricular hypertrophy (LVH) is an established independent
predictor of morbidity and mortality.
1-3
However, the geometry
of the heart in hypertensive LVH is a heterogeneous change.
Some patients develop a concentric pattern where wall thickness
increases out of proportion to chamber diameter, while others
develop eccentric LVH where wall thickness increases in parallel
with chamber diameters.
4
The possibility that LV geometric
patterns may refine the ability to predict cardiovascular events
beyond LVH was suggested two decades ago,
5
and more
recent evidence provides substantial support for this notion in
hypertensives
6,7
in the general population
8
following myocardial
infarction,
9
in diabetes mellitus,
10
and in those with a normal
LV ejection fraction.
11,12
Therefore an important goal of therapy
in hypertensives and other patient groups should be to reduce
the prevalence of concentric LVH, eccentric LVH and LV
remodelling.
Although some
13-18
but not all
19,20
studies have demonstrated
that antihypertensive therapy decreases both LVH and relative
wall thickness, these studies were largely conducted in ethnic
groups with a low prevalence of concentric LVH at baseline
(6–30%).
11,13-15
Those studies reporting on the prevalence of
concentric LVH and remodelling before and after drug therapy
suggest that after therapy, six to 16% of patients may have
concentric LVH and only a small proportion, concentric LV
remodelling.
13-15
Whether the same low residual prevalence rates
of concentric LVH or remodelling remain after drug therapy in
patient populations with a high prevalence of concentric LVH
or remodelling at baseline is unknown. In this regard it is well
recognised that LV relative wall thickness is higher in patients of
African ancestry than in other patient populations.
21
Therefore,
in the present study, we aimed to identify the ability of 13
months of antihypertensive therapy to normalise LV structure
in hypertensives of African ancestry and the blood pressure
parameter most closely associated with residual LV structural
abnormalities.
Methods
The protocol was approved by the University of theWitwatersrand
Committee for Research in Human Subjects (approval number:
M940106). The Baragwanath Hypertension Study was a single-
centre, randomised, open-label trial conducted at the Chris
Hani-Baragwanath Hospital from 1994 to 1997. The enrolment
Department of Cardiology, University of the Witwatersrand,
and Chris Hani Baragwanath Hospital, Johannesburg,
South Africa
ELENA N LIBHABER, PhD,
MOHAMMED R ESSOP, MD
Department of Nuclear Medicine, University of the
Witwatersrand, Johannesburg, South Africa
CARLOS D LIBHABER, MD
Department of Surgery, University of the Witwatersrand,
Johannesburg, South Africa
GEOFFREY P CANDY, PhD
Cardiovascular Pathophysiology and Genomics Research
Unit, School of Physiology, Faculty of Health Sciences,
University of the Witwatersrand, Johannesburg, South Africa
ELENA N LIBHABER, PhD
GAVIN R NORTON, PhD
ANGELA J WOODIWISS, PhD
PINHAS SARELI, MD
