CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 4, July/August 2014
170
AFRICA
adequately balanced for atherosclerosis, between infliximab- and
prednisolone-treated patients, were compared using a two-tailed
t
-test. Categorical data were compared by contingency tables,
and between each treatment group and normal controls by the
χ
2
test or Fisher exact test when five patients or fewer were included
in each cell.
Continuous variables were tested for normality using the
Kolmogorov–Smirnov test. Normally distributed variables
are given as mean and standard deviation (SD). Spearman
correlation analysis was used to determine bivariate correlations.
Because biomarkers had a non-normal distribution, data are
expressed as median (interquartile range) and were analysed
after transformation into ranks.
Analysis of variance (ANOVA) for repeated measurements
was applied to compare the effects of infliximab versus
prednisolone, with measurements at baseline and three months
post treatment used as a within-subject factor, and type of
treatment as between-subject factor. The
F
- and
p
-values of
interaction between time measurement of the examined markers
and type of treatment were calculated.
Post hoc
comparisons were performed within Bonferroni’s
correction. Comparisons between controls and each treatment
group at baseline or three months were performed using the
unpaired
t
-test (normally distributed variables) andMann–Whitney
test (non-normally distributed variables). Statistical significance
was considered as
p
<
0.05. All statistical analysis was performed
using SPSS for Windows (release 15.0, SPSS Inc, Chicago, Illinois).
Results
The demographic, clinical, biochemical and conventional
echocardiographic parameters are given in Tables 1 and 2. All
RA patients were seropositive. The mean DAS was 6.4
±
0.7 and
the disease duration was 85.7
±
66.8 months.
Age, cardiac medication, cardiovascular risk factors, systolic
and diastolic blood pressure, heart rate, and cholesterol, fasting
glucose and creatinine levels were similar between the control
group and the RA patients and also in the infliximab- and
prednisolone-treated patients. Therefore our patients had similar
characteristics regarding risk factors for atherosclerosis.
Control group patients had normal electrocardiograms,
transthoracic echocardiography and treadmill tests. Baseline
CRP, DAS 28 and RF values showed significant differences.
None of the subjects was excluded from the study because of
adverse effects or discontinuation of therapy.
On transthoracic echocardiography there was no pericardial
effusion or significant valvular heart disease. Parameters showing
diastolic function such as LV diastolic filling pressure (E/E
′
),
A-wave values, deceleration time (DT) and isovolumic relaxation
time (IVRT) were significantly higher in the RA patients. E/A
ratio showed a significant reduction (
p
<
0.05). E/E
′
was found
to be decreased in prednisolone- compared to infliximab-treated
patients (
p
<
0.05).
Significant improvement in RA parameters, as assessed by
CRP, DAS 28 and DASI were achieved in both treatment groups
(
p
<
0.05) (Table 3).
Table 1. Clinical and biochemical characteristics of the study population
Controls
(
n
=
30)
RA patients
(
n
=
38)
Infliximab-treated
patients (
n
=
20)
Prednisolone-treated
patients (
n
=
18)
p
-value* p-value
#
DAS-28
–
6.4
±
0.7
6.4
±
0.5
6.1
±
0.8
–
0.06
Disease duration (months)
–
85.7
±
66.8
98.4
±
77.4
71.6
±
51.1
–
0.21
RF (mg/dl)
–
226.8 (25.2–66.1)
194.4 (25.2–321.8)
165.8 (30.5–366.1)
–
0.57
Age (years)
50.7
±
3.4
52.1
±
11.1
53.4
±
13.5
50.7
±
7.6
0.52
0.44
Body mass index (kg/m
2
)
30.5
±
3.7
30.5
±
5.5
31.0
±
5.9
29.9
±
5.2
0.91
0.70
Obesity (%)
7 (23)
5 (13)
2 (10)
3 (16)
0.21
0.47
Hypertension (%)
10 (33)
17 (44)
9 (45)
8 (44)
0.24
0.63
Current smoking (%)
8 (26)
5 (13)
2 (10)
3 (16)
0.13
0.32
Dyslipidaemia (%)
8 (26)
8 (21)
3 (15)
5 (27)
0.39
0.56
Diabetes mellitus (%)
2 (6)
8 (21)
4 (20)
4 (22)
0.09
0.24
Medication
RAAS blocker (%)
5 (16)
11 (28)
6 (30)
5 (27)
0.18
0.48
β
-blocker (%)
5 (16)
4 (10)
1 (5)
3 (16)
0.34
0.43
CaCh blocker (%)
4 (13)
4 (10)
3 (15)
1 (5)
0.5
0.62
Statin (%)
7 (23)
4 (10)
2 (10)
2 (11)
0.13
0.36
SBP (mmHg)
121.6
±
9.8
124.7
±
13.9
122.1
±
14.4
127.4
±
13.2
0.33
0.24
DBP (mmHg)
79.0
±
6.6
78.7
±
8.9
75.5
±
9.1
82.2
±
7.5
0.92
0.12
HR (beats/min)
70.6
±
6.3
74.4
±
10.5
74.9
±
12.2
71.1
±
7.7
0.45
0.5
Total cholesterol (mg/dl)
171.1
±
29.7
163.0
±
24.6
170.3
±
20.2
166.5
±
10.8
0.4
0.74
HDL cholesterol (mg/dl)
39.1
±
8.1
41.3
±
11.3
40.4
±
12.9
43.7
±
9.5
0.36
0.53
LDL cholesterol (mg/dl)
112.4
±
16.4
117.2
±
26.6
115.6
±
25.4
119.0
±
22.9
0.44
0.76
Glucose (mg/dl)
96.7
±
10.7
98.4
±
15.9
102.3
±
13.1
98.6
±
10.0
0.77
0.47
Creatinine (mg/dl)
0.8
±
0.1
0.8
±
0.2
0.8
±
0.1
0.8
±
0.1
0.62
0.82
CRP (mg/dl)
1.2 (0.6–4.3)
20.4 (8.0–34.9)
20.4 (10.5–34.9)
17.6 (8.0–33.5)
<
0.01
0.16
Values are expressed as mean
±
SD. Values for CRP and RF are median and interquartile range.
*For comparisons between RA patients and control group.
#
For comparisons between infliximab- and prednisolone-treated patients.
DAS-28
=
disease activity score, RF
=
rheumatoid factor, RAAS
=
renin–angiotensin–aldosteron system, CaCh
=
calcium channel, SBP
=
systolic
blood pressure, DBP
=
diastolic blood pressure, HR
=
heart rate, CRP
=
C-reactive protein.
