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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017
AFRICA
101
V
4
), lateral (I, aVL, V
5
and V
6
) and inferior (II, III and aVF)
region. STEaVR of
≥
0.05 mV was recorded. Transthoracic
echocardiography was performed in a standard manner during
hospitalisation, and left ventricular ejection fraction (LVEF) was
calculated using the biplane Simpson’s method.
All patients underwent cardiac catheterisation within five
days of presentation with NSTEACS. All patients underwent
CABG within two weeks of presentation with NSTEACS. An
independent cardiologist blinded to the clinical data reviewed all
coronary angiography results for the purposes of comparative
assessment with the primary treating cardiologist.
Coronary angiography and SYNTAX score analysis
Coronary angiography was performed by the Judkins technique.
All lesions causing
≥
50% stenosis in a coronary artery with a
diameter of
≥
1.5 mm were included in the SS calculation. For
calculation, the website software
(http://www.SYNTAXcore.com) was used.
The score was calculated for each patient with regard to
the following parameters: coronary dominance, number of
lesions, segments included per lesion, the presence of total
occlusion, bifurcation, trifurcation, aorto-osteal lesion, severe
tortuosity, calcification, thrombus, diffuse/small-vessel disease,
and lesion length
>
20 mm. SS was calculated separately by two
interventional cardiologists blinded to the study protocol and
patient characteristics. In the case of a contradiction between
two results, the opinion of a senior interventional cardiologist
was applied and a common consensus was obtained. SS was
divided into two groups:
≥
23: high,
<
23: low.
Statistical analysis
Statistical analysis was performed using the SPSS (version 20.0,
SPSS Inc, Chicago, Illinois) software package. Continuous
variables are expressed as mean
±
standard deviation (mean
±
SD) and categorical variables are expressed as percentage
(%). The Kolmogorov–Smirnov test was used to evaluate the
distribution of variables. Student’s
t
-test was used to evaluate
continuous variables showing a normal distribution, and the
Mann–Whitney
U
-test was used to evaluate variables that did
not show a normal distribution. A
p
-value
<
0.05 was considered
statistically significant.
To identify predictors of increased SS, the following variables
were initially assessed in a univariate model: age, hypertension,
diabetes, STD in anterior, lateral and inferior leads, and STEaVR.
Significant variables in univariate analysis were then entered
into a multivariate logistic regression analysis using backward
stepwise selection.
Results
A total of 117 patients who underwent coronary angiography
within five days and CABG within two weeks of presentation
with the diagnosis of NSTEACS were included in the analysis.
Among the 117 patients, 80 (68.4%) had a STEaVR of
≥
0.05 mV.
The patients’ characteristics are summarised and presented in
Table 1. Patients with STEaVR were older, with a higher peak
cTnT value (Table 1). With regard to ECG findings, patients with
a STEaVR were more likely to have concomitant STD. Among
80 patients with STEaVR, 68 presented with concomitant STD,
comprising anterior (56 patients), lateral (62 patients) and
inferior (45 patients) STD (Table 1).
Patients with STaVR had a significantly higher rate of
LM/3VD and higher SS than those without STEaVR (86.2 vs
72.9%,
p
=
0.03; 85 vs 67.6%,
p
<
0.001, respectively) (Table 1).
The results of univariate analysis are presented in Table 2. On
univariate analysis, age, HT, DM, ST-segment elevation in lead
aVR and STD in the anterior, lateral and inferior leads were
associated with a high SS (Table 2). On multivariate analysis
STEaVR and STD in the anterior leads were independent
predictors for a high SS (OR 2.12; 95% CI: 1.34–4.13,
p
<
0.001;
OR 1.64; 95% CI: 1.24–2.86,
p
=
0.02, respectively) (Table 3).
Discussion
Our study showed that STEaVR and STD in the anterior leads
were independently associated with a high SS and higher rates of
LM/3VD in patients with NSTEACS. To our knowledge, this is
the first study to evaluate STEaVR in patients with NSTEACS
who underwent coronary angiography followed by CABG
surgery.
Table 1. General characteristics of the patients
Patient characteristics
ST elevation in lead aVR
p
-value
+
(
n
=
80)
(68.4%)
–
(
n
=
37)
(31.6%)
Age, years
63.3
±
7.4 59.4
±
8.1
0.027
Male gender,
n
(%)
27 (73.0)
62 (77.5)
0.485
Hypertension,
n
(%)
24 (64.8)
51(63.7)
0.352
Diabetes mellitus,
n
(%)
38 (47.5)
13 (35.1)
<
0.001
Current smoking,
n
(%)
33 (41.2)
14 (37.9)
0.754
SYNTAX score
27.4
±
4.9 23.1
±
5.4
0.002
High SYNTAX score ratio,
n
(%)
68 (86)
25 (67.6)
<
0.001
Inferior ST-segment depression,
n
(%)
45 (56.2)
12 (32.4)
<
0.001
Lateral ST-segment depression,
n
(%)
62 (77)
14 (37.8)
<
0.001
Anterior ST-segment depression,
n
(%)
56 (70)
14 (37.8)
<
0.001
Left ventricular ejection fraction (%)
58.5
±
4.2 61.7
±
5.6
0.652
Left main/three-vessel disease,
n
(%)
69 (86.2)
27 (72.9)
0.03
Peak troponin T (ng/ml)
1.8
±
0.5 0.36
±
0.12 0.002
Table 2. Univariate analysis of predictors for a high SYNTAX score
Predictor variables
OR (95% CI)
p
-value
Age
2.723 (1.534–4.842)
<
0.001
Diabetes mellitus
1.246 (0.827–1.543)
0.54
Hypertension
1.14 (0.784–1.457)
0.37
Inferior ST-segment depression
1.924 (1.465–3.147)
<
0.001
Lateral ST-segment depression
2.416 (1.354–4.249)
<
0.001
Anterior ST-segment depression
2.160 (1.527–3.895)
<
0.001
ST-elevation in lead aVR
3.012 (1.974–4.243)
<
0.001
Table 3. Multivariate analysis of predictors for high SYNTAX score
Predictor variables
OR (95% CI)
p
-value
Age
1.23 (0.652–1.524)
0.42
Inferior ST-segment depression
1.324 (0.465–2.862)
0.39
Lateral ST-segment depression
2.351 (1.524–4.243)
<
0.001
Anterior ST-segment depression
1.214 (0.527–1.253)
0.48
ST elevation in lead aVR
2.827 (1.873–4.368)
<
0.001