Cardiovascular Journal of Africa: Vol 30 No 1 (January/February 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 1, January/February 2019 AFRICA 9
Clinical and echocardiographic correlates of pulmonary
hypertension among heart failure patients in Lagos,
south-western Nigeria
OA Kushimo, AC Mbakwem, JNA Ajuluchukwu, CE Amadi
Abstract
Background: Pulmonary hypertension (PH) is very prevalent
among heart failure (HF) subjects and is now recognised
as an independent predictor of poor prognosis. There is a
paucity of data in our environment about the frequency and
correlates of PH in HF. We aimed to determine the frequency
of PH in HF patients in an academic hospital and assess its
correlates using echocardiography.
Methods: A total of 219 heart failure patients in NYHA
functional class II to IV, and without co-morbidities that
could cause PH, were consecutively recruited. Demographic,
clinical and echocardiographic data were obtained from all
subjects.
Results: The frequency of PH was 38.8%, using an estimated
pulmonary artery systolic pressure (PASP) cut-off value of
> 36 mmHg. HF subjects with PH tended to be male with a
worse NYHA functional class compared with subjects with-
out PH. HF subjects with PH also had significantly higher
left ventricular (LV) filling pressures (higher left atrial volume
index and E/e′ ratio), more severe mitral regurgitation (MR),
poorer LV systolic function, and worse parameters of right
ventricular (RV) structure and function compared with those
without PH. Echocardiographic variables that correlated
significantly with PASP include LV filling pressures ( p < 0.001
for all), mitral regurgitant volume (r = 0.269, p < 0.001) and
LV ejection fraction (r = –0.239, p > 0.001). On multivariate
analysis, the left atrial volume index and E/e′ ratio were inde-
pendently associated with PASP.
Conclusion: PH is common among HF subjects in our envi-
ronment and is associated with higher LV filling pressure,
more severe MR, poorer LV systolic function and worse RV
remodelling. Routine screening for PH among HF patients is
recommended for better risk stratification and management.
Keywords: pulmonary hypertension, heart failure, correlates,
echocardiography
Submitted 16/4/18, accepted 22/10/18
Published online 5/11/18
Cardiovasc J Afr 2019; 30: 9–14
DOI: 10.5830/CVJA-2018-053
Pulmonary hypertension (PH) is very prevalent among heart
failure (HF) subjects and is now recognised as an independent
predictor of poor prognosis. 1,2 PH develops initially from passive
congestion of the pulmonary venous circulation, secondary to
elevated filling pressures of the left cardiac chambers. Later,
functional and structural changes may occur in the pulmonary
venous and distal arterial circulation, resulting in a fixed or
reactive form of PH.3
The key correlates of PH in HF are factors associated with
increased pulmonary venous pressure.4 These include elevated
left ventricular (LV) filling pressures and mitral regurgitation
(MR), which have been demonstrated by several studies.1,2,5-7 The
role of other factors, such as clinical parameters and LV systolic
function is less clear. Right heart catheterisation is the gold-
standard method for making a definitive diagnosis in selected
patients.8,9 Echocardiography is a convenient, non-invasive
investigation widely used in clinical practice to screen for PH, as
suggested by the guidelines.8,9
Not much is known presently about the frequency and
correlates of PH in HF in our environment. We therefore
evaluated the frequency of PH in an academic hospital in south-
western Nigeria, and its correlates using echocardiography. It
is expected that results from this study will help improve risk
stratification, management and prognostication in our patients
with HF.
Methods
This was a cross-sectional study carried out at the Lagos
University Teaching Hospital in south-western Nigeria. We
consecutively recruited 219 HF patients of 18 years or older, who
were in New York Heart Association (NYHA) functional class
II to IV and were referred to the emergency unit, medical wards
and the cardiology out-patient clinic of our hospital. Heart
failure was diagnosed using the Framingham criteria.
We excluded patients with a known history of co-existing
conditions that can cause PH, besides left heart disease. These
included patients with sickle cell disease, chronic parenchymal
lung disease, human immunodeficiency virus infection, chronic
liver disease with portal hypertension, congenital heart disease,
obstructive sleep apnoea, chronic kidney disease, chronic
exposure to high altitude, and use of anorexigenic agents.
Approval for this study was obtained from the Health
Research and Ethics Committee of the Lagos University
Cardiology Unit, Department of Medicine, Lagos University
Teaching Hospital, Nigeria
OA Kushimo, MB BS, MWACP, FMCP,
AC Mbakwem, MB BS, FWACP, FESC, FACC
JNA Ajuluchukwu, MB BS, M.MED, FMCP, FESC
CE Amadi, MBBS, MSc, FMCP
College of Medicine, University of Lagos, Nigeria
AC Mbakwem, MB BS, FWACP, FESC, FACC
JNA Ajuluchukwu, MB BS, M.MED, FMCP, FESC
CE Amadi, MB BS, MSc, FMCP