CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 4, May 2012
AFRICA
197
The impact of cardiovascular risk factors on the site and
extent of coronary artery disease
AF ZAND PARSA, H ZIAI, L HAGHIGHI
Abstract
Background:
In patients with coronary artery disease (CAD),
the site and extent of coronary artery involvement in terms of
proximal versus distal stenosis and multi- versus single-vessel
disease have a crucial effect on patients’ outcome. This study
was designed to evaluate the relationship between cardiovas-
cular risk factors and the site and extent of coronary artery
involvement.
Methods:
In this study of patients who had undergone coro-
nary angiography in our hospital, 125 with proximal lesions
were enrolled as the case group (group 1) and an equal age-
and gender-matched number of patients with non-proximal
lesions were selected as the control group (group 2). The two
groups were compared based on the presence or absence of
diabetes mellitus (DM), hypercholesterolaemia, hypertrigly-
ceridaemia, hypertension (HTN) and cigarette smoking.
Results:
The frequency of DM was 33.6 and 10.4% in the
case and control groups, respectively, which was statistically
significant (
p
<
0.0001). However, the frequency of hyper-
cholesterolaemia in the case and control groups was 30.4
and 29.6% (
p
=
0.89), respectively; for hypertriglyceridaemia
it was 19.2 and 16.8% (
p
=
0.062), respectively; for HTN it
was 33.6 and 28.8% (
p
=
0.4), respectively; and for cigarette
smoking it was 28.8 and 39.2% (
p
=
0.08), respectively, which
were not statistically significant. Diabetic patients compared
to non-diabetics had more multi-vessel disease (89.1 vs 61%,
p
<
0.0001, respectively), which was statistically significant.
There was no relationship between hypercholesterolaemia,
hypertriglyceridaemia, HTN and cigarette smoking and
extent (multi-vessel involvement) of CAD (
p
=
NS).
Conclusion:
Proximal and multi-vessel involvement of the
coronary arteries in patients with CAD was related to a
history of DM but not of hypercholesterolaemia, HTN, ciga-
rette smoking and hypertiglyceridaemia.
Keywords:
coronary artery disease, coronary angiography,
proximal versus distal stenosis, cardiovascular risk factors
Submitted 15/10/10, accepted 6/9/11
Cardiovasc J Afr
2012;
23
: 197–199
DOI: 10.5830/CVJA-2011-052
Coronary artery disease (CAD) is one of the leading causes of
morbidity and mortality worldwide. As atherosclerotic CAD is
a heterogeneous disease in terms of severity, extent and site of
involvement, these are the most important predictors of outcome
of patients with coronary artery disease. The main question is
whether or not these heterogeneities have any relationship with
cardiovascular risk factors, and if so, which is responsible for
which kind of lesion.
Although in some studies a relationship between diabetes
mellitus (DM)
1-5
and hyperlipidaemia,
4-6
and severity of CAD
has been reported, these studies were focused on the severity of
lesions according to the scoring system used and not to the site of
lesion in terms of proximal versus distal stenosis. In our study we
tried to evaluate the impact of major cardiovascular risk factors
such as DM, hypercholesterolaemia, hypertriglyceridaemia,
hypertension (HTN) and cigarette smoking on the site and extent
of coronary artery involvement in terms of proximal versus distal
and multi- versus single-vessel disease.
Methods
This study was a prospective case–control study that included
patients who had undergone coronary angiography in our
hospital. Patients with normal coronary arteries were excluded
from the study. The case group included 125 patients with
significant proximal coronary artery stenosis (
≥
50% luminal
narrowing) and the control group included 125 patients with
significant non-proximal stenosis, and matched with case group
regarding gender and age.
Coronary angiography of all patients was re-evaluated by
an expert cardiologist and in the case of controversy, by two
experts who were not aware of the patients’ risk factors or other
clinical conditions. The two groups were compared for major
cardiovascular risk factors such as hyperlipidaemia, HTN, DM
and cigarette smoking.
Statistical analysis
SPSS version 11.5 was used for analysing the data. The Student’s
t
-student test and Chi-square test were used for numerical and
continuous variables, respectively. For evaluating data, odds
ratio (OR) with 95% confidence interval (CI) were used and
p
>
0.05 was considered significant.
Results
In the case group 87 patients (69.6%) and in the control group 95
patients (76%) were male. The mean age in the case and control
groups was 59.6
±
10.8 and 58.8
±
10.9 years, respectively.
Regarding gender and age, there was no significant difference
between the two groups (
p
=
0.556 and
p
=
0.256, respectively).
Clinical and demographic characteristics of patients are presented
in Table 1.
Diabetes mellitus was more prevalent in the case group than
the control (33.6 vs 10.4%,
p
<
0.0001, OR
=
4.36; 95% CI:
2.2–8.6, respectively) and it was statistically significant. There
Division of Cardiology, Imam Khomeini Medical Center,
Tehran University of Medical Sciences, Tehran, Iran
AF ZAND PARSA, MD,
H ZIAI, MD
Shahid Akbari Hospital, Iran University of Medical Sciences,
Tehran, Iran
L HAGHIGHI, MD
