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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 1, January/February 2018
AFRICA
49
class impacts negatively on the prognosis and outcome of heart
failure patients.
15
This fact was also shown in our study where
the severity of the NYHA functional class of the patient at
presentation was found to be a determinant of outcome.
In this study, 10% of the patients were lost to follow up and
all attempts at location were futile. The reasons were not clear.
The rehospitalisation rate for HF in this study was 35.6%,
which is higher than figures from the United States where Ross
et al
.,
34
using data from the Medicare, documented 30-day
re-admission rates after HF hospitalisation of 23.0% in 2004,
23.3% in 2005 and 22.9% in 2006. Therefore hospitalisation
and rehospitalisation of HF patients continues to be a great
public heath burden, especially in a developing economy such
as Nigeria.
The mortality rate of 13.1% in this study is similar to the
figures documented for hypertensive HF patients in the same
institution about two decades ago, where investigators reported
a mortality rate of 13.6%.
35
This finding suggests that mortality
rate from HF in our environment has remained relatively stable
despite advances in treatment modalities. This rate is also
comparable to the mortality rate of 10% reported in the northern
part of Nigeria.
36
It is however much lower than the 30.8%
documented from western Nigeria,
33
and the 35% documented
in Lusaka, Zambia.
37
The high mortality rate from western Nigeria may be
attributable to late presentation, with more than 90% of patients
presenting in NYHA class IV, whereas the Zambian investigators
admitted logistic and financial challenges that made it difficult
to optimise a patient’s treatment. However Ogah
et el
.
38
in a
recent study in the south-west region of Nigeria reported a
rehospitalisation rate of 12.2% and mortality rate of 4.2% at six
months of follow up.
The determinants of rehospitalisation in this study were
NYHA class at presentation (higher NYHA class was associated
with higher re-admission rate), type of heart failure (systolic
heart failure), low haemoglobin level (
<
10 g/dl) and low eGFR
(
<
60 ml/min), while the identified determinants or predictors of
six-month mortality were high NYHA class (class III and IV)
and low LVEF (
<
25%). These findings agree with the results of
other studies done within and outside Africa.
Falase
et al
.
39
reported the prognostic importance of anaemia
in HF patients, Karaye
et al
.
36
noted the poor prognostic value of
low LVEF of
<
40%, Familoni
et al
.
15
reported factors associated
with poor outcome inHF patients to include anaemia, low eGFR,
increased age and low haemoglobin level of
<
10 g/dl. Nohria
et
al
.
3
documented high NYHA class, low LVEF, advanced age, low
eGFR, anaemia and other co-morbid conditions as factors that
negatively affect outcome in HF patients.
Ogah
et al
.
38
from south-western Nigeria however identified
factors associated with six-month rehospitalisation to include
presence of mitral regurgitation, age
≥
60 years, presence of
tricuspid regurgitation and atrial fibrillation, and LVEF. Using
data from the sub-Saharan African Survey of Heart Failure
(THESUS-HF), Sliwa
et al
.
40
also noted that the main predictors
of 60-day re-admission or death were a history of malignancy
and severe lung disease, admission systolic blood pressure, heart
rate and signs of congestion (rales), kidney dysfunction (BUN),
anaemia, HIV positivity and echocardiographic ejection fraction.
The determinants of mortality in our study were similar to
findings from other parts of Nigeria and sub-Saharan Africa.
This is probably because the aetiology of heart failure in this
region is similar and due mainly to hypertension, cardiomyopathy
and rheumatic valvular heart disease.
Conclusion
As in other studies of HF patients in sub-Saharan Africa, HF
patients in the south-south region of Nigeria were relatively
young, being in their fifth to sixth decades of life, and presented
in advanced NYHA functional class. The determinants of
mortality were high NYHA class, low eGFR and anaemia, while
the determinants of rehospitalisation were anaemia, low LVEF,
systolic heart failure and impaired renal function.
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Table 4. Logistic regression analysis of
some variables with mortality
Variable
B
p
-value
R
2
NYHA class
0.284
Class II
<
0.001
Class III
–3.96
0.001*
Class IV
–4.76
<
0.001*
Haemoglobin (g/dl)
0.048
0.950
LVEF (%)
≥
40
0.018
25–39.99
0.587
0.643
<
25
2.682
0.014*
NYHA
=
New York Heart Association; LVEF
=
left ventricular ejection frac-
tion; *significant
p
-value.