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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 4, July/August 2018
238
AFRICA
The main aim of this study was to investigate management
patterns of stable angina pectoris in private healthcare settings in
SA. In particular, we sought to: investigate how frequent medical
versus surgical interventions were used as first-line therapy
in patients with stable angina pectoris; assess the rationale of
choice of surgical interventions over medical interventions; and
assess the need for subsequent surgical interventions, if surgical
therapy was preferred over medical interventions.
Methods
This was a retrospective inferential study conducted using a
database of reimbursement by a medical scheme in the private
healthcare sector. An inferential data analysis aims to deduce
whether the observed pattern(s) will hold in another population(s)
as opposed to individuals.
20
All patients diagnosed with ischaemic
heart disease (IHD) or angina and authorised for reimbursement
between 2009 and 2014 were included for analysis.
To determine the duration between the first and second
interventions, themonth and year inwhich the second intervention
was done was subtracted from the month and year in which the
first intervention was carried out. In those instances where the
month was not indicated or only the year was indicated, it was
assumed that the intervention was done in January.
The protocol was given full ethics approval by the Research
Ethics Committee, University of KwaZulu-Natal (Ref BE
398/14).
Statistical analysis
Variables were characterised using 95% confidence intervals (CIs).
Means with standard deviations for continuous variables were
used to analyse proportions/ratios for the categorical data. Binary
logistic regression was used to identify independent associations
between the first intervention (revascularisation) versus the
second intervention, and between OMT versus revascularisation.
Associations were considered statistically significant if
p
≤
0.05.
The GraphPad Prism version 5.0 with the freeware package R
version 2.13.1 was used for statistical manipulations and analyses.
The outliers were included, unless otherwise stated.
Results
A total of 922 patient files were included in the analysis
in this study. There were 585 (63%) males and 337 (37%)
females, with average ages of 64.7 (SD
±
12.9) and 64.7 (SD
±
14.3) years, respectively. Angina-related co-morbidities included
hypertension, hyperlipidaemia and diabetes, present in 45, 36
and 20% of patients, respectively. These co-morbidities, when
they existed separately, were spread evenly between males and
females. However, as shown in Table 1, co-existing incidences
of hypertension and hyperlipidaemias were significantly (
p
<
0.05) twice as high in males as females. The incidence of other
conditions in males compared to females was not statistically
significantly different.
One hundred and seventy-eighty or 54%, 156 (43%) and 86
(63%) patients with hypertension, hyperlipidaemia and diabetes,
respectively, were treated with surgery only. For these patients,
PCIs were significantly (
p
<
0.0001) the preferred first-line
interventions over OMT. A combination of OMT and surgery
as a preferred intervention accounted for only 8% of all patients
studied. As a result, a total of 436 (47%) of all patients studied
were managed with surgery only, while only 25% (227) were
managed with OMT, as shown in Table 2. About 71% of patients
who received medical therapy were placed on only one drug, the
so-called sub-optimal medical therapy (SOMT).
In some cases, reasons or motivation for not using OMT
as the first-line intervention were provided. For example OMT
was considered inappropriate/contra-indicated in 3.5, 5.2, 5.2,
3.8, 1.5 and 0.8% of patients with asthma, chronic obstructive
pulmonary disease, hypotension, heart failure, poor lung
function and uncontrolled diabetes, respectively. The use of a
beta-blocker was stopped in 1.2% of patients due to intolerance,
asthma, wheezing, poor lung function and depression. Large-
vessel occlusion, heart failure, peripheral vessel disease and
single-vessel disease were stated as motivating factors for
revascularisation. Unfortunately and without explanation, 20%
(183) of patients, although diagnosed with stable angina pectoris,
did not receive any treatment.
Fifty-six per cent (or 520 of all patients studied, that
is 333 males and 187 females) were treated with one type
or another of revascularisation with or without medicine.
Subsequently, 139 (42%) males and 94 (50%) females who
were treated with revascularisation needed a second surgical
intervention. However, the differences in the need for the second
surgical intervention between males and females were marginally
significantly different (
p
=
0.06). Thereafter, about 18% (25) of
males and 21% (20) of females who received the second surgical
Table 1.The relationship between various co-morbidities
and gender in patients with stable angina pectoris
Co-morbidities
Males
n
(%)
Females
n
(%)
Both
n
(%)
Hypertension (H)
74 (8.03)
52 (5.64)
126 (13.67)
Hyperlipidaemia (HL)
44 (4.77)
21 (2.28)
65 (7.05)
Diabetes (D)
48 (5.21)
24 (2.6)
72 (7.81)
H + HL + D
30 (3.25)
13 (1.41)
43 (4.66)
H + HL
136 (14.75)
66 (7.16)
202 (21.91)
H + D
31 (3.36)
16 (1.74)
47 (5.1)
HL + D
17 (1.84)
5 (0.54)
22 (2.39)
Other*
205 (22.23)
140 (15.18)
345 (37.42)
Total
585 (63.44)
337 (36.55)
922 (100)
*Other co-morbidities were asthma, chronic obstructive pulmonary disease,
hypotension and heart failure.
Table 2. Use of OMT versus surgical interventions in patients
with stable angina pectoris with different co-morbidities
Co-morbidities
OMT
n
(%)
OMT plus PCIs
n
(%)
PCIs only
n
(%)
Hypertension (H)
16 (1.74)
13 (1.41)
52 (5.64)
Hyperlipidaemia (HL)
90 (0.98)
4 (0.43)
41 (4.45)
Diabetes (D)
7 (0.76)
5 (0.54)
33 (3.58)
H + HL + D
7 (0.76)
6 (0.65)
22 (2.39)
H + HL
68 (7.38)
23 (2.49)
83 (9)
H + D
9 (0.98)
7 (0.76)
21 (2.28)
HL + D
5 (0.54)
3 (0.33)
10 (1.08)
Other*
25 (2.71)
15 (1.63)
174 (18.87)
Total**
227 (24.6)
76 (8.2)
436 (47.3)
*Other co-morbidities were asthma, chronic obstructive pulmonary disease,
hypotension and heart failure.
**20% (183) of patients, although diagnosed with stable angina pectoris, did not
receive any treatment.